Significant Severe Weather Outbreak Possible 04/26-30/2014

[Cyclenall]

That's the Vilonia tornado, classic monster.

There is a confirmed tornado near Jackson AR again, this supercell is in command.

[RL3AO]

Storms starting to fire along the boundary in Eastern OK.

[EF-5bigj]

That thing is still going...

[Cyclenall]

There is a tornado on the ground in Tuckerman AR right now.

[RL3AO]

...TORNADO EMERGENCY FOR SWIFTON...

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHEASTERN JACKSON AND
EAST CENTRAL INDEPENDENCE COUNTIES UNTIL 945 PM CDT...

AT 926 PM CDT...STORM SPOTTERS AND NATIONAL WEATHER SERVICE
METEOROLOGISTS WERE TRACKING A CONFIRMED TORNADO WITH REPORTS OF
DAMAGE. THIS POTENTIALLY DEADLY TORNADO WAS LOCATED 3 MILES
NORTHWEST OF TUCKERMAN...OR 9 MILES NORTH OF NEWPORT...MOVING
NORTHEAST AT 40 MPH.

THIS IS A TORNADO EMERGENCY FOR SWIFTON. TAKE COVER NOW.

[Cyclenall]

Look at that...

[CrazyC83]

Late special update removed the High Risk based on 00Z models. Some models don't redevelop the storms (but others do).

SPC AC 280232

DAY 1 CONVECTIVE OUTLOOK AMEND 1
NWS STORM PREDICTION CENTER NORMAN OK
0932 PM CDT SUN APR 27 2014

VALID 280230Z - 291200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER MUCH OF AR AND VICINITY...

...THERE IS A SLGT RISK OF SVR TSTMS ARCING FROM ERN NEB/IA SWD TO
NERN TX/NRN LA/MS...

AMENDED TO REMOVE THE MODERATE RISK FROM MOST OF MISSOURI...AND THE
HIGH RISK FROM ARKANSAS

...SUMMARY...
STRONG TO SEVERE THUNDERSTORMS WILL CONTINUE TO AFFECT AREAS FROM
THE MID MISSOURI VALLEY SOUTHEASTWARD AND SOUTHWARD ACROSS THE LOWER
MISSOURI AND MID MISSISSIPPI VALLEY AND OZARKS REGION INTO PARTS OR
EASTERN TEXAS AND NORTHERN LOUISIANA. THE AREA WHERE THE GREATEST
RISK FOR SEVERE WEATHER -- INCLUDING POTENTIAL FOR A COUPLE OF
STRONG TORNADOES -- WILL REMAIN CENTERED ON THE ARKANSAS VICINITY.

...MO/AR AND VICINITY...
SEVERE THUNDERSTORM RISK ACROSS WESTERN MISSOURI HAS DIMINISHED OVER
THE PAST 1-2 HOURS...AS CONVECTION HAS LARGELY MOVED EAST OF THE
NARROW AXIS OF GREATER INSTABILITY NEAR THE KS/MO BORDER.
MARGINALLY SEVERE HAIL AND LOCALLY GUSTY WINDS WILL REMAIN POSSIBLE
ACROSS NORTHERN MO AND NWD INTO IA AND POSSIBLY ERN NEB....BUT
GREATEST SEVERE RISK SHOULD REMAIN CONFINED TO AREAS FARTHER SOUTH
INCLUDING SWRN MO AND INTO AR AND VICINITY.

WHILE ONGOING STRONG/SEVERE STORMS CONTINUE MOVING ACROSS NORTHEAST
AR INTO SERN MO AND VICINITY...CONVECTION IS REDEVELOPING ACROSS ERN
OK. IN ADDITION..HIGH-RES MODEL FORECASTS SUGGEST POTENTIAL FOR
ADDITIONAL DEVELOPMENT FROM ERN OK/AR SWD INTO PARTS OF E TX AND LA
OVERNIGHT. GIVEN THE DEGREE OF INSTABILITY AND SHEAR ACROSS THIS
REGION...ANY CONVECTIVE REDEVELOPMENT WILL BE ACCOMPANIED BY THE
RISK FOR ISOLATED TORNADOES ALONG WITH LARGE HAIL AND DAMAGING
WINDS.

...IA/IL/WRN KY/WRN TN/MS...
WIDESPREAD -- BUT PRIMARILY ELEVATED -- STORMS ARE EXPECTED TO
CONTINUE IN AN ARC ALONG AND E OF THE MS VALLEY TONIGHT...AS A
LOW-LEVEL JET INCREASES/VEERS WITH TIME. ALONG WITH RISK FOR A FEW
STRONGER WIND GUSTS...HAIL IS EXPECTED WITH THE STRONGER STORMS AS
CONVECTION SHIFTS ACROSS THIS AREA THIS EVENING/OVERNIGHT.

