[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 031754
SWOMCD
SPC MCD 031754 
SDZ000-032030-

MESOSCALE DISCUSSION 1925
NWS STORM PREDICTION CENTER NORMAN OK
1254 PM CDT WED AUG 03 2005

AREAS AFFECTED...SD

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 031754Z - 032030Z

TSTMS WILL INCREASE ACROSS WRN-CNTRL SD THROUGH THIS AFTN WITH
THREATS FOR LARGE HAIL AND DAMAGING WINDS.  PARTS OF THE REGION MAY
NEED A WW.

17Z SFC ANALYSIS PLACES THE SYNOPTIC COLD FRONT FROM SERN ND TO THE
BLACK HILLS AND INTO NERN WY.  MOIST NLY UPSLOPE FLOW WAS DEEPENING
ACROSS WRN SD PER VWP AT RAPID CITY BEHIND THIS FRONT. COMBINATION
OF THE ENHANCED UPSLOPE FLOW AND LARGE SCALE ASCENT ASSOCIATED WITH
A WY SHORTWAVE TROUGH ARE BECOMING FAVORABLE FOR INCREASING
TSTMS...BOTH OVER THE BLACK HILLS AND IN ELEVATED BANDS N OF THE
FRONT. 

MESOANALYSIS INDICATES A THERMAL RIDGE HAS DEVELOPED AHEAD OF THE
FRONT FROM THE BLACK HILLS EWD INTO CNTRL SD.  RUC SOUNDINGS SUGGEST
THAT THE AIR MASS REMAINS CAPPED ON THE PLAINS...BUT AS HEATING
CONTINUES...ELEVATED/HIGHER BASED TSTMS WILL HAVE A GREATER
PROBABILITY IN ROOTING INTO THE VERY UNSTABLE BOUNDARY LAYER. 
EFFECTIVE VERTICAL SHEAR OF 40-45 KTS WILL BE SUFFICIENT FOR
SUPERCELLS WITH LARGE HAIL.  DAMAGING WINDS COULD BECOME A FACTOR
IF/WHEN TSTMS DEVELOP INTO THE BOUNDARY LAYER.

TSTMS SHOULD CONTINUE EVOLVING ALONG/N OF THE FRONT THROUGH
21Z...THEN POSSIBLY EWD INTO THE THERMAL RIDGE AXIS ACROSS CNTRL/SRN
SD LATER THIS AFTN.

..RACY.. 08/03/2005

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

ATTN...WFO...FSD...ABR...UNR...

44160352 44860170 45850002 45639800 44859708 43789759
43349858 43090109 43550342 

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