[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 181917
SWOMCD
SPC MCD 181917 
NEZ000-WYZ000-MTZ000-182115-

MESOSCALE DISCUSSION 0743
NWS STORM PREDICTION CENTER NORMAN OK
0217 PM CