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CaptinCrunch
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#81 Postby CaptinCrunch » Tue Apr 26, 2005 2:32 pm

MESOSCALE DISCUSSION 0695
NWS STORM PREDICTION CENTER NORMAN OK
0154 PM CDT TUE APR 26 2005


AREAS AFFECTED...SE MS INTO CNTRL/SRN AL/SW GA/WRN FL PNHDL

CONCERNING...SEVERE THUNDERSTORM WATCH 205...

VALID 261854Z - 262000Z

Image

TRENDS CONTINUE TO BE MONITORED FOR POSSIBILITY OF NEW WW. CURRENT
INDICATIONS ARE WW 205 WILL BE ALLOWED TO EXPIRE AT 21Z.

CONVECTIVELY-GENERATED BOUNDARY HAS PROGRESSED INTO THE INTERSTATE
65 CORRIDOR OF SOUTHERN ALABAMA. HOWEVER...SOUTHWARD ADVANCE TOWARD
SOUTHERN MISSISSIPPI COASTAL AREAS HAS BEEN A BIT SLOWER...WITH MID-
LEVEL TROUGH AXIS JUST NOW PROGRESSING THROUGH CENTRAL
MISSISSIPPI/SOUTH CENTRAL LOUISIANA. BAND OF FORCING ALONG/AHEAD OF
THIS FEATURE HAS BECOME FOCUS FOR CONVECTIVE DEVELOPMENT...SOUTH OF
BOUNDARY NEAR LAKE PONCHARTRAIN INTO AREAS NORTH OF
BOUNDARY...ACROSS SOUTHWEST ALABAMA.

CAPE IN MIXED BOUNDARY LAYER SOUTH OF OUTFLOW...AND MOIST LAYER
ABOVE OUTFLOW...IS ON THE ORDER OF 1000 J/KG...AND WILL REMAIN
SUPPORTIVE OF LARGE HAIL THREAT IN FAVORABLE COOL/SHEARED
ENVIRONMENT THROUGH THE AFTERNOON. TO THIS POINT...HAIL HAS ONLY
BEEN MARGINALLY IN EXCESS OF SEVERE LIMITS...BUT ACTIVITY SOUTH OF
OUTFLOW COULD STILL INTENSIFY A BIT FURTHER THIS AFTERNOON AS IT
SPREADS ACROSS THE MOBILE AREA INTO THE FLORIDA PANHANDLE.
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#82 Postby CaptinCrunch » Fri Apr 29, 2005 11:05 am

MESOSCALE DISCUSSION 0706
NWS STORM PREDICTION CENTER NORMAN OK
0934 AM CDT FRI APR 29 2005


AREAS AFFECTED...NRN/CNTRL AR...NW MS

CONCERNING...SEVERE THUNDERSTORM WATCH 209...

VALID 291434Z - 291630Z

Image

SEVERE THREAT CONTINUES...WW 209 LIKELY WILL BE REPLACED WITH NEW WW
TO BETTER REFLECT THREAT AREA.

SHORT WAVE PROGRESSING INTO THE OKLAHOMA/TEXAS PANHANDLE REGION IS
BECOMING SHEARED AS IT PROGRESSES INTO CONFLUENCE BETWEEN NORTHERN
AND SOUTHERN BRANCHES OF WESTERLIES. PRIMARY SOUTHERN BRANCH SHORT
WAVE TROUGH IS STILL WELL UPSTREAM....ACROSS THE SOUTHERN PLATEAU...
AND...IN ADVANCE OF THIS FEATURE...MID-LEVEL WARMING MAY ULTIMATELY
LEAD TO DEMISE OF ONGOING CONVECTIVE CLUSTER ACROSS CENTRAL
ARKANSAS. HOWEVER...MODELS SUGGEST SOUTHERLY LOW-LEVEL JET WILL
BACK TO A MORE SOUTHERLY COMPONENT THROUGH MID DAY...FROM EASTERN
TEXAS INTO CENTRAL ARKANSAS. THIS MAY PROVIDE SUFFICIENT FORCING
ABOVE RAIN-COOLED OUTFLOW TO MAINTAIN VIGOROUS CONVECTIVE
DEVELOPMENT AT LEAST ANOTHER FEW HOURS...NORTHWEST THROUGH NORTHEAST
OF LITTLE ROCK.
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#83 Postby CaptinCrunch » Fri Apr 29, 2005 12:33 pm

MESOSCALE DISCUSSION 0707
NWS STORM PREDICTION CENTER NORMAN OK
1225 PM CDT FRI APR 29 2005


AREAS AFFECTED...CNTRL AR INTO WRN TN

CONCERNING...SEVERE THUNDERSTORM WATCH 209...

VALID 291725Z - 291800Z

Image

SCATTERED VIGOROUS THUNDERSTORM ACTIVITY CONTINUES TO DEVELOP IN
LOW-LEVEL WARM ADVECTION REGIME ABOVE/NORTH OF SURFACE OUTFLOW
BOUNDARY. GIVEN FAVORABLE SHEAR...SUFFICIENT INSTABILITY EXISTS TO
MAINTAIN RISK FOR LARGE HAIL. NEW WW IS CURRENTLY PLANNED BY THE
18Z EXPIRATION OF WW 209.
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#84 Postby CaptinCrunch » Fri Apr 29, 2005 3:12 pm

MESOSCALE DISCUSSION 0708
NWS STORM PREDICTION CENTER NORMAN OK
0217 PM CDT FRI APR 29 2005


AREAS AFFECTED...ARKLATEX THRU SRN AR

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 291917Z - 292115Z

Image

TRENDS ARE BEING MONITORED FOR POSSIBILITY OF A TORNADO WATCH.

