SPC MD 1586

MD 1586 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR NWRN/N-CNTRL KS…SWRN/S-CNTRL INTO NERN NEB…SERN SD


MESOSCALE DISCUSSION 1586
NWS STORM PREDICTION CENTER NORMAN OK
0252 PM CDT WED JUL 25 2012

AREAS AFFECTED...NWRN/N-CNTRL KS...SWRN/S-CNTRL INTO NERN NEB...SERN
SD

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 251952Z - 252145Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THE AREA IS BEING MONITORED FOR AN INCREASING SVR TSTM
POTENTIAL...AND THE ISSUANCE OF A SVR TSTM WATCH IS POSSIBLE ACROSS
PARTS OF THE AREA.

DISCUSSION...A SLOW-MOVING COLD FRONT EXTENDING FROM NERN NEB TO
W-CNTRL KS MARKS THE CONTRAST BETWEEN A DEEPLY/WELL-MIXED BOUNDARY
LAYER FEATURING HOT SFC TEMPS IN THE MID/UPPER 90S TO 102 DEGREES TO
ITS SE...FROM SLIGHTLY COOLER/MORE MOIST CONDITIONS TO ITS NW.
HOWEVER...AROUND THE MOIST AXIS CHARACTERIZED BY MIDDLE/UPPER 60S
DEWPOINTS NW OF THE COLD FRONT -- AND SOUTHEAST OF A DIFFERENTIAL
HEATING ZONE LYING PARALLEL TO...AND 60-75 MILES NW OF...THE COLD
FRONT -- CLOUD-FREE AREAS ARE CONTRIBUTING TO MLCAPE UP TO 2000 J/KG
PER MODIFIED NORTH PLATTE/OMAHA 12Z RAOBS. VISIBLE SATELLITE IMAGES
DEPICT ARCS/ZONES OF CUMULUS DEVELOPMENT WITHIN THIS ZONE...WITH
HIGHER-BASED CUMULUS DEVELOPMENT CLOSER TO THE COLD FRONT. ISOLATED
TO SCATTERED THUNDERSTORMS ARE EXPECTED TO EVOLVE FROM THIS CUMULUS
DURING THE NEXT COUPLE OF HOURS. AND...WITH 20-30 KT OF EFFECTIVE
BULK SHEAR -- HIGHEST NEAR THE DIFFERENTIAL HEATING ZONE --
MULTICELL CLUSTERS WITH DMGG WIND GUSTS AND PERHAPS SVR HAIL WILL BE
OF CONCERN. THESE FACTORS MAY WARRANT SVR TSTM WATCH ISSUANCE ACROSS
PARTS OF THE AREA...ESPECIALLY NEAR AND TO THE NORTHEAST OF THE
KS/NEB BORDER WHERE THE DIFFERENTIAL HEATING ZONE IS MORE
PRONOUNCED.

..COHEN/HART.. 07/25/2012

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

ATTN...WFO...FSD...OAX...TOP...ICT...GID...LBF...DDC...GLD...

LAT...LON   43249669 42519651 41209639 40159717 39209858 38660007
            38700095 39030154 39760152 40630076 41489936 42849822
            43429771 43519710 43249669

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