Hot on the heels of this round of severe weather, the SPC has called out on another event:
ZCZC SPCSWOD48 ALL
ACUS48 KWNS 241000
SPC AC 241000
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0400 AM CST THU FEB 24 2011
VALID 271200Z - 041200Z
...DISCUSSION...
ANOTHER STRONG STORM SYSTEM IS FORECAST TO AFFECT PORTIONS OF THE
PLAINS AND MS VALLEY ON SUN/D4 WITH A PROBABLE SEVERE WEATHER
OUTBREAK.
THE ECMWF AS WELL AS THE MAJORITY OF MREF MEMBERS ARE IN GOOD
AGREEMENT WITH THE POSITION OF THE MEAN UPPER TROUGH OVER THE SWRN
U.S...AND RESPECTABLY CLOSE WITH THE LOCATION OF THE UPPER LOW
CENTERED SOMEWHERE BETWEEN THE LOWER CO RIVER VALLEY AND CNTRL AZ BY
12Z SUN. AS THE TROUGH CONTINUES INTO THE CNTRL/SRN PLAINS BY
00Z...AND TO THE MS RIVER BY 12Z MON...MREF MEMBERS ARE SHOWING A
SLOW AND FAST CLUSTERING OF SOLUTIONS...THE SLOWEST OF WHICH MATCHES
WELL WITH THE ECMWF SOLUTION...WHICH IS TYPICALLY THE PREFERRED
MODEL.
USING THE SLOWER SOLUTIONS...A STRONG LOW PRESSURE CENTER IS
FORECAST TO BE ACROSS KS OR POSSIBLY NWRN OK AT 00Z. BY THEN...A
BROAD SLY FETCH OFF THE GULF OF MEXICO WILL HAVE RESULTED IN MID 60S
F BOUNDARY LAYER DEWPOINTS NWD INTO OK AND AR...WITH NEAR 60 F
DEWPOINTS POSSIBLY INTO SERN KS AND SRN MO. FORECAST SOUNDINGS
ACROSS THE WARM SECTOR INDICATE CAPPING DURING THE DAY BUT STORM
SHOULD ERUPT ALONG THE DRYLINE/COLD FRONT BY LATE AFTERNOON...AND
PERHAPS ALONG THE RETREATING WARM FROM KS INTO MO AND SRN IL.
ALTHOUGH PRECISE STORM MODE IS DIFFICULT TO DISCERN AT THIS
TIME...STRONG SHEAR PROFILES AND MODERATE INSTABILITY WILL LIKELY
FAVOR SUPERCELLS AND BOWING STRUCTURES CAPABLE OF
TORNADOES...DAMAGING WINDS AND LARGE HAIL.
THE SEVERE THREAT WILL LIKELY PERSIST INTO MON/D5 BUT TO A LESSER
EXTENT ACROSS PORTIONS OF THE SE...TN AND OH VALLEYS...BUT
PREDICTABILITY BECOMES TOO LOW FOR ANY AREAS.
..JEWELL.. 02/24/2011
CLICK TO GET WUUS48 PTSD48 PRODUCT
Another severe weather outbreak? February 27-28
Moderator: S2k Moderators
Forum rules
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K.
-
TwisterFanatic
- Category 5
- Posts: 1041
- Joined: Mon Jun 28, 2010 12:43 pm
- Location: Sallisaw, Oklahoma
Yea, this one looks more potent that the one going on today. Looks like discrete supercells look like a better bet than today also, which could mean a Tornado Outbreak. This is the one I have been watching closely for a while.
0 likes
Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.
-
TwisterFanatic
- Category 5
- Posts: 1041
- Joined: Mon Jun 28, 2010 12:43 pm
- Location: Sallisaw, Oklahoma
The NAM looks to be trending up with the CAPE across Oklahoma according to the 12Z, and the EHI was also between 2-3 for East Oklahoma.
0 likes
Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.
-
WeatherGuesser
- Category 5
- Posts: 2672
- Joined: Tue Jun 29, 2010 6:46 am
-
CrazyC83
- Professional-Met
- Posts: 34001
- Joined: Tue Mar 07, 2006 11:57 pm
- Location: Deep South, for the first time!
Still a high-end SLGT. I would expect a MDT as soon as models show higher confidence.
SPC AC 260654
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1254 AM CST SAT FEB 26 2011
VALID 271200Z - 281200Z
...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SRN PLAINS...ARKLATEX
TO LOWER OH VALLEY REGION...
...SYNOPSIS...
UPPER-AIR PATTERN FCST TO REMAIN QUASI-ZONAL ACROSS MOST OF
CONUS...PRIMARY PERTURBATION BEING STG SHORTWAVE TROUGH AND EMBEDDED
LOW LOCATED OVER NRN CA AS OF 26/05Z. THIS FEATURE IS FCST TO DIG
SSEWD THEN TURN EWD ACROSS LOWER CO RIVER VALLEY AREA NEAR START OF
PERIOD. GIVEN SLIGHTLY LAGGED UPSTREAM PATTERN OF HEIGHT FALLS AND
RUN-TO-RUN TRENDS IN PROGS...WILL MAINTAIN EARLY-PERIOD FCST CLOSER
TO CONSISTENTLY SLOWER ECMWF POSITION...AS OPPOSED TO FASTER
OPERATIONAL SPECTRAL...WITH 500-MB CYCLONE POSITIONED OVER LAS-EED
AREA AT START OF PERIOD. THIS ALSO RESEMBLES ETA MEMBERS OF SREF.
TROUGH IS FCST TO ASSUME PRONOUNCED POSITIVE TILT EARLY IN PERIOD
AND DEVOLVE TO OPEN WAVE...MOVING EWD TO AXIS FROM CENTRAL HIGH
PLAINS TO S-CENTRAL/SWRN NM BY 28/00Z. TROUGH THEN SHOULD MOVE EWD
BY 28/12Z TO NEAR KS/MO BORDER...SERN OK...AND N-CENTRAL TX...BY
WHICH TIME ECMWF ACCELERATES SYSTEM INTO SREF MEAN POSITION.
AT SFC...LEE TROUGHING OVER CO LATE DAY-1 SHOULD CONSOLIDATE RAPIDLY
INTO STG SFC CYCLONE THERE BY ABOUT 27/18Z AS UPPER WAVE
APCHS...WITH WARM FRONT EWD ACROSS PORTIONS KS/MO. SFC LOW THEN
SHOULD PIVOT SEWD/EWD OVER SRN KS DURING AFTERNOON/EVENING. SFC LOW
PRESSURE THEN SHOULD BECOME ELONGATED SW-NE ALONG SFC FRONTAL ZONE
BY END OF PERIOD...WITH NEWER CENTER POSSIBLE OVER LOWER MI AND
ORIGINAL LOW OVER MO OR IL. COLD FRONT TRAILING SFC LOW WILL MOVE
EWD FROM CENTRAL/SRN ROCKIES ACROSS OK AND MOST OF TX BY 28/12Z.
DRYLINE SHOULD MOVE EWD ACROSS PORTIONS CENTRAL/N-CENTRAL TX AND
CENTRAL/ERN OK DURING AFTERNOON/EVENING...INTERSECTING FRONTAL ZONE
NEAR S-CENTRAL/SERN KS SFC LOW.
...SRN PLAINS...ARKLATEX TO LOWER OH VALLEY REGION...
MOST CONCENTRATED AND SIGNIFICANT SVR THREAT IS FCST DURING
EVENING/OVERNIGHT HOURS IN AND NEAR OZARKS...WITH MORE CONDITIONAL
SVR RISK BEGINNING AS EARLY AS MID-LATE AFTERNOON AND AS FAR W AS
CENTRAL/ERN PORTIONS OF KS/OK. BULK OF SVR EVENTS SHOULD BE
DAMAGING WIND...ALTHOUGH A FEW STG TORNADOES AND LARGE/DAMAGING HAIL
ALSO ARE POSSIBLE.
INITIAL/DIURNAL CONVECTIVE DEVELOPMENT...AND TSTM COVERAGE THROUGH
AROUND 28/00Z...REMAIN RATHER UNCERTAIN/CONDITIONAL...AS AREAS ALONG
AND E OF DRYLINE OVER SRN KS...NE TX AND OK SHOULD BE CAPPED FOR
MOST OF AFTERNOON BENEATH ELEVATED MIXED-LAYER AIR. ISOLATED SVR
TSTMS ARE POSSIBLE...WHICH COULD INCLUDE SUPERCELLS.
EXPECT MAJOR INCREASE IN CONVECTIVE COVERAGE DURING 28/00Z-28/06Z AS
LIFT STRENGTHENS ON ALL SCALES...AND STRONGER FORCING IMPINGES UPON
PROGRESSIVELY MORE MOIST LOW-LEVEL AIR MASS. KINEMATIC ENVIRONMENT
WILL BECOME MORE FAVORABLE WITH TIME DURING AFTERNOON/EVENING AS
STRENGTHENING FLOW AND ASCENT ALOFT SPREADS OVER PROGRESSIVELY
MOISTENING WARM SECTOR E OF DRYLINE. LEFT-EXIT REGION OF
INTENSIFYING...SOMEWHAT CYCLONICALLY CURVED...125-150 KT 250-MB JET
WILL BE SPREADING ACROSS MUCH OF OK...KS...OZARKS AND INTO LOWER OH
VALLEY REGION DURING LATTER HALF OF PERIOD. MEANWHILE...EXPECT
BROAD AREA OF 60-80 KT 500-MB WINDS TO SPREAD OVER SVR RISK AREAS
DURING EVENING AND OVERNIGHT...CONTRIBUTING TO FAVORABLE DEEP-LAYER
SHEAR...E.G. EFFECTIVE SHEAR MAGNITUDES 50-60 KT IN MANY FCST
SOUNDINGS. LOW-LEVEL HODOGRAPHS ALSO WILL ENLARGE CONSIDERABLY
AFTER 00Z FROM ERN OK THROUGH PORTIONS AR/MO/SRN IL/WRN KY/WRN
TN...WITH 0-1 KM SRH 250-400 J/KG UNDER 45-60 KT LLJ.
MEANWHILE...60S F SFC DEW POINTS SHOULD BECOME COMMON OVER MOIST
SECTOR AND S OF ABOUT I-70 OVERNIGHT...CONTRIBUTING TO SFC-BASED
PARCELS WITH MLCAPE IN 500-1500 J/KG RANGE.
THOUGH SUBSTANTIAL SVR OUTBREAK IS POSSIBLE...A FEW FACTORS PRECLUDE
MORE SPECIFIC CORRIDOR OF GREATER PROBABILITIES ATTM. IN ADDITION
TO TIMING/LOCATION OF INITIATION...EVOLUTION OF CONVECTIVE MODE
REMAINS HIGHLY UNCLEAR THIS FAR IN ADVANCE. ANY RELATIVELY DISCRETE
SUPERCELLS THAT CAN FORM IN SUCH FAST AMBIENT FLOW MAY TRAVEL LONG
DISTANCES WITH TORNADO POTENTIAL...WHILE DAMAGING QLCS DEVELOPMENT
WITH BOWS/LEWPS APPEARS LIKELY AT SOME POINT OVERNIGHT. SWD
BACKBUILDING OF OVERNIGHT CONVECTION ALSO IS LIKELY...AFFECTING
LOWER MS VALLEY REGION...THOUGH CAPPING WILL MAKE THIS RISK MORE
CONDITIONAL WITH SWD EXTENT TOWARD GULF.
..EDWARDS.. 02/26/2011
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
CURRENT UTC TIME: 1611Z (11:11AM), RELOAD THIS PAGE TO UPDATE THE TIME
SPC AC 260654
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1254 AM CST SAT FEB 26 2011
VALID 271200Z - 281200Z
...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SRN PLAINS...ARKLATEX
TO LOWER OH VALLEY REGION...
...SYNOPSIS...
