Historic Multi Day Tornado/Flooding Event 4/23-28/2011

[Ptarmigan]

The last thing we need to hear up here in the Ohio Valley is anything about more rain...

We could use the rain. Give it to us! In fact give all the rain to us!

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE WILMINGTON OH
145 PM EDT SAT APR 23 2011

THE NATIONAL WEATHER SERVICE IN WILMINGTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
BOONE COUNTY IN NORTHERN KENTUCKY...
CAMPBELL COUNTY IN NORTHERN KENTUCKY...
CARROLL COUNTY IN NORTHERN KENTUCKY...
GALLATIN COUNTY IN NORTHERN KENTUCKY...
NORTHERN GRANT COUNTY IN NORTHERN KENTUCKY...
KENTON COUNTY IN NORTHERN KENTUCKY...
NORTHWESTERN OWEN COUNTY IN NORTHERN KENTUCKY...
NORTHERN PENDLETON COUNTY IN NORTHERN KENTUCKY...
DEARBORN COUNTY IN SOUTHEAST INDIANA...
SOUTHERN FRANKLIN COUNTY IN SOUTHEAST INDIANA...
OHIO COUNTY IN SOUTHEAST INDIANA...
RIPLEY COUNTY IN SOUTHEAST INDIANA...
SWITZERLAND COUNTY IN SOUTHEAST INDIANA...
HAMILTON COUNTY IN SOUTHWEST OHIO...

* UNTIL 745 PM EDT.

* AT 142 PM EDT...RADAR INDICATED A LARGE AREA OF THUNDERSTORMS
MOVING NORTHEAST INTO THE REGION FROM SOUTHERN INDIANA AND
NORTH CENTRAL KENTUCKY.

* HEAVY RAIN WILL FALL ACROSS THE WARNED AREA WITH 1 TO 3 INCHES
POSSIBLE THROUGH 745 PM EDT. RUNOFF FROM THIS EXCESSIVE RAINFALL
MAY CAUSE FLASH FLOODING TO OCCUR.

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...ALEXANDRIA...
ANDERSON TOWNSHIP...AURORA...BATESVILLE...BELLEVUE...BLUE ASH...
BRIGHT...BURLINGTON...CARROLLTON...CHEVIOT...CINCINNATI AND
CLARYVILLE.

[CrazyC83]

St. Louis tornado: AT LEAST EF4 (maybe EF5?)

http://www.crh.noaa.gov/lsx/?n=04_22_2011

[WeatherGuesser]

And the beat goes on....................


SPC AC 240600

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT SUN APR 24 2011

VALID 251200Z - 261200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS A LARGE PORTION OF
ARKANSAS AND INTO SOUTHERN MISSOURI...

...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN PORTIONS OF THE SRN
PLAINS EWD/NEWD INTO THE MID AND LOWER MS/MID AND LOWER OH/TN
VALLEYS...

...SYNOPSIS...
A LARGE UPPER TROUGH IS FORECAST TO REMAIN ANCHORED OVER THE CENTRAL
U.S. THIS PERIOD...WHILE AN EMBEDDED SHORT-WAVE TROUGH MOVES ACROSS
THE SRN PLAINS AND EVENTUALLY INTO THE MO VALLEY LATE.

AS THIS STRONG FEATURE PROGRESSES ACROSS THE S CENTRAL
CONUS...SURFACE CYCLOGENESIS IS FORECAST...AS A DEEPENING LOW
TRANSLATES NEWD FROM THE SRN PLAINS ACROSS MO THROUGH THE AFTERNOON
AND EVENING. THIS LOW -- AND AN ACCOMPANYING SURFACE FRONT
PROGRESSING SEWD ACROSS THE SRN PLAINS -- WILL BE A FOCUS FOR
DEVELOPMENT OF POTENTIALLY SIGNIFICANT SEVERE THUNDERSTORMS THIS
PERIOD.

...NERN TX/SERN OK/SERN KS EWD/NEWD INTO THE MID AND LOWER
MS/TN/LOWER AND MID OH VALLEYS...
POTENTIALLY SIGNIFICANT SEVERE WEATHER EVENT IS EXPECTED DAY 2
/MONDAY APRIL 25/ FROM ERN PORTIONS OF THE SRN PLAINS INTO THE MID
MS/LOWER OH/TN VALLEY REGION...WITH POTENTIAL FOR STRONG TORNADOES
IN ADDITION TO VERY LARGE HAIL AND DAMAGING WINDS.

WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST TO BE ONGOING AT
THE START OF THE PERIOD...MAINLY ALONG AND N OF THE SURFACE WARM
FRONT FROM PARTS OF OK/KS EWD INTO THE OH VALLEY. AS THE STRONG
SHORT-WAVE TROUGH INVOF THE TX PANHANDLE REGION EARLY SHIFTS EWD
ACROSS TX/OK DURING THE DAY...A WEAK/BROAD SURFACE LOW INITIALLY
FORECAST INVOF N TX/OK IS FORECAST TO UNDERGO
CYCLOGENESIS...SHIFTING NEWD INTO MO THROUGH THE DAY. THIS WILL
ALLOW A SLOW NWD SHIFT OF THE COLD FRONT ACROSS SRN AND CENTRAL
MO/SRN IL...WHILE A COLD FRONT SHARPENS AND SWEEPS EWD ACROSS ERN
OK.

WHILE CLOUD COVER SHOULD ACT TO INHIBIT HEATING -- AND THUS MORE
SUBSTANTIAL DESTABILIZATION -- PARTICULARLY ACROSS NRN PORTIONS OF
THE RISK AREA...MIXED-LAYER CAPE OF 1000 TO 2000 J/KG IS FORECAST TO
DEVELOP AHEAD OF THE FRONT FROM E TX ACROSS THE ARKLATEX INTO AR/SRN
MO AND INTO THE MID MS VALLEY REGION. AS THE TROUGH SHIFTS EWD AND
THE FRONT SHARPENS...EXPECT VIGOROUS STORM DEVELOPMENT TO OCCUR
ACROSS SWRN MO...ERN OK...AND E TX DURING THE AFTERNOON WHICH --
GIVEN STRONG/FAVORABLY VEERING FLOW WITH HEIGHT -- SHOULD QUICKLY
BECOME SUPERCELLULAR. ALONG WITH THREATS FOR VERY LARGE
HAIL...ESPECIALLY ACROSS E TX AND THE ARKLATEX REGION...TORNADOES
ARE ALSO EXPECTED -- A FEW POSSIBLY STRONG/DAMAGING. THESE INTENSE
STORMS SHOULD SHIFT NEWD ACROSS THIS REGION WITH TIME TOWARD THE MID
MS VALLEY...WITH THE LIKELIHOOD FOR UPSCALE GROWTH OVERNIGHT INTO
LINEAR CLUSTERS. ALONG WITH A CONTINUED THREAT FOR A FEW
TORNADOES...MORE WIDESPREAD DAMAGING WIND THREAT COULD EVOLVE AS
STORMS SHIFT ACROSS THE MID MS AND LOWER OH VALLEY REGIONS THROUGH
THE EVENING/OVERNIGHT.

..GOSS.. 04/24/2011

[WeatherGuesser]

In the meantime, the Ohio River has had about all it can take:

http://water.weather.gov/ahps2/index.ph ... 8,2,9,15,6

[StormingB81]

That video from the airport was crazy! Amazing noone died..good thing!

[GCANE]

Looks like the worst of the upcoming event will be late Tuesday evening and early Wednesday morning thru LA and MS.

[GCANE]

GFS is lagging SREF by about 12 hrs.

[WeatherGuesser]

Points to Ponder..............

Will the Ohio meet or exceed 1997 levels?

[Dave]

Couple pictures from a family whose located about 6 miles from my house. Before & after shots from after Friday nights storms...small creek can be seen on the top picture right side. It runs the length of the property. Pictures are taken from the front yard, house actually sits up on a small hill approx 50 feet from where these pictures were taken. Everyone is safe.






Just issued....

FLOOD ADVISORY
NATIONAL WEATHER SERVICE WILMINGTON OH
904 AM EDT SUN APR 24 2011

INC029-115-137-155-KYC015-037-041-077-081-117-187-191-OHC061-241900-
/O.NEW.KILN.FA.Y.0039.110424T1304Z-110424T1900Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SWITZERLAND IN-OHIO IN-DEARBORN IN-RIPLEY IN-KENTON KY-OWEN KY-
PENDLETON KY-BOONE KY-CAMPBELL KY-CARROLL KY-GALLATIN KY-GRANT KY-
HAMILTON OH-
904 AM EDT SUN APR 24 2011

