Severe Weather Threat. April 21st-25th, 2010 High Risk!

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#281 Postby Dave » Sat Apr 24, 2010 1:10 am

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DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1257 AM CDT SAT APR 24 2010

VALID 241200Z - 251200Z

...THERE IS A HIGH RISK OF SVR TSTMS PORTIONS SERN AR...NERN
LA...MS...CENTRAL/NRN AL...

...THERE IS A MDT RISK OF SVR TSTMS ELSEWHERE FROM PORTIONS E TX TO
CENTRAL/NRN LA...AL...WRN GA...TN...SRN/CENTRAL KY...EXTREME SERN
MO...CENTRAL/SRN/ERN AR....

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING MDT RISK...FROM
GULF COAST OF SE TX TO FL PANHANDLE...TO PORTIONS WV/OH...TO
PORTIONS LOWER MO VALLEY REGION...TO E TX....

OUTBREAK OF NUMEROUS SVR TSTMS IS EXPECTED TODAY...GREATEST
CONCENTRATION/INTENSITY OF WHICH SHOULD INCLUDE STG-VIOLENT TORNADO
THREAT AFFECTING MID-SOUTH...MS DELTA REGION...AND TN VALLEY.

...SYNOPSIS...
SPLIT-FLOW PATTERN IN MID-UPPER LEVELS FEATURES CYCLONE INITIALLY
LOCATED OVER CENTRAL HIGH PLAINS...FCST TO MOVE EWD ACROSS KS TO WRN
MO BY 25/00Z AND WEAKEN ALONG WITH ITS SFC MANIFESTATION.
MEANWHILE...STG SHORTWAVE TROUGH AND SPEED MAX ALOFT -- WHICH
COMPRISED MOST OF INITIAL UPPER CYCLONE OVER SWRN CONUS DURING
PREVIOUS FEW DAYS -- IS FCST TO EJECT NEWD FROM CENTRAL TX TO ERN
MO/SRN IL AREA BY 25/00Z...TAKING OVER AGAIN AS PRIMARY 500 MB LOW.
BY THAT TIME...CORRESPONDING SFC CYCLONE WILL FORM ALONG OCCLUSION
TRIPLE POINT E OF ORIGINAL...AND CLOSE TO NEWER MID-UPPER CYCLONE
CENTER. THIS PROCESS WILL RESULT IN REINFORCEMENT/ACCELERATION OF
INITIALLY STALLED FRONTAL SEGMENT NOW OVER SWRN/CENTRAL TX NNEWD
OVER ERN OK. FRONT SHOULD MOVE ACROSS MUCH OF LA...WRN MS AND WRN
PORTIONS TN/KY BY 25/00Z...TO FL PANHANDLE...AL...MIDDLE-ERN TN AND
ERN KY BY END OF PERIOD....WHEN MID-UPPER CYCLONE SHOULD BE OVER NRN
PORTIONS IL/INDIANA...AND SRN LM AREA.

...LOWER MS VALLEY...MID-SOUTH AND TN VALLEY REGIONS...
TSTMS SHOULD BE INCREASING IN COVERAGE/INTENSITY AROUND BEGINNING OF
PERIOD OVER E TX...LA AND ARKLATEX REGION. FOREGOING AIR MASS --
ALREADY MOISTENED/DESTABILIZED FAVORABLY BY PRIOR/OVERNIGHT THETAE
ADVECTION...WILL FURTHER DESTABILIZE AMIDST SFC DIABATIC HEATING.
AMOUNT OF HEATING IS SOMEWHAT IN QUESTION BECAUSE OF POTENTIAL FOR
CLOUD/ANVIL DEBRIS SPREADING DOWNSTREAM IN MID-UPPER LEVELS FROM
EARLY CONVECTION...PERHAPS INCLUDING TEMPORAL EXTENSION OF ACTIVITY
NOW OVER S TX. STILL...AWAY FROM EXISTING CONVECTION...EVERY
REASONABLE SCENARIO INDICATES THAT MLCINH GENERALLY WILL WEAKEN WITH
NWD EXTENT FROM GULF COAST...SUPPORTING EARLY AND RAPID DEVELOPMENT
AND INTENSIFICATION OF TSTMS FROM MID-MORNING THROUGH
MID-AFTERNOON...AND SUSTAINED THREAT SHIFTING EWD AND NEWD ACROSS
OUTLOOK AREA INTO EVENING/OVERNIGHT HOURS.