UPPER-AIR PATTERN FCST TO REMAIN QUASI-ZONAL ACROSS MOST OF
CONUS...PRIMARY PERTURBATION BEING STG SHORTWAVE TROUGH AND EMBEDDED
LOW LOCATED OVER NRN CA AS OF 26/05Z. THIS FEATURE IS FCST TO DIG
SSEWD THEN TURN EWD ACROSS LOWER CO RIVER VALLEY AREA NEAR START OF
PERIOD. GIVEN SLIGHTLY LAGGED UPSTREAM PATTERN OF HEIGHT FALLS AND
RUN-TO-RUN TRENDS IN PROGS...WILL MAINTAIN EARLY-PERIOD FCST CLOSER
TO CONSISTENTLY SLOWER ECMWF POSITION...AS OPPOSED TO FASTER
OPERATIONAL SPECTRAL...WITH 500-MB CYCLONE POSITIONED OVER LAS-EED
AREA AT START OF PERIOD. THIS ALSO RESEMBLES ETA MEMBERS OF SREF.
TROUGH IS FCST TO ASSUME PRONOUNCED POSITIVE TILT EARLY IN PERIOD
AND DEVOLVE TO OPEN WAVE...MOVING EWD TO AXIS FROM CENTRAL HIGH
PLAINS TO S-CENTRAL/SWRN NM BY 28/00Z. TROUGH THEN SHOULD MOVE EWD
BY 28/12Z TO NEAR KS/MO BORDER...SERN OK...AND N-CENTRAL TX...BY
WHICH TIME ECMWF ACCELERATES SYSTEM INTO SREF MEAN POSITION.
AT SFC...LEE TROUGHING OVER CO LATE DAY-1 SHOULD CONSOLIDATE RAPIDLY
INTO STG SFC CYCLONE THERE BY ABOUT 27/18Z AS UPPER WAVE
APCHS...WITH WARM FRONT EWD ACROSS PORTIONS KS/MO. SFC LOW THEN
SHOULD PIVOT SEWD/EWD OVER SRN KS DURING AFTERNOON/EVENING. SFC LOW
PRESSURE THEN SHOULD BECOME ELONGATED SW-NE ALONG SFC FRONTAL ZONE
BY END OF PERIOD...WITH NEWER CENTER POSSIBLE OVER LOWER MI AND
ORIGINAL LOW OVER MO OR IL. COLD FRONT TRAILING SFC LOW WILL MOVE
EWD FROM CENTRAL/SRN ROCKIES ACROSS OK AND MOST OF TX BY 28/12Z.
DRYLINE SHOULD MOVE EWD ACROSS PORTIONS CENTRAL/N-CENTRAL TX AND
CENTRAL/ERN OK DURING AFTERNOON/EVENING...INTERSECTING FRONTAL ZONE
NEAR S-CENTRAL/SERN KS SFC LOW.
...SRN PLAINS...ARKLATEX TO LOWER OH VALLEY REGION...
MOST CONCENTRATED AND SIGNIFICANT SVR THREAT IS FCST DURING
EVENING/OVERNIGHT HOURS IN AND NEAR OZARKS...WITH MORE CONDITIONAL
SVR RISK BEGINNING AS EARLY AS MID-LATE AFTERNOON AND AS FAR W AS
CENTRAL/ERN PORTIONS OF KS/OK. BULK OF SVR EVENTS SHOULD BE
DAMAGING WIND...ALTHOUGH A FEW STG TORNADOES AND LARGE/DAMAGING HAIL
ALSO ARE POSSIBLE.
INITIAL/DIURNAL CONVECTIVE DEVELOPMENT...AND TSTM COVERAGE THROUGH
AROUND 28/00Z...REMAIN RATHER UNCERTAIN/CONDITIONAL...AS AREAS ALONG
AND E OF DRYLINE OVER SRN KS...NE TX AND OK SHOULD BE CAPPED FOR
MOST OF AFTERNOON BENEATH ELEVATED MIXED-LAYER AIR. ISOLATED SVR
TSTMS ARE POSSIBLE...WHICH COULD INCLUDE SUPERCELLS.
EXPECT MAJOR INCREASE IN CONVECTIVE COVERAGE DURING 28/00Z-28/06Z AS
LIFT STRENGTHENS ON ALL SCALES...AND STRONGER FORCING IMPINGES UPON
PROGRESSIVELY MORE MOIST LOW-LEVEL AIR MASS. KINEMATIC ENVIRONMENT
WILL BECOME MORE FAVORABLE WITH TIME DURING AFTERNOON/EVENING AS
STRENGTHENING FLOW AND ASCENT ALOFT SPREADS OVER PROGRESSIVELY
MOISTENING WARM SECTOR E OF DRYLINE. LEFT-EXIT REGION OF
INTENSIFYING...SOMEWHAT CYCLONICALLY CURVED...125-150 KT 250-MB JET
WILL BE SPREADING ACROSS MUCH OF OK...KS...OZARKS AND INTO LOWER OH
VALLEY REGION DURING LATTER HALF OF PERIOD. MEANWHILE...EXPECT
BROAD AREA OF 60-80 KT 500-MB WINDS TO SPREAD OVER SVR RISK AREAS
DURING EVENING AND OVERNIGHT...CONTRIBUTING TO FAVORABLE DEEP-LAYER
SHEAR...E.G. EFFECTIVE SHEAR MAGNITUDES 50-60 KT IN MANY FCST
SOUNDINGS. LOW-LEVEL HODOGRAPHS ALSO WILL ENLARGE CONSIDERABLY
AFTER 00Z FROM ERN OK THROUGH PORTIONS AR/MO/SRN IL/WRN KY/WRN
TN...WITH 0-1 KM SRH 250-400 J/KG UNDER 45-60 KT LLJ.
MEANWHILE...60S F SFC DEW POINTS SHOULD BECOME COMMON OVER MOIST
SECTOR AND S OF ABOUT I-70 OVERNIGHT...CONTRIBUTING TO SFC-BASED
PARCELS WITH MLCAPE IN 500-1500 J/KG RANGE.
THOUGH SUBSTANTIAL SVR OUTBREAK IS POSSIBLE...A FEW FACTORS PRECLUDE
MORE SPECIFIC CORRIDOR OF GREATER PROBABILITIES ATTM. IN ADDITION
TO TIMING/LOCATION OF INITIATION...EVOLUTION OF CONVECTIVE MODE
REMAINS HIGHLY UNCLEAR THIS FAR IN ADVANCE. ANY RELATIVELY DISCRETE
SUPERCELLS THAT CAN FORM IN SUCH FAST AMBIENT FLOW MAY TRAVEL LONG
DISTANCES WITH TORNADO POTENTIAL...WHILE DAMAGING QLCS DEVELOPMENT
WITH BOWS/LEWPS APPEARS LIKELY AT SOME POINT OVERNIGHT. SWD
BACKBUILDING OF OVERNIGHT CONVECTION ALSO IS LIKELY...AFFECTING
LOWER MS VALLEY REGION...THOUGH CAPPING WILL MAKE THIS RISK MORE
CONDITIONAL WITH SWD EXTENT TOWARD GULF.
..EDWARDS.. 02/26/2011
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
CURRENT UTC TIME: 1611Z (11:11AM), RELOAD THIS PAGE TO UPDATE THE TIME
0 likes
-
srainhoutx
- S2K Supporter
- Posts: 6919
- Age: 67
- Joined: Sun Jan 14, 2007 11:34 am
- Location: Haywood County, NC
- Contact:
Re: Another severe weather outbreak? February 27-28
Another Moderate Risk...
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CST SAT FEB 26 2011
VALID 271200Z - 281200Z
...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF EASTERN
OK/MUCH OF AR/SOUTHERN MO/SOUTHERN IL/FAR SOUTHWEST INDIANA/WESTERN
KY/WESTERN TN/NORTHERN MS...
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SOUTHERN PLAINS TO THE
LOWER/MIDDLE MS VALLEY AND LOWER OH VALLEY...
...SYNOPSIS...
CLOSED UPPER LOW CURRENTLY CENTERED OVER CA IS EXPECTED TO
OPEN/SHIFT EASTWARD OVER AZ/NM DURING THE DAY ON SUNDAY...AND TAKE
ON MORE OF A NEUTRAL/SLIGHT NEGATIVE TILT AS IT REACHES THE SOUTHERN
PLAINS/OZARKS LATE SUNDAY NIGHT. A REGIONAL OUTBREAK OF SEVERE
TSTMS...INCLUDING THE POSSIBILITY OF WIDESPREAD DAMAGING
WINDS/STRONG TORNADOES...SEEMS PROBABLE LATE SUNDAY AFTERNOON AND
ESPECIALLY SUNDAY NIGHT.
...SOUTHERN PLAINS/ARKLATEX/OZARKS/MID-SOUTH/LOWER OH VALLEY...
THE POSSIBILITY OF WIDESPREAD DAMAGING WINDS AND TORNADOES
/INCLUDING SOME STRONG/...IN ADDITION TO AN INITIAL BOUT OF LARGE
HAIL...WILL BEGIN LATE SUNDAY AFTERNOON...AND CONTINUE WELL THROUGH
THE NIGHT/EARLY MORNING HOURS OF MONDAY ACROSS PORTIONS OF THE
OZARKS/MID-SOUTH TO MIDDLE MS VALLEY/LOWER OH VALLEY.
INITIAL/DIURNAL DEEP CONVECTIVE COVERAGE IS A STILL A BIT UNCERTAIN
ALONG THE DRYLINE ACROSS OK/NORTH TX/FAR SOUTHERN KS DURING THE
DAYLIGHT HOURS...AS MUCH OF THE WARM SECTOR SHOULD REMAIN CAPPED
BENEATH AN ELEVATED MIXED LAYER. NONETHELESS...CURRENT THINKING IS
THAT AT LEAST AN ISOLATED INITIAL THREAT FOR SEVERE TSTMS WILL
DEVELOP BY SUNSET...WITH INITIALLY ISOLATED SUPERCELLS CAPABLE OF
LARGE HAIL AND A TORNADO THREAT ACROSS PORTIONS OF OK/FAR NORTH TX
AND PERHAPS FAR SOUTHERN KS.
OTHERWISE...A SEASONALLY MOIST LOW LEVEL AIRMASS...GENERALLY
CHARACTERIZED BY LOWER 60S F SURFACE DEWPOINTS...WILL BECOME
ESTABLISHED WITHIN A RELATIVELY BROAD WARM SECTOR ACROSS THE REGION
DURING THE AFTERNOON/NIGHT. A CONSIDERABLE INCREASE IN DEEP
CONVECTIVE COVERAGE/INTENSITY IS ANTICIPATED THROUGH THE
EVENING...AS LARGE SCALE FORCING FOR ASCENT/DEEP TROPOSPHERIC WIND
FIELD DRAMATICALLY INCREASE ATTENDANT TO THE ADVANCING UPPER
TROUGH/POLAR JET. WITH DEEP LAYER SHEAR ON THE ORDER OF 50-70
KT...SUFFICIENT INSTABILITY ON THE ORDER OF 750-1250 J/KG MLCAPE
WILL SUPPORT A POTENTIALLY WIDESPREAD SEVERE THREAT. GIVEN STRONG
LOW LEVEL SRH AS AIDED BY A STRENGTHENING 60+ KT LOW LEVEL JET...A
MIXED CONVECTIVE MODE INCLUDING QUASI-LINEAR BOWING
SEGMENTS/LINE-LEADING SEMI-DISCRETE SUPERCELLS WILL BE CAPABLE OF
WIDESPREAD DAMAGING WINDS/STRONG TORNADOES...AS THE SEVERE THREAT
CONTINUES WELL INTO THE EARLY MORNING HOURS OF MONDAY TOWARD THE
MIDDLE/LOWER MS AND TN/LOWER OH RIVER VALLEYS.
..GUYER.. 02/26/2011
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CST SAT FEB 26 2011
VALID 271200Z - 281200Z
...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF EASTERN
OK/MUCH OF AR/SOUTHERN MO/SOUTHERN IL/FAR SOUTHWEST INDIANA/WESTERN
KY/WESTERN TN/NORTHERN MS...
