Another severe weather outbreak? February 27-28

[srainhoutx]

We have busy day ahead. Perhaps we should focus on the current event in this thread and leave the future speculations to another place and time.

[Metalicwx220]

Another one WAY OUT there. I guess this is our new pattern.

[Metalicwx220]

We have busy day ahead. Perhaps we should focus on the current event in this thread and leave the future speculations to another place and time.

Ohh yeah wonder if this severe weather outbrek will include Georgia......
Tornado condition index off TWC has a 6/10 today for Arkansas which means there is a 60% chance of a tornado within 50 miles of wherever.

[srainhoutx]

Dave, that PSWO almost suggests a High Risk may be coming in future updates. With the SPC mentioning a "PDS" statement, that certainly raises an eyebrow.

[CrazyC83]

Moderate risk tomorrow as well. QLCS setup with extensive derecho-like winds and embedded tornadoes, a few strong, appear likely.

SPC AC 271730

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CST SUN FEB 27 2011

VALID 281200Z - 011200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS MUCH OF TN/KY AND
NORTHERN PORTIONS OF MS/AL/GA TO SOUTHERN WV AND WESTERN PORTIONS OF
VA/NC/SC...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE TN/OH VALLEYS AND
SOUTHEAST/MID-ATLANTIC STATES...

...SYNOPSIS...
UPPER LOW...CURRENTLY OPENING/ACCELERATING OVER AZ/NM AS OF SUNDAY
AFTERNOON...WILL CONTINUE TO ACCELERATE NORTHEASTWARD FROM THE
SOUTHERN PLAINS/LOWER MO VALLEY EARLY MONDAY TO THE NORTHEAST
STATES/MID-ATLANTIC SEABOARD BY MONDAY EVENING. AT THE SURFACE...THE
PRIMARY SURFACE LOW IS EXPECTED TO STEADILY ADVANCE NORTHEASTWARD
FROM THE UPPER OH VALLEY/LOWER GREAT LAKES TO NEW ENGLAND...WITH
SECONDARY SURFACE LOW DEVELOPMENT POSSIBLE TOWARD THE
APPALACHIANS/MID-ATLANTIC STATES AHEAD AN EASTWARD-ADVANCING PACIFIC
COLD FRONT/EARLY DAY CONVECTION. A POTENTIALLY WIDESPREAD SEVERE
EPISODE IS LIKELY ON MONDAY...INCLUDING THE POSSIBILITY OF
WIDESPREAD SWATHS OF DAMAGING WINDS IN ADDITION TO TORNADOES.

...TN VALLEY/LOWER OH VALLEY TO SOUTHEAST/MID-ATLANTIC STATES...
AN ONGOING DAMAGING WIND/TORNADO RISK IS PROBABLE ACROSS PORTIONS OF
THE TN VALLEY/LOWER OH VALLEY VICINITIES AT THE BEGINNING OF THE
PERIOD...REFERENCE DAY 1 OUTLOOKS FOR ADDITIONAL GUIDANCE. WITH
AROUND 60 F SURFACE DEWPOINTS ALREADY ESTABLISHED THIS AFTERNOON
ACROSS THE TN VALLEY...AND MIDDLE 60S F DEWPOINTS ALONG THE GULF
COAST...ROBUST NORTHEASTWARD MOISTURE TRANSPORT /AS AIDED BY 50-70
KT SOUTHWESTERLY WINDS AROUND 1-2 KM/ WILL CONTINUE TO OCCUR THROUGH
TONIGHT AND THE DAY ON MONDAY.