DESPITE SUBSTANTIAL CLOUD COVER...MOIST WARM SECTOR BOUNDARY LAYER
CONTINUES TO WARM/DEEPEN ALONG AND SOUTH OF OUTFLOW BOUNDARY ACROSS
SOUTH CENTRAL ARKANSAS INTO VICINITY OF SURFACE LOW NEAR TEXARKANA.
SOME DEEPENING OF LOW IS OCCURRING...BUT PRIMARY UPSTREAM SOUTHERN
BRANCH IMPULSE IS JUST NOW BEGINNING TO SHIFT INTO THE SOUTHERN
ROCKIES. DOWNSTREAM MID/UPPER RIDGING IS EVIDENT IN SATELLITE
IMAGERY...AND MAY TEND TO DELAY/SUPPRESS DEEP CONVECTIVE
DEVELOPMENT.

HOWEVER...LATEST OBJECTIVE ANALYSIS SUGGESTS SOME WEAKENING OF
INHIBITION ACROSS SOUTHWEST ARKANSAS...JUST EAST OF SURFACE LOW...
WHERE LOW-LEVEL CONVERGENCE IS FOCUSED AND SURFACE DEW POINTS ARE
CLIMBING INTO THE MID/UPPER 60S. MIXED LAYER CAPE IS INCREASING IN
EXCESS OF 1000 J/KG...AND BY 21-22Z AT LEAST ISOLATED STORMS APPEAR
POSSIBLE. IF CONVECTION DEVELOPS...STRONG SHEAR PROFILES SHOULD
SUPPORT QUICK EVOLUTION OF SUPERCELLS...WITH POTENTIAL FOR VERY
LARGE HAIL. DAMAGING WIND GUSTS AND ISOLATED TORNADOES WILL ALSO BE
POSSIBLE...AS ACTIVITY DEVELOPS EASTWARD THROUGH THE REMAINDER OF
THE AFTERNOON.
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#85 Postby CaptinCrunch » Mon May 02, 2005 8:02 am

MESOSCALE DISCUSSION 0731
NWS STORM PREDICTION CENTER NORMAN OK
0302 AM CDT MON MAY 02 2005


AREAS AFFECTED...NERN NM...NWRN TX PNHDL...WRN OK PNHDL

CONCERNING...HEAVY SNOW

VALID 020802Z - 021400Z

Image

VERY UNUSUAL EARLY MAY SNOWSTORM WAS EVOLVING OVER NERN NM AND PARTS
OF THE TX/OK PANHANDLES EARLY TODAY. SNOWFALL RATES THROUGH DAYBREAK
COULD LOCALLY APPROACH 1/2 TO 1 INCH PER HOUR BASED ON LATEST
SHORT-TERM AND MESOSCALE MODEL DATA. GREATEST POTENTIAL FOR THESE
RATES IN THE NEXT 3-4 HOURS APPEARS TO BE OVER A NARROW CORRIDOR
FROM LVS ENEWD TO EXTREME NWRN TX PNHDL. HOWEVER...HEAVY WET SNOW
COULD SPREAD FARTHER EAST INTO THE TX/OK PNHDLS AFTER DAYBREAK.

LATEST OBSERVATIONAL DATA WAS CONFIRMING MESOSCALE MODEL OUTPUT OF
VERY STRONG UPWARD MOTION ACROSS NERN NM AND THE TX/OK PNHDLS. A
WEST-TO-EAST BAND OF INTENSE SLOPED ASCENT WAS OCCURRING IN A
SATURATED LAYER ACROSS THE REGION. THIS LIFT IS EXPECTED TO PERSIST
FOR SEVERAL MORE HOURS BEFORE GRADUALLY MOVING EAST. PER MODEL
SOUNDINGS...DIABATIC PROCESSES HAVE PRODUCED A DEEP LAYER OF
SUB-FREEZING TEMPERATURES JUST ABOVE THE BOUNDARY LAYER. AS HEAVIER
PRECIPITATION DEVELOPS...NEAR FREEZING SFC TEMPERATURES... ARE
EXPECTED TO SUPPORT WET SNOW DEVELOPING EAST WITH TIME.