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SOUTHERN PLAINS TO THE
LOWER/MIDDLE MS VALLEY AND LOWER OH VALLEY...
...SYNOPSIS...
CLOSED UPPER LOW CURRENTLY CENTERED OVER CA IS EXPECTED TO
OPEN/SHIFT EASTWARD OVER AZ/NM DURING THE DAY ON SUNDAY...AND TAKE
ON MORE OF A NEUTRAL/SLIGHT NEGATIVE TILT AS IT REACHES THE SOUTHERN
PLAINS/OZARKS LATE SUNDAY NIGHT. A REGIONAL OUTBREAK OF SEVERE
TSTMS...INCLUDING THE POSSIBILITY OF WIDESPREAD DAMAGING
WINDS/STRONG TORNADOES...SEEMS PROBABLE LATE SUNDAY AFTERNOON AND
ESPECIALLY SUNDAY NIGHT.
...SOUTHERN PLAINS/ARKLATEX/OZARKS/MID-SOUTH/LOWER OH VALLEY...
THE POSSIBILITY OF WIDESPREAD DAMAGING WINDS AND TORNADOES
/INCLUDING SOME STRONG/...IN ADDITION TO AN INITIAL BOUT OF LARGE
HAIL...WILL BEGIN LATE SUNDAY AFTERNOON...AND CONTINUE WELL THROUGH
THE NIGHT/EARLY MORNING HOURS OF MONDAY ACROSS PORTIONS OF THE
OZARKS/MID-SOUTH TO MIDDLE MS VALLEY/LOWER OH VALLEY.
INITIAL/DIURNAL DEEP CONVECTIVE COVERAGE IS A STILL A BIT UNCERTAIN
ALONG THE DRYLINE ACROSS OK/NORTH TX/FAR SOUTHERN KS DURING THE
DAYLIGHT HOURS...AS MUCH OF THE WARM SECTOR SHOULD REMAIN CAPPED
BENEATH AN ELEVATED MIXED LAYER. NONETHELESS...CURRENT THINKING IS
THAT AT LEAST AN ISOLATED INITIAL THREAT FOR SEVERE TSTMS WILL
DEVELOP BY SUNSET...WITH INITIALLY ISOLATED SUPERCELLS CAPABLE OF
LARGE HAIL AND A TORNADO THREAT ACROSS PORTIONS OF OK/FAR NORTH TX
AND PERHAPS FAR SOUTHERN KS.
OTHERWISE...A SEASONALLY MOIST LOW LEVEL AIRMASS...GENERALLY
CHARACTERIZED BY LOWER 60S F SURFACE DEWPOINTS...WILL BECOME
ESTABLISHED WITHIN A RELATIVELY BROAD WARM SECTOR ACROSS THE REGION
DURING THE AFTERNOON/NIGHT. A CONSIDERABLE INCREASE IN DEEP
CONVECTIVE COVERAGE/INTENSITY IS ANTICIPATED THROUGH THE
EVENING...AS LARGE SCALE FORCING FOR ASCENT/DEEP TROPOSPHERIC WIND
FIELD DRAMATICALLY INCREASE ATTENDANT TO THE ADVANCING UPPER
TROUGH/POLAR JET. WITH DEEP LAYER SHEAR ON THE ORDER OF 50-70
KT...SUFFICIENT INSTABILITY ON THE ORDER OF 750-1250 J/KG MLCAPE
WILL SUPPORT A POTENTIALLY WIDESPREAD SEVERE THREAT. GIVEN STRONG
LOW LEVEL SRH AS AIDED BY A STRENGTHENING 60+ KT LOW LEVEL JET...A
MIXED CONVECTIVE MODE INCLUDING QUASI-LINEAR BOWING
SEGMENTS/LINE-LEADING SEMI-DISCRETE SUPERCELLS WILL BE CAPABLE OF
WIDESPREAD DAMAGING WINDS/STRONG TORNADOES...AS THE SEVERE THREAT
CONTINUES WELL INTO THE EARLY MORNING HOURS OF MONDAY TOWARD THE
MIDDLE/LOWER MS AND TN/LOWER OH RIVER VALLEYS.
..GUYER.. 02/26/2011
0 likes
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Ike/Harvey
Member: National Weather Association
Wx Infinity Forums
http://wxinfinity.com/index.php
Facebook.com/WeatherInfinity
Twitter @WeatherInfinity
Member: National Weather Association
Wx Infinity Forums
http://wxinfinity.com/index.php
Facebook.com/WeatherInfinity
Twitter @WeatherInfinity
-
Ivanhater
- Storm2k Moderator
- Posts: 11153
- Age: 38
- Joined: Fri Jul 01, 2005 8:25 am
- Location: Pensacola
Re: Another severe weather outbreak? February 27-28
Along the Gulf coast we have been seeing a long stretch of above normal temps in the 70's and 80's. That will really help raise the Gulf temps and help with instability.
0 likes
Michael
Re: Another severe weather outbreak? February 27-28
We dodged the first round Thursday - I'm hoping we dodge this one, too...
000
FXUS64 KOHX 262124
AFDOHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
324 PM CST SAT FEB 26 2011
.DISCUSSION...MAIN CONCERN CONTINUES TO BE THE NEXT ROUND OF
SEVERE WEATHER EXPECTED SUNDAY NIGHT AND MONDAY ACROSS MID
TENNESSEE. MODELS CONTINUE TO INDICATE POTENTIAL DAMAGING
WINDS...HAIL AND ISOLATED TORNADOES.
IN THE SHORTER TERM...MID TN WAS HAVING A NICE BREAK FROM
SIGNIFICANT WX. SKIES WERE MAINLY SUNNY AND TEMPERATURES WERE IN
THE UPPER 50S TO LOWER 60S. THIS WAS GIVING MID TN RESIDENTS
IMPACTED BY THURSDAY NIGHTS SEVERE WX A CHANCE TO CLEAN UP.
THIS EVENING WILL BE CLEAR TO PARTLY CLOUDY...WITH JUST THIN
CIRRUS OVERHEAD. TEMPERATURES WILL PROBABLY FALL NEAR OUR EXPECTED
OVERNIGHT LOWS BY MIDNIGHT...THEN READINGS WILL BE NEARLY STEADY
IN THE LATE NIGHT HOURS AS CLOUDS THICKEN. BY DAYBREAK SUNDAY...A
BRISK FLOW OF WARMER AND MOIST AIR WILL BE DEVELOPING OVER THE
BOUNDARY LAYER. MID LEVEL WINDS WILL BE BACKING IN RESPONSE TO A
SYSTEM OVER THE SOUTHWEST STATES. THIS PATTERN WILL BRING ENOUGH
MOISTURE AND ELEVATED INSTABILITY TO GENERATE SCATTERED SHOWERS
AND SOME NON-SEVERE THUNDER...ESPECIALLY OVER OUR NORTHWEST
COUNTIES.
ON SUNDAY...A WARM ADVECTION REGIME WILL CONTINUE WITH A MOIST
SOUTHWEST FLOW ALOFT. WE WILL HAVE A CHANCE FOR SHOWERS/STORMS
MAINLY SUNDAY MORNING. WE DO NOT EXPECT A TOTAL WASHOUT. SOME
SUNSHINE WILL BREAK THROUGH THE CLOUDS BRIEFLY AT TIMES...AND
TEMPS WILL BE MILD. SOUTH WINDS WILL INCREASE TO 10-20 MPH.
FOR SUNDAY NIGHT INTO MONDAY...ENERGY WILL BE COMING OUT OF THE
WEST...CROSSING THE PLAINS AND MOVING INTO THE OHIO VALLEY. THE
FIRST WAVE WILL REACH THE OH VALLEY LATE SUNDAY NIGHT...WITH THE
NEXT MORE SIGNIFICANT WAVE COMING THROUGH ON MONDAY. THIS SETUP
IS COMPLEX...AND IT WILL BE DIFFICULT TO KNOW FAR IN ADVANCE
EXACTLY WHERE VARIOUS MODES OF CONVECTION WILL DEVELOP.
HOWEVER...INGREDIENTS WILL BE AVAILABLE FOR A SIGNIFICANT SEVERE WX
OUTBREAK TO DEVELOP OVER THE MID MS VALLEY SUNDAY NIGHT...MOVING
INTO THE TN VALLEY LATE SUNDAY NIGHT AND MONDAY.
FORECAST PARAMETERS FOR MID TN ARE IMPRESSIVE...WITH SB CAPES
EXCEEDING 1000 J/KG...LI VALUES TO -5...TOTALS INDEX IN THE MID
50S...AND SWEAT INDEX VALUES 400-500. THERE ARE SOME TIMING
UNCERTAINTIES WITH FROPA ON MONDAY. EARLIER WE THOUGH MOST OF THE
ACTIVITY WOULD BE MONDAY MORNING...BUT THE FROPA MAY BE MID
AFTERNOON FOR BNA...AND LATER FOR THE PLATEAU. A LATER FROPA WILL
ALLOW MORE TIME FOR DESTABILIZATION...INCREASING THE SEVERE WX
POTENTIAL. A FASTER AND EARLIER FROPA WOULD MEAN LIMITED
INSTABILITY...AND LESS INTENSE SEVERE WX. FOR NOW OUR PRODUCTS
WILL HIGHLIGHT SUNDAY NIGHT THROUGH MONDAY...AND LATER SHIFTS CAN
REFINE THE TIMING.
AFTER MONDAY...WE WILL HAVE SEVERAL DAYS OF FAIR WX. TUESDAY WILL
START A LITTLE COOL...BUT MILD CONDITIONS WILL RETURN
QUICKLY...WITH TEMPS REACHING THE 60S MID/LATE WEEK. UNSETTLED WX
WILL RETURN NEXT WEEKEND.
&&
000
FXUS64 KOHX 262124
AFDOHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
324 PM CST SAT FEB 26 2011
.DISCUSSION...MAIN CONCERN CONTINUES TO BE THE NEXT ROUND OF
SEVERE WEATHER EXPECTED SUNDAY NIGHT AND MONDAY ACROSS MID
TENNESSEE. MODELS CONTINUE TO INDICATE POTENTIAL DAMAGING
WINDS...HAIL AND ISOLATED TORNADOES.
IN THE SHORTER TERM...MID TN WAS HAVING A NICE BREAK FROM
SIGNIFICANT WX. SKIES WERE MAINLY SUNNY AND TEMPERATURES WERE IN
THE UPPER 50S TO LOWER 60S. THIS WAS GIVING MID TN RESIDENTS
IMPACTED BY THURSDAY NIGHTS SEVERE WX A CHANCE TO CLEAN UP.
THIS EVENING WILL BE CLEAR TO PARTLY CLOUDY...WITH JUST THIN
CIRRUS OVERHEAD. TEMPERATURES WILL PROBABLY FALL NEAR OUR EXPECTED
OVERNIGHT LOWS BY MIDNIGHT...THEN READINGS WILL BE NEARLY STEADY
IN THE LATE NIGHT HOURS AS CLOUDS THICKEN. BY DAYBREAK SUNDAY...A
BRISK FLOW OF WARMER AND MOIST AIR WILL BE DEVELOPING OVER THE
BOUNDARY LAYER. MID LEVEL WINDS WILL BE BACKING IN RESPONSE TO A
SYSTEM OVER THE SOUTHWEST STATES. THIS PATTERN WILL BRING ENOUGH
MOISTURE AND ELEVATED INSTABILITY TO GENERATE SCATTERED SHOWERS
AND SOME NON-SEVERE THUNDER...ESPECIALLY OVER OUR NORTHWEST
COUNTIES.
ON SUNDAY...A WARM ADVECTION REGIME WILL CONTINUE WITH A MOIST
SOUTHWEST FLOW ALOFT. WE WILL HAVE A CHANCE FOR SHOWERS/STORMS
MAINLY SUNDAY MORNING. WE DO NOT EXPECT A TOTAL WASHOUT. SOME
SUNSHINE WILL BREAK THROUGH THE CLOUDS BRIEFLY AT TIMES...AND
TEMPS WILL BE MILD. SOUTH WINDS WILL INCREASE TO 10-20 MPH.
FOR SUNDAY NIGHT INTO MONDAY...ENERGY WILL BE COMING OUT OF THE
WEST...CROSSING THE PLAINS AND MOVING INTO THE OHIO VALLEY. THE
FIRST WAVE WILL REACH THE OH VALLEY LATE SUNDAY NIGHT...WITH THE
NEXT MORE SIGNIFICANT WAVE COMING THROUGH ON MONDAY. THIS SETUP
IS COMPLEX...AND IT WILL BE DIFFICULT TO KNOW FAR IN ADVANCE
EXACTLY WHERE VARIOUS MODES OF CONVECTION WILL DEVELOP.
HOWEVER...INGREDIENTS WILL BE AVAILABLE FOR A SIGNIFICANT SEVERE WX
OUTBREAK TO DEVELOP OVER THE MID MS VALLEY SUNDAY NIGHT...MOVING
INTO THE TN VALLEY LATE SUNDAY NIGHT AND MONDAY.
FORECAST PARAMETERS FOR MID TN ARE IMPRESSIVE...WITH SB CAPES
EXCEEDING 1000 J/KG...LI VALUES TO -5...TOTALS INDEX IN THE MID
50S...AND SWEAT INDEX VALUES 400-500. THERE ARE SOME TIMING
UNCERTAINTIES WITH FROPA ON MONDAY. EARLIER WE THOUGH MOST OF THE
ACTIVITY WOULD BE MONDAY MORNING...BUT THE FROPA MAY BE MID
AFTERNOON FOR BNA...AND LATER FOR THE PLATEAU. A LATER FROPA WILL
ALLOW MORE TIME FOR DESTABILIZATION...INCREASING THE SEVERE WX
POTENTIAL. A FASTER AND EARLIER FROPA WOULD MEAN LIMITED
INSTABILITY...AND LESS INTENSE SEVERE WX. FOR NOW OUR PRODUCTS
WILL HIGHLIGHT SUNDAY NIGHT THROUGH MONDAY...AND LATER SHIFTS CAN
REFINE THE TIMING.
AFTER MONDAY...WE WILL HAVE SEVERAL DAYS OF FAIR WX. TUESDAY WILL
START A LITTLE COOL...BUT MILD CONDITIONS WILL RETURN
QUICKLY...WITH TEMPS REACHING THE 60S MID/LATE WEEK. UNSETTLED WX
WILL RETURN NEXT WEEKEND.
&&
0 likes
-
CrazyC83
- Professional-Met
- Posts: 34001
- Joined: Tue Mar 07, 2006 11:57 pm
- Location: Deep South, for the first time!
Re: Another severe weather outbreak? February 27-28
breeze wrote:We dodged the first round Thursday - I'm hoping we dodge this one, too...
This looks to be an overnight (or early morning) event for you, so those are more dangerous...
I wonder if they will go HIGH risk for tomorrow?
0 likes
-
WeatherGuesser
- Category 5
- Posts: 2672
- Joined: Tue Jun 29, 2010 6:46 am
-
CrazyC83
- Professional-Met
- Posts: 34001
- Joined: Tue Mar 07, 2006 11:57 pm
- Location: Deep South, for the first time!
SPC AC 270541
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1141 PM CST SAT FEB 26 2011
VALID 271200Z - 281200Z
...THERE IS A MDT RISK OF SVR TSTMS OVER SRN IL...EXTREME SWRN
IND...FAR W KY...WRN TN...SERN MO...CNTRL/NRN AR AND EXTREME ECNTRL
OK...
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS TO THE
LOWER OH VALLEY/MIDWEST...
...SYNOPSIS...
POSITIVE-TILT MID-LEVEL TROUGH LOCATED OVER THE GREAT BASIN AND SWRN
STATES IS EXPECTED TO MIGRATE ENE TODAY AND TONIGHT AS UPSTREAM
IMPULSE DIGS OFF BRITISH COLUMBIA COAST. THE WEAKER NRN PORTION OF
THE TROUGH WILL EJECT FASTER...REACHING THE MID-MS VLY THIS EVENING
AND THE MIDWEST TONIGHT. SFC REFLECTION WILL DEVELOP ALONG A NWD
MOVING WARM FRONT FROM CNTRL MO TO NRN IND BY TONIGHT.
MEANWHILE...COLDER AND STRONGER SRN PARTS OF THE TROUGH... CURRENTLY
APPROACHING THE SRN CA COAST...WILL OPEN INTO A WAVE AND MOVE INTO
THE CNTRL/SRN PLAINS THIS EVENING/TONIGHT. WEAK CYCLOGENESIS WILL
OCCUR WITH THIS FEATURE OVER THE OZARKS AS A DRYLINE MIXES EWD INTO
ERN OK AND NE TX BY TONIGHT.
...SRN PLAINS TO THE MID-SOUTH/MIDWEST...
BI-MODAL SVR EVENT IS LIKELY LATER THIS AFTERNOON THROUGH THE
OVERNIGHT WITH DAMAGING WINDS...TORNADOES AND LARGE HAIL LIKELY OVER
A LARGE REGION.
FIRST CONCERN WILL REVOLVE AROUND THE AFOREMENTIONED WEAK LEAD
IMPULSE THAT WILL MOVE INTO THE MIDWEST BY TONIGHT. VERY STRONG
SWLY FLOW OF 65+ KTS WILL TRANSPORT SFC DEW POINTS OF 58+F NWD TO
SRN EDGE OF THE SNOWPACK...ROUGHLY ECNTRL MO TO SRN IND BY
MID-EVENING. MODEST LARGE-SCALE HEIGHT FALLS WILL CONTRIBUTE TO
MOISTENING/ASCENT OVER A LARGE REGION THIS AFTERNOON AND EVENING
WITH MLCAPES 500-1000 J/KG FROM THE LOWER OH VLY AND MID-SOUTH.
PRIMARY QUESTION WILL BE IF THE WARM SECTOR CAP WILL WEAKEN ENOUGH
TO SUPPORT DEEP MOIST CONVECTION. THERE WILL CERTAINLY BE SUPPORT
FOR INCREASING BANDS OF ELEVATED TSTMS ALONG/N OF I-70...BUT CONCERN
IS FOR ANY DISCRETE AND/OR CLUSTERS OF MORE SFC-BASED STORMS IN THE
DEEPENING MOIST/MORE UNSTABLE AIR MASS ACROSS THE LWR OH
VLY/MID-SOUTH...PRIMARILY LATE AFTERNOON/EVENING. THESE STORMS WILL
BE EMBEDDED IN AN ENVIRONMENT CHARACTERIZED BY LARGE-CURVED
LOW-LEVEL HODOGRAPHS AND STRONG DEEP-LAYER SHEAR.
TORNADOES...DAMAGING WINDS WILL BE LIKELY WITH THESE STORMS
/PARTICULARLY IN NRN PORTIONS OF MDT RISK/...ALTHOUGH LARGE HAIL
WILL BE MORE LIKELY N OF THE WARM FRONT IN CNTRL PORTIONS OF IL/IND.
THIS ACTIVITY WILL DEVELOP/TRANSLATE ENE INTO THE MID-OH VALLEY/KY
COALFIELDS BY 12Z MONDAY WITH A LOWER SVR PROBABILITY WITH EWD
EXTENT.
MEANWHILE...A LATE NIGHT SURGE IN THE SEVERE THREAT WILL OCCUR
FARTHER SW AS SRN EXTENT OF THE EJECTING TROUGH ARRIVES LATE AT
NIGHT. EXPECT ANY REMAINING CAP TO WEAKEN WITH A GRADUAL INCREASE
IN STORMS ALONG/E OF THE DRYLINE/PRE-FRONTAL TROUGH FROM THE MO
OZARKS SWWD INTO ERN OK/NE TX AFTER 06Z. THESE STORMS WILL LIKELY
GROW QUICKLY UPSCALE INTO A QLCS BY 09Z WHILE ACCELERATING ENE
TOWARD THE LWR OH VLY/MID-SOUTH 09-12Z. GIVEN POSITIVE-TILT NATURE
TO THE TROUGH...DEEP-LAYER WIND FIELDS WILL BE COMPARATIVELY MORE
UNIDIRECTIONAL AND ORIENTED MORE PARALLEL TO THE INITIATING BOUNDARY
THAT THE ENVIRONMENT EARLIER IN THE NIGHT. AS SUCH...BOWING LINE
SEGMENTS WILL BE FAVORED WITH POSSIBLE SIGNIFICANT CORRIDORS OF WIND
EVOLVING. THERE IS ALSO A POSSIBILITY OF EMBEDDED
TORNADOES...ALTHOUGH FORECAST HODOGRAPHS SHOW A VEERING-BACKING
PATTERN WITH HEIGHT THAT MAY BE DETRIMENTAL IN STORM STRUCTURES
NORMALLY CONDUCIVE FOR SIGNIFICANT TORNADOES. NONETHELESS...GIVEN
NEARLY 100 KTS OF MID-LEVEL WINDS EJECTING NEWD AND FAVORABLE
BUOYANCY/ FORCING...STILL EXPECT A BUSY SEVERE WEATHER NIGHT AHEAD
ACROSS THE MID-SOUTH AND LWR OH VALLEY AND THE MDT RISK HAS BEEN
MAINTAINED.
..RACY/COHEN.. 02/27/2011
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
CURRENT UTC TIME: 0546Z (12:46AM), RELOAD THIS PAGE TO UPDATE THE TIME
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1141 PM CST SAT FEB 26 2011
VALID 271200Z - 281200Z
...THERE IS A MDT RISK OF SVR TSTMS OVER SRN IL...EXTREME SWRN
IND...FAR W KY...WRN TN...SERN MO...CNTRL/NRN AR AND EXTREME ECNTRL
OK...
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS TO THE
LOWER OH VALLEY/MIDWEST...
...SYNOPSIS...
POSITIVE-TILT MID-LEVEL TROUGH LOCATED OVER THE GREAT BASIN AND SWRN
STATES IS EXPECTED TO MIGRATE ENE TODAY AND TONIGHT AS UPSTREAM
IMPULSE DIGS OFF BRITISH COLUMBIA COAST. THE WEAKER NRN PORTION OF
THE TROUGH WILL EJECT FASTER...REACHING THE MID-MS VLY THIS EVENING
AND THE MIDWEST TONIGHT. SFC REFLECTION WILL DEVELOP ALONG A NWD
MOVING WARM FRONT FROM CNTRL MO TO NRN IND BY TONIGHT.
MEANWHILE...COLDER AND STRONGER SRN PARTS OF THE TROUGH... CURRENTLY
APPROACHING THE SRN CA COAST...WILL OPEN INTO A WAVE AND MOVE INTO
THE CNTRL/SRN PLAINS THIS EVENING/TONIGHT. WEAK CYCLOGENESIS WILL
OCCUR WITH THIS FEATURE OVER THE OZARKS AS A DRYLINE MIXES EWD INTO
ERN OK AND NE TX BY TONIGHT.
...SRN PLAINS TO THE MID-SOUTH/MIDWEST...
BI-MODAL SVR EVENT IS LIKELY LATER THIS AFTERNOON THROUGH THE
OVERNIGHT WITH DAMAGING WINDS...TORNADOES AND LARGE HAIL LIKELY OVER
A LARGE REGION.