THE NATIONAL WEATHER SERVICE IN WILMINGTON HAS ISSUED A

* FLOOD ADVISORY FOR...
BOONE COUNTY IN NORTHERN KENTUCKY...
CAMPBELL COUNTY IN NORTHERN KENTUCKY...
CARROLL COUNTY IN NORTHERN KENTUCKY...
GALLATIN COUNTY IN NORTHERN KENTUCKY...
GRANT COUNTY IN NORTHERN KENTUCKY...
KENTON COUNTY IN NORTHERN KENTUCKY...
OWEN COUNTY IN NORTHERN KENTUCKY...
PENDLETON COUNTY IN NORTHERN KENTUCKY...
DEARBORN COUNTY IN SOUTHEAST INDIANA...
OHIO COUNTY IN SOUTHEAST INDIANA...
RIPLEY COUNTY IN SOUTHEAST INDIANA...
SWITZERLAND COUNTY IN SOUTHEAST INDIANA...
HAMILTON COUNTY IN SOUTHWEST OHIO...

* UNTIL 300 PM EDT.

[Stephanie]

OMG DAVE!

I am so thankful that there were no deaths from the St. Louis tornado. They say that the people in the path of the tornado had a warning 30 minutes before this thing hit. Well done NWS and spotters!

[cheezyWXguy]

That video from the airport was crazy! Amazing noone died..good thing!

could someone post a link, because I dont see it.

[ravyrn]

That video from the airport was crazy! Amazing noone died..good thing!

could someone post a link, because I dont see it.

St Louis Airport CCTV

[cheezyWXguy]

That video from the airport was crazy! Amazing noone died..good thing!

could someone post a link, because I dont see it.

St Louis Airport CCTV

Thanks, pretty crazy situation up there.

I guess there's no one else from texas on right now, but a pretty decent severe weather episode is unfolding in central texas right now, and looks like itll make a pass at the metroplex later tonight. Tornadoes and baseball to softball size hail already reported near the abilene area.

[Stephanie]

I guess there's no one else from texas on right now, but a pretty decent severe weather episode is unfolding in central texas right now, and looks like itll make a pass at the metroplex later tonight. Tornadoes and baseball to softball size hail already reported near the abilene area.

I just hope it brings LOTS of rain to the fire ravaged areas.

[CrazyC83]

Now the flooding seems to be about to grab the headlines. Offices are using harsh wording. This looks like a repeat of May 1-2 last year.

[WeatherGuesser]

Moderates up now for Monday, Tuesday and Wednesday.

[GCANE]

NE TX & SE OK looks to be under the gun for severe tornadoes late this afternoon.

The threat area could extend down to Houston with more a chance for large hail overnight.

IMHO, a MCS will most likely fire up in the NE TX / SE OK / W AR area and then move NE into AR overnight.

A strong cap will be in place and most likely break late afternoon in 3000 CAPE air.

Strong helicity & shear as well at that time.

The threat in AR overnight could be more related to winds from a bowing squall line and large hail.

[CrazyC83]

Today

SPC AC 251236

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0736 AM CDT MON APR 25 2011

VALID 251300Z - 261200Z

...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON INTO TONIGHT FROM
NE TX/SE OK ACROSS CENTRAL/SRN AR...NW LA...NW MS...AND FAR WRN
TN...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK
AREA...FROM ERN TX/OK NEWD TO THE LOWER OH VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR ERN
OH AND PA...

...SYNOPSIS...
A PRONOUNCED MIDLEVEL SHORTWAVE AND ASSOCIATED 70-80 KT MIDLEVEL JET
OVER NM THIS MORNING WILL PROGRESS EWD OVER N TX/OK TODAY...AND NEWD
OVER AR/MO TONIGHT. AN ASSOCIATED SURFACE CYCLONE IS EXPECTED TO
DEVELOP NEWD FROM S CENTRAL OK THIS MORNING TO SW MO THIS EVENING
AND NW IL LATE TONIGHT. A GRADUAL INCREASE IN THE WARM SECTOR
SLY/SSWLY LLJ IS EXPECTED LATER TODAY INTO TONIGHT AS THE MIDLEVEL
TROUGH EJECTS ENEWD AND THE SURFACE CYCLONE DEEPENS. INCREASING
VERTICAL SHEAR IN A MOIST/UNSTABLE WARM SECTOR WILL SUPPORT A RISK
FOR SIGNIFICANT SEVERE STORMS TODAY INTO TONIGHT...THOUGH SEVERAL
MESOSCALE FACTORS ADD UNCERTAINTY TO THE FORECAST.