INTENSE VERTICAL WIND PROFILES WILL SPREAD ACROSS BROAD WARM/MOIST
SECTOR TODAY...MUCH OF WHICH ALREADY IS IN PLACE ACROSS MUCH OF
LA...MS AND COASTAL AL. THIS AIR MASS WILL SPREAD INLAND TOWARD TN
VALLEY AS CONVECTION/PRECIP NOW OVER TN/AL/GA SHIFTS NEWD. SFC DEW
POINTS WILL BE 70S INVOF GULF COAST...TRANSITIONING TO UPPER 60S AS
FAR N AS TN AND LOW-MID 60S TO OH VALLEY. WEAKENING LAPSE RATES
ALOFT AND BUOYANCY WITH NWD EXTENT...FROM TN VALLEY TO OH VALLEY AND
GREAT LAKES...RENDER PROGRESSIVELY MORE CONDITIONAL NATURE TO SVR
THREAT...THOUGH KINEMATIC PROFILES WILL BECOME FAVORABLE OVER VERY
LARGE AREA S OF GREAT LAKES BY EVENING/OVERNIGHT HOURS.

MULTIPLE CONVECTIVE EPISODES AND STORM MODES ARE EXPECTED IN THIS
SITUATION...AGGREGATE OF WHICH SHOULD YIELD DENSE CONCENTRATION OF
SVR EVENTS BY END OF PERIOD ACROSS MDT/HIGH CATEGORICAL RISK AREAS.
THOUGH DISCRETE/CYCLIC TORNADIC SUPERCELLS ARE MOST POTENTIALLY
DANGEROUS THREAT...ESPECIALLY OVER HIGH RISK AREA...CLUSTERED AND
QUASI-LINEAR CONVECTIVE ELEMENTS WITH EMBEDDED BOW/LEWP FORMATIONS
AND SUPERCELLS ALSO APPEAR PROBABLE. STRENGTHENING DEEP-LAYER WINDS
AND RELATED FAST STORM MOTIONS PORTEND LONG TRACKS FOR SUPERCELLS
AND FOR SOME OF THEIR TORNADOES...AS WELL AS FOR SWATHS OF DAMAGING
WIND WITH ANY BOW/LEWP FEATURES. THIS SUPPORTS RATHER ROBUST
PROBABILITIES FOR ALL SEVERE MODES.

PARAMETER SPACES IN FCST SOUNDINGS OVER HIGH RISK AREA -- SHIFTING
NEWD FROM LATE MORNING THROUGH AFTERNOON -- INCLUDE 50-60 KT LLJ
SUPPORTING VERY LARGE HODOGRAPHS WITH 0-1 AND 0-1 KM SRH 300-600
J/KG. ALSO EXPECT 50-60 KT EFFECTIVE SHEAR MAGNITUDES BENEATH
110-140 KT 250 MB JET MAX AND 60-90 KT 500 MB WINDS...POTENTIALLY
JUXTAPOSED WITH MLCAPE 1500-2500 J/KG.

SUPERCELL/TORNADO THREAT MAY CARRY INTO EVENING/OVERNIGHT HOURS OVER
CENTRAL/SRN APPALACHIANS REGION AND WRN GA BEFORE DIMINISHING.

...IA...MO VALLEY REGION...
SCATTERED STG-SVR TSTMS ARE EXPECTED TO DEVELOP ACROSS THIS AREA
INVOF LARGE CYCLONE ALOFT...AS STEEP MID-UPPER LEVEL LAPSE RATES
COLLOCATED WITH BROAD AREA OF LOW-LEVEL CONVERGENCE AND
DIABATIC/DIURNAL DESTABILIZATION OF BOUNDARY LAYER. MAIN CONCERN
WILL BE SVR HAIL...THOUGH POTENTIAL FOR DAMAGING GUSTS EXISTS. SVR
POTENTIAL SHOULD WANE SIGNIFICANTLY AFTER SUNSET.

..EDWARDS/GARNER.. 04/24/2010
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#282 Postby Dave » Sat Apr 24, 2010 1:12 am

Image

Image

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#283 Postby Dave » Sat Apr 24, 2010 1:40 am

Image
MESOSCALE DISCUSSION 0364
NWS STORM PREDICTION CENTER NORMAN OK
0120 AM CDT SAT APR 24 2010

AREAS AFFECTED...NERN TX THROUGH NRN LA AND SWRN AR

CONCERNING...TORNADO WATCH 82...

VALID 240620Z - 240645Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 82 CONTINUES.

TORNADO WATCH 82 WILL BE REPLACED SOON BY ANOTHER TORNADO WATCH THAT
WILL EXTEND THROUGH NERN TX...SWRN AR AND NRN LA.