THE COMBINATION OF LOW/MID LEVEL MOISTURE FLUX INTO THE ZONE OF
FOCUSED ASCENT...AND WEAK CONVECTIVE DESTABILIZATION...WAS RESULTING
IN RELATIVELY HIGH MODEL QPF. PRECIP AMOUNTS OF 0.30-0.50 INCHES PER
3 HOURS WERE BEING FCST FROM THE LATEST RUC AND NAM. WHILE SOME OF
THIS PRECIPITATION WILL LIKELY FALL AS RAIN...IT IS ENTIRELY
POSSIBLE THAT SOME LOCATIONS COULD PICK UP SEVERAL INCHES OF WET
SNOW. LATEST RUC AND NAM...AS WELL AS 4KM WRF-NMM...APPEAR TO
SUGGEST THAT HEAVY WET SNOW COULD DEVELOP EAST ACROSS THE WRN HALF
OF THE TX PNHDL AFTER 12Z.
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#86 Postby CaptinCrunch » Wed May 04, 2005 7:59 am

MESOSCALE DISCUSSION 0732
NWS STORM PREDICTION CENTER NORMAN OK
0530 AM CDT WED MAY 04 2005


AREAS AFFECTED...CNTRL/NRN FL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 041030Z - 041300Z

Image

ISOLATED TSTMS WERE DEVELOPING ACROSS PORTIONS OF NCNTRL FL EARLY
THIS MORNING. HAIL IS POSSIBLE FROM SOME OF THE MORE INTENSE CELLS.

RADAR IMAGERY WAS INDICATING A GRADUAL INCREASE IN TSTMS NEAR A WARM
FRONT SITUATED ACROSS NCNTRL FL EARLY THIS MORNING. PERSISTENT LOW
LEVEL WARM AIR ADVECTION AND MOISTENING ACROSS THE BOUNDARY WAS
EVIDENT IN VWP DATA AND SHORT-TERM MODEL FCST SOUNDINGS. A
CONTINUATION OF THIS PROCESS WILL LIKELY PROMPT ADDITIONAL STORM
DEVELOPMENT OVER THE NEXT FEW HOURS. STEEP LOW THROUGH MID LEVEL
LAPSE RATES AND VERY MOIST BOUNDARY LAYER WERE CONTRIBUTING TO
MUCAPE VALUES AROUND 1000 J/KG ALONG AND SOUTH OF THE FRONT.
FURTHERMORE...LOW LEVEL ELY FLOW WAS TOPPED BY 30-40KT MID LEVEL
FLOW RESULTING IN SUFFICIENT EFFECTIVE DEEP LAYER SHEAR TO SUPPORT
UPDRAFT PERSISTENCE AND ORGANIZATION. WHILE STRONGER ASCENT IS FCST
TO DEVELOP ACROSS THE REGION LATER TODAY AS LARGE SCALE UPPER TROUGH
APPROACHES FROM THE WEST...IT CURRENTLY APPEARS THAT MESOSCALE/CLOUD
PROCESSES ARE ADEQUATE FOR A FEW INTENSE CELLS TO DEVELOP OVER THE
NEXT COUPLE OF HOURS. ISOLATED HAIL APPEARS TO BE THE FOREMOST
HAZARD FROM THIS ACTIVITY. A WATCH COULD BE CONSIDERED IF
INTENSITY/COVERAGE TRENDS DICTATE.
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#87 Postby CaptinCrunch » Wed May 04, 2005 11:56 am

MESOSCALE DISCUSSION 0733
NWS STORM PREDICTION CENTER NORMAN OK
1045 AM CDT WED MAY 04 2005


AREAS AFFECTED...N CNTRL THROUGH S CNTRL FL

CONCERNING...SEVERE THUNDERSTORM WATCH 219...

VALID 041545Z - 041745Z

Image

THREAT FOR ISOLATED DAMAGING WIND AND HAIL WILL PERSIST INTO THE
AFTERNOON PRIMARILY FROM CNTRL THROUGH S CNTRL FL.

A STATIONARY FRONT EXTENDS FROM NEAR TAMPA WWD TO S OF MELBOURNE.
RICH LOW LEVEL MOISTURE WITH DEWPOINTS IN THE LOWER 70S PERSIST NEAR
AND S OF THIS BOUNDARY. HOWEVER...THE MAIN LIMITING FACTOR CONTINUES
TO BE REDUCED HEATING DUE TO EXTENSIVE ANVIL DEBRIS ORIGINATING FROM
LARGE MCS OVER THE ERN GULF AS WELL AS THE STABILIZING EFFECTS OF
EARLY CONVECTION. TRENDS HAVE BEEN FOR STORMS DEVELOPING OVER THE
ERN GULF TO DECREASE AS THEY ENCOUNTER THE MORE STABLE BOUNDARY
LAYER INLAND. HOWEVER...BREAKS IN THE CIRRUS ARE RESULTING IN
STRONGER SURFACE HEATING OVER PARTS OF S CNTRL AND S FL GENERALLY S
OF THE STATIONARY BOUNDARY. PERSISTENT BUT MODEST SSWLY LOW LEVEL
FLOW SHOULD HELP TRANSPORT THE HIGHER THETA-E AIR NWD...AND STORMS
MAY STILL HAVE SOME POTENTIAL TO INCREASE IN INTENSITY THIS
AFTERNOON.
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#88 Postby CaptinCrunch » Wed May 04, 2005 11:57 am

MESOSCALE DISCUSSION 0734
NWS STORM PREDICTION CENTER NORMAN OK
1111 AM CDT WED MAY 04 2005


AREAS AFFECTED...SRN FL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 041611Z - 041815Z

Image

THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER SRN FL BY MID AFTERNOON.
POTENTIAL WILL EXIST FOR THE STRONGER STORMS TO PRODUCE ISOLATED
DAMAGING WIND AND LARGE HAIL. AREA WILL CONTINUE TO BE MONITORED FOR
A POSSIBLE WW.