..GOSS.. 04/28/2014

CLICK TO GET WUUS01 PTSDY1 PRODUCT

NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
CURRENT UTC TIME: 0248Z (10:48PM), RELOAD THIS PAGE TO UPDATE THE TIME

[CrazyC83]

6 confirmed dead in Faulkner County, AR (7 total in Arkansas).

[SeGaBob]

That is really bad...

[aggiecutter]

Tornado damage from Mayflower, Arkansas from Jeff Piotrowski:
http://telly.com/1J4VE7S

[cycloneye]

BREAKING: 6 confirmed dead in Vilonia and Mayflower, 3 dead in Pulaski County, and 1 reported dead in White County (El Paso, AR).

[CrazyC83]

MESOSCALE DISCUSSION 0440
NWS STORM PREDICTION CENTER NORMAN OK
0959 PM CDT SUN APR 27 2014

AREAS AFFECTED...PORTIONS OF ARKANSAS...FAR EASTERN OKLAHOMA...FAR
NORTHEAST TEXAS

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

VALID 280259Z - 280430Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...A NEW TORNADO WATCH WILL LIKELY BE ISSUED PRIOR TO 0400Z.

DISCUSSION...WITH MODERATELY TO STRONGLY UNSTABLE AIR CONTINUING TO
RESIDE OVER THE AREA -- TO THE E OF A SYNOPTIC STATIONARY BOUNDARY
AND INTERSECTING DRYLINE -- AND WITH A MID-LEVEL VORT MAX PIVOTING
THROUGH THE SRN SEMICIRCLE OF A DEEP CNTRL-CONUS CYCLONE PER WATER
VAPOR IMAGERY...SEVERE THUNDERSTORM RE-DEVELOPMENT WILL REMAIN
POSSIBLE THROUGH THE NIGHT. A QLCS FROM NEAR FORT SMITH AR TO
MCCURTAIN COUNTY OK MAY BE THE MANIFESTATION OF THE STRONGER DEEP
ASCENT OVERTAKING THE WRN PERIPHERY OF THE MORE UNSTABLE AIR...AND
THIS ACTIVITY IS EXPECTED TO SUPPORT A SVR RISK AS IT ENTERS/CROSSES
AR. ADDITIONAL CONVECTION MAY ALSO DEVELOP AHEAD OF THIS ACTIVITY
AND TO ITS S...WHILE UNSTABLE CONDITIONS SPREAD NEWD IN THE WAKE OF
A RETREATING WARM FRONT DRAPED ACROSS CNTRL/NRN AR. MLCAPE AROUND
1000-2000 J/KG AMIDST 45-65 KT OF EFFECTIVE BULK SHEAR WILL SUPPORT
PERSISTENT/SUSTAINED UPDRAFTS WITH LARGE HAIL AND DAMAGING WINDS.
STRONG LOW-LEVEL SHEAR SAMPLED BY AREA VWPS WILL CONTINUE TO
MAINTAIN A RISK FOR TORNADOES.

..COHEN/HART.. 04/28/2014


ATTN...WFO...LZK...SHV...TSA...

LAT...LON 34979451 35899387 36079223 35389140 33909169 33119264
32969395 33489464 34979451

[CrazyC83]

As for tomorrow, how high does the SPC go? I would say leave it at MDT initially, with mention of a HIGH upgrade. 15H tornado focused on MS and north AL.

[CrazyC83]

SEL4

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 104
NWS STORM PREDICTION CENTER NORMAN OK
1035 PM CDT SUN APR 27 2014

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF
CENTRAL ARKANSAS

* EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 1035 PM
UNTIL 600 AM CDT.

* PRIMARY THREATS INCLUDE...
A FEW TORNADOES POSSIBLE
SCATTERED LARGE HAIL AND ISOLATED VERY LARGE HAIL EVENTS TO 2
INCHES IN DIAMETER POSSIBLE
SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 25 MILES SOUTH OF FORT SMITH
ARKANSAS TO 55 MILES EAST NORTHEAST OF PINE BLUFF ARKANSAS. FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU4).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 100...WW 102...WW 103...

DISCUSSION...THUNDERSTORMS ALONG THE OK/AR BORDER WILL SPREAD
EASTWARD ACROSS THE WATCH AREA OVERNIGHT. THE MAIN UPPER SYSTEM
WILL OVERSPREAD THIS REGION DURING THE OVERNIGHT
PERIOD...MAINTAINING THE RISK OF LARGE HAIL...DAMAGING WINDS...AND A
FEW 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

[CrazyC83]

MESOSCALE DISCUSSION 0441
NWS STORM PREDICTION CENTER NORMAN OK
1045 PM CDT SUN APR 27 2014

AREAS AFFECTED...PORTIONS OF EASTERN TX...WRN LA...FAR SWRN AR

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 280345Z - 280545Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...THE AREA IS BEING MONITORED FOR THE POSSIBILITY OF AN
INCREASING SEVERE THUNDERSTORM RISK OVERNIGHT TONIGHT...AND FOR
POSSIBLE WW ISSUANCE.