LINE OF STORMS OVER NERN TX IS EXPECTED TO CONTINUE EWD THROUGH
MODERATELY UNSTABLE ATMOSPHERE. RECENT OBJECTIVE ANALYSIS INDICATES
THE ATMOSPHERE REMAINS CAPPED FROM NERN TX TROUGH NRN LA.
HOWEVER...RADAR DATA INDICATE THE LINE IS ORGANIZED WITH ROTATING
COMMA HEAD AND IS EMBEDDED WITHIN STRONG VERTICAL SHEAR. STRONG
CONVERGENCE ALONG THE CONVECTIVE OUTFLOW BOUNDARY WILL LIKELY
MAINTAIN THIS ACTIVITY AS IT DEVELOPS EAST. POTENTIAL WILL EXIST FOR
THE CAP TO WEAKEN WITHIN THE DEVELOPING WARM ADVECTION REGIME AND AS
HEIGHTS FALL DOWNSTREAM FROM ADVANCING UPPER TROUGH. THIS COULD
SUPPORT MORE DISCRETE STORMS MAY DEVELOPING EAST OF THE LINE LATER
THIS MORNING.

..DIAL.. 04/24/2010


ATTN...WFO...JAN...LCH...SHV...HGX...FWD...
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#284 Postby Bunkertor » Sat Apr 24, 2010 3:39 am

Spooky sounding

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#285 Postby KWT » Sat Apr 24, 2010 3:45 am

Yeah fully justifies the idea to upgrade today to a high risk day, looking very impressive it has to be said and no doubt it'll be a long ole day!
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#286 Postby brunota2003 » Sat Apr 24, 2010 6:12 am

I honestly would not be surprised if we see an EF4 or EF5 today. I hope everyone is taking this seriously
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Re: Severe Weather Threat. April 21st-25th, 2010 High Risk!

#287 Postby brunota2003 » Sat Apr 24, 2010 6:19 am

This is the AFD for my parents, who live in Eastern KY (it looks like they might be right on the edge of the 15H for tornadoes)

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
329 AM EDT SAT APR 24 2010

.SHORT TERM.../TODAY THROUGH MONDAY/...UPDATED

THE MODELS CONTINUE TO BE NEARLY SCHIZOPHRENIC IN TRYING TO TIME THE
VARIOUS CONVECTIVE FEATURES ACROSS THE AREA. I AM NOT SURE WHETHER
THIS BECAUSE THIS SYSTEM IS SO ROBUST THAT CONVECTIVE FEEDBACK IS
CAUSING THE MODELS PROBLEMS OR EXACTLY WHAT IS GOING ON. THIS IS
PROBABLY THE WORST SUSTAINED MODEL PERFORMANCE I HAVE SEEN IN A LONG
TIME.
AS SUCH...HAVE BASED THE FIRST PORTION OF THE FORECAST ON A
BLEND BETWEEN EXTRAPOLATION AND THE SREF AND THEN BLENDED THE SREF
AND GFS FOR SATURDAY NIGHT AND SUNDAY AND TRANSITIONED TO THE GFS FOR
MONDAY. SPC HAS PUT THE AREA EAST OF I 75 INTO A MODERATE RISK FOR
SEVERE WEATHER. THE SHEAR THIS AFTERNOON IS PRETTY
IMPRESSIVE...HOWEVER THE STABILITY WITH LIFTED IN DEXES OF -2 TO -3 AND
CAPE OF AROUND 600 JOULES IS NOT QUITE AS IMPRESSIVE. THE OTHER ISSUE
IS THE EXTENSIVE CLOUDINESS. FOR THE SEVERE TO HAVE A GOOD
CHANCE...WE WILL NEED TO SEE SOME BREAKS IN THE CLOUDS. IF THE BREAKS
OCCUR...THE SHEAR WILL BE VERY CONDUCIVE TO PRODUCING SOME SUPER
CELLS...SO WILL HAVE TO KEEP A CLOSE EYE ON THE SITUATION.

