Friday, March 30, 2012

MESO: Mesoscale Discussion 0390

ACUS11 KWNS 302020
SWOMCD
SPC MCD 302020
IAZ000-NEZ000-SDZ000-302145-

MESOSCALE DISCUSSION 0390
NWS STORM PREDICTION CENTER NORMAN OK
0320 PM CDT FRI MAR 30 2012

AREAS AFFECTED...ERN NEB...WRN IA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 302020Z - 302145Z

ISOLATED THUNDERSTORMS ARE FORECAST TO DEVELOP ACROSS ERN NEB AND
WRN IA THIS AFTERNOON AND EVENING. A SVR STORM WILL BE
POSSIBLE...BUT THE THREAT IS TOO MARGINAL FOR A WW.

MESOANALYSIS AT 19-20Z SHOWS A BAROCLINIC ZONE COLLOCATED WITH
CONFLUENT SURFACE STREAMLINES EXTENDING SEWD OUT OF SRN SD TOWARD
OMA AND INTO NRN MO. MEANWHILE...A MIDLEVEL IMPULSE IS MOVING SEWD
TOWARD ERN NEB/WRN IA. STEEP LOW-LEVEL LAPSE RATES INDICATIVE OF
ROBUST BOUNDARY LAYER DESTABILIZATION ARE DEVELOPING EWD TOWARD THE
SURFACE BOUNDARY. THIS DESTABILIZATION COMBINED WITH ASCENT
ASSOCIATED WITH THE MIDLEVEL IMPULSE APPEAR TO BE AIDING IN SURFACE
BASED CUMULUS DEVELOPMENT INVOF BUB AND ONL...WHICH MAY
DEEPEN/EVOLVE INTO ISOLATED THUNDERSTORMS AS RELATIVELY DEEPER
MOISTER IS ENCOUNTERED OVER ERN NEB. COMBINATION OF STEEP MIDLEVEL
LAPSE RATES FROM 7-8 C/KM...SURFACE TEMPERATURES IN THE MID 70S AND
DEWPOINTS IN THE 40S TO LOW 50S WILL AID IN MLCAPE VALUES NEAR 500
J/KG. GIVEN THE PRESENCE OF LOW-LEVEL SWLYS VEERING TO W-NWLY IN THE
MIDLEVELS...VERTICAL SHEAR PROFILES...CHARACTERIZED BY 0-6 KM BULK
WIND DIFFERENCE FROM 30-50 KT...WILL SUPPORT ORGANIZED THUNDERSTORM
DEVELOPMENT INCLUDING SUPERCELLS. THESE STORMS WILL BE DRIVEN SEWD
ALONG THE BAROCLINIC ZONE COINCIDENT WITH THE PASSAGE OF THE
MIDLEVEL IMPULSE...AND POSE A THREAT FOR ISOLATED DAMAGING WIND
GUSTS AND LARGE HAIL. HOWEVER...GIVEN ONLY MARGINAL MOISTURE AND
BUOYANCY...THE SVR THREAT SHOULD BE NARROWLY CONFINED TO THE
BAROCLINIC ZONE...AND BE TOO LIMITED FOR A WW.

..GARNER.. 03/30/2012

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

ATTN...WFO...DMX...FSD...OAX...GID...LBF...

LAT...LON 40609564 40679673 41419833 42269874 42859837 42599652
41929479 40889452 40609564

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