[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 312239
SWOMCD
SPC MCD 312238 
MNZ000-IAZ000-SDZ000-NEZ000-KSZ000-010115-

MESOSCALE DISCUSSION 1685
NWS STORM PREDICTION CENTER NORMAN OK
0538 PM CDT MON JUL 31 2006

AREAS AFFECTED...PORTIONS SWRN-CENTRAL-NERN NEB...SWRN MN...SERN
SD...NWRN KS.

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 312238Z - 010115Z

TSTM COVERAGE SHOULD INCREASE FOR ANOTHER HOUR OR TWO IN NE-SW
ORIENTED CORRIDOR FROM SW MN TO NW KS...WITH ISOLATED/SHORT-LIVED
DAMAGING WIND AMD MRGL SVR HAIL EVENTS PSBL.  POTENTIAL SHOULD PEAK
BEFORE SUNSET THEN DIMINISH CONSIDERABLY. WW NOT ANTICIPATED ATTM.

SFC ANALYSIS SHOWS PRONOUNCED COLD FRONT EXTENDING FROM OUTFLOW
BOUNDARY INTERSECTION IN CENTRAL MN...NEAR SW EDGE WW 664...SWWD
NEAR LINE FROM MHE...OGA...LIC...AS OF 22Z.  EXPECT FRONT TO MOVE
SEWD 10-20 KT ACROSS MOST OF THIS AREA...GRADUALLY OVERTAKING
PREFRONTAL TROUGH AND CONFLUENCE LINE THAT WAS ANALYZED FROM
LAA...BBW...40 SE ANW. LIFT ALONG FRONT AND PREFRONTAL TROUGH...AS
WELL AS INTENSE SFC HEATING WITH WARM SECTOR TEMPS AOA 100 F...IS
CONTRIBUTING TO CONVECTIVE INITIATION ACROSS THIS AREA.  ADDITIONAL
LIFT WILL OCCUR LOCALLY ALONG OUTFLOW BOUNDARIES AND THEIR
INTERSECTIONS. DEEP LAYER OF 20-40 KT LOW LEVEL SWLY/SSWLY FLOW IS
EVIDENT AHEAD OF FRONT...HOWEVER WEAKER MIDLEVEL WINDS CONTRIBUTE TO
VERY SMALL DEEP-LAYER SHEAR.  FCST SLOW STORM MOTION PARALLEL TO
FRONT/TROUGH -- COMBINED WITH PROGRESSIVE NATURE OF FRONT --
INDICATES EFFECTIVELY ANAFRONTAL REGIME WITH MULTICELLULAR ACTIVITY
BEING UNDERCUT BY FRONTS/OUTFLOWS...AND RELATIVELY SHORT LIFESPAN
FOR ANY GIVEN TSTM OR SMALL CLUSTER.  MLCAPES NOW IN 1000-2000 J/KG
RANGE -- BASED ON MODIFIED RAOBS AND RUC SOUNDINGS -- SHOULD
DIMINISH AFTER ABOUT 1Z WITH LOSS OF SFC DIABATIC HEATING.

..EDWARDS.. 07/31/2006

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

ATTN...WFO...MPX...FSD...OAX...ABR...GID...LBF...GLD...

38950169 41000169 45699570 43909572 

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