LATEST VISIBLE IMAGERY SHOWS CIRRUS CLOUDS THINNING AND STRONG
SURFACE HEATING IS OCCURRING OVER SRN FL WHERE TEMPERATURES IN THE
LOW TO MID 80S AND BOUNDARY LAYER DEWPOINTS IN THE LOWER 70S ARE
CONTRIBUTING TO MLCAPE FROM 2000 TO 2500 J/KG. 12Z RAOB DATA FROM
MIAMI AND LATEST OBJECTIVE ANALYSIS DATA SUGGEST THE ATMOSPHERE OVER
S FL IS ONLY WEAKLY CAPPED...AND SEA-BREEZE CIRCULATIONS ARE
EXPECTED TO BE SUFFICIENT TO INITIATE STORMS THIS AFTERNOON.
VERTICAL SHEAR PROFILES ARE NOT PARTICULARLY STRONG WITH SFC-6 KM
SHEAR AROUND 30 KT. MULTICELLS STORMS ARE EXPECTED TO BE THE
DOMINANT STORM TYPE. HOWEVER...SOME SUPERCELL STRUCTURES WILL BE
POSSIBLE...ESPECIALLY WITH ANY DEVIANT STORM MOTIONS ASSOCIATED WITH
STORM-OUTFLOW BOUNDARY INTERACTIONS.
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#89 Postby CaptinCrunch » Thu May 05, 2005 11:17 am

MESOSCALE DISCUSSION 0738
NWS STORM PREDICTION CENTER NORMAN OK
1111 AM CDT THU MAY 05 2005


AREAS AFFECTED...E CNTRL THROUGH SERN FL PENINSULA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 051611Z - 051815Z

Image

THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY
THIS AFTERNOON...PRIMARILY OVER THE SERN FL PENINSULA. ISOLATED
LARGE HAIL AND DAMAGING WIND WILL BE THE MAIN THREATS. AREA WILL
CONTINUE TO BE MONITORED FOR A WW.

TEMPERATURES NEAR 80 AND BOUNDARY LAYER DEWPOINTS AROUND 70 ARE
CONTRIBUTING TO MODERATE INSTABILITY OVER THE SRN FL PENINSULA WITH
MLCAPE FROM 1000 TO 1500 J/KG. WHILE FURTHER DESTABILIZATION IS
LIKELY...PARTICULARLY OVER THE SERN PORTION OF THE PENINSULA WHERE
SOME SURFACE HEATING IS POSSIBLE...EXTENSIVE CONVECTIVE DEBRIS FROM
THUNDERSTORM CLUSTERS OVER THE GULF WILL LIMIT THE DEGREE OF
INSOLATION. LIMITED INSOLATION ALSO APPEARS TO BE DELAYING THE ONSET
OF THE SEA-BREEZE CIRCULATION ALONG THE EAST COAST. HOWEVER...ONCE
ESTABLISHED...ADDITIONAL STORMS WILL BE LIKELY GIVEN WEAK CAP. SOME
INTENSIFICATION HAS RECENTLY BEEN OBSERVED WITH STORMS MOVING NEWD
INTO HENDRY COUNTY AND ADDITIONAL STRONG TO SEVERE STORMS ARE
EXPECTED INTO THE AFTERNOON. SHEAR PROFILES APPEAR SUPPORTIVE OF
MULTICELL AS WELL AS SOME SUPERCELL STRUCTURES.
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#90 Postby CaptinCrunch » Thu May 05, 2005 1:13 pm

MESOSCALE DISCUSSION 0739
NWS STORM PREDICTION CENTER NORMAN OK
1202 PM CDT THU MAY 05 2005


AREAS AFFECTED...FAR SERN ND...NRN/CENTRAL MN AND NERN SD

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 051702Z - 051930Z

Image

ISOLATED SVR TSTMS ARE EXPECTED TO DEVELOP OVER FAR SERN ND/NERN SD
AND PARTS OF NRN/CENTRAL MN BETWEEN 18-20Z.

16Z SFC ANALYSIS SHOWS A COLD FRONT MOVING SEWD ACROSS NCENTRAL
SD...SERN ND AND FAR NWRN MN. AHEAD OF THIS FRONT...A BAND OF MID
LEVEL CONVECTION WAS MOVING EWD ACROSS THE AREA. RECENT RUC/NAM FCST
SOUNDINGS SUGGEST THAT THIS ELEVATED CONVECTION MAY BECOME SURFACE
BASED WITHIN THE NEXT FEW HOURS...AS LOW LEVELS CONTINUE TO
WARM/DESTABILIZE REMOVING THE REMAINING CINH. IN ADDITION...SFC
BASED CONVECTIVE DEVELOPMENT WILL BE POSSIBLE AHEAD OF THE COLD
FRONT...AND AHEAD OF A PREFRONTAL TROUGH OVER CENTRAL MN /NORTH OF
THE MSP AREA/. A SLOW INCREASE IN DEWPTS SEEN OVER THE LAST FEW
HOURS SHOULD BEGIN TO STEADY OR FALL SLIGHTLY AS DEEPER MIXING
OFFSETS LOW LEVEL ADVECTION. FCST SOUNDINGS WITH A SFC PARCEL OF
LOWER 70S/UPPER 40S INDICATES AROUND 1000-1200 J/KG OF SBCAPE. 35 TO
40 KTS OF CLOUD BEARING SHEAR WILL SUPPORT ROTATING UPDRAFTS AND A
SVR HAIL THREAT. IN ADDITION...A DEEPLY MIXED BOUNDARY LAYER WILL
FAVOR OUTFLOW GENERATION AND THE POTENTIAL FOR A DAMAGING WIND
THREAT ESPECIALLY A FEW HOURS AFTER SFC BASED CONVECTION INITIATES.
THE OVERALL LIMITED NATURE OF THE INSTABILITY MAY LIMIT THE SVR
THREAT TO MORE MARGINAL HAIL/DAMAGING WINDS.
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#91 Postby CaptinCrunch » Fri May 06, 2005 4:06 pm