AT THE BEGINNING OF THE PERIOD...THE MOST PROBABLE SCENARIO WOULD
INCLUDES THE POSSIBILITY OF SEMI-DISCRETE SUPERCELLS AHEAD OF
INCREASINGLY LINEAR/QLCS-TYPE CONVECTION ROUGHLY ATTENDANT TO THE
EASTWARD ADVANCING PACIFIC FRONT...WHICH SHOULD BE NEARING THE MS
RIVER VICINITY EARLY IN THE MORNING. EVEN WITH AN UNFAVORABLE
CLIMATOLOGY TIME OF DAY /NEAR 12Z/...SURFACE BASED TSTMS SEEM
PROBABLE GIVEN THE DEGREE OF MOISTURE/TURBULENT MIXING...AS
SUPPORTED BY VARIOUS FORECAST SOUNDINGS...WITH CORRESPONDING
POTENTIAL FOR DAMAGING WIND AND EVEN STRONG TORNADO RISK ONGOING AT
THE BEGINNING OF THE PERIOD VIA QLCS/EMBEDDED SUPERCELLULAR MODES.
IN ADDITION...ALONG/NORTH OF THE SURFACE FRONTAL ZONE ACROSS THE OH
VALLEY/MIDWEST...AN EARLY DAY ELEVATED HAIL THREAT COULD EXIST AS
WELL.

SUBSEQUENT ADDITIONAL/BACKBUILDING TYPE DEVELOPMENT IS EXPECTED
THROUGH THE DAY ALONG/AHEAD OF THE COLD FRONT AS ACTIVITY
DEVELOPS/QUICKLY SPREADS EASTWARD TOWARD THE APPALACHIANS/SOUTHEAST
STATES. IN ALL...A BROAD AREA OF STRONG DEEP-LAYER FLOW/STRONG SPEED
SHEAR IS EXPECTED COINCIDENT WITH A SEASONALLY MOIST AND AT LEAST
MARGINALLY UNSTABLE WARM SECTOR. FAST-MOVING/WELL-ORGANIZED
QUASI-LINEAR/BOWING CONVECTION...IN ADDITION TO QUASI-DISCRETE OR
EMBEDDED SUPERCELLS...WILL SUPPORT THE POTENTIAL FOR WIDESPREAD
SWATHS OF DAMAGING WINDS AS WELL AS SOME TORNADOES.

..GUYER.. 02/27/2011

CLICK TO GET WUUS02 PTSDY2 PRODUCT

NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z
CURRENT UTC TIME: 1751Z (12:51PM), RELOAD THIS PAGE TO UPDATE THE TIME

[Metalicwx220]

Special Weather Statement
Statement as of 4:01 AM CST on February 27, 2011


... Another round of severe storms possible tonight into Monday
morning...

Another strong storm system is forecast to track northeast across the
plains this evening to the Ohio Valley by midday Monday. Strong
winds aloft and unstable atmospheric conditions could lead to
locally severe storms. The potential for severe storms appears
greatest from late tonight into the early morning hours on
Monday. Large hail... damaging winds... and tornadoes are possible.

Compared to the Thursday evening storm system... the potential for
severe weather appears somewhat higher. The potential for severe
weather will extend farther north across the remainder of southeast
Missouri and western Kentucky... as well as southwest Indiana and
southern Illinois.

Late night events are particularly dangerous because many people are
unaware of their situation until it is too late. In addition... due
to the expected very fast northeast motion of the storms... you will
have less time than you think to take appropriate action. Review
your emergency plan now and be prepared to act quickly when the
storms approach.

Stay tuned for later statements concerning this potential severe
weather outbreak. Details concerning the timing and type of storms
will become more clear as the event draws closer.

[CrazyC83]

Dave, that PSWO almost suggests a High Risk may be coming in future updates. With the SPC mentioning a "PDS" statement, that certainly raises an eyebrow.

That wording is usually used on High Risk days indeed. Maybe at 2000Z there will be one.

[Metalicwx220]

The National Weather Service in Lincoln has issued a

* Severe Thunderstorm Warning for...
Cass County in west central Illinois...
northwestern Morgan County in west central Illinois...

* until 1215 PM CST.

* At 1138 am CST... National Weather Service meteorologists detected a
severe thunderstorm capable of producing quarter size hail. This
storm was located near Arenzville... or 9 miles south of
Beardstown... and moving northeast at 70 mph.

* Locations impacted include...
Virginia... Bluff Springs... Literberry... Chandlerville...
Philadelphia and Newmansville.

Precautionary/preparedness actions...

Severe thunderstorms produce damaging wind in excess of 60 miles per
hour... destructive hail... deadly lightning... and very heavy rain. For
your protection move to an interior room on the lowest floor of your
home or business. Heavy rains flood roads quickly so do not drive
into areas where water covers the Road.


