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

[CrazyC83]

MESOSCALE DISCUSSION 0571
NWS STORM PREDICTION CENTER NORMAN OK
0128 PM CDT MON APR 25 2011

AREAS AFFECTED...NORTH-CENTRAL/NORTHEAST TX AND EASTERN OK TO
AR/NORTHWEST LA

CONCERNING...TORNADO WATCH 201...

VALID 251828Z - 252000Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 201 CONTINUES.

TORNADO WATCH 201 CONTINUES UNTIL 23Z...WITH A RISK OF
TORNADOES/LARGE HAIL AND DAMAGING WINDS.

A NUMBER OF STRONG/SEVERE TSTMS...WITH A COMPLEX CONVECTIVE
MODE...CONTINUE TO OCCUR WITHIN A CORRIDOR OF PRE-FRONTAL CONFLUENCE
FROM NORTHEAST TX INTO SOUTHEAST OK/FAR WESTERN AR...WITH OTHER MORE
RECENT/SEPARATE DEVELOPMENT BEGINNING TO OCCUR FARTHER WEST NEAR THE
MERGING COLD FRONT/DRYLINE FORM SOUTH-CENTRAL OK INTO NORTH-CENTRAL
TX. IN THE WESTERNMOST PORTIONS OF TORNADO WATCH 201...VISIBLE
SATELLITE/SURFACE OBSERVATIONS REFLECT A NARROW CORRIDOR OF STRONGER
IMPLIED SURFACE BASED DESTABILIZATION READILY OCCURRING
ALONG/IMMEDIATELY AHEAD OF AND NEAR THE MERGING SOUTHEAST MOVING
COLD FRONT/EASTWARD ADVANCING DRYLINE. HERE...MODIFICATIONS OF THE
12Z DALLAS-FORT WORTH OBSERVED RAOB ARE NOW SUGGESTIVE OF 3500+ J/KG
OF WEAKLY CAPPED MLCAPE AMID UPPER 60S F SURFACE DEWPOINTS. WITH AN
INITIALLY MORE ISOLATED/SEMI-DISCRETE INITIATION EXPECTED...THESE
STORMS MAY PROVIDE THE MOST CONSEQUENTIAL TORNADO/VERY LARGE HAIL
THREAT THROUGH THE AFTERNOON ACROSS WW 201.

THAT SAID...ANY STORMS...AHEAD OF THE ENE-ADVANCING OK SURFACE LOW
AND ALONG/SOUTH OF THE WEST-EAST CONVECTIVELY REINFORCED BOUNDARY
FROM EAST-CENTRAL OK INTO CENTRAL AR...AND POINTS WEST-SOUTHWARD
INTO THE WARM SECTOR...MAY POSE A TORNADO THREAT WITH A RELATIVELY
RICH SRH ENVIRONMENT PER REGIONAL WSR-88D VWPS/PROFILERS.

WITH NORTH EXTENT...SURFACE BASED DESTABILIZATION REMAINS MORE
UNCERTAIN ACROSS NORTHEAST OK/NORTHERN AR OWING TO CONSIDERABLE
ONGOING CONVECTION...ALTHOUGH THESE AREAS WILL BE MONITORED FOR
BOUNDARY LAYER RECOVERY/DESTABILIZATION THROUGH THE AFTERNOON. IN
SPITE OF THE EXTENSIVE ONGOING CONVECTION...AT LEAST SOME NORTHWARD
ADVANCEMENT OF THE AFOREMENTIONED WEST-EAST BOUNDARY SEEMS PROBABLE
AHEAD OF THE SURFACE LOW THIS AFTERNOON/EARLY EVENING.

..GUYER.. 04/25/2011


ATTN...WFO...LZK...SHV...TSA...FWD...OUN...