MESOSCALE DISCUSSION 0747
NWS STORM PREDICTION CENTER NORMAN OK
0341 PM CDT FRI MAY 06 2005


AREAS AFFECTED...WRN SD/NW NEB

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 062041Z - 062245Z

Image

STORMS WILL INCREASE IN COVERAGE AND INTENSITY AS INHIBITION
CONTINUES TO WEAKEN. WW MAY BE NEEDED WITHIN NEXT FEW HOURS.

OBSERVED SOUNDINGS AT 18Z FROM BOTH RAPID CITY AND NORTH PLATTE
INDICATED SLIGHT CAP STILL IN PLACE...BUT MODIFIED SOUNDINGS WITH
20Z DATA SUGGEST INHIBITION IS RAPIDLY WEAKENING. ATTEMPTS AT SFC
BASED CONVECTION ARE ONGOING OVER THE BLACK HILLS ATTM...WITH LATEST
MLCAPE ESTIMATED IN THE 1000-1500 J/KG RANGE. SHORTWAVE TROUGH
APPROACHING FROM THE SOUTHWEST WILL STEEPEN MID LEVEL LAPSE RATES
AND INCREASE LARGE SCALE LIFT...THEREFORE COVERAGE OF STORMS WILL
INCREASE. FAVORABLE DEEP LAYER SHEAR AND MODERATE INSTABILITY WILL
SUPPORT A SEVERE THREAT FOR MAINLY HAIL AND DAMAGING WIND EVENTS
ONCE STORMS BECOME SFC BASED.
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#92 Postby CaptinCrunch » Fri May 06, 2005 4:07 pm

MESOSCALE DISCUSSION 0746
NWS STORM PREDICTION CENTER NORMAN OK
0314 PM CDT FRI MAY 06 2005


AREAS AFFECTED...E CNTRL THROUGH SERN NM AND SWRN TX

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 062014Z - 062215Z

Image

ISOLATED TO WIDELY SCATTERED THUNDERSTORMS MAY DEVELOP OVER THE
HIGHER TERRAIN OF E CNTRL THROUGH SERN NM INTO SW TX. POTENTIAL WILL
EXIST FOR SUPERCELLS WITH ISOLATED LARGE HAIL AND DAMAGING WIND THE
MAIN THREATS. WILL CONTINUE TO MONITOR THIS AREA FOR A WW.

HEIGHT FALLS DOWNSTREAM FROM SHORTWAVE TROUGH OVER AZ SHOULD HELP
MAINTAIN SELY BOUNDARY LAYER FLOW OVER THE SRN HIGH PLAINS...AND
THIS SHOULD HELP HOLD SURFACE DEWPOINTS TO AROUND 50 CLOSE TO THE
HIGH TERRAIN OF SERN NM AND SWRN TX. STRONG SURFACE HEATING AND
STEEP LAPSE RATES WILL CONTRIBUTE TO FURTHER DESTABILIZATION WITH
MLCAPE FROM 1500 TO 2000 J/KG. ISOLATED TO WIDELY SCATTERED STORMS
ARE EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN OF SERN NM INTO SWRN
TX WHERE VISIBLE IMAGERY ALREADY SHOWS CUMULUS INCREASING. AN
ISOLATED STORM HAS ALSO DEVELOPED OVER THE MOUNTAINS JUST N OF
MARFA. VERTICAL SHEAR PROFILES SHOULD CONTINUE TO INCREASE TOWARD
EVENING WITH EFFECTIVE SHEAR FROM 40-45 KT SUPPORTIVE OF SUPERCELLS.
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#93 Postby CaptinCrunch » Mon May 09, 2005 3:56 pm

MESOSCALE DISCUSSION 0795
NWS STORM PREDICTION CENTER NORMAN OK
0303 PM CDT MON MAY 09 2005


AREAS AFFECTED...TX HILL COUNTRY

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 092003Z - 092200Z

Image

...THREAT FOR LARGE HAIL IS POSSIBLE THIS AFTN GIVEN STORM
DEVELOPMENT...