FIRST CONCERN WILL REVOLVE AROUND THE AFOREMENTIONED WEAK LEAD
IMPULSE THAT WILL MOVE INTO THE MIDWEST BY TONIGHT. VERY STRONG
SWLY FLOW OF 65+ KTS WILL TRANSPORT SFC DEW POINTS OF 58+F NWD TO
SRN EDGE OF THE SNOWPACK...ROUGHLY ECNTRL MO TO SRN IND BY
MID-EVENING. MODEST LARGE-SCALE HEIGHT FALLS WILL CONTRIBUTE TO
MOISTENING/ASCENT OVER A LARGE REGION THIS AFTERNOON AND EVENING
WITH MLCAPES 500-1000 J/KG FROM THE LOWER OH VLY AND MID-SOUTH.
PRIMARY QUESTION WILL BE IF THE WARM SECTOR CAP WILL WEAKEN ENOUGH
TO SUPPORT DEEP MOIST CONVECTION. THERE WILL CERTAINLY BE SUPPORT
FOR INCREASING BANDS OF ELEVATED TSTMS ALONG/N OF I-70...BUT CONCERN
IS FOR ANY DISCRETE AND/OR CLUSTERS OF MORE SFC-BASED STORMS IN THE
DEEPENING MOIST/MORE UNSTABLE AIR MASS ACROSS THE LWR OH
VLY/MID-SOUTH...PRIMARILY LATE AFTERNOON/EVENING. THESE STORMS WILL
BE EMBEDDED IN AN ENVIRONMENT CHARACTERIZED BY LARGE-CURVED
LOW-LEVEL HODOGRAPHS AND STRONG DEEP-LAYER SHEAR.
TORNADOES...DAMAGING WINDS WILL BE LIKELY WITH THESE STORMS
/PARTICULARLY IN NRN PORTIONS OF MDT RISK/...ALTHOUGH LARGE HAIL
WILL BE MORE LIKELY N OF THE WARM FRONT IN CNTRL PORTIONS OF IL/IND.
THIS ACTIVITY WILL DEVELOP/TRANSLATE ENE INTO THE MID-OH VALLEY/KY
COALFIELDS BY 12Z MONDAY WITH A LOWER SVR PROBABILITY WITH EWD
EXTENT.
MEANWHILE...A LATE NIGHT SURGE IN THE SEVERE THREAT WILL OCCUR
FARTHER SW AS SRN EXTENT OF THE EJECTING TROUGH ARRIVES LATE AT
NIGHT. EXPECT ANY REMAINING CAP TO WEAKEN WITH A GRADUAL INCREASE
IN STORMS ALONG/E OF THE DRYLINE/PRE-FRONTAL TROUGH FROM THE MO
OZARKS SWWD INTO ERN OK/NE TX AFTER 06Z. THESE STORMS WILL LIKELY
GROW QUICKLY UPSCALE INTO A QLCS BY 09Z WHILE ACCELERATING ENE
TOWARD THE LWR OH VLY/MID-SOUTH 09-12Z. GIVEN POSITIVE-TILT NATURE
TO THE TROUGH...DEEP-LAYER WIND FIELDS WILL BE COMPARATIVELY MORE
UNIDIRECTIONAL AND ORIENTED MORE PARALLEL TO THE INITIATING BOUNDARY
THAT THE ENVIRONMENT EARLIER IN THE NIGHT. AS SUCH...BOWING LINE
SEGMENTS WILL BE FAVORED WITH POSSIBLE SIGNIFICANT CORRIDORS OF WIND
EVOLVING. THERE IS ALSO A POSSIBILITY OF EMBEDDED
TORNADOES...ALTHOUGH FORECAST HODOGRAPHS SHOW A VEERING-BACKING
PATTERN WITH HEIGHT THAT MAY BE DETRIMENTAL IN STORM STRUCTURES
NORMALLY CONDUCIVE FOR SIGNIFICANT TORNADOES. NONETHELESS...GIVEN
NEARLY 100 KTS OF MID-LEVEL WINDS EJECTING NEWD AND FAVORABLE
BUOYANCY/ FORCING...STILL EXPECT A BUSY SEVERE WEATHER NIGHT AHEAD
ACROSS THE MID-SOUTH AND LWR OH VALLEY AND THE MDT RISK HAS BEEN
MAINTAINED.
..RACY/COHEN.. 02/27/2011
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
CURRENT UTC TIME: 0546Z (12:46AM), RELOAD THIS PAGE TO UPDATE THE TIME
0 likes
Re: Another severe weather outbreak? February 27-28
No High Risk area forecast yet.
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0653 AM CST SUN FEB 27 2011
VALID 271300Z - 281200Z
...THERE IS A MDT RISK OF SVR TSTMS OVER PORTIONS OF AR...SERN
MO...WRN PARTS OF TN AND KY...SRN IL AND FAR SWRN IND...
...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE CNTRL/SRN
PLAINS NEWD THROUGH MUCH OF THE OH VALLEY...
...SYNOPSIS...
MID AND UPPER-LEVEL CYCLONE OVER THE LOWER CO VALLEY WILL BECOME
INCREASINGLY SHEARED WHILE TRANSLATING EWD INTO CONFLUENT FLOW
REGIME IN PLACE E OF THE ROCKIES. THE LEADING PORTION OF THIS
SYSTEM IS FORECAST TO REACH THE CNTRL/SRN HIGH PLAINS BY AFTERNOON
PRIOR TO LOSING AMPLITUDE WHILE EJECTING NEWD INTO THE UPPER MIDWEST
OVERNIGHT. IN ITS WAKE...THE MORE SUBSTANTIAL...REMAINING PORTION
OF MIDLEVEL TROUGH WILL SHIFT EWD THROUGH THE CNTRL/SRN PLAINS
TOWARD THE MID/LOWER MS VALLEYS BY 28/12Z.
AT THE SURFACE...LEE CYCLONE NOW DEEPENING OVER ERN CO IS FORECAST
TO DEVELOP TO THE VICINITY OF THE OK/KS BORDER NEAR OR JUST W OF
I-35 BY 28/00Z BEFORE ACCELERATING NEWD THROUGH CNTRL MO AND THE OH
VALLEY TONIGHT. AN ASSOCIATED WARM FRONT WILL LIFT NWD THROUGH THE
OZARKS AND MID MS/OH VALLEYS IN ADVANCE OF THIS INITIAL SURFACE LOW
WHILE A TRAILING COLD FRONT PUSHES SEWD THROUGH THE SRN PLAINS.
ELSEWHERE...A DRYLINE WILL MIX EWD TO THE VICINITY OF I-35 IN OK/N
TX BY LATE AFTERNOON BEFORE BEING OVERTAKEN BY PACIFIC FRONT WHICH
WILL SURGE EWD TOWARD THE LOWER MS VALLEY IN TANDEM WITH PRIMARY
PORTION OF UPPER TROUGH. THERE IS SOME INDICATION THAT A SECONDARY
SURFACE LOW MAY FORM TONIGHT AT THE INTERSECTION OF THE COLD AND
PACIFIC FRONTS NEAR THE CONFLUENCE OF THE MS AND OH VALLEYS.
...CNTRL/SRN PLAINS INTO THE OH VALLEY AND MID-SOUTH...
LATEST MESOSCALE AND CONVECTION-ALLOWING MODEL GUIDANCE HAS TRENDED
TOWARD A HIGHER PROBABILITY OF DIURNAL TSTM DEVELOPMENT THIS
AFTERNOON INTO EVENING FROM THE VICINITY OF SURFACE TRIPLE POINT
OVER S-CNTRL KS/N-CNTRL OK NEWD TOWARD MKC. HERE...DEEP ASCENT IN
EXIT REGION OF UPPER JET STREAK /ATTENDANT TO LEAD IMPULSE MENTIONED
ABOVE/ COUPLED WITH A STRENGTHENING FRONTOGENETICAL CIRCULATION ARE
EXPECTED TO OVERCOME CAP...SUPPORTING TSTM DEVELOPMENT ALONG OR ON
IMMEDIATE COOL SIDE OF SURFACE BOUNDARY. STEEP MIDLEVEL LAPSE RATES
AND BOUNDARY LAYER DEW POINTS IN THE UPPER 50S TO LOWER 60S WILL
YIELD A MODERATELY UNSTABLE ENVIRONMENT WITH MLCAPE VALUES
APPROACHING 1000 J/KG. MOREOVER...LOCALLY BACKED NEAR-SURFACE WINDS
BENEATH SWLY MIDLEVEL FLOW INCREASING TO 80-90 KT WILL RESULT IN
MORE THAN SUFFICIENT VERTICAL SHEAR FOR ORGANIZED STORMS INCLUDING
SUPERCELLS. THE PRIMARY HAZARD APPEARS TO BE HAIL...THOUGH A
TORNADO OR TWO IS POSSIBLE WITH ANY STORMS ROOTED IN THE BOUNDARY
LAYER.
EXPECT A RAPID DOWNSTREAM EXPANSION IN STRONG TO SEVERE TSTMS
TONIGHT FROM THE MID MS VALLEY EWD THROUGH THE OH VALLEY ALONG AND S
OF WARM FRONT AND IN ADVANCE OF MIGRATORY SURFACE LOW. AMBIENT
ENVIRONMENT WILL BE CHARACTERIZED BY MARGINAL INSTABILITY /I.E.
MLCAPE VALUES GENERALLY LESS THAN 500 J PER KG/ BUT VERY STRONG LOW
AND DEEP-LAYER SHEAR. AS SUCH...THE POTENTIAL WILL EXIST FOR
FAST-MOVING SUPERCELL AND/OR BOWING STORM CLUSTERS WITH A THREAT FOR
DAMAGING WINDS AND TORNADOES.
A SECOND...POTENTIALLY HIGHER IMPACT TSTM REGIME MAY DEVELOP LATE
THIS AFTERNOON OR MID/LATE EVENING FROM PORTIONS OF CNTRL/NERN AR
NEWD INTO THE LOWER OH VALLEY...ALONG RETREATING WARM FRONT OR
PERHAPS IN THE WAKE OF THE FRONT ALONG A CONFLUENCE ZONE DEVELOPING
WITHIN THE OPEN WARM SECTOR. HERE...SEVERAL MESOSCALE AND
CONVECTION-ALLOWING MODELS DEVELOP A DISTINCTLY SEPARATE AREA OF
CONVECTIVE PRECIPITATION WHICH EVENTUALLY MERGES WITH
ABOVE-MENTIONED CORRIDOR OF STORMS TRAVERSING THE OH VALLEY. GIVEN
THE MOIST/LOW LCL ENVIRONMENT...STRONG VERTICAL SHEAR AND POTENTIAL
FOR A MORE DISCRETE STORM MODE...IT APPEARS THAT THIS SETUP WOULD
FOSTER THE GREATEST THREAT FOR SIGNIFICANT TORNADOES IN ADDITION TO
HAIL AND LOCALLY DAMAGING WIND GUSTS.
A THIRD SVR TSTM EPISODE IS EXPECTED TO TAKE SHAPE ACROSS PARTS OF
ERN OK/WRN AR THIS EVENING INTO TONIGHT AS A PACIFIC FRONT OVERTAKES
THE DRYLINE AND SURGES EWD IN CONCERT WITH THE MAIN PORTION OF THE
UPPER TROUGH. INITIAL STORM MODE MAY BE SUPERCELLULAR...THOUGH A
RAPID TRANSITION TO QLCS IS EXPECTED WITH THE CONVECTIVE SYSTEM
REACHING WRN TN AND THE MS DELTA REGION BY THE END OF THE D1 PERIOD.
HERE TOO...VERTICAL SHEAR WILL BE QUITE STRONG AND SUPPORTIVE OF
EMBEDDED SUPERCELL AND/OR BOWING STRUCTURES CAPABLE OF POTENTIALLY
WIDESPREAD DAMAGING WINDS AND A FEW TORNADOES.
..MEAD/HURLBUT.. 02/27/2011
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0653 AM CST SUN FEB 27 2011
VALID 271300Z - 281200Z
...THERE IS A MDT RISK OF SVR TSTMS OVER PORTIONS OF AR...SERN
MO...WRN PARTS OF TN AND KY...SRN IL AND FAR SWRN IND...