THE ANTECEDENT CONDITIONS HAVE BEEN SO DRY...THAT WE EXPECT THE
GROUND TO BE ABLE TO HANDLE THE PRECIPITATION THAT FALLS TODAY AND
TONIGHT. IN THE VICINITY OF ANY TRAINING STORMS...MAY SEE SOME WATER
IN LOW WATER CROSSING AND SOME FULL DITCHES...BUT EXPECT THE RIVERS
WILL NOT HAVE ANY PROBLEM HANDLING THE RUNOFF. FOR TEMPS...DID A
BLEND OF THE GFS AND NAM MOS WHICH DID NOT CHANGE THE DAY SHIFT
FORECAST VERY MUCH.
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#288 Postby RL3AO » Sat Apr 24, 2010 6:45 am

Whats going on at Talladega today?
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Re:

#289 Postby badger70 » Sat Apr 24, 2010 7:26 am

RL3AO wrote:Whats going on at Talladega today?


Didn't see anything on their web site, but tornadic storms should be moving into that area a little after the 2 PM start time.

Added on edit:
Severe weather is expected to cause problems for Talladega NASCAR event

Posted: April 24, 2010 - 1:59am

http://jacksonville.com/sports/racing/2 ... scar-event

The storms are supposed to be scattered, so the track decided to hope for enough sunshine between the waves of bad weather to complete the Aaron's 312.

Qualifying for the Aaron's 499 for the Sprint Cup Series is this morning at 11:30.

If that race is rained out, it likely will be moved to Sunday as part of a racing doubleheader, Hunter said.

One third of the state's highway patrol has been assigned to Talladega, Lynch said, and there are 200 other fire and rescue people on the property. That's why the track decided to ride out the bad weather.



Image

Hope they can stay safe.
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Re:

#290 Postby baygirl_1 » Sat Apr 24, 2010 7:37 am

RL3AO wrote:Whats going on at Talladega today?

I know that Talladega and NASCAR are saying right now the race will proceed as scheduled but they are monitoring the weather. Also, the area TV stations have been warning campers at the speedway to have a plan if a tornado warning is issued. Sounds like a scary situation, though!
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#291 Postby Dave » Sat Apr 24, 2010 7:42 am

MESOSCALE DISCUSSION 0370
NWS STORM PREDICTION CENTER NORMAN OK
0735 AM CDT SAT APR 24 2010

AREAS AFFECTED...SERN MO / SRN IL / WRN KY

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 241235Z - 241330Z

THE THREAT FOR SEVERE STORMS INCLUDING SUPERCELLS AND BOWING
STRUCTURES IS EXPECTED TO INCREASE ACROSS THE AREA BY AS EARLY AS
14-15Z. A NEW TORNADO WATCH WILL BE REQUIRED BY MID TO LATE
MORNING.

LATEST MESOANALYSIS INDICATES A DEEPENING SURFACE LOW NEAR HOT WHILE
AN ASSOCIATED WARM FRONT ARCS NEWD THROUGH NRN MS AND THEN SEWD
THROUGH W-CNTRL AL. LATEST SHORT TERM GUIDANCE INDICATES THAT THIS
LOW WILL CONTINUE TO DEEPEN WHILE DEVELOPING NNEWD TO THE VICINITY
OF POF BY 18Z. AT THE SAME TIME...A RAPID INTENSIFICATION AND NWD
MIGRATION OF THE LLJ WILL OCCUR THROUGH THE LOWER MS
VALLEY...HASTENING THE DESTABILIZATION OF THE BOUNDARY LAYER ACROSS
THE DISCUSSION AREA.

A BOW ECHO COMPLEX WHICH FORMED LAST NIGHT OVER NERN TX HAS RECENTLY
RE-INTENSIFIED OVER NERN AR /NEAR BVX/...AIDED BY A LARGER-SCALE MCV
ATTENDANT TO THE SYSTEM. WHILE THIS SYSTEM MAY STILL BE SLIGHTLY
ELEVATED...THE RAPID AIR MASS DESTABILIZATION WILL ALLOW IT TO
BECOME SURFACE-BASED...AND EXTRAPOLATION OF CURRENT MOTION TAKES IT
N OF TORNADO WATCH 91 PRIOR TO 14Z.
ADDITIONAL STORMS...LIKELY SUPERCELLS ARE EXPECTED TO DEVELOP
THROUGH THE MORNING WITHIN THE MOISTENING/DESTABILIZING AIR MASS.
GIVEN ANTICIPATED STRENGTHENING OF THE WIND FIELD
FORECAST...CONDITIONS WILL BE FAVORABLE FOR TORNADOES /SOME
SIGNIFICANT/ IN ADDITION TO DAMAGING WINDS AND HAIL.

..MEAD.. 04/24/2010


ATTN...WFO...PAH...LSX...
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#292 Postby Dave » Sat Apr 24, 2010 7:42 am

MESOSCALE DISCUSSION 0369
NWS STORM PREDICTION CENTER NORMAN OK
0725 AM CDT SAT APR 24 2010

AREAS AFFECTED...NRN LA...EXTREME E-CNTRL TX AND SRN AR

CONCERNING...TORNADO WATCH 89...90...

