SPC MD 1490

MD 1490 CONCERNING SEVERE THUNDERSTORM WATCH 437… FOR PORTIONS OF SRN MO…FAR SERN KS…A LARGE PART OF AR…SRN IL…SWRN INDIANA…WRN KY


MESOSCALE DISCUSSION 1490
NWS STORM PREDICTION CENTER NORMAN OK
0713 PM CDT TUE JUL 23 2013

AREAS AFFECTED...PORTIONS OF SRN MO...FAR SERN KS...A LARGE PART OF
AR...SRN IL...SWRN INDIANA...WRN KY

CONCERNING...SEVERE THUNDERSTORM WATCH 437...

VALID 240013Z - 240145Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 437
CONTINUES.

SUMMARY...THE SVR POTENTIAL CONTINUES ACROSS WW 437...AND ISOLATED
SVR STORMS MAY OCCUR FARTHER E ACROSS THE OHIO RIVER VALLEY.

DISCUSSION...CLUSTERS OF VIGOROUS CONVECTION CONTINUE NEAR AND S OF
A FRONTAL ZONE EXTENDING FROM SRN KS INTO SRN MO AND SRN IL/INDIANA.
WWD-MOVING OUTFLOW BOUNDARIES ARE EVIDENT ACROSS N-CNTRL AR AND
S-CNTRL MO...WITH NEW CONVECTIVE DEVELOPMENT ON THE COOL SIDE OF THE
BOUNDARIES. THESE BOUNDARIES MAY ALSO BOOST STORM INTENSITY AS THEY
INTERACT WITH SFC-BASED CONVECTION SHIFTING SEWD/SWD OVER NWRN AR.
THE MOST UNSTABLE AIR MASS IS CONFINED TO NWRN AR...SWRN MO...AND
ADJACENT FAR SERN KS...WHERE CONVECTIVE OVERTURNING HAS BEEN THE
LEAST WIDESPREAD THUS FAR AND THE HIGHEST CONDITIONAL SVR POTENTIAL
WILL EXIST. OTHERWISE...AT LEAST SOME SVR POTENTIAL WILL REMAIN INTO
THE EVENING WITH SVR HAIL/DMGG WIND POSSIBLE WITH MODEST MID-LEVEL
FLOW LIKELY FOSTERING MULTICELLULAR CONVECTION.

ADDITIONAL CONVECTION DEVELOPING E OF WW 437 NEAR A SYNOPTIC
BOUNDARY FROM SERN MO INTO FAR SWRN INDIANA MAY POSE AN ISOLATED SVR
THREAT INTO THE EVENING. HOWEVER...THE SPATIOTEMPORAL EXTENT OF ANY
SVR POTENTIAL SHOULD BE TOO LIMITED FOR WW ISSUANCE E OF WW 437 AS
NOCTURNAL STABILIZATION OCCURS AMIDST FORCING FOR ASCENT.

..COHEN.. 07/24/2013

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

ATTN...WFO...PAH...MEG...LSX...LZK...SGF...SHV...TSA...

LAT...LON   36649436 37199496 37799480 37829358 37819216 37859001
            38268819 37768729 36948819 36569050 36239117 35229140
            33809205 33429283 34589420 36649436

via SPC Forecast Products http://www.spc.noaa.gov/products/md/md1490.html