Lat... Lon 4006 9026 4006 9022 4007 9016 4007 9012
4008 9011 4010 9001 3998 9000 3991 9003
3976 9046 3989 9055
time... Mot... loc 1740z 235deg 62kt 3991 9038
wind... hail <50mph 1.00in


I get these from Wunderground.com that is why it is not capatilized. lol Kind of llate with this.

[CrazyC83]

Watch coming soon perhaps. If storms initialize soon, we could see a short-term 'caretaker' watch until early evening before the main event. Otherwise we might be waiting and they may go big numbers.

MESOSCALE DISCUSSION 0147
NWS STORM PREDICTION CENTER NORMAN OK
1244 PM CST SUN FEB 27 2011

AREAS AFFECTED...NERN AR / NWRN MS / WRN TN / MO BOOTHEEL / FAR WRN
KY

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 271844Z - 272015Z

NEXT 1-2 HRS WILL BE MONITORING FOR STORM DEVELOPMENT/SUSTENANCE
OVER NERN AR AND WRN TN AND A CONDITIONAL RISK FOR ISOLD TORNADOES.
IF/ONCE UPDRAFTS BECOME ROOTED IN THE BOUNDARY LAYER...AN ENSUING
ISOLD TORNADO THREAT WILL LIKELY EXIST.

RECENT VISIBLE SATELLITE IMAGERY SHOWS THINNING HIGHER LEVEL CLOUD
COVER ACROSS ERN AR EWD INTO NWRN MS AND WRN TN LEADING TO POCKETS
OF INCREASED HEATING. IN THE LOW LEVELS...SURFACE TEMPS GENERALLY
NEAR AND S OF I-40 ARE IN THE LOWER 70S WITH DEWPOINTS RISING INTO
THE LOWER 60S WITHIN A MOIST PLUME EXTENDING UP THE MS RIVER VALLEY.
THIS IN TURN IS RESULTING IN 500-1000 J/KG MLCAPE AND A WEAKENED
CAP. REPEATED CONVECTIVE ATTEMPTS INVOF THE MS/AR/TN BORDER MAY
EVENTUALLY BREACH THE REMAINING CAP AND LEADING TO ISOLD-SCTD STORMS
BY MID AFTERNOON. THE LAST FEW RUNS OF THE HRRR HAVE SUGGESTED
SHALLOW CONVECTION NEAR MIDDAY WILL GRADUALLY DEEPEN BY 20Z.
IF/ONCE THIS OCCURS...SIZABLE CLOCKWISE CURVED LOW LEVEL HODOGRAPHS
PER NQA VAD DATA /30 KTS 0-1 KM SHEAR/ WITHIN AN INCREASINGLY
MOIST/DESTABILIZING BOUNDARY LAYER WILL SUPPORT UPDRAFT ROTATION AND
AN ATTENDANT TORNADO THREAT.

..SMITH.. 02/27/2011


ATTN...WFO...OHX...PAH...MEG...LZK...

LAT...LON 34709075 35179109 36728938 36678844 36298803 35578804
34578999 34709075

[CrazyC83]

Severe Thunderstorm Watch coming for areas on the northern edge where convection has already developed.

MESOSCALE DISCUSSION 0148
NWS STORM PREDICTION CENTER NORMAN OK
1246 PM CST SUN FEB 27 2011

AREAS AFFECTED...SRN/ERN KS...WCNTRL MO

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 271846Z - 271945Z

ELEVATED CONVECTION IS BEGINNING TO DEEPEN ACROSS SCNTRL KS JUST
NORTH OF A WELL ESTABLISHED SFC FRONT. THIS ACTIVITY IS LIKELY
ROOTED NEAR 850MB WHERE MUCAPE COULD APPROACH...OR EVEN EXCEED 1500
J/KG. LATEST SHORT RANGE MODEL GUIDANCE SUGGEST SFC LOW WILL
TRANSLATE ALONG THIS BOUNDARY ALONG THE OK/KS BORDER BEFORE SHIFTING
INTO SWRN MO LATE THIS EVENING. STRENGTHENING LOW LEVEL WARM
ADVECTION ALONG THE COOL SIDE OF THE FRONTAL ZONE WILL ENSURE UPWARD
EXPANDING/INTENSIFYING ELEVATED THUNDERSTORM CLUSTERS AND ISOLATED
SUPERCELLS. FORECAST SOUNDINGS STRONGLY SUGGEST LARGE HAIL WILL
ACCOMPANY THE STRONGEST UPDRAFTS. CURRENT THINKING IS ANY
MEANINGFUL THREAT FOR TORNADOES WILL REMAIN ALONG/SOUTH OF WIND
SHIFT AND THIS WILL BE ADDRESSED WITH A TORNADO WATCH AS CONDITIONS
WARRANT LATER THIS AFTERNOON.