TOWERING CUMULUS ARE INCREASING ACROSS THE TX HILL COUNTRY BETWEEN
SAN ANGELO AND BURNETT PER LATEST VISIBLE SATELLITE IMAGERY WITH LTG
RECENTLY OBSERVED. ALTHOUGH CONVERGENCE IS WEAK...STRONG HEATING
COMBINED WITH DEWPOINTS IN THE MID 60S/LOWER 70S IS CONTRIBUTING TO
VERY STRONG INSTABILITY. RUC ANALYSIS/FORECAST SOUNDINGS SUGGEST
SBCAPE VALUES MAY EXCEED 3000 J/KG WITH ADDITIONAL HEATING. IT MAY
TAKE ANOTHER HOUR OR TWO OF CONTINUED MIXING...BUT IF STORMS
FORM...VERY LARGE HAIL WILL BE A THREAT IN THIS VERY STEEP LAPSE
RATE ENVIRONMENT. AREA WILL BE MONITORED FOR THE POSSIBILITY OF A
SVR TSTM WATCH.
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#94 Postby CaptinCrunch » Mon May 09, 2005 3:57 pm

MESOSCALE DISCUSSION 0796
NWS STORM PREDICTION CENTER NORMAN OK
0331 PM CDT MON MAY 09 2005


AREAS AFFECTED...WI...NRN IL

CONCERNING...SEVERE THUNDERSTORM WATCH 239...

VALID 092031Z - 092200Z

Image

A LINE OF STORMS WILL MOVE EWD REACHING LAKE MICHIGAN AS NEW CELLS
DEVELOP TO THE WEST ACROSS SCNTRL WI AND POSSIBLY NRN IL. A HAIL AND
ISOLATED WIND DAMAGE SHOULD EXIST WITH ANY NEW CELLS THAT INITIATE
OVER THE NEXT FEW HOURS ACROSS WW 239.

20Z SFC ANALYSIS SHOWS A COLD FRONT IN PLACE ACROSS SE MN AND ERN IA
WITH A SFC TROUGH LOCATED FROM NWRN WI EXTENDING SEWD INTO NRN IL. A
LINE OF STORMS IS CURRENTLY EAST OF THE TROUGH AXIS BUT NEW CELLS
ARE INITIATING BACK TO THE WEST WHERE STRONGER INSTABILITY IS
LOCATED AND VERTICAL SHEAR IS STRONG ENOUGH FOR ORGANIZED CONVECTION
AS SHOWN ON OBJECTIVE ANALYSIS FIELDS. THESE NEW CELLS APPEAR TO
HAVE THE BEST POTENTIAL FOR HAIL AND/OR WIND DAMAGE AS THE CELLS
MOVE NEWD INTO A POCKET OF HIGHER SFC DEWPOINTS ENE OF I-90.
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#95 Postby CaptinCrunch » Tue May 10, 2005 12:59 pm

MESOSCALE DISCUSSION 0801
NWS STORM PREDICTION CENTER NORMAN OK
1133 AM CDT TUE MAY 10 2005


AREAS AFFECTED...SE AL...SRN AND ERN GA...WRN SC

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 101633Z - 101830Z

Image

SCATTERED TO NUMEROUS STORMS WILL LIKELY DEVELOP QUICKLY THIS
AFTERNOON ACROSS SE AL...SRN GA...ERN GA AND WRN SC. THE STRONGER
CELLS WILL HAVE A POTENTIAL FOR LARGE HAIL AND ISOLATED WIND DAMAGE.
A WW MAY BECOME NECESSARY THIS AFTERNOON ACROSS THE REGION.

WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-TROUGH MOVING EWD
ACROSS WRN GA WITH THE RUC ANALYSIS SHOWING A SECONDARY VORT MAX
ACROSS MS. THESE FEATURES WILL PROVIDE STRONG SUPPORT FOR SCATTERED
TO NUMEROUS THUNDERSTORMS ALONG THE INSTABILITY AXIS AS SFC TEMPS
WARM THIS AFTERNOON. OBJECTIVE ANALYSIS CURRENTLY SHOWS SBCAPE
VALUES ABOVE 1000 J/KG ACROSS ERN GA AND PARTS OF SRN AL WITH
MODERATE DEEP LAYER SHEAR MAINLY FROM SWRN GA EXTENDING WWD ACROSS
THE SRN HALF OF MS. AS CELLS INITIATE ALONG AND NORTHWEST OF THE
INSTABILITY AXIS AND MOVE SEWD...THE MODERATE SHEAR AND COLD AIR
ALOFT ASSOCIATED WITH THE UPPER-TROUGH SHOULD BE ENOUGH FOR LARGE
HAIL AND/OR ISOLATED WIND DAMAGE.
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#96 Postby CaptinCrunch » Tue May 10, 2005 2:08 pm

MESOSCALE DISCUSSION 0802
NWS STORM PREDICTION CENTER NORMAN OK
0135 PM CDT TUE MAY 10 2005


AREAS AFFECTED...FAR ERN MS...NCNTRL AL...FAR WRN GA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 101835Z - 102030Z

Image

STORM INITIATION IS CURRENTLY ONGOING ACROSS NRN AL. THE ENVIRONMENT
SUGGESTS ANY STORMS THAT DEVELOP WILL HAVE A POTENTIAL FOR LARGE
HAIL AND/OR ISOLATED WIND DAMAGE. A WW MAY BECOME NECESSARY THIS
AFTERNOON ONCE STORM COVERAGE CAN BE DETERMINED.