...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE CNTRL/SRN
PLAINS NEWD THROUGH MUCH OF THE OH VALLEY...
...SYNOPSIS...
MID AND UPPER-LEVEL CYCLONE OVER THE LOWER CO VALLEY WILL BECOME
INCREASINGLY SHEARED WHILE TRANSLATING EWD INTO CONFLUENT FLOW
REGIME IN PLACE E OF THE ROCKIES. THE LEADING PORTION OF THIS
SYSTEM IS FORECAST TO REACH THE CNTRL/SRN HIGH PLAINS BY AFTERNOON
PRIOR TO LOSING AMPLITUDE WHILE EJECTING NEWD INTO THE UPPER MIDWEST
OVERNIGHT. IN ITS WAKE...THE MORE SUBSTANTIAL...REMAINING PORTION
OF MIDLEVEL TROUGH WILL SHIFT EWD THROUGH THE CNTRL/SRN PLAINS
TOWARD THE MID/LOWER MS VALLEYS BY 28/12Z.
AT THE SURFACE...LEE CYCLONE NOW DEEPENING OVER ERN CO IS FORECAST
TO DEVELOP TO THE VICINITY OF THE OK/KS BORDER NEAR OR JUST W OF
I-35 BY 28/00Z BEFORE ACCELERATING NEWD THROUGH CNTRL MO AND THE OH
VALLEY TONIGHT. AN ASSOCIATED WARM FRONT WILL LIFT NWD THROUGH THE
OZARKS AND MID MS/OH VALLEYS IN ADVANCE OF THIS INITIAL SURFACE LOW
WHILE A TRAILING COLD FRONT PUSHES SEWD THROUGH THE SRN PLAINS.
ELSEWHERE...A DRYLINE WILL MIX EWD TO THE VICINITY OF I-35 IN OK/N
TX BY LATE AFTERNOON BEFORE BEING OVERTAKEN BY PACIFIC FRONT WHICH
WILL SURGE EWD TOWARD THE LOWER MS VALLEY IN TANDEM WITH PRIMARY
PORTION OF UPPER TROUGH. THERE IS SOME INDICATION THAT A SECONDARY
SURFACE LOW MAY FORM TONIGHT AT THE INTERSECTION OF THE COLD AND
PACIFIC FRONTS NEAR THE CONFLUENCE OF THE MS AND OH VALLEYS.
...CNTRL/SRN PLAINS INTO THE OH VALLEY AND MID-SOUTH...
LATEST MESOSCALE AND CONVECTION-ALLOWING MODEL GUIDANCE HAS TRENDED
TOWARD A HIGHER PROBABILITY OF DIURNAL TSTM DEVELOPMENT THIS
AFTERNOON INTO EVENING FROM THE VICINITY OF SURFACE TRIPLE POINT
OVER S-CNTRL KS/N-CNTRL OK NEWD TOWARD MKC. HERE...DEEP ASCENT IN
EXIT REGION OF UPPER JET STREAK /ATTENDANT TO LEAD IMPULSE MENTIONED
ABOVE/ COUPLED WITH A STRENGTHENING FRONTOGENETICAL CIRCULATION ARE
EXPECTED TO OVERCOME CAP...SUPPORTING TSTM DEVELOPMENT ALONG OR ON
IMMEDIATE COOL SIDE OF SURFACE BOUNDARY. STEEP MIDLEVEL LAPSE RATES
AND BOUNDARY LAYER DEW POINTS IN THE UPPER 50S TO LOWER 60S WILL
YIELD A MODERATELY UNSTABLE ENVIRONMENT WITH MLCAPE VALUES
APPROACHING 1000 J/KG. MOREOVER...LOCALLY BACKED NEAR-SURFACE WINDS
BENEATH SWLY MIDLEVEL FLOW INCREASING TO 80-90 KT WILL RESULT IN
MORE THAN SUFFICIENT VERTICAL SHEAR FOR ORGANIZED STORMS INCLUDING
SUPERCELLS. THE PRIMARY HAZARD APPEARS TO BE HAIL...THOUGH A
TORNADO OR TWO IS POSSIBLE WITH ANY STORMS ROOTED IN THE BOUNDARY
LAYER.
EXPECT A RAPID DOWNSTREAM EXPANSION IN STRONG TO SEVERE TSTMS
TONIGHT FROM THE MID MS VALLEY EWD THROUGH THE OH VALLEY ALONG AND S
OF WARM FRONT AND IN ADVANCE OF MIGRATORY SURFACE LOW. AMBIENT
ENVIRONMENT WILL BE CHARACTERIZED BY MARGINAL INSTABILITY /I.E.
MLCAPE VALUES GENERALLY LESS THAN 500 J PER KG/ BUT VERY STRONG LOW
AND DEEP-LAYER SHEAR. AS SUCH...THE POTENTIAL WILL EXIST FOR
FAST-MOVING SUPERCELL AND/OR BOWING STORM CLUSTERS WITH A THREAT FOR
DAMAGING WINDS AND TORNADOES.
A SECOND...POTENTIALLY HIGHER IMPACT TSTM REGIME MAY DEVELOP LATE
THIS AFTERNOON OR MID/LATE EVENING FROM PORTIONS OF CNTRL/NERN AR
NEWD INTO THE LOWER OH VALLEY...ALONG RETREATING WARM FRONT OR
PERHAPS IN THE WAKE OF THE FRONT ALONG A CONFLUENCE ZONE DEVELOPING
WITHIN THE OPEN WARM SECTOR. HERE...SEVERAL MESOSCALE AND
CONVECTION-ALLOWING MODELS DEVELOP A DISTINCTLY SEPARATE AREA OF
CONVECTIVE PRECIPITATION WHICH EVENTUALLY MERGES WITH
ABOVE-MENTIONED CORRIDOR OF STORMS TRAVERSING THE OH VALLEY. GIVEN
THE MOIST/LOW LCL ENVIRONMENT...STRONG VERTICAL SHEAR AND POTENTIAL
FOR A MORE DISCRETE STORM MODE...IT APPEARS THAT THIS SETUP WOULD
FOSTER THE GREATEST THREAT FOR SIGNIFICANT TORNADOES IN ADDITION TO
HAIL AND LOCALLY DAMAGING WIND GUSTS.
A THIRD SVR TSTM EPISODE IS EXPECTED TO TAKE SHAPE ACROSS PARTS OF
ERN OK/WRN AR THIS EVENING INTO TONIGHT AS A PACIFIC FRONT OVERTAKES
THE DRYLINE AND SURGES EWD IN CONCERT WITH THE MAIN PORTION OF THE
UPPER TROUGH. INITIAL STORM MODE MAY BE SUPERCELLULAR...THOUGH A
RAPID TRANSITION TO QLCS IS EXPECTED WITH THE CONVECTIVE SYSTEM
REACHING WRN TN AND THE MS DELTA REGION BY THE END OF THE D1 PERIOD.
HERE TOO...VERTICAL SHEAR WILL BE QUITE STRONG AND SUPPORTIVE OF
EMBEDDED SUPERCELL AND/OR BOWING STRUCTURES CAPABLE OF POTENTIALLY
WIDESPREAD DAMAGING WINDS AND A FEW TORNADOES.
..MEAD/HURLBUT.. 02/27/2011
0 likes
-
CrazyC83
- Professional-Met
- Posts: 34001
- Joined: Tue Mar 07, 2006 11:57 pm
- Location: Deep South, for the first time!
ZCZC SPCPWOSPC ALL
WOUS40 KWNS 271025
ARZ000-ILZ000-INZ000-KYZ000-MOZ000-TNZ000-271800-
PUBLIC SEVERE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0425 AM CST SUN FEB 27 2011
...SIGNIFICANT SEVERE THUNDERSTORMS EXPECTED OVER PARTS OF THE OZARK
PLATEAU INTO MID-SOUTH/LOWER OHIO VALLEY LATER TODAY AND TONIGHT...
THE NWS STORM PREDICTION CENTER IN NORMAN OKLAHOMA IS FORECASTING
THE DEVELOPMENT OF A FEW STRONG TORNADOES AND POTENTIALLY WIDESPREAD
DAMAGING WINDS OVER PARTS OF THE OZARK PLATEAU INTO MID-SOUTH/LOWER
OHIO VALLEY LATER TODAY AND TONIGHT.
THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE
MUCH OF ARKANSAS
SOUTHERN ILLINOIS
FAR SOUTHWEST INDIANA
WESTERN KENTUCKY
SOUTHEAST MISSOURI
WESTERN TENNESSEE
ELSEWHERE...SEVERE STORMS ARE ALSO POSSIBLE FROM PORTIONS OF THE
CENTRAL AND SOUTHERN PLAINS EAST/NORTHEAST THROUGH THE MID
MISSISSIPPI/OHIO VALLEYS AND MID-SOUTH.
A POWERFUL UPPER-LEVEL STORM SYSTEM AND ASSOCIATED 100+ MPH JET
STREAM OVER THE SOUTHWESTERN DESERTS THIS MORNING WILL PROGRESS EAST
THROUGH THE SOUTHERN ROCKIES...CENTRAL AND SOUTHERN PLAINS...
REACHING THE MIDDLE AND LOWER MISSISSIPPI VALLEY BY MONDAY MORNING.
MEANWHILE...AN AREA OF LOW PRESSURE IN THE LOWER ATMOSPHERE FORMING
OVER SOUTHEAST COLORADO WILL MOVE EAST ACROSS SOUTHERN KANSAS OR
NORTHERN OKLAHOMA BEFORE ACCELERATING NORTHEAST THROUGH CENTRAL
MISSOURI AND THE OHIO VALLEY TONIGHT. SOUTHERLY WINDS IN ADVANCE OF
THIS LOW PRESSURE WILL DRAW A WARM AND HUMID AIR MASS NORTH THROUGH
THE CENTRAL AND SOUTHERN PLAINS...MIDDLE/LOWER MISSISSIPPI AND OH
VALLEYS.
INITIAL SEVERE THUNDERSTORM DEVELOPMENT IS EXPECTED THIS AFTERNOON
INTO EVENING OVER PORTIONS OF EASTERN KANSAS INTO WESTERN MISSOURI
AS THE UPPER-AIR DISTURBANCE BEGINS TO INTERACT WITH THE
MOIST...UNSTABLE AIR MASS. STRONG VERTICAL WIND SHEAR WILL PROMOTE
THE DEVELOPMENT OF INTENSE STORMS CAPABLE OF LARGE HAIL...DAMAGING
WINDS AND A FEW TORNADOES. THIS ACTIVITY IS EXPECTED TO RAPIDLY
MOVE AND/OR DEVELOP EAST AND NORTHEAST THROUGH THE MID MISSISSIPPI
AND OHIO VALLEYS TONIGHT IN CONJUNCTION WITH THE SURFACE LOW
PRESSURE CENTER.
A SEPARATE AREA OF SEVERE THUNDERSTORMS IS EXPECTED TO DEVELOP THIS
EVENING INTO TONIGHT FROM THE VICINITY OF A PACIFIC FRONT/DRYLINE
OVER EASTERN OKLAHOMA AND WESTERN ARKANSAS NORTHEAST TOWARD THE
CONFLUENCE OF THE MISSISSIPPI AND OHIO RIVERS. THESE STORMS WILL
MOVE EAST THROUGH THE EARLY MORNING HOURS MONDAY WITH A RISK FOR
POTENTIALLY WIDESPREAD DAMAGING WINDS AND TORNADOES /SOME POSSIBLY
STRONG/ FROM THE OZARK PLATEAU ACROSS PARTS OF THE MID-SOUTH.
STATE AND LOCAL EMERGENCY MANAGERS ARE MONITORING THIS DEVELOPING
SITUATION. THOSE IN THE THREATENED AREA ARE URGED TO REVIEW SEVERE
WEATHER SAFETY RULES AND TO LISTEN TO RADIO...TELEVISION...AND NOAA
WEATHER RADIO FOR POSSIBLE WATCHES...WARNINGS...AND STATEMENTS LATER
TODAY.