VALID 241225Z - 241400Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 89...90...CONTINUES.

TORNADO WATCH 89 THAT WAS SCHEDULED TO EXPIRE AT 13Z IS BEING
LOCALLY EXTENDED UNTIL 15Z. TORNADO WATCH 90 REMAINS IN EFFECT UNTIL
14Z. THREAT FOR ISOLATED TORNADOES...LARGE HAIL AND DAMAGING WIND
WILL PERSIST NEXT 2-3 HOURS.

STORMS ARE INTENSIFYING FROM EXTREME ERN TX INTO NRN LA AND SRN AR
ALONG A CONVECTIVELY MODIFIED BOUNDARY. A MESO-LOW HAS DEVELOPED IN
SWRN AR AND THE LOW-LEVEL JET HAS STRENGTHENED TO AROUND 60 KT
RESULTING IN VERY LARGE 0-2 KM HODOGRAPHS WITHIN A MODERATELY
UNSTABLE WARM SECTOR. DEEPER ASCENT ASSOCIATED WITH A SHORTWAVE
TROUGH EJECTING NEWD THROUGH TX IS BEGINNING TO OVERTAKE THE
BOUNDARY...RESULTING IN A MORE FAVORABLE THERMODYNAMIC ENVIRONMENT
FOR STORMS TO DEEPEN AND INTENSIFY. SUPERCELLS AND BOWING SEGMENTS
WITH TORNADOES...DAMAGING WIND AND LARGE HAIL WILL REMAIN LIKELY
WITH THE STRONGER STORMS.

..DIAL.. 04/24/2010


ATTN...WFO...JAN...LZK...LCH...SHV...
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#293 Postby Dave » Sat Apr 24, 2010 7:47 am

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 91
NWS STORM PREDICTION CENTER NORMAN OK
600 AM CDT SAT APR 24 2010

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

EASTERN ARKANSAS
NORTHEAST LOUISIANA
CENTRAL AND NORTHERN MISSISSIPPI
SOUTHWEST TENNESSEE

EFFECTIVE THIS SATURDAY MORNING AND AFTERNOON FROM 600 AM UNTIL
100 PM CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

DESTRUCTIVE TORNADOES...LARGE HAIL TO 3 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 100 STATUTE
MILES EAST AND WEST OF A LINE FROM 25 MILES NORTH NORTHEAST OF
MEMPHIS TENNESSEE TO 55 MILES WEST OF PINE BELT MISSISSIPPI. 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 89...WW 90...

DISCUSSION...CLUSTERS OF SEVERE THUNDERSTORMS ARE EXPECTED TO
INTENSIFY THIS MORNING AS LOW LEVEL JET STRENGTHENS AND UPPER TROUGH
APPROACHES. A COMBINATION OF HIGH MOISTURE VALUES...MODERATE
CAPE...AND EXTREMELY STRONG SHEAR PROFILES WILL POSE A RISK OF
TORNADIC SUPERCELLS THROUGH THE MORNING. STRONG TORNADOES ARE
POSSIBLE.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 24040.


...HART

Hazard Tornadoes EF2+ Tornadoes
Likelihood High Moderate
Severe Wind 65 kt+ Wind
High Moderate
Severe Hail 2"+ Hail
High Moderate
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#294 Postby Dave » Sat Apr 24, 2010 7:48 am

:uarrow:

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Re: Severe Weather Threat. April 21st-25th, 2010 High Risk!

#295 Postby brunota2003 » Sat Apr 24, 2010 7:49 am

New Day 1 posted, High and Moderate Risks expanded

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0735 AM CDT SAT APR 24 2010

VALID 241300Z - 251200Z

...THERE IS A HIGH RISK OF SVR TSTMS TODAY AND TONIGHT ACROSS PARTS
OF CENTRAL/NORTHERN MS...CENTRAL/NORTHERN AL...AND A SMALL PART OF
SOUTHERN MIDDLE TN...

...THERE IS A MDT RISK OF SVR TSTMS FROM EASTERN LA INTO WESTERN
GA...AND NORTHWARD ACROSS MUCH OF TN/KY...INTO SOUTHEAST
MO...SOUTHERN IL...AND SOUTHEAST IND...

...THERE IS A SLGT RISK OF SVR TSTMS OVER MUCH OF THE LOWER/MIDDLE
MS...TN....AND OH VALLEYS...