DISCUSSION...WATER VAPOR LOOPS IMPLY THAT MID-LEVEL ASCENT IS
OVERTAKING MOIST/STRONGLY UNSTABLE AIR E OF A WAVY DRYLINE ANALYZED
FROM ERN PARTS OF THE DFW METROPLEX TO WACO TO THE LOWER RIO GRANDE
VALLEY. IR IMAGERY DEPICTS ACCAS DEVELOPMENT OVER N-CNTRL TX FROM
WHICH COMPOSITE RADAR LOOPS SUGGEST CONVECTION BEGINNING TO BLOSSOM
NEAR/E OF THE DRYLINE. STRENGTHENING DEEP ASCENT AND ASSOCIATED
MID-LEVEL COOLING MAY OFFSET NOCTURNAL STABILIZATION TO ENCOURAGE
CONVECTIVE DEVELOPMENT INTO THE OVERNIGHT HOURS. WITH MLCAPE AROUND
2500-4000 J/KG OVERLAPPING WITH 45-70 KT OF EFFECTIVE BULK
SHEAR...INTENSE/SUSTAINED UPDRAFTS SUPPORTING LARGE HAIL AND
DAMAGING WINDS MAY ENSUE. CONVECTION COULD EVOLVE INTO QLCS SEGMENTS
PERHAPS SUPPORTING A GREATER DMGG WIND RISK. GIVEN 30-40 KT OF
0-1-KM BULK SHEAR PER VWP DATA...A TORNADO POTENTIAL WILL EXIST.

..COHEN/HART.. 04/28/2014


ATTN...WFO...LCH...SHV...HGX...FWD...

LAT...LON 31299709 32469662 33719580 33029341 30909348 30209608
31299709

[Alyono]

what NOT to do in a violent tornado

[HurricaneBill]

From the SPC Storm Reports page:

0050 VILONIA FAULKNER AR 3508 9221 TWO HOUSES ON CEMETARY ROAD HAVE BEEN WIPED CLEAN TO THE FOUNDATION. (LZK)

[CrazyC83]

SEL5

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 105
NWS STORM PREDICTION CENTER NORMAN OK
1110 PM CDT SUN APR 27 2014

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF
SOUTHWEST ARKANSAS
NORTHWEST LOUISIANA
EXTREME SOUTHEAST OKLAHOMA
NORTHEAST TEXAS

* EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 1110 PM
UNTIL 500 AM CDT.

* PRIMARY THREATS INCLUDE...
A COUPLE TORNADOES POSSIBLE
SCATTERED LARGE HAIL AND ISOLATED VERY LARGE HAIL EVENTS TO 2
INCHES IN DIAMETER POSSIBLE
SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 45 MILES NORTH NORTHEAST OF
TEXARKANA ARKANSAS TO 60 MILES SOUTH SOUTHEAST OF CORSICANA
TEXAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 102...WW 103...WW 104...

DISCUSSION...THUNDERSTORMS ARE RAPIDLY DEVELOPING ALONG THE SURFACE
DRYLINE FROM SOUTHEAST OK INTO NORTHEAST TX. THESE STORMS ARE
EXPECTED TO INTENSIFY AND SPREAD ACROSS THE WATCH AREA THROUGH THE
OVERNIGHT PERIOD. LARGE HAIL AND DAMAGING WINDS ARE THE MAIN
THREATS. HOWEVER...STRONG LOW LEVEL VERTICAL SHEAR MAY BE
SUFFICIENT FOR ISOLATED TORNADOES AS WELL.

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 25035.


...HART

[CrazyC83]

If that is true, construction standards are key. That is an EF-5 indicator IF they are very strongly built. But are they? I'm skeptical.

[Alyono]

If that is true, construction standards are key. That is an EF-5 indicator IF they are very strongly built. But are they? I'm skeptical.

and that is a TERRIBLE way to estimate winds. By including construction standards, you are finding the LEAST POSSIBLE WIND, not the MAX WINDS, which is how a tornado is supposed to be rated.

This is one major beef I have with the engineering community... they are finding wind speeds that the meteorological community is not interested in (it is important what they are doing for building codes and the like). However, their findings should be used with extreme caution in extreme winds as they will inherently underestimate high winds due to their methodology