Mesoscale Discussion 535

Issued

Apr 23, 2011, 12:56 PM CDT (17:56 UTC)

Expired

Apr 23, 2011, 2:00 PM CDT

In force

64 min

Issued by

the Storm Prediction Center

The Dallas/Ft Worth radar (KFWS), 73 km from the middle of the area, began a volume at 17:54 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.

• Severe Thunderstorm Watch 187Apr 23, 3:10 PM CDT

264 
ACUS11 KWNS 231756
SWOMCD
SPC MCD 231756 
OKZ000-TXZ000-231900-

MESOSCALE DISCUSSION 0535
NWS STORM PREDICTION CENTER NORMAN OK
1256 PM CDT SAT APR 23 2011

AREAS AFFECTED...EXTREME SRN OK...CNTRL/NRN TX

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 231756Z - 231900Z

TSTMS WILL INITIATE 19-22Z FROM EXTREME SRN OK INTO NRN AND PERHAPS
CNTRL TX.  SUPERCELLS WITH VERY LARGE HAIL...DAMAGING WIND GUSTS AND
A COUPLE TORNADOES WILL BE POSSIBLE LATE AFTN/EARLY EVENING. 
TRANSITION TO CLUSTERS/BOWS POSSIBLE MID-LATE EVENING.  WEATHER
WATCH ISSUANCE THROUGH LATE AFTERNOON OVER PARTS OF THE REGION IS
LIKELY...GREATER THAN 70 PERCENT PROBABILITY.

17Z MESOANALYSIS PLACES A LOW OVER WRN N TX WITH A COLD FRONT NEWD
THROUGH SERN OK AND SWWD TO THE CNTRL EDWARDS PLATEAU.  A
PRE-DRYLINE CONFLUENCE EXISTS FROM NEAR KSJT NEWD TO WEST OF KABI
WHERE IT INTERSECTS THE COLD FRONT.  

HIGH PLAINS PROFILERS/WATER VAPOR SUGGESTS THAT A WEAK
MID/UPPER-LEVEL SHORTWAVE TROUGH WAS EJECTING NEWD THROUGH W TX
EARLY THIS AFTERNOON.  ASCENT ASSOCIATED WITH THIS FEATURE WILL
ENCROACH OK/N TX THROUGH EVENING.  WARM SECTOR HAS BEEN
DESTABILIZING...ALBEIT CAPPED SO FAR.  BUT...AS TEMPERATURES CLIMB
INTO THE MID-UPR 80S...EML WILL WEAKEN AND SET THE STAGE FOR STORM
INITIATION.  IN FACT...TCU FIELD APPEARS TO BE SPROUTING OVER WRN N
TX E OF THE SFC LOW/TROUGH AND S OF THE COLD FRONT AS OF 1750Z.

VERTICAL SHEAR PROFILES WILL BE SOMEWHAT ON THE LOWER-END OF THE
SUPERCELL SPECTRUM...BUT THE VERY STEEP MID-LEVEL LAPSE RATES OF 8
DEG C PER KM WILL COMPENSATE AND VIGOROUS ROTATING STORMS ARE
POSSIBLE FOR A COUPLE HOURS AFTER INITIATION.  THEREAFTER...STORMS
WILL LIKELY EVOLVE INTO CLUSTERS/BOWS AS THEY MOVE SLOWLY ESE ACROSS
N/CNTRL TX AND FAR SE OK.  SUPERCELLS WILL HAVE POTENTIAL FOR VERY
LARGE HAIL.  A COUPLE OF TORNADOES ARE POSSIBLE...PARTICULARLY
NCNTRL/NERN TX AND FAR SERN OK WHERE STRONGER SLY LOW-LEVEL FLOW IS
EXPECTED.  

HIGHER PROBABILITIES FOR STORMS WILL EXIST ACROSS NRN TX AND SRN
OK...WITH MORE ISOLATED ACTIVITY FARTHER S THROUGH THE TX BIG
COUNTRY/CONCHO VALLEY.

..RACY.. 04/23/2011

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

ATTN...WFO...SHV...TSA...FWD...OUN...SJT...

LAT...LON   31849999 32509991 33079979 33599953 33919858 34239750
            34309687 34399597 34669517 34659487 34389484 34079520
            33459572 32749685 32039820 31139903 30839991 30860040
            31849999

Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Oklahoma, 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.