...WIDESPREAD OUTBREAK OF SEVERE THUNDERSTORMS INCLUDING STRONG
TORNADOES IS EXPECTED TODAY FROM THE MID MS AND LOWER OH VALLEYS
SOUTHWARD INTO THE CENTRAL GULF COAST STATES...

MORNING SATELLITE LOOPS SHOW A LARGE UPPER TROUGH OVER THE CENTRAL
UNITED STATES...WITH A VIGOROUS SHORTWAVE TROUGH ROTATING ACROSS TX
AND BECOMING NEGATIVELY TILTED. THIS FEATURE WILL EJECT EASTWARD
TODAY ACROSS THE MS/TN VALLEYS AND RESULT IN WIDESPREAD INTENSE
THUNDERSTORM ACTIVITY. MULTIPLE WAVES OF STRONG/SEVERE STORMS ARE
POSSIBLE AND LEAD TO A COMPLEX FORECAST SCENARIO.

...LA/MS/AL/TN...
THUNDERSTORMS HAVE BEEN INCREASING IN COVERAGE AND INTENSITY THIS
MORNING ACROSS PARTS OF LA/AR/MS...ALONG AND AHEAD OF THE PRIMARY
SURFACE COLD FRONT. RAPIDLY STRENGTHENING LOW LEVEL WINDS AND WARM
ADVECTION ARE LEADING TO DISCRETE CONVECTIVE INITIATION...WITH
NUMEROUS STORMS SHOWING MID LEVEL ROTATION. THIS ACTIVITY WILL
SPREAD EASTWARD INTO AL AND TN WITH THE POTENTIAL FOR LARGE
HAIL...DAMAGING WINDS...AND TORNADOES THROUGH THE MORNING.

A FEW HOURS OF HEATING WILL LIKELY PROMOTE ANOTHER ROUND OF SEVERE
STORMS BY EARLY AFTERNOON OVER EASTERN MS...MUCH OF AL...AND
POTENTIALLY INTO MIDDLE TN. THESE STORMS ARE FORECAST TO BE THE
MORE SIGNIFICANT OF THIS EVENT...WITH THE RISK OF DAMAGING TORNADOES
AND WIDESPREAD DAMAGING WINDS. STORMS WILL TRACK EASTWARD INTO
WESTERN GA DURING THE EVENING HOURS.

...MID MS AND LOWER OH VALLEYS...
ALL MODEL GUIDANCE AGREES ON RAPID SURFACE CYCLOGENESIS OVER PARTS
OF MO/IL BY EARLY AFTERNOON AS THE EXIT REGION OF A 90+ KNOT MID
LEVEL SPEED MAX NOSES INTO THE AREA. STRONG SOUTHEASTERLY LOW LEVEL
WINDS WILL TRANSPORT MOISTURE NORTHWARD AND HELP TO DESTABILIZE
PARTS OF MO/IL/IND/KY AHEAD OF THE SURFACE LOW. FORECAST SOUNDINGS
SUGGEST VERTICAL SHEAR AND CAPE PROFILES QUITE FAVORABLE FOR
TORNADIC SUPERCELLS DURING THE AFTERNOON. THE MAIN FORECAST
QUESTION IN THIS AREA INVOLVES THE EVOLUTION OF CONVECTION FARTHER
SOUTH AND WHETHER IT WILL IMPEDE MOISTURE RETURN THROUGH THE DAY.
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Re: Severe Weather Threat. April 21st-25th, 2010 High Risk!

#296 Postby CrazyC83 » Sat Apr 24, 2010 7:49 am

MESOSCALE DISCUSSION 0370
NWS STORM PREDICTION CENTER NORMAN OK
0735 AM CDT SAT APR 24 2010

AREAS AFFECTED...SERN MO / SRN IL / WRN KY

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 241235Z - 241330Z

THE THREAT FOR SEVERE STORMS INCLUDING SUPERCELLS AND BOWING
STRUCTURES IS EXPECTED TO INCREASE ACROSS THE AREA BY AS EARLY AS
14-15Z. A NEW TORNADO WATCH WILL BE REQUIRED BY MID TO LATE
MORNING
.