LAT...LON 31939833 33529824 36149600 35749343 34259363 32439446
31939833

[CrazyC83]

FLASH FLOOD WARNING
ARC007-015-087-143-OKC001-021-035-041-091-097-101-107-111-115-131-
135-145-260000-
/O.NEW.KTSA.FF.W.0019.110425T1805Z-110426T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TULSA OK
105 PM CDT MON APR 25 2011

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
ADAIR COUNTY IN NORTHEAST OKLAHOMA...
BENTON COUNTY IN NORTHWEST ARKANSAS...
CARROLL COUNTY IN NORTHWEST ARKANSAS...
CHEROKEE COUNTY IN EAST CENTRAL OKLAHOMA...
DELAWARE COUNTY IN NORTHEAST OKLAHOMA...
EASTERN CRAIG COUNTY IN NORTHEAST OKLAHOMA...
EASTERN OKMULGEE COUNTY IN NORTHEAST OKLAHOMA...
EASTERN ROGERS COUNTY IN NORTHEAST OKLAHOMA...
MADISON COUNTY IN NORTHWEST ARKANSAS...
MAYES COUNTY IN NORTHEAST OKLAHOMA...
MCINTOSH COUNTY IN SOUTHEAST OKLAHOMA...
MUSKOGEE COUNTY IN EAST CENTRAL OKLAHOMA...
NORTHWESTERN SEQUOYAH COUNTY IN EAST CENTRAL OKLAHOMA...
OTTAWA COUNTY IN NORTHEAST OKLAHOMA...
SOUTHEASTERN OKFUSKEE COUNTY IN EAST CENTRAL OKLAHOMA...
WAGONER COUNTY IN NORTHEAST OKLAHOMA...
WASHINGTON COUNTY IN NORTHWEST ARKANSAS...

* UNTIL 700 PM CDT ...THIS EXTENDS THE TIME OF THE PREVIOUS WARNING.

* AT 1256 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR
INDICATED THUNDERSTORMS WITH VERY HEAVY RAIN OVER THE WARNED
AREA...ESPECIALLY FROM MCINTOSH COUNTY NORTHEAST TO
BENTON...WASHINGTON AND CARROLL COUNTIES IN NORTHWEST ARKANSAS. FIVE
TO 10 INCHES OF RAIN HAS FALLEN OVER THE LAST THREE DAYS. 1 TO 2
INCHES IS FALLING PER HOUR UNDER THE THUNDERSTORMS. VIRTUALLY ALL OF
THAT RAIN WILL BE RUNOFF INTO STREAMS AND LOW LYING AREAS. TWO TO
FOUR INCHES OF ADDITIONAL RAIN WILL BE POSSIBLE DURING THE
AFTERNOON...AS MORE THUNDERSTORMS ARE EXPECTED. HIGH WATER AND ROAD
CLOSINGS HAVE BEEN REPORTED FROM MANY PARTS OF THE AREA.

IN SOME AREAS...THE FLOODING IS BECOMING OR MAY BE CATASTROPHIC.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT COULD EXPERIENCE FLOODING INCLUDE...
BENTONVILLE...BERRYVILLE...EUREKA SPRINGS...FAYETTEVILLE...
HUNTSVILLE...JAY...MIAMI...MUSKOGEE...PRYOR...ROGERS...SILOAM
SPRINGS...SPRINGDALE...STILWELL...TAHLEQUAH...VINITA...WAGONER...
ADAIR...AFTON...ALPENA...AURORA...BALD HILL...BARON...BEAVER...
BELLA VISTA...BERNICE...BIG CABIN...BLACKBURN...BLUEJACKET...BOSTON
AND BOYNTON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE ROAD TO
UNKNOWN DEPTHS. IT ONLY TAKES TWO FEET OF RUSHING WATER TO CARRY AWAY
MOST SPORT UTILITY VEHICLES AND PICKUPS. TAKE A DIFFERENT ROUTE TO
REACH YOUR DESTINATION OR WAIT UNTIL THE WATER RECEDES. REMEMBER...
MOST FLOOD RELATED DEATHS OCCUR IN AUTOMOBILES.

&&

LAT...LON 3612 9346 3602 9342 3587 9351 3577 9351
3576 9448 3566 9448 3516 9597 3529 9598
3531 9613 3700 9506 3699 9461 3650 9461
3650 9329 3613 9328

$$

[ravyrn]

One thought: with the Mississippi rising so high, if it maintains itself, could it cause a Katrina-like flood in New Orleans?

While I assume anything is possible when it comes to weather, the Mississippi River in Louisiana has a couple spillways to divert water when needed. I was from SW Louisiana, but I did live a year or two in Baton Rouge. I know there are at least two spillways upstream from New Orleans. One is the Bonnet Carré Spillway which diverts water into Lake Pontchartrain. The other is the Morganza Spillway which is upstream from Baton Rouge, that would divert water into the Atchafalaya Basin.

