[MCD] SWOMCD

Mon Mar 20 18:45:12 UTC 2006

ACUS11 KWNS 201847
SWOMCD
SPC MCD 201847 
OKZ000-TXZ000-202015-

MESOSCALE DISCUSSION 0332
NWS STORM PREDICTION CENTER NORMAN OK
1247 PM CST MON MAR 20 2006

AREAS AFFECTED...SWRN OK / NWRN TX

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 201847Z - 202015Z

TSTM DEVELOPMENT IS EXPECTED TO BECOME INCREASINGLY LIKELY BY MID
AFTERNOON /20-21Z/ ACROSS DISCUSSION AREA.  IT APPEARS THAT ISOLATED
LARGE HAIL WILL BE THE PRIMARY SEVERE WEATHER THREAT WITH THE MOST
INTENSE STORMS.

AS OF 18Z...MESOANALYSIS INDICATED PRIMARY SURFACE LOW OVER THE TX
PNHDL /N OF AMA/ WITH ATTENDANT WARM FRONT EXTENDING SEWD THROUGH
W-CNTRL OK INTO AND INTO FAR SWRN AR.  DEEPENING BOUNDARY-LAYER
MIXING HAS RESULTED IN THE EROSION OF LOW CLOUDINESS ACROSS NWRN TX
INTO SWRN OK...WHICH IN TURN HAS SUPPORTED INCREASED DIABATIC
HEATING AND A NWD MOVEMENT OF THIS WARM FRONT OVER THE PAST COUPLE
OF HOURS.  MOREOVER...THIS INSOLATION IN CONJUNCTION WITH COLD
MID-LEVEL TEMPERATURES ASSOCIATED WITH UPPER LOW OVER THE TX PNHDL
ARE CONTRIBUTING TO STEEPENING LAPSE RATES AND THE DEVELOPMENT OF
WEAK CONVECTIVE INSTABILITY FROM SWRN OK INTO WRN TX.

LATEST SHORT TERM MODEL GUIDANCE INDICATES THAT SURFACE LOW WILL
DEVELOP SEWD INTO SWRN OK LATER THIS AFTERNOON...ON CYCLONIC SIDE OF
100 KT MID-LEVEL JET STREAK ROTATING NEWD INTO THE ARKLATEX. 
CONTINUED HEATING/DESTABILIZATION AHEAD OF THIS LOW...COUPLED WITH
INCREASED LARGE-SCALE FORCING FOR ASCENT IS EXPECTED TO RESULT IN AN
INCREASE IN CONVECTIVE DEVELOPMENT BY MID AFTERNOON MAINLY ALONG AND
TO THE N OF THE RED RIVER.

WHILE SOME BACKING OF NEAR SURFACE WINDS WILL LIKELY OCCUR AHEAD OF
THIS LOW...IT APPEARS THAT THE RELATIVELY WEAK LOW-LEVEL SHEAR AND
MARGINAL LOW-LEVEL MOISTURE /I.E. DEWPOINTS IN THE 40S/ WILL
PRECLUDE A MORE SIGNIFICANT LOW-TOPPED SUPERCELL/TORNADO THREAT. 
HOWEVER...GIVEN THE STEEP LAPSE RATES...POTENTIAL WILL EXIST FOR
ISOLATED LARGE HAIL WITH THE MOST INTENSE STORMS.

..MEAD.. 03/20/2006

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

ATTN...WFO...FWD...OUN...LUB...AMA...

34970019 35440003 35459927 35209818 34789724 34049698
33699726 33589814 33869923 34289998 

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