LATEST MESOANALYSIS INDICATES A DEEPENING SURFACE LOW NEAR HOT WHILE
AN ASSOCIATED WARM FRONT ARCS NEWD THROUGH NRN MS AND THEN SEWD
THROUGH W-CNTRL AL. LATEST SHORT TERM GUIDANCE INDICATES THAT THIS
LOW WILL CONTINUE TO DEEPEN WHILE DEVELOPING NNEWD TO THE VICINITY
OF POF BY 18Z. AT THE SAME TIME...A RAPID INTENSIFICATION AND NWD
MIGRATION OF THE LLJ WILL OCCUR THROUGH THE LOWER MS
VALLEY...HASTENING THE DESTABILIZATION OF THE BOUNDARY LAYER ACROSS
THE DISCUSSION AREA.

A BOW ECHO COMPLEX WHICH FORMED LAST NIGHT OVER NERN TX HAS RECENTLY
RE-INTENSIFIED OVER NERN AR /NEAR BVX/...AIDED BY A LARGER-SCALE MCV
ATTENDANT TO THE SYSTEM. WHILE THIS SYSTEM MAY STILL BE SLIGHTLY
ELEVATED...THE RAPID AIR MASS DESTABILIZATION WILL ALLOW IT TO
BECOME SURFACE-BASED...AND EXTRAPOLATION OF CURRENT MOTION TAKES IT
N OF TORNADO WATCH 91 PRIOR TO 14Z.
ADDITIONAL STORMS...LIKELY SUPERCELLS ARE EXPECTED TO DEVELOP
THROUGH THE MORNING WITHIN THE MOISTENING/DESTABILIZING AIR MASS.
GIVEN ANTICIPATED STRENGTHENING OF THE WIND FIELD
FORECAST...CONDITIONS WILL BE FAVORABLE FOR TORNADOES /SOME
SIGNIFICANT/
IN ADDITION TO DAMAGING WINDS AND HAIL.

..MEAD.. 04/24/2010


ATTN...WFO...PAH...LSX...

LAT...LON 36779019 37349018 37908989 38208941 38398861 38488781
37548720 36908763 36518865 36558946 36779019
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#297 Postby CrazyC83 » Sat Apr 24, 2010 7:50 am

Gulf Coast watch, probs are 50/30.

SEL2

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 92
NWS STORM PREDICTION CENTER NORMAN OK
615 AM CDT SAT APR 24 2010

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

SOUTHWEST ALABAMA
FAR WESTERN FLORIDA PANHANDLE
SOUTH-CENTRAL AND SOUTHEAST LOUISIANA
SOUTHERN MISSISSIPPI
COASTAL WATERS

EFFECTIVE THIS SATURDAY MORNING AND AFTERNOON FROM 615 AM UNTIL
100 PM CDT.

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 60 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 35 MILES WEST OF LAFAYETTE
LOUISIANA TO 55 MILES EAST NORTHEAST OF MOBILE ALABAMA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU2).

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 89...WW 90...WW 91...

DISCUSSION...TSTMS /SUPERCELLS/ ARE EXPECTED TO INCREASE IN AREAL
COVERAGE THIS MORNING AS DEEP ASCENT IS ENHANCED BY STRENGTHENING
LLJ. THE COMBINATION OF A MOIST/MODERATELY UNSTABLE AIR MASS AND
STRONG LOW AND DEEP-LAYER SHEAR INDICATE THE THREAT FOR TORNADOES IN
ADDITION TO DAMAGING WINDS AND HAIL.

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
500. MEAN STORM MOTION VECTOR 22035.


...MEAD
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CrazyC83
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Re: Severe Weather Threat. April 21st-25th, 2010 High Risk!

#298 Postby CrazyC83 » Sat Apr 24, 2010 7:51 am

This watch will almost certainly be PDS as well.

MESOSCALE DISCUSSION 0371
NWS STORM PREDICTION CENTER NORMAN OK
0743 AM CDT SAT APR 24 2010

AREAS AFFECTED...CNTRL AND NRN AL

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 241243Z - 241445Z

STORMS ARE EXPECTED TO INCREASE DURING THE MORNING ACROSS CNTRL AND
NRN AL. PRIMARY INITIAL THREAT WILL BE LARGE HAIL AND DAMAGING
WIND...BUT THE THREAT FOR STRONG TORNADOES WILL INCREASE LATER THIS
MORNING AND ESPECIALLY THIS AFTERNOON.