It is more likely that the flooding would occur in the Atchafalaya Basin before it would in New Orleans. The Atchafalaya Basin is fairly rural though there are a few cities along the Atchafalaya River such as Krotz Springs, Melville, Simmesport, and the largest which is Morgan City.

[GCANE]

Tornado warned cell SW of Fort Worth.

Looks like possible hook forming.

44K-ft top



WWUS54 KFWD 251902
SVSFWD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
202 PM CDT MON APR 25 2011

TXC143-221-425-251945-
/O.CON.KFWD.TO.W.0023.000000T0000Z-110425T1945Z/
HOOD TX-ERATH TX-SOMERVELL TX-
202 PM CDT MON APR 25 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 245 PM CDT FOR
SOMERVELL...EAST CENTRAL ERATH AND SOUTHERN HOOD COUNTIES...

AT 202 PM CDT...STORM SPOTTERS AND DOPPLER RADAR OBSERVED A TORNADO.
THIS TORNADO WAS LOCATED 11 MILES WEST OF DINOSAUR VALLEY STATE
PARK...MOVING EAST AT 30 MPH. THIS IS A DANGEROUS SITUATION.

THE TORNADO WILL BE NEAR...
DINOSAUR VALLEY STATE PARK AROUND 220 PM CDT...
GLEN ROSE AROUND 230 PM CDT...

[GCANE]

Two chasers intercepting the cell SW of Ft Worth

http://weather.wdtinc.com/popout/index. ... 26&O=10195

http://weather.wdtinc.com/popout/index. ... 26&O=10194

[GCANE]

The cell SW of Ft Worth is moving into a high STP bulls-eye.

This could rapidly intensify.

[Texas Snowman]

Two chasers intercepting the cell SW of Ft Worth

http://weather.wdtinc.com/popout/index. ... 26&O=10195

http://weather.wdtinc.com/popout/index. ... 26&O=10194

WFAA-TV Channel 8 chaser confirmed touchdown of tornado in Hood County.

Video is on http://www.wfaa.com.

[Texas Snowman]

The cell SW of Ft Worth is moving into a high STP bulls-eye.

This could rapidly intensify.

Problem with that one is that it looks to me as if it may skirt the southern portion of the DFW Metroplex...

EDIT: Ok, on second glance, I was wrong. Looks like it will go just south of the DFW area...

[GCANE]

Two chasers intercepting the cell SW of Ft Worth

http://weather.wdtinc.com/popout/index. ... 26&O=10195

http://weather.wdtinc.com/popout/index. ... 26&O=10194

WFAA-TV Channel 8 chaser confirmed touchdown of tornado in Hood County.

Video is on http://www.wfaa.com.

Passiontwist is in great position

http://weather.wdtinc.com/popout/index. ... 26&O=10194

[Texas Snowman]

Tornado may have gone through Broken Bow, Okla. and caused damage.

This is from a tornado warned cell in western Arkansas at the moment:

weather.gov
National Weather Service

Watches, Warnings & Advisories
Local weather forecast by "City, St" or zip code
6 products issued by NWS for: 6 Miles NW De Queen, Helms Sevier County Airport AR
--------------------------------------------------------------------------------


Tornado Warning
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
231 PM CDT MON APR 25 2011

ARC061-133-OKC089-251945-
/O.CON.KSHV.TO.W.0019.000000T0000Z-110425T1945Z/
SEVIER AR-HOWARD AR-MCCURTAIN OK-
231 PM CDT MON APR 25 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 245 PM CDT FOR
MCCURTAIN...HOWARD AND SEVIER COUNTIES...

AT 226 PM CDT...USING DOPPLER RADAR...NATIONAL WEATHER SERVICE
METEOROLOGISTS CONTINUED TO DETECT A POSSIBLE TORNADO. THIS
POSSIBLE TORNADO WAS LOCATED 10 MILES SOUTHWEST OF GILLHAM...OR
7 MILES WEST OF DE QUEEN...MOVING EAST AT 55 MPH. REPORTS OF
WIDESPREAD DAMAGE ACROSS THE CITY OF BROKEN BOW HAS BEEN REPORTED
WITH THIS STORM.

EDIT: Sounds like a fair amount of damage, may have been straight line winds though.