...NE TX/SE OK ENEWD TO WRN TN/NW MS THROUGH TONIGHT...
COMPLICATED SCENARIO IS ALREADY UNFOLDING THIS MORNING WITH THE
WEAKENING COLD POOL FROM OVERNIGHT CONVECTION BEING OVERTAKEN BY
ANOTHER MCS MOVING ALONG THE OUTFLOW BOUNDARY INTO SW AR. THIS MCS
WILL LIKELY PERSIST THROUGH MUCH OF THE DAY WHILE PROGRESSING ACROSS
MUCH OF CENTRAL/SRN AR...GENERATING ANOTHER COLD POOL AND INHIBITING
NWD PROGRESS OF THE WARM SECTOR IN AR. THE MCS WILL INITIALLY POSE
A THREAT FOR DAMAGING WINDS AND LARGE HAIL...THOUGH THERE IS SOME
RISK FOR SUPERCELLS TO EVOLVE ON THE S/SW FLANK OF THE MCS AS THE
BOUNDARY LAYER DESTABILIZES FROM NE TX INTO SRN AR. FARTHER W IN
N/NE TX AND SE OK...SOME NWD RECOVERY IS EXPECTED IN THE WAKE OF THE
MORNING STORMS...AND IN ADVANCE OF THE SURFACE CYCLONE. STRONG
INSTABILITY /MLCAPE OF 2500-3500 J PER KG/ IS EXPECTED E/SE OF THE
COLD FRONT/DRYLINE TRIPLE POINT IN N TX...AS A RESULT OF UPPER 60S
BOUNDARY LAYER DEWPOINTS BENEATH 7-8 C/KM MIDLEVEL LAPSE RATES.

ADDITIONAL SEVERE THUNDERSTORM DEVELOPMENT IS LIKELY BY EARLY-MID
AFTERNOON NEAR THE TRIPLE POINT...WHERE THE STRONG INSTABILITY AND
EFFECTIVE BULK SHEAR IN EXCESS OF 50 KT WILL FAVOR SUPERCELLS WITH
VERY LARGE HAIL. THE BOUNDARY LAYER WILL BE SUFFICIENTLY MOIST AND
LOW-LEVEL SHEAR WILL BE SUFFICIENTLY STRONG /EFFECTIVE SRH OF
250-350 M2 PER S2/ TO SUPPORT THE RISK FOR A FEW STRONG TORNADOES
BEGINNING THIS AFTERNOON IN NE TX/SE OK...AND SPREADING INTO NW LA
AND CENTRAL/SRN AR LATER THIS EVENING AND CONTINUING INTO TONIGHT.

...NRN AR/SRN MO/IL THROUGH TONIGHT...
THE NRN EXTENT OF THE MORE SIGNIFICANT SEVERE THUNDERSTORM/TORNADO
THREAT IS QUITE UNCERTAIN GIVEN THE STABILIZING IMPACTS OF ONGOING
AND EXPECTED THUNDERSTORM CLUSTERS. AT THIS TIME...IT APPEARS THAT
THE NWD EXTENT OF THE STRONGER INSTABILITY WILL BE LIMITED BY
MULTIPLE THUNDERSTORM CLUSTERS AND CONVECTIVE OUTFLOWS...SUCH THAT
ONLY WEAK INSTABILITY IS LIKELY INVOF THE DEEPENING SURFACE CYCLONE
THIS EVENING INTO TONIGHT. DEEP-LAYER AND LOW-LEVEL VERTICAL SHEAR
WILL BE SUFFICIENT FOR ORGANIZED SEVERE STORMS...BUT THE WEAK
INSTABILITY AND WIDESPREAD CONVECTION FARTHER TO THE S WILL TEND TO
LIMIT THE OVERALL DAMAGING WIND AND TORNADO RISK THIS FAR N.