..MEAD.. 02/27/2011
$$
WOUS40 KWNS 271025
ARZ000-ILZ000-INZ000-KYZ000-MOZ000-TNZ000-271800-
PUBLIC SEVERE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0425 AM CST SUN FEB 27 2011
...SIGNIFICANT SEVERE THUNDERSTORMS EXPECTED OVER PARTS OF THE OZARK
PLATEAU INTO MID-SOUTH/LOWER OHIO VALLEY LATER TODAY AND TONIGHT...
THE NWS STORM PREDICTION CENTER IN NORMAN OKLAHOMA IS FORECASTING
THE DEVELOPMENT OF A FEW STRONG TORNADOES AND POTENTIALLY WIDESPREAD
DAMAGING WINDS OVER PARTS OF THE OZARK PLATEAU INTO MID-SOUTH/LOWER
OHIO VALLEY LATER TODAY AND TONIGHT.
THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE
MUCH OF ARKANSAS
SOUTHERN ILLINOIS
FAR SOUTHWEST INDIANA
WESTERN KENTUCKY
SOUTHEAST MISSOURI
WESTERN TENNESSEE
ELSEWHERE...SEVERE STORMS ARE ALSO POSSIBLE FROM PORTIONS OF THE
CENTRAL AND SOUTHERN PLAINS EAST/NORTHEAST THROUGH THE MID
MISSISSIPPI/OHIO VALLEYS AND MID-SOUTH.
A POWERFUL UPPER-LEVEL STORM SYSTEM AND ASSOCIATED 100+ MPH JET
STREAM OVER THE SOUTHWESTERN DESERTS THIS MORNING WILL PROGRESS EAST
THROUGH THE SOUTHERN ROCKIES...CENTRAL AND SOUTHERN PLAINS...
REACHING THE MIDDLE AND LOWER MISSISSIPPI VALLEY BY MONDAY MORNING.
MEANWHILE...AN AREA OF LOW PRESSURE IN THE LOWER ATMOSPHERE FORMING
OVER SOUTHEAST COLORADO WILL MOVE EAST ACROSS SOUTHERN KANSAS OR
NORTHERN OKLAHOMA BEFORE ACCELERATING NORTHEAST THROUGH CENTRAL
MISSOURI AND THE OHIO VALLEY TONIGHT. SOUTHERLY WINDS IN ADVANCE OF
THIS LOW PRESSURE WILL DRAW A WARM AND HUMID AIR MASS NORTH THROUGH
THE CENTRAL AND SOUTHERN PLAINS...MIDDLE/LOWER MISSISSIPPI AND OH
VALLEYS.
INITIAL SEVERE THUNDERSTORM DEVELOPMENT IS EXPECTED THIS AFTERNOON
INTO EVENING OVER PORTIONS OF EASTERN KANSAS INTO WESTERN MISSOURI
AS THE UPPER-AIR DISTURBANCE BEGINS TO INTERACT WITH THE
MOIST...UNSTABLE AIR MASS. STRONG VERTICAL WIND SHEAR WILL PROMOTE
THE DEVELOPMENT OF INTENSE STORMS CAPABLE OF LARGE HAIL...DAMAGING
WINDS AND A FEW TORNADOES. THIS ACTIVITY IS EXPECTED TO RAPIDLY
MOVE AND/OR DEVELOP EAST AND NORTHEAST THROUGH THE MID MISSISSIPPI
AND OHIO VALLEYS TONIGHT IN CONJUNCTION WITH THE SURFACE LOW
PRESSURE CENTER.
A SEPARATE AREA OF SEVERE THUNDERSTORMS IS EXPECTED TO DEVELOP THIS
EVENING INTO TONIGHT FROM THE VICINITY OF A PACIFIC FRONT/DRYLINE
OVER EASTERN OKLAHOMA AND WESTERN ARKANSAS NORTHEAST TOWARD THE
CONFLUENCE OF THE MISSISSIPPI AND OHIO RIVERS. THESE STORMS WILL
MOVE EAST THROUGH THE EARLY MORNING HOURS MONDAY WITH A RISK FOR
POTENTIALLY WIDESPREAD DAMAGING WINDS AND TORNADOES /SOME POSSIBLY
STRONG/ FROM THE OZARK PLATEAU ACROSS PARTS OF THE MID-SOUTH.
STATE AND LOCAL EMERGENCY MANAGERS ARE MONITORING THIS DEVELOPING
SITUATION. THOSE IN THE THREATENED AREA ARE URGED TO REVIEW SEVERE
WEATHER SAFETY RULES AND TO LISTEN TO RADIO...TELEVISION...AND NOAA
WEATHER RADIO FOR POSSIBLE WATCHES...WARNINGS...AND STATEMENTS LATER
TODAY.
..MEAD.. 02/27/2011
$$
0 likes
-
srainhoutx
- S2K Supporter
- Posts: 6919
- Age: 67
- Joined: Sun Jan 14, 2007 11:34 am
- Location: Haywood County, NC
- Contact:
Re: Another severe weather outbreak? February 27-28
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1030 AM CST SUN FEB 27 2011
VALID 271630Z - 281200Z
...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON INTO TONIGHT FROM
AR NEWD TO THE LOWER OH VALLEY...
...THERE IS A SLGT RISK OF SVR TSTMS FROM SRN KS...NRN AND ERN
OK...AND NE TX NEWD INTO THE OH VALLEY...
...MID SOUTH/LOWER OH VALLEY THIS AFTERNOON THROUGH TONIGHT...
THE AXIS OF RICHEST LOW-LEVEL MOISTURE EXTENDS NEWD FROM SE TX TO NW
MS AND ERN AR...ALONG THE LLJ AXIS. CONTINUED NWD/NEWD EXPANSION OF
THE WARM SECTOR AND SOME SURFACE HEATING IN CLOUD BREAKS WILL RESULT
IN SUFFICIENT DESTABILIZATION /MLCAPE OF 1000-1500 J PER KG/ FOR
SEVERE STORMS IN THE WARM SECTOR BY MID-LATE AFTERNOON. VERTICAL
SHEAR PROFILES WILL BE FAVORABLE FOR SUPERCELLS WITH EFFECTIVE BULK
SHEAR IN EXCESS OF 50 KT AND EFFECTIVE SRH AOA 300 M2/S2.
THE PRIMARY CONCERNS THIS AREA DURING THE AFTERNOON WILL BE A FOCUS
FOR STORM INITIATION...THE INFLUENCE OF CLOUDS ON SURFACE
HEATING...AND EWD EXPANSION OF THE ELEVATED MIXED LAYER/CAP.
ASSUMING A FEW STORMS CAN FORM THIS AFTERNOON FROM NE AR INTO WRN
TN...THE ENVIRONMENT WILL BE FAVORABLE FOR TORNADIC SUPERCELLS...AND
THE POTENTIAL FOR A STRONG TORNADO OR TWO. OTHERWISE...AN INCREASE
IN THUNDERSTORMS IS EXPECTED OVERNIGHT IN ADVANCE OF THE EJECTING
MIDLEVEL TROUGH AND ALONG THE LLJ CORRIDOR...ALONG/IN ADVANCE OF THE
COLD FRONT MOVING EWD FROM OK ACROSS AR. THE PRE-FRONTAL CONVECTION
MAY CONTAIN SUPERCELLS WITH A CONTINUED TORNADO RISK OVERNIGHT INTO
THE LOWER OH VALLEY...WHILE A MORE LINEAR CONVECTIVE MODE IS
EXPECTED TO EVOLVE ALONG THE COLD FRONT BY 09-12Z. DAMAGING WINDS
WILL BE THE MAIN THREAT WITH THE FRONTAL CONVECTIVE BAND...THOUGH
QLCS TORNADOES WILL ALSO BE POSSIBLE.
...KS/OK BORDER THIS EVENING INTO NRN MO/IL OVERNIGHT...
THE INITIAL LEE CYCLONE IN SE CO WILL DEVELOP EWD ALONG THE KS/OK
BORDER THIS EVENING INTO EARLY TONIGHT IN RESPONSE TO THE MIDLEVEL
SHORTWAVE TROUGH THAT WILL EJECT ENEWD OVER THE SRN HIGH PLAINS.
SLY FLOW INDUCED BY THE LEE CYCLONE HAS RESULTED IN AN INCREASE IN
LOW-LEVEL MOISTURE IN THE WARM SECTOR INTO OK...WITH BOUNDARY LAYER
DEWPOINTS EXPECTED TO HOLD IN THE LOW 60S THROUGH THE AFTERNOON.
SURFACE HEATING WILL BE INHIBITED BY LOW STRATUS AND A SEPARATE BELT
OF MID-HIGH CLOUDS NOW OVERSPREADING THE ERN TX PANHANDLE/NW TX AND
WRN OK. HOWEVER...CLEARING FROM THE W IS EXPECTED OVER THE DRYLINE
AND TRIPLE POINT BY ABOUT 21Z...AND THIS SURFACE HEATING WILL
CORRESPOND WITH INCREASING LOW-LEVEL ASCENT AND LOCAL WEAKENING OF
CONVECTIVE INHIBITION. THUS...AT LEAST ISOLATED THUNDERSTORM
DEVELOPMENT IS EXPECTED IN THE 22-00Z TIME FRAME NEAR THE TRIPLE
POINT INVOF THE KS/OK BORDER...W OF I-35.
A COMBINATION OF 7-8 C/KM MIDLEVEL LAPSE RATES ABOVE BOUNDARY LAYER
DEWPOINTS OF 58-62 F...AND AFTERNOON SURFACE TEMPERATURES IN THE LOW
70S...WILL SUPPORT MLCAPE NEAR 1500 J/KG. EFFECTIVE BULK SHEAR OF
50-70 KT WILL FAVOR SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL...AND
A COUPLE OF TORNADOES WILL BE POSSIBLE BEFORE STORMS CROSS INTO THE
COOL AIR N OF THE WARM FRONT. OTHERWISE... ELEVATED THUNDERSTORMS
WILL EXPAND NEWD ACROSS SRN AND ERN KS INTO MO AND IL OVERNIGHT IN
ADVANCE OF THE SURFACE LOW...WITH A CONTINUED RISK FOR LARGE HAIL.
..THOMPSON/SMITH.. 02/27/2011
NWS STORM PREDICTION CENTER NORMAN OK
1030 AM CST SUN FEB 27 2011
VALID 271630Z - 281200Z
...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON INTO TONIGHT FROM
AR NEWD TO THE LOWER OH VALLEY...
...THERE IS A SLGT RISK OF SVR TSTMS FROM SRN KS...NRN AND ERN
OK...AND NE TX NEWD INTO THE OH VALLEY...
...MID SOUTH/LOWER OH VALLEY THIS AFTERNOON THROUGH TONIGHT...
THE AXIS OF RICHEST LOW-LEVEL MOISTURE EXTENDS NEWD FROM SE TX TO NW
MS AND ERN AR...ALONG THE LLJ AXIS. CONTINUED NWD/NEWD EXPANSION OF
THE WARM SECTOR AND SOME SURFACE HEATING IN CLOUD BREAKS WILL RESULT
IN SUFFICIENT DESTABILIZATION /MLCAPE OF 1000-1500 J PER KG/ FOR
SEVERE STORMS IN THE WARM SECTOR BY MID-LATE AFTERNOON. VERTICAL
SHEAR PROFILES WILL BE FAVORABLE FOR SUPERCELLS WITH EFFECTIVE BULK
SHEAR IN EXCESS OF 50 KT AND EFFECTIVE SRH AOA 300 M2/S2.
THE PRIMARY CONCERNS THIS AREA DURING THE AFTERNOON WILL BE A FOCUS
FOR STORM INITIATION...THE INFLUENCE OF CLOUDS ON SURFACE
HEATING...AND EWD EXPANSION OF THE ELEVATED MIXED LAYER/CAP.