THIS MORNING A WARM FRONT EXTENDS FROM SWRN GA THROUGH CNTRL AL INTO
NRN MS AND WRN AR. THIS BOUNDARY SEPARATES WARM MOIST GULF AIR WITH
LOW 70S DEWPOINTS AND MODERATE INSTABILITY IN THE WARM SECTOR FROM A
MODIFIED CP BOUNDARY LAYER TO THE NORTH. THE FRONT WILL LIFT NWD AS
AN INTENSE LOW-LEVEL JET DEVELOPS THROUGH THE LOWER MS VALLEY IN
RESPONSE TO AN EWD EJECTING SHORTWAVE TROUGH NOW OVER TX. STORMS
CURRENTLY MOVING OUT OF MS WILL INITIALLY POSE A THREAT FOR MAINLY
LARGE HAIL AND DAMAGING WIND. HOWEVER...AS THE BOUNDARY LAYER
CONTINUES TO MOISTEN AND DESTABILIZE...THE RISK FOR TORNADIC
SUPERCELLS WILL INCREASE GIVEN THE SIZE OF HODOGRAPHS /SRH AOA 400
M2/S2 ALONG THE STRENGTHENING LOW LEVEL JET.

..DIAL.. 04/24/2010


ATTN...WFO...BMX...HUN...MOB...

LAT...LON 34508813 34608721 33508638 32848604 32268602 32028703
32378827 34508813
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Dave
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Contact:

#299 Postby Dave » Sat Apr 24, 2010 7:55 am

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LOUISVILLE KY
345 AM EDT SAT APR 24 2010 /245 AM CDT SAT APR 24 2010/

...SEVERE WEATHER OUTBREAK POSSIBLE THIS AFTERNOON AND EVENING...

LOW AND MID-LEVEL WINDS WILL INCREASE IN RESPONSE TO A DEEPENING
SURFACE LOW...WHICH WILL INCREASE WIND SHEAR AS WELL. AS A
RESULT...SATURDAY AFTERNOON AND EVENING...CONDITIONS WILL BECOME
FAVORABLE FOR ONE OR MORE INTENSE LINES OF STORMS AND ROTATING
SUPERCELLS ESPECIALLY OVER SOUTH CENTRAL KENTUCKY.

THE MAIN HAZARDS FROM THESE STORMS WILL BE WIND DAMAGE...
POTENTIALLY SIGNIFICANT...AND A FEW TORNADOES. HEAVY RAIN...HAIL AND
CLOUD-TO-GROUND LIGHTNING ARE LIKELY AS WELL.

A LARGE OUTBREAK OF SEVERE STORMS IS EXPECTED SOUTH OF KENTUCKY
SATURDAY WHICH MAY HAVE SOME INFLUENCE ON THE SEVERE POTENTIAL
OVER CENTRAL KENTUCKY AND SOUTH CENTRAL INDIANA. NEVERTHELESS...IT
APPEARS THAT SOUTH CENTRAL INDIANA AND ESPECIALLY CENTRAL KENTUCKY
WILL SEE SOME SEVERE STORMS...AND A SEVERE WEATHER OUTBREAK
INCLUDING A FEW TORNADOES IS QUITE POSSIBLE IN OUR AREA AS WELL.

RESIDENTS NEED TO MONITOR LATER FORECASTS AND STATEMENTS FROM THE
NATIONAL WEATHER SERVICE AND LOCAL MEDIA FOR UPDATES ON THIS
DEVELOPING HAZARDOUS WEATHER SITUATION
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Re: Severe Weather Threat. April 21st-25th, 2010 High Risk!

#300 Postby CrazyC83 » Sat Apr 24, 2010 8:02 am

SEL3

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 93
NWS STORM PREDICTION CENTER NORMAN OK
800 AM CDT SAT APR 24 2010

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

CENTRAL AND NORTHERN ALABAMA
MIDDLE TENNESSEE

EFFECTIVE THIS SATURDAY MORNING AND AFTERNOON FROM 800 AM UNTIL
200 PM CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

DESTRUCTIVE TORNADOES...LARGE 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 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 20 MILES NORTH NORTHWEST OF
NASHVILLE TENNESSEE TO 30 MILES SOUTH SOUTHWEST OF SELMA ALABAMA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU3).

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 89...WW 90...WW 91...WW
92...

DISCUSSION...THUNDERSTORMS OVER MS WILL SPREAD EASTWARD INTO AL AND
MIDDLE TN THROUGH THE MORNING...WITH SCATTERED SUPERCELLS POSSIBLE.
STORMS WILL BE INITIALLY ELEVATED...BUT RAPID DESTABILIZATION WILL
INCREASE THE RISK OF TORNADOES BY LATE MORNING. VERY STRONG SHEAR
PROFILES ALSO SUPPORT A RISK OF SIGNIFICANT TORNADOES.


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
500. MEAN STORM MOTION VECTOR 24035.


...HART
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