..DARROW.. 02/27/2011


ATTN...WFO...EAX...TOP...ICT...DDC...

LAT...LON 38229855 39809396 39509251 38729310 37929554 37029840
38229855

[Dave]

I won't be surprised at a PDS later today and tomorrow. Also heating up fast up here, now at 60 and still climbing.

[Dave]

Kansas & Missouri coming up with a tornado watch also later this afternoon...

MESOSCALE DISCUSSION 0148
NWS STORM PREDICTION CENTER NORMAN OK
1246 PM CST SUN FEB 27 2011

AREAS AFFECTED...SRN/ERN KS...WCNTRL MO

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 271846Z - 271945Z

ELEVATED CONVECTION IS BEGINNING TO DEEPEN ACROSS SCNTRL KS JUST
NORTH OF A WELL ESTABLISHED SFC FRONT. THIS ACTIVITY IS LIKELY
ROOTED NEAR 850MB WHERE MUCAPE COULD APPROACH...OR EVEN EXCEED 1500
J/KG. LATEST SHORT RANGE MODEL GUIDANCE SUGGEST SFC LOW WILL
TRANSLATE ALONG THIS BOUNDARY ALONG THE OK/KS BORDER BEFORE SHIFTING
INTO SWRN MO LATE THIS EVENING. STRENGTHENING LOW LEVEL WARM
ADVECTION ALONG THE COOL SIDE OF THE FRONTAL ZONE WILL ENSURE UPWARD
EXPANDING/INTENSIFYING ELEVATED THUNDERSTORM CLUSTERS AND ISOLATED
SUPERCELLS. FORECAST SOUNDINGS STRONGLY SUGGEST LARGE HAIL WILL
ACCOMPANY THE STRONGEST UPDRAFTS. CURRENT THINKING IS ANY
MEANINGFUL THREAT FOR TORNADOES WILL REMAIN ALONG/SOUTH OF WIND
SHIFT AND THIS WILL BE ADDRESSED WITH A TORNADO WATCH AS CONDITIONS
WARRANT LATER THIS AFTERNOON.

..DARROW.. 02/27/2011


ATTN...WFO...EAX...TOP...ICT...DDC...

[Dave]

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 20
NWS STORM PREDICTION CENTER NORMAN OK
115 PM CST SUN FEB 27 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

SOUTH CENTRAL INTO EAST CENTRAL KANSAS
PARTS OF WESTERN AND NORTHERN MISSOURI

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 115 PM UNTIL 900
PM CST.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 45
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 70 MILES NORTHEAST
OF KNOB NOSTER MISSOURI TO 40 MILES SOUTHWEST OF HUTCHINSON
KANSAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

DISCUSSION...ELEVATED THUNDERSTORMS ARE BEGINNING TO INTENSIFY OVER
S CENTRAL KS...IMMEDIATELY N OF A SURFACE WARM FRONT. STEEP LAPSE
RATES AND A FEED OF MOISTURE ABOVE THE COOL AIR MASS WILL SUPPORT
MUCAPE ON THE ORDER OF 1500 J/KG...WHILE DEEP-LAYER VERTICAL SHEAR
WILL BE FAVORABLE FOR EMBEDDED SUPERCELLS. LARGE HAIL WILL BE THE
MAIN SEVERE THREAT...THOUGH AREAS IMMEDIATELY S OF THE WATCH AREA
WILL BE MONITORED FOR A POSSIBLE TORNADO THREAT WITH STORMS ON THE
WARM FRONT A LITTLE LATER THIS AFTERNOON.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM
MOTION VECTOR 24040.


