Mesoscale Discussion 571

Issued

Apr 25, 2011, 1:28 PM CDT (18:28 UTC)

Expired

Apr 25, 2011, 3:00 PM CDT

In force

92 min

Issued by

the Storm Prediction Center

The Dallas/Ft Worth radar (KFWS), 171 km from the middle of the area, began a volume at 18:27 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

• Tornado Watch 205Apr 25, 3:25 PM CDT

835 
ACUS11 KWNS 251829
SWOMCD
SPC MCD 251828
ARZ000-TXZ000-OKZ000-252000-

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

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

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

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

Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Oklahoma, 2011Mesoscale Discussions in Arkansas, 2011Every mesoscale discussion in 2011

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.