SPC MD 1397

MD 1397 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR NW AL…NE MS…WRN TN


MESOSCALE DISCUSSION 1397
NWS STORM PREDICTION CENTER NORMAN OK
0146 PM CDT SUN JUL 14 2013

AREAS AFFECTED...NW AL...NE MS...WRN TN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 141846Z - 142015Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...SMALL WEAKLY ROTATING STORMS WILL CONTINUE FOR THE NEXT
FEW HOURS...WITH A LIMITED RISK FOR A DOWNBURST OR WEAK/BRIEF
TORNADO.  THE MAGNITUDE OF THE RISK APPEARS TO BE A LITTLE TOO
MARGINAL TO WARRANT A WATCH.

DISCUSSION...A BELT OF SMALL CONVECTIVE SHOWERS...SOME WITH
LIGHTNING... CONTINUES TO DEVELOP NWWD FROM NW AL ACROSS NE MS INTO
WRN TN.  THIS CONVECTION IS OCCURRING WITHIN THE CORRIDOR OF RICHEST
MOISTURE /PW VALUES OF 1.75-2 INCHES/ ESE OF THE CLOSED LOW MOVING
WSWWD FROM MO/AR TO KS/OK.  THE CONVECTION IS ALSO COINCIDENT WITH A
WEAK LOW-LEVEL CONFLUENCE ZONE...AND SOMEWHAT STRONGER DEEP-LAYER
SELY SHEAR.  THOUGH LOW-MIDLEVEL LAPSE RATES ARE RATHER POOR...THE
RICH MOISTURE AND EFFECTIVE BULK SHEAR OF 30-35 KT WILL BE
SUPPORTIVE OF SMALL STORMS WITH AT LEAST MARGINAL SUPERCELL
CHARACTERISTICS.  OVERALL...THE POOR LAPSE RATES WILL TEND TO LIMIT
THE POTENTIAL FOR STRONG DOWNDRAFTS AND/OR MOMENTUM TRANSFER TO THE
GROUND...WHILE LOW-LEVEL SHEAR WILL REMAIN SOMEWHAT WEAK GIVEN
STRAIGHT HODOGRAPHS.  THUS...WHILE ISOLATED STRONG/DAMAGING GUSTS OR
A BRIEF/WEAK TORNADO CANNOT BE RULED OUT...THE OVERALL RISK APPEARS
A LITTLE TOO MARGINAL TO WARRANT A WATCH.

..THOMPSON/CORFIDI.. 07/14/2013

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

ATTN...WFO...OHX...BMX...HUN...MEG...JAN...

LAT...LON   34448740 33818718 32988713 32598730 32598782 33228842
            34918913 35448927 35848914 36088887 36118842 35598795
            34448740

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