[Texas Snowman]

Another tornado on the ground south of the Metroplex:

From WFAA.com:

3:08 p.m. Funnel has formed two miles east of Georges Creek looking directly east in Johnson County. It has touched down. - WFAA storm chaser Craig Curlee and Chief Meteorologist Pete Delkus

[Bunkertor]

MESOSCALE DISCUSSION 0574
NWS STORM PREDICTION CENTER NORMAN OK
0308 PM CDT MON APR 25 2011

AREAS AFFECTED...MUCH OF AR/NORTHERN LA

CONCERNING...SEVERE POTENTIAL...WATCH NEEDED SOON

VALID 252008Z - 252045Z

AN ADDITIONAL TORNADO WATCH WILL BE ISSUED SOON FOR NORTHERN/CENTRAL
PORTIONS OF AR AND NORTHERN LA.

THE AIRMASS CONTINUES TO DESTABILIZE ALONG/SOUTH OF A MODIFYING
WEST-EAST OUTFLOW BOUNDARY ACROSS AR AMID A REGIONAL OF STRONG
SURFACE PRESSURE FALLS...WITH ADDITIONAL DESTABILIZATION /ALBEIT
MODEST/ EXPECTED INTO NORTHERN AR AS THE AFOREMENTIONED BOUNDARY
MIXES/SHIFTS NORTHWARD AS AN EFFECTIVE WARM FRONT. AS SAMPLED BY THE
18Z LITTLE ROCK OBSERVED RAOB...STRONG SHEAR WILL CONTINUE TO
SUPPORT A THREAT FOR TORNADOES /PERHAPS SOME STRONG/...IN ADDITION
TO SEVERE HAIL/DAMAGING WINDS.

..GUYER.. 04/25/2011

[CrazyC83]

I leave for a couple hours and all heck breaks loose.

[CrazyC83]

PDS watch. Probs are 90/60.

SEL5

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 205
NWS STORM PREDICTION CENTER NORMAN OK
325 PM CDT MON APR 25 2011

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

MUCH OF ARKANSAS
NORTHERN LOUISIANA
SOUTH CENTRAL MISSOURI
EXTREME SOUTHEAST OKLAHOMA
NORTHEAST TEXAS

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 325 PM UNTIL
1100 PM CDT.

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

DESTRUCTIVE TORNADOES...LARGE HAIL TO 2.5 INCHES IN DIAMETER...
THUNDERSTORM WIND GUSTS TO 80 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 15 MILES NORTH OF WEST PLAINS
MISSOURI TO 30 MILES SOUTHWEST OF SHREVEPORT LOUISIANA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU5).

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 201...WW 202...WW
203...WW 204...

DISCUSSION...NUMEROUS STRONG/SUPERCELL THUNDERSTORMS ARE NOW
AFFECTING PORTIONS OF NORTHEAST TX/SOUTHEAST OK INTO WESTERN AR.
FAVORABLE AND INTENSIFYING LOW LEVEL WIND FIELDS...COUPLED WITH A
RAPIDLY DESTABILIZING AIR MASS WILL SUPPORT A RISK OF TORNADOES
/SOME STRONG/ AS WELL AS VERY LARGE HAIL AND DAMAGING WINDS THROUGH
MUCH OF THE EVENING.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 25035.


...HART

[GCANE]

Very strong helicity in AR.

Hodo is current RUC, mid AR.

[CrazyC83]

On the other side...two CEM's

ARC143-252300-

BULLETIN - EAS ACTIVATION REQUESTED
CIVIL EMERGENCY MESSAGE
RELAYED BY NATIONAL WEATHER SERVICE TULSA OK
309 PM CDT MON APR 25 2011

THE FOLLOWING MESSAGE IS TRANSMITTED AT THE REQUEST OF WASHINGTON
COUNTY ARKANSAS EMERGENCY MANAGEMENT.

WASHINGTON COUNTY EMERGENCY MANAGEMENT IS DISCOURAGING TRAVEL
THROUGHOUT AND INTO THE COUNTY. CATASTROPHIC FLOODING IS OCCURRING
ACROSS MUCH OF THE COUNTY. MANY ROADS ARE FLOODED AND
IMPASSABLE...AND NUMEROUS WATER RESCUES ARE IN PROGRESS.

$$
--------------------------------------------------------------------------------
OKC001-252300-

BULLETIN - EAS ACTIVATION REQUESTED
CIVIL EMERGENCY MESSAGE
RELAYED BY NATIONAL WEATHER SERVICE TULSA OK
245 PM CDT MON APR 25 2011

THE FOLLOWING MESSAGE IS TRANSMITTED AT THE REQUEST OF THE ADAIR
COUNTY EMERGENCY MANAGEMENT.