ASSUMING A FEW STORMS CAN FORM THIS AFTERNOON FROM NE AR INTO WRN
TN...THE ENVIRONMENT WILL BE FAVORABLE FOR TORNADIC SUPERCELLS...AND
THE POTENTIAL FOR A STRONG TORNADO OR TWO. OTHERWISE...AN INCREASE
IN THUNDERSTORMS IS EXPECTED OVERNIGHT IN ADVANCE OF THE EJECTING
MIDLEVEL TROUGH AND ALONG THE LLJ CORRIDOR...ALONG/IN ADVANCE OF THE
COLD FRONT MOVING EWD FROM OK ACROSS AR. THE PRE-FRONTAL CONVECTION
MAY CONTAIN SUPERCELLS WITH A CONTINUED TORNADO RISK OVERNIGHT INTO
THE LOWER OH VALLEY...WHILE A MORE LINEAR CONVECTIVE MODE IS
EXPECTED TO EVOLVE ALONG THE COLD FRONT BY 09-12Z. DAMAGING WINDS
WILL BE THE MAIN THREAT WITH THE FRONTAL CONVECTIVE BAND...THOUGH
QLCS TORNADOES WILL ALSO BE POSSIBLE.
...KS/OK BORDER THIS EVENING INTO NRN MO/IL OVERNIGHT...
THE INITIAL LEE CYCLONE IN SE CO WILL DEVELOP EWD ALONG THE KS/OK
BORDER THIS EVENING INTO EARLY TONIGHT IN RESPONSE TO THE MIDLEVEL
SHORTWAVE TROUGH THAT WILL EJECT ENEWD OVER THE SRN HIGH PLAINS.
SLY FLOW INDUCED BY THE LEE CYCLONE HAS RESULTED IN AN INCREASE IN
LOW-LEVEL MOISTURE IN THE WARM SECTOR INTO OK...WITH BOUNDARY LAYER
DEWPOINTS EXPECTED TO HOLD IN THE LOW 60S THROUGH THE AFTERNOON.
SURFACE HEATING WILL BE INHIBITED BY LOW STRATUS AND A SEPARATE BELT
OF MID-HIGH CLOUDS NOW OVERSPREADING THE ERN TX PANHANDLE/NW TX AND
WRN OK. HOWEVER...CLEARING FROM THE W IS EXPECTED OVER THE DRYLINE
AND TRIPLE POINT BY ABOUT 21Z...AND THIS SURFACE HEATING WILL
CORRESPOND WITH INCREASING LOW-LEVEL ASCENT AND LOCAL WEAKENING OF
CONVECTIVE INHIBITION. THUS...AT LEAST ISOLATED THUNDERSTORM
DEVELOPMENT IS EXPECTED IN THE 22-00Z TIME FRAME NEAR THE TRIPLE
POINT INVOF THE KS/OK BORDER...W OF I-35.
A COMBINATION OF 7-8 C/KM MIDLEVEL LAPSE RATES ABOVE BOUNDARY LAYER
DEWPOINTS OF 58-62 F...AND AFTERNOON SURFACE TEMPERATURES IN THE LOW
70S...WILL SUPPORT MLCAPE NEAR 1500 J/KG. EFFECTIVE BULK SHEAR OF
50-70 KT WILL FAVOR SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL...AND
A COUPLE OF TORNADOES WILL BE POSSIBLE BEFORE STORMS CROSS INTO THE
COOL AIR N OF THE WARM FRONT. OTHERWISE... ELEVATED THUNDERSTORMS
WILL EXPAND NEWD ACROSS SRN AND ERN KS INTO MO AND IL OVERNIGHT IN
ADVANCE OF THE SURFACE LOW...WITH A CONTINUED RISK FOR LARGE HAIL.
..THOMPSON/SMITH.. 02/27/2011
0 likes
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Ike/Harvey
Member: National Weather Association
Wx Infinity Forums
http://wxinfinity.com/index.php
Facebook.com/WeatherInfinity
Twitter @WeatherInfinity
Member: National Weather Association
Wx Infinity Forums
http://wxinfinity.com/index.php
Facebook.com/WeatherInfinity
Twitter @WeatherInfinity
-
Metalicwx220
-
Metalicwx220
-
Dave
- Retired Staff
- Posts: 13442
- Age: 74
- Joined: Tue Aug 01, 2006 3:57 pm
- Location: Milan Indiana
- Contact:
ZCZC SPCPWOSPC ALL
WOUS40 KWNS 271721
ARZ000-ILZ000-INZ000-KYZ000-MOZ000-TNZ000-280200-
PUBLIC SEVERE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1121 AM CST SUN FEB 27 2011
...SEVERE THUNDERSTORMS EXPECTED OVER PARTS OF ARKANSAS
NORTHEASTWARD TO THE LOWER OHIO VALLEY THIS AFTERNOON AND TONIGHT...
THE NWS STORM PREDICTION CENTER IN NORMAN OK IS FORECASTING THE
DEVELOPMENT OF A FEW STRONG TORNADOES OVER PARTS OF ARKANSAS
NORTHEASTWARD TO THE LOWER OHIO VALLEY THIS AFTERNOON AND TONIGHT.
THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE
CENTRAL AND NORTHEAST ARKANSAS
SOUTHERN ILLINOIS
EXTREME SOUTHWEST INDIANA
WESTERN KENTUCKY
SOUTHEAST MISSOURI
NORTHWEST TENNESSEE
ELSEWHERE...SEVERE STORMS ARE ALSO POSSIBLE FROM PARTS OF
KANSAS...OKLAHOMA...AND NORTHEAST TEXAS TO THE OHIO VALLEY.
A STRONG UPPER LEVEL STORM SYSTEM OVER ARIZONA AND NEW MEXICO AS OF
LATE MORNING WILL MOVE EAST-NORTHEASTWARD OVER KANSAS AND OKLAHOMA
THIS EVENING...AND CONTINUING OVER ARKANSAS AND MISSOURI OVERNIGHT.
THE UPPER LEVEL SYSTEM WILL BE PRECEDED BY A SURFACE LOW PRESSURE
CENTER WHICH WILL DEVELOP EASTWARD ALONG THE KANSAS AND OKLAHOMA
BORDER THIS EVENING...AND THEN NORTHEASTWARD INTO THE OHIO VALLEY
OVERNIGHT. A MOIST AND UNSTABLE AIR MASS IS SPREADING NORTHWARD
ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY IN ADVANCE
OF THIS STORM SYSTEM...AND THIS WILL SET THE STAGE FOR SEVERAL
ROUNDS OF SEVERE THUNDERSTORMS BEGINNING THIS AFTERNOON AND
CONTINUING INTO TONIGHT.
THE MOST SIGNIFICANT THREAT FOR TORNADOES SHOULD BEGIN LATER THIS
AFTERNOON ACROSS THE NORTHEAST ARKANSAS AND WESTERN TENNESSEE
AREA...AND THEN CONTINUE OVERNIGHT WHILE SPREADING NORTHEASTWARD
ACROSS SOUTHEAST MISSOURI...SOUTHERN ILLINOIS...WESTERN
KENTUCKY...AND EXTREME SOUTHWEST INDIANA. A COUPLE OF STRONG
TORNADOES WILL BE POSSIBLE IN THIS AREA...ALONG WITH DAMAGING WINDS
AND LARGE HAIL. A FEW SEVERE STORMS ARE ALSO EXPECTED BY LATE
AFTERNOON/EVENING FROM NORTHERN OKLAHOMA INTO SOUTHEAST
KANSAS...WHERE A FEW TORNADOES AND LARGE HAIL WILL BE THE MAIN
THREATS.
STATE AND LOCAL EMERGENCY MANAGERS ARE MONITORING THIS POTENTIALLY
VERY DANGEROUS SITUATION. THOSE IN THE THREATENED AREA ARE URGED TO
REVIEW SEVERE WEATHER SAFETY RULES AND TO LISTEN TO
RADIO...TELEVISION...AND NOAA WEATHER RADIO FOR POSSIBLE
WATCHES...WARNINGS...AND STATEMENTS LATER TODAY.
..THOMPSON.. 02/27/2011
$$
WOUS40 KWNS 271721
ARZ000-ILZ000-INZ000-KYZ000-MOZ000-TNZ000-280200-
PUBLIC SEVERE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1121 AM CST SUN FEB 27 2011
...SEVERE THUNDERSTORMS EXPECTED OVER PARTS OF ARKANSAS
NORTHEASTWARD TO THE LOWER OHIO VALLEY THIS AFTERNOON AND TONIGHT...
THE NWS STORM PREDICTION CENTER IN NORMAN OK IS FORECASTING THE
DEVELOPMENT OF A FEW STRONG TORNADOES OVER PARTS OF ARKANSAS
NORTHEASTWARD TO THE LOWER OHIO VALLEY THIS AFTERNOON AND TONIGHT.
THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE
CENTRAL AND NORTHEAST ARKANSAS
SOUTHERN ILLINOIS
EXTREME SOUTHWEST INDIANA
WESTERN KENTUCKY
SOUTHEAST MISSOURI
NORTHWEST TENNESSEE
ELSEWHERE...SEVERE STORMS ARE ALSO POSSIBLE FROM PARTS OF
KANSAS...OKLAHOMA...AND NORTHEAST TEXAS TO THE OHIO VALLEY.
A STRONG UPPER LEVEL STORM SYSTEM OVER ARIZONA AND NEW MEXICO AS OF
LATE MORNING WILL MOVE EAST-NORTHEASTWARD OVER KANSAS AND OKLAHOMA
THIS EVENING...AND CONTINUING OVER ARKANSAS AND MISSOURI OVERNIGHT.
THE UPPER LEVEL SYSTEM WILL BE PRECEDED BY A SURFACE LOW PRESSURE
CENTER WHICH WILL DEVELOP EASTWARD ALONG THE KANSAS AND OKLAHOMA
BORDER THIS EVENING...AND THEN NORTHEASTWARD INTO THE OHIO VALLEY
OVERNIGHT. A MOIST AND UNSTABLE AIR MASS IS SPREADING NORTHWARD
ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY IN ADVANCE
OF THIS STORM SYSTEM...AND THIS WILL SET THE STAGE FOR SEVERAL
ROUNDS OF SEVERE THUNDERSTORMS BEGINNING THIS AFTERNOON AND
CONTINUING INTO TONIGHT.
THE MOST SIGNIFICANT THREAT FOR TORNADOES SHOULD BEGIN LATER THIS
AFTERNOON ACROSS THE NORTHEAST ARKANSAS AND WESTERN TENNESSEE
AREA...AND THEN CONTINUE OVERNIGHT WHILE SPREADING NORTHEASTWARD
ACROSS SOUTHEAST MISSOURI...SOUTHERN ILLINOIS...WESTERN
KENTUCKY...AND EXTREME SOUTHWEST INDIANA. A COUPLE OF STRONG
TORNADOES WILL BE POSSIBLE IN THIS AREA...ALONG WITH DAMAGING WINDS
AND LARGE HAIL. A FEW SEVERE STORMS ARE ALSO EXPECTED BY LATE
AFTERNOON/EVENING FROM NORTHERN OKLAHOMA INTO SOUTHEAST
KANSAS...WHERE A FEW TORNADOES AND LARGE HAIL WILL BE THE MAIN
THREATS.
STATE AND LOCAL EMERGENCY MANAGERS ARE MONITORING THIS POTENTIALLY
VERY DANGEROUS SITUATION. THOSE IN THE THREATENED AREA ARE URGED TO
REVIEW SEVERE WEATHER SAFETY RULES AND TO LISTEN TO
RADIO...TELEVISION...AND NOAA WEATHER RADIO FOR POSSIBLE
WATCHES...WARNINGS...AND STATEMENTS LATER TODAY.
..THOMPSON.. 02/27/2011
$$
0 likes
Return to “USA & Caribbean Weather”
Who is online
Users browsing this forum: AnnularCane and 47 guests