OBJECTIVE ANALYSIS CONTINUES TO SHOW DESTABILIZATION OCCURRING
ACROSS NRN AL WHERE SBCAPE VALUES RANGE FROM 1500 TO 2000 J/KG. AS A
RESULT OF SFC HEATING...THE CAPPING INVERSION IS GONE. IN
ADDITION...THE PROFILER IN NE MS IS SHOWING A WIND SPEED INCREASE AT
6 KM WHICH MIGHT SHOW EVIDENCE OF A LOW TO MID-LEVEL SPEED MAX IN NW
FLOW BEHIND THE UPPER-TROUGH. AS CELLS INITIATE FROM THE TOWERING CU
EVIDENT ON VIS IMAGERY...THE SPEED MAX MAY ENHANCE THE SEVERE THREAT
LATE THIS AFTERNOON. THE INSTABILITY ALONG WITH COLD AIR ALOFT
ASSOCIATED WITH THE UPPER-LOW AND THE ENHANCED SHEAR WILL MAKE LARGE
HAIL AND ISOLATED WIND DAMAGE POSSIBLE WITH THE STRONGEST CELLS.
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#97 Postby CaptinCrunch » Tue May 10, 2005 2:09 pm

MESOSCALE DISCUSSION 0803
NWS STORM PREDICTION CENTER NORMAN OK
0155 PM CDT TUE MAY 10 2005


AREAS AFFECTED...ERN OH...WRN PA...WV...WRN VA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 101855Z - 102030Z

Image

A MARGINAL SEVERE THREAT WILL EXIST WITH THE STRONGER STORMS THAT
DEVELOP ACROSS THE REGION. HOWEVER...DUE TO WEAK VERTICAL SHEAR...A
WW IS NOT ANTICIPATED ATTM.

SFC ANALYSIS CURRENTLY SHOWS A MOIST AXIS FROM CNTRL KY EXTENDING
NEWD ACROSS OH WITH SFC DEWPOINTS IN THE UPPER 50S AND LOWER 60S F.
CELLS HAVE INITIATED ALONG AND TO THE EAST OF THE MOIST AXIS ALONG A
BAND OF STRONG ASCENT ASSOCIATED WITH AN EWD MOVING TROUGH. CELLS
SHOULD INCREASE IN COVERAGE MOVING EWD INTO ERN OH...WRN PA AND WV
THIS AFTERNOON. FORECAST SOUNDINGS FOR LATE THIS AFTERNOON ACROSS
THE REGION SHOW ABOUT 20 KT OF 0-6 KM SHEAR WHICH COMBINED WITH THE
INSTABILITY MAY BE ENOUGH FOR AN ISOLATED STRONG TO MARGINALLY
SEVERE STORM NEAR PEAK HEATING. HOWEVER...WEAK LAPSE RATES AND
LIMITED LOW-LEVEL MOISTURE SHOULD KEEP THE HAIL AND WIND DAMAGE
THREAT MARGINAL.
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#98 Postby CaptinCrunch » Tue May 10, 2005 2:59 pm

MESOSCALE DISCUSSION 0804
NWS STORM PREDICTION CENTER NORMAN OK
0223 PM CDT TUE MAY 10 2005


AREAS AFFECTED...WRN/SWRN TX AND FAR SERN NM

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 101923Z - 102130Z

Image

ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE ALONG THE DRYLINE IN
WRN/SWRN TX AND FAR SERN NM THROUGH THIS EVENING. ONCE INITIATION
BECOMES EVIDENT...WW WILL LIKELY BE NEEDED FOR THIS REGION.

DRYLINE CONTINUES TO BECOME BETTER DEFINED...EXTENDING AT 19Z FROM
THE ERN TX PANHANDLE SSWWD TO NEAR LBB AND INTO THE DAVIS MTNS AREA.
RICH GULF MOISTURE PERSISTS EAST OF THE DRYLINE...WITH LOW 70S
DEWPOINTS PROGRESSING UP THE RIO GRANDE VALLEY AND READINGS NEAR 60
AROUND MAF AND BETWEEN LBB/CDS. THE 18Z RUC SHOWS CONTINUED SURFACE
PRESSURE FALLS ALONG LEE TROUGH EXTENDING FROM E-CENTRAL CO SWD INTO
ERN NM AND FAR SWRN TX. IF THE ISOBARIC RESPONSE MAINTAINS A SSELY
SURFACE WIND ACROSS THE DISCUSSION AREA...CONVERGENCE ALONG/NEAR
DRYLINE SHOULD BE SUFFICIENT FOR ISOLATED THUNDERSTORM DEVELOPMENT
DURING THE LATE AFTERNOON AND EARLY EVENING HOURS. ALSO...MID-LEVEL
CONDITIONS SHOULD BECOME SLIGHTLY MORE FAVORABLE FOR THUNDERSTORM
DEVELOPMENT...AS 500MB SHORTWAVE RIDGE AXIS TRANSLATES INTO ERN TX
BY 00Z. VISIBLE IMAGERY SHOWS THE START OF TOWERING CU ALONG THE
DAVIS MTNS AND SCATTERED ALONG THE AXIS OF THE DRYLINE ACROSS WRN
TX.