...ERN OH/PA THIS AFTERNOON/EVENING...
A LOW-AMPLITUDE SHORTWAVE TROUGH OVER THE LOWER OH RIVER THIS
MORNING WILL EJECT ENEWD TOWARD NE OH/NW PA BY THIS EVENING...AND
THIS WAVE WILL BE PRECEDED BY A WEAK SURFACE LOW ALONG A SLOW-MOVING
WARM FRONT THAT WILL DRIFT NWD ACROSS PA TODAY. THE FOCUS FOR
THUNDERSTORM DEVELOPMENT WILL BE BETTER DEFINED ACROSS ERN OH/NW PA
THIS AFTERNOON ALONG THE PATH OF THE WEAK WAVE...BUT THERE ARE SOME
CONCERNS REGARDING THE MAGNITUDE OF THE INSTABILITY BASED ON
LINGERING CLOUDS/RAIN. FARTHER E IN PA...SOMEWHAT RICHER LOW-LEVEL
MOISTURE AND STRONGER SURFACE HEATING ARE EXPECTED E OF THE
MOUNTAINS. HERE...THERE WILL BE NO CLEAR FOCUS FOR STORM
DEVELOPMENT ASIDE FROM THE WARM FRONT. IF STORMS DO FORM...VERTICAL
SHEAR AND INSTABILITY COULD SUPPORT SUPERCELLS WITH DAMAGING WINDS
AND SOME HAIL.

...TX PANHANDLE THIS AFTERNOON...
THERE WILL BE A NARROW WINDOW OF OPPORTUNITY FOR SURFACE-BASED
THUNDERSTORM DEVELOPMENT THIS AFTERNOON IN A NW-SE CORRIDOR ALONG
THE COLD FRONT...WITH THE MIDLEVEL TROUGH OVERHEAD. SURFACE HEATING
AND 500 MB TEMPERATURES NEAR -20 C COULD SUPPORT
HIGH-BASED/LOW-TOPPED STORMS ALONG THE FRONT. GIVEN COLD
TEMPERATURES ALOFT AND INVERTED-V PROFILES IN THE LOW LEVELS...HAIL
AND STRONG OUTFLOW WINDS WILL BE POSSIBLE WITH MARGINAL
SUPERCELL-TYPE STORMS.

..THOMPSON/COHEN.. 04/25/2011

CLICK TO GET WUUS01 PTSDY1 PRODUCT

NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
CURRENT UTC TIME: 1412Z (10:12AM), RELOAD THIS PAGE TO UPDATE THE TIME

[CrazyC83]

Tomorrow

SPC AC 250600

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT MON APR 25 2011

VALID 261200Z - 271200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS FAR NORTHEAST
TEXAS...SOUTHERN AND EASTERN ARKANSAS...WESTERN
TENNESSEE...NORTHWEST MISSISSIPPI...AND NORTHERN LOUISIANA...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS A LARGER PORTION OF THE
EASTERN U.S. FROM THE NORTHEAST/E COAST STATES TO THE LOWER MS
VALLEY/SRN PLAINS...

...SYNOPSIS...
VERY LARGE UPPER TROUGH WILL REMAIN IN PLACE OVER THE CENTRAL
CONUS...AS ONE SHORTER-WAVELENGTH FEATURE SHIFTS INTO THE GREAT
LAKES AND A SECOND DIGS SEWD OUT OF THE ROCKIES. A SURFACE
BAROCLINIC ZONE IS EXPECTED TO EXTEND FROM THE GREAT LAKES/OH VALLEY
SWWD INTO N TX...AND WILL SERVE AS A FOCUS FOR WIDESPREAD SEVERE
CONVECTION -- INCLUDING THE POSSIBILITY OF A LOCAL SEVERE WEATHER
OUTBREAK FOCUSED FROM THE ARKLATEX REGION INTO THE MID MS VALLEY
REGION.

...ARKLATEX REGION ENEWD INTO THE LOWER/MID MS VALLEY...
COMPLEX -- BUT POTENTIALLY SIGNIFICANT/DANGEROUS -- SEVERE WEATHER
EVENT IS UNFOLDING FOR THIS AREA FOR DAY 2 /TUE. AND EARLY WED./.
STORMS WILL LIKELY BE ONGOING AT THE START OF THE PERIOD...SHIFTING
EWD/ENEWD INTO THE OH/TN VALLEYS ALONG WITH ONGOING SEVERE
POTENTIAL.

GREATER SEVERE THREAT FOR THIS REGION HOWEVER WILL EVOLVE LATER IN
THE DAY...AS AN INITIAL SHORT-WAVE TROUGH DEPARTING NEWD IS FOLLOWED
BY A SECOND/DIGGING FEATURE SHIFTING QUICKLY SEWD OUT OF THE ROCKIES
AND INTO THE SRN PLAINS.

AS THIS OCCURS...BACKING/INTENSIFYING LOW-LEVEL FLOW FIELD IS
FORECAST...WITH A 70-PLUS KT LOW-LEVEL JET TO SHIFT EWD FROM NE TX
ACROSS AR/LA DURING THE EVENING...BENEATH MID-LEVEL WLYS INCREASING
TO 70 TO 80 KT.

