SPC MD 1801

MD 1801 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR WRN KS / OK PANHANDLE / NRN TX PANHANDLE


MESOSCALE DISCUSSION 1801
NWS STORM PREDICTION CENTER NORMAN OK
0320 PM CDT THU AUG 23 2012

AREAS AFFECTED...WRN KS / OK PANHANDLE / NRN TX PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 232020Z - 232115Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...ISOLD STRONG-SEVERE STORMS ARE EXPECTED TO DEVELOP LATER
THIS AFTERNOON THROUGH THE EVENING HOURS.  A SEVERE WATCH IS BEING
CONSIDERED FOR PORTIONS OF NWRN AND WRN KS WHERE THE GREATEST THREAT
IS ANTICIPATED.

DISCUSSION...LATEST SURFACE MESOANALYSIS PLACES A LOW INVOF THE
CO/KS BORDER WITH A WEAK FRONT ARCING FROM NWRN KS SWWD INTO SERN
CO.  A LOW LEVEL CONFLUENCE AXIS/SURFACE TROUGH EXTENDS SWD FROM THE
LOW INTO THE NWRN TX PANHANDLE WITH AN INVERTED TROUGH EXTENDING
NEWD FROM NWRN KS THRU NERN NEB.  VISIBLE SATELLITE IMAGERY SHOWS A
SLOW TO DISSIPATE CLOUD SHIELD FROM FAR NRN KS NWD...ACTING TO
PROMOTE A DIFFERENTIAL HEATING ZONE ON THE S-END OF THE CLOUD
SHIELD.  A BOUNDARY LAYER CU FIELD HAS RECENTLY DEVELOPED OVER NWRN
KS DURING THE PAST HR.

DESPITE AN ABSENCE OF STRONG UPPER LEVEL FORCING ACROSS THE
AREA...WEAK LOW LEVEL CONFLUENCE INVOF THE AFOREMENTIONED
BOUNDARIES/SURFACE LOW...ALONG WITH CONTINUED HEATING ARE ACTING TO
WEAKEN THE CAP AND FURTHER DESTABILIZE THE AIRMASS.  A PLUME OF
GREATER MOISTURE /CHARACTERIZED BY LOWER 60S DEG F DEWPOINTS/ WITH
TEMPS NEAR 90 ARE CONTRIBUTING TO A STRONGLY UNSTABLE AIRMASS
/1500-2000 J/KG MLCAPE/ PER RAP SOUNDINGS.  FURTHERMORE...25 KT WLY
MID-LEVEL FLOW /GLD VAD/ WILL ACT TO FAVOR ORGANIZED
MULTICELLS...POSING AN ISOLD LARGE HAIL/SEVERE WIND GUST RISK.  THE
SEVERE RISK WILL PROBABLY LINGER WELL INTO THE EVENING HOURS...AS
STORM COVERAGE WILL LIKELY INCREASE DURING THE EVENING COINCIDENT
WITH THE ONSET OF A 40 KT LLJ.

..SMITH/MEAD.. 08/23/2012

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

ATTN...WFO...GID...DDC...GLD...AMA...PUB...

LAT...LON   38529936 36120110 36410228 39450161 40089962 38529936

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