MODERATE TO STRONG INSTABILITY /MLCAPE VALUES 1500-3000 J/KG/ AND
VERY STEEP MID-LEVEL LAPSE RATES /UP TO 9 C/KM/ SHOULD SUPPORT
VIGOROUS UPDRAFTS. ADDITIONALLY...SFC-6KM SHEAR AROUND 40KT SHOULD
SUPPORT SUPERCELL STORM STRUCTURES. PRIMARY THREAT SHOULD BE LARGE
HAIL...HOWEVER...SUPERCELLS INTERACTING WITH 60+ DEWPOINTS...MINIMAL
CIN...AND SELY SURFACE WINDS IN A NARROW CORRIDOR EAST OF THE
DRYLINE MAY BE CAPABLE OF PRODUCING TORNADOES 22-01Z.
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#99 Postby CaptinCrunch » Wed May 11, 2005 9:06 am

MESOSCALE DISCUSSION 0815
NWS STORM PREDICTION CENTER NORMAN OK
0841 AM CDT WED MAY 11 2005


AREAS AFFECTED...NE KS...NRN MO...FAR WRN IL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 111341Z - 111545Z

Image

A SEVERE THREAT MAY CONTINUE OVER NE KS...NRN MO AND FAR WRN IL AS
ELEVATED STORMS CONTINUE AND MOVE EWD ACROSS THE REGION.

SFC ANALYSIS SHOWS A QUASI-STATIONARY FRONT LOCATED ACROSS NRN KS
EXTENDING EWD INTO NRN MO. ISOLATED STRONG CELLS ARE ONGOING NEAR
THE BOUNDARY BUT ARE ELEVATED IN NATURE DUE TO A CAPPING INVERSION
EVIDENT ON THE TOP 12Z SOUNDING. A VORTICITY MAX IS CURRENTLY MOVING
THROUGH CNTRL KS AS SHOWN ON THE RUC ANALYSIS. ALTHOUGH NOT YET
CERTAIN...INCREASED LIFT AS THE VORTICITY MAX MOVES ACROSS NE KS AND
NWRN MO...COULD AID NEW DEVELOPMENT THIS MORNING ALONG THE BOUNDARY
ACROSS NCNTRL MO AND POSSIBLY NE KS AS SUGGESTED BY THE
NAM40/SREF/WRF MODELS. OBJECTIVE ANALYSIS SHOWS LIFTED INDEX VALUES
OF -4 TO -8 NEAR THE BOUNDARY AND MODERATE DEEP LAYER SHEAR ALONG
AND NORTH OF THE BOUNDARY WHICH WILL BE SUFFICIENT FOR SUPERCELLS.
HOWEVER...THE CAPPING INVERSION SHOULD KEEP THE STORMS ELEVATED WITH
LARGE HAIL THE MAIN THREAT.
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#100 Postby CaptinCrunch » Wed May 11, 2005 11:06 am

MESOSCALE DISCUSSION 0816
NWS STORM PREDICTION CENTER NORMAN OK
1045 AM CDT WED MAY 11 2005


AREAS AFFECTED...SERN GA AND NRN/CENTRAL FL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 111545Z - 111815Z

Image

SCATTERED THUNDERSTORM DEVELOPMENT IS EXPECTED ACROSS SRN GA/NRN AND
CENTRAL FL THROUGH THE MID-AFTERNOON HOURS. THREAT EXISTS FOR LARGE
HAIL WITH LONG-LIVED/STRONG CORES. REGION WILL BE MONITORED FOR
POSSIBLE WW AND A SLGT RISK WILL BE ADDED TO THE 1630Z DAY 1
OUTLOOK.

THE 700-500MB THERMAL LOW ANALYZED ACROSS SERN GA THIS MORNING WILL
PROGRESS SEWD ALONG THE NERN FL COAST AND INTO THE ADJACENT SERN
ATLANTIC OCEAN THIS AFTERNOON. MORNING SOUNDINGS REVEAL THAT THIS
FEATURE HAS ESTABLISHED STEEP MID-LEVEL LAPSE RATES OF AROUND 7.0
C/KM AT JAX AND CHS. VISIBLE SATELLITE IMAGERY SUGGESTS STRONG
BOUNDARY LAYER HEATING IS LIKELY ACROSS THE DISCUSSION AREA THROUGH
AFTERNOON WHICH SHOULD RESULT IN MLCAPE VALUES UP TO 2000 J/KG WITH
MINIMAL CONVECTIVE INHIBITION. DEVELOPING SEABREEZES AND OTHER
SMALL-SCALE BOUNDARIES SHOULD PROVIDE A FOCUS FOR CONVECTIVE
INITIATION DURING THE EARLY AFTERNOON. SFC-6KM SHEAR OF 20-30KT FROM
THE NW SHOULD SUPPORT A FEW LONG-LIVED CELLS AND MULTICELLULAR STORM
CLUSTERS ACROSS SERN GA AND NRN/CENTRAL FL THROUGH THE PEAK HEATING
PERIOD. THERMODYNAMIC ENVIRONMENT SHOULD SUPPORT LARGE HAIL WITH
STRONGER CORES...AS WELL AS THE POTENTIAL FOR ISOLATED DAMAGING
WINDS WITH CONVECTIVE DOWNDRAFTS.
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