AS THE UPPER SYSTEM APPROACHES...SURFACE CYCLOGENESIS WILL OCCUR
ALONG THE WARM FRONT...SHIFTING EWD ACROSS N TX AND AR TOWARD THE
MID MS VALLEY LATE. STORMS SHOULD INITIATE DURING THE AFTERNOON
ACROSS NE TX AND QUICKLY BECOME SUPERCELLULAR...WITH LARGE
HAIL...DAMAGING WINDS...AND TORNADOES EXPECTED. A SUBSTANTIAL
TORNADO THREAT APPEARS LIKELY TO EVOLVE -- SPREADING ACROSS NRN
LA/AR AND THEN INTO WRN TN/NWRN MS LATE. ALONG WITH TORNADO
POTENTIAL...DAMAGING WIND/LARGE HAIL THREAT WILL ALSO ACCOMPANY THE
STORMS THROUGH THE END OF THE PERIOD -- POSSIBLY EXTENDING AS FAR E
AS MIDDLE TN/NRN AR/NWRN GA BY 27/12Z.

...LOWER GREAT LAKES REGION/OH AND TN VALLEYS...
THUNDERSTORMS ONGOING AT THE START OF THE PERIOD WILL CONTINUE
SHIFTING NEWD ACROSS THE TN/OH VALLEYS AND INTO THE LOWER GREAT
LAKES REGION. THIS WILL OCCUR AS STRONG SHORT-WAVE TROUGH SHIFTS
ACROSS THIS AREA FOCUSING LARGE-SCALE UVV ALONG A SURFACE COLD FRONT
EXTENDING SWWD ACROSS THE MID MS VALLEY INTO TX. WHILE AFTERNOON
HEATING MAY BE HINDERED BY WIDESPREAD PRECIPITATION/CLOUD
COVER...LOCAL AREAS OF GREATER DESTABILIZATION WILL SUPPORT
AFTERNOON INCREASE IN STORM COVERAGE AND INTENSITY -- AS FAR NE AS
PA AND NY NEAR THE SURFACE WARM FRONT.

WITH A STRONG SWLY FLOW FIELD ALOFT ACROSS THIS ENTIRE AREA
/LOW-LEVEL FLOW INCREASING FROM 50 TO 65 KT IN THE 850 TO 500 MB
LAYER/...SHEAR WILL SUPPORT ORGANIZED/ROTATING STORMS...ALONG WITH
LINEAR/BOWING SEGMENTS. ALONG WITH SOME THREAT FOR HAIL...DAMAGING
WINDS WILL BE LIKELY ALONG WITH THE POTENTIAL FOR ISOLATED
TORNADOES. THE THREAT SHOULD SPREAD EWD WITH TIME AS THE FRONT
SLOWLY ADVANCES...WITH SOME THREAT LIKELY LINGERING INTO THE
OVERNIGHT HOURS INTO NY/PA/WV.

...CAROLINAS/VA...
WEAK SHORT-WAVE FEATURES SHIFTING NEWD ACROSS THIS REGION --
EMBEDDED WITHIN CYCLONIC FLOW FIELD AHEAD ON THE ERN FRINGE OF THE
LARGE CENTRAL U.S. TROUGH -- WILL SUPPORT A BROAD ZONE OF AFTERNOON
THUNDERSTORM DEVELOPMENT ACROSS THIS AREA. WITH HEATING OF THE
MOIST BOUNDARY LAYER AIRMASS OCCURING THROUGH THE DAY...INSTABILITY
WILL BECOME SUFFICIENT -- IN CONJUNCTION WITH MODERATE/VEERING FLOW
WITH HEIGHT -- TO SUPPORT ORGANIZED/LOCALLY SEVERE
STORMS...INCLUDING THREATS FOR HAIL AND DAMAGING WINDS...AND AN
ISOLATED TORNADO. WITHOUT A CLEAR LOW-LEVEL FOCUSING
MECHANISM...WITH MAINTAIN ONLY 15%/SLIGHT RISK FORECAST ATTM --
GIVEN THE BROAD/UNFOCUSED THREAT AREA.

..GOSS.. 04/25/2011

CLICK TO GET WUUS02 PTSDY2 PRODUCT

NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
CURRENT UTC TIME: 1412Z (10:12AM), RELOAD THIS PAGE TO UPDATE THE TIME