ADAIR COUNTY EMERGENCY MANAGEMENT IS DISCOURAGING TRAVEL ACROSS
AND INTO THE COUNTY. CATASTROPHIC FLOODING IS OCCURRING ACROSS A
LARGE PORTION OF ADAIR COUNTY...AND MANY ROADS ARE IMPASSABLE AT
THIS TIME.

$$

[Texas Snowman]

WFAA.com live streaming - Itasca, Texas fire department reports a tornado touchdown.

This storm has cycled up and down with multiple touchdowns, some damage, and plenty of funnels.

[Texas Snowman]

From NWS Tulsa:

12 TO 14 INCHES OF TOTAL RAIN HAS FALLEN IN PORTIONS OF ADAIR AND
WASHINGTON COUNTY...AND ALSO EASTERN BENTON AND FAR WESTERN CARROLL
COUNTIES IN ARKANSAS. MANY ROADS ARE CLOSED...AND FLOOD WATERS ARE
RISING INTO HOMES IN SOME AREAS.

[CrazyC83]

MESOSCALE DISCUSSION 0575
NWS STORM PREDICTION CENTER NORMAN OK
0434 PM CDT MON APR 25 2011

AREAS AFFECTED...PORTIONS NRN MS...ERN AR...WRN TN...SERN MO...SRN
IL...EXTREME SWRN INDIANA...EXTREME WRN KY.

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 252134Z - 252230Z

ANOTHER WW IS LIKELY ACROSS MS VALLEY REGION E AND NE OF WW 205.

SVR TSTMS OVER NERN PORTIONS AR IN WW 205 MAY BE MAINTAINED AS THEY
MOVE NEWD INTO DESTABILIZING AIR MASS OVER THIS REGION. MAIN
UNCERTAINTY INVOLVES NRN EXTENT OF FAVORABLE/SFC-BASED EFFECTIVE
INFLOW...GIVEN ROBUST STRENGTH OF COLD POOL OVER MO OZARKS AND
LIMITED TIME FOR DESTABILIZATION TO ITS E. SFC MESOANALYSIS SHOWED
SRN EDGE OF THAT COLD POOL FROM NEAR FLP NEWD ACROSS CARTER COUNTY
MO THEN NWD TOWARD SWRN FRINGES STL AREA...E OF WHICH 3-4 MB/2-HOUR
FALLS ARE FOCUSED ACROSS SERN MO/NERN AR REGION. THIS TENDENCY IS
CONSISTENT WITH SFC LOW SHIFT/DEVELOPMENT NEWD INTO REGION...WHILE
RELATED ISALLOBARIC FORCING WILL MAINTAIN BACKED NEAR-SFC WINDS AND
ENLARGED LOW-LEVEL HODOGRAPHS FAVORABLE FOR SUPERCELLS/TORNADO
POTENTIAL. DEEP-LAYER SHEAR WILL REMAIN SUITABLE ALSO...WITH
EFFECTIVE SHEAR MAGNITUDES AROUND 45-55 KT. OUTFLOW BOUNDARY...N OF
WHICH HODOGRAPHS ARE FURTHER ENLARGED...WAS ANALYZED FROM WRN KY MCS
SWWD ACROSS MEM AREA THEN NWWD OVER NERN AR. HOWEVER...SFC DIABATIC
HEATING IS DESTABILIZING AIR MASS TO ITS N SUCH THAT 500-1500 MLCAPE
MAY DEVELOP ACROSS SERN MO INTO SRN IL AND WRN KY BEFORE SUNSET.
WAA WILL MAINTAIN FAVORABLE BUOYANCY IN PRE-STORM ENVIRONMENT.

..EDWARDS.. 04/25/2011


ATTN...WFO...OHX...PAH...MEG...JAN...LSX...LZK...

LAT...LON 35319163 37059086 38158966 38228882 38158778 37468767
35638842 34088901 33879075 34299180 35319163

[CrazyC83]

New watch coming out.