...THOMPSON

[srainhoutx]

I suspect a PDS High Risk ahead at 20Z. Some of the recent data I'm seeing is very concerning. Clearing skies and further destablization is looking likely as the afternoon wears on.

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For official information, please refer to NWS products.

[CrazyC83]

SEL0

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 20
NWS STORM PREDICTION CENTER NORMAN OK
115 PM CST SUN FEB 27 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

SOUTH CENTRAL INTO EAST CENTRAL KANSAS
PARTS OF WESTERN AND NORTHERN MISSOURI

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 115 PM UNTIL 900
PM CST.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 45
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 70 MILES NORTHEAST
OF KNOB NOSTER MISSOURI TO 40 MILES SOUTHWEST OF HUTCHINSON
KANSAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

DISCUSSION...ELEVATED THUNDERSTORMS ARE BEGINNING TO INTENSIFY OVER
S CENTRAL KS...IMMEDIATELY N OF A SURFACE WARM FRONT. STEEP LAPSE
RATES AND A FEED OF MOISTURE ABOVE THE COOL AIR MASS WILL SUPPORT
MUCAPE ON THE ORDER OF 1500 J/KG...WHILE DEEP-LAYER VERTICAL SHEAR
WILL BE FAVORABLE FOR EMBEDDED SUPERCELLS. LARGE HAIL WILL BE THE
MAIN SEVERE THREAT...THOUGH AREAS IMMEDIATELY S OF THE WATCH AREA
WILL BE MONITORED FOR A POSSIBLE TORNADO THREAT WITH STORMS ON THE
WARM FRONT A LITTLE LATER THIS AFTERNOON.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM
MOTION VECTOR 24040.


...THOMPSON

[CrazyC83]

2000Z update might be delayed it seems, perhaps some internal discussions at the SPC on whether to jump to HIGH.

[CrazyC83]

2000Z update: Little change. Tornado area expanded somewhat but overall categories basically left alone.

SPC AC 272000

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0200 PM CST SUN FEB 27 2011

VALID 272000Z - 281200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS MUCH OF AR/SOUTHERN MO
AND TO SOUTHERN IL/SOUTHWEST INDIANA TO WESTERN PORTIONS OF TN/KY...

...THERE IS A SLGT RISK OF SVR TSTMS FROM SOUTHERN KS AND
NORTHERN/EASTERN OK AND NORTHEAST TX NEWD TO THE OH/TN VALLEYS...

...MID-SOUTH/OZARKS/MIDDLE MS VALLEY/LOWER OH VALLEY...
SURFACE BASED INHIBITION CONTINUES TO WEAKEN THIS AFTERNOON IN THE
PRESENCE OF RETREATING MOISTURE AS CURRENTLY GENERALIZED BY LOWER
60S F SURFACE DEWPOINTS. GIVEN THIS WEAKENING INHIBITION...AT THE
VERY LEAST...A CONDITIONAL SURFACE BASED SUPERCELL/TORNADO THREAT
WILL EXIST AMID THE RETREATING BOUNDARY/ZONE OF DIFFERENTIAL HEATING
IN PROXIMITY TO A STRENGTHENING LOW LEVEL JET AXIS. PERHAPS
CORRELATED TO A BAND OF MID LEVEL ASCENT IMPLIED NEAR THE ARKLATEX
AT MID AFTERNOON PER SATELLITE IMAGERY...12Z BASED GUIDANCE SUCH AS
THE NAM/WRF-NMM AS WELL AS VARIOUS HRRR RUNS REFLECT SUCH POTENTIAL
WITHIN THIS CORRIDOR. A MORE WIDESPREAD/SUBSTANTIAL SEVERE
THREAT...INCLUDING THE POSSIBILITY OF STRONG TORNADOES AND DAMAGING
WINDS...IS STILL EXPECTED TO OTHERWISE EVOLVE LATER TONIGHT.

...SOUTHERN PLAINS/LOWER MO VALLEY/OZARKS...
ELEVATED TSTMS CAPABLE OF SEVERE HAIL WILL CONTINUE TO INCREASE THIS
AFTERNOON ON THE COOL SIDE OF THE SOUTHWEST-NORTHEAST ORIENTED
SURFACE FRONTAL ZONE. ADDITIONAL SURFACE BASED TSTM WILL BE POSSIBLE
BY AROUND LATE AFTERNOON ACROSS OK/SOUTHEAST KS INTO SOUTHERN
MO/NORTHERN AR...SEE PRIOR DISCUSSION BELOW AND SUBSEQUENT MESOSCALE
DISCUSSIONS/POSSIBLE WATCHES.

..GUYER.. 02/27/2011

[CrazyC83]

MESOSCALE DISCUSSION 0149
NWS STORM PREDICTION CENTER NORMAN OK
0212 PM CST SUN FEB 27 2011

AREAS AFFECTED...NRN OK...SERN KS...SWRN MO

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 272012Z - 272145Z

LEADING EDGE OF STEEPER LOW LEVEL LAPSE RATE PLUME IS
DEVELOPING/SPREADING EWD ACROSS THE TX/OK PANHANDLE REGION INTO WRN
OK. THIS IS AFFIRMED IN THE LATEST DIAGNOSTIC DATA WHERE DRY
ADIABATIC LAPSE RATES ARE NOTED AT LEAST THROUGH 3KM.
ADDITIONALLY...VIS IMAGERY INDICATES BOUNDARY LAYER CU FIELD IS
DEVELOPING FROM THE OK PANHANDLE...SEWD ALONG THE OK/TX BORDER TO
NEAR I-40. AS THIS CU FIELD APPROACHES A MORE MOIST/UNSTABLE
AIRMASS DOWNSTREAM IT APPEARS THUNDERSTORMS SHOULD EVOLVE ACROSS THE
WARM SECTOR OVER NWRN OK. SUPERCELLS ARE CERTAINLY POSSIBLE GIVEN
THE VERY STRONG SHEAR AND ISOLATED TORNADOES CAN BE EXPECTED.
TORNADO WATCH MAY BE WARRANTED IN THE NEXT FEW HOURS TO ACCOUNT FOR
THIS EVOLVING THREAT.

..DARROW.. 02/27/2011


ATTN...WFO...SGF...TSA...ICT...OUN...

LAT...LON 36839807 38019456 37289361 36509449 36109764 36839807

[CrazyC83]

New Tornado Watch just issued for OK/KS.

SEL1

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 21
NWS STORM PREDICTION CENTER NORMAN OK
250 PM CST SUN FEB 27 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

SMALL PART OF SOUTH CENTRAL AND SOUTHEAST KANSAS
NORTH CENTRAL OKLAHOMA

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 250 PM UNTIL 900
PM CST.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 40 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 35 MILES SOUTH SOUTHWEST OF
ALVA OKLAHOMA TO 25 MILES EAST SOUTHEAST OF CHANUTE KANSAS. FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU1).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 20...

DISCUSSION...VISIBLE IMAGERY SHOWS DEEPENING CUMULUS NEAR AND E OF
THE TRIPLE POINT ACROSS N CENTRAL OK. A SEPARATE BAND OF HIGH-BASED
CUMULUS IN NW OK DEMARCATES THE STRONG DRY SURGE AND SUGGESTS AN
INCREASE IN LOW-LEVEL CONVERGENCE/ASCENT NEAR THE TRIPLE POINT IN
THE NEXT COUPLE OF HOURS. NOW THAT SURFACE TEMPERATURES HAVE WARMED
INTO THE 70S...THE CAP IS WEAKENING AND THUNDERSTORM DEVELOPMENT
APPEARS PROBABLE BY 22-23Z. STRONG DEEP-LAYER SHEAR AND MLCAPE
APPROACHING 1500 J/KG WILL SUPPORT SUPERCELLS CAPABLE OF PRODUCING
LARGE HAIL. A COUPLE OF TORNADOES WILL BE POSSIBLE GIVEN 0-1 KM SRH
AOA 200 M2/S2 AND THE POTENTIAL FOR STORMS TO MOVE NEAR/ALONG THE
SURFACE WARM FRONT THIS EVENING.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
450. MEAN STORM MOTION VECTOR 25040.


...THOMPSON

[badger70]

Huge hail core east of Ottawa, KS, and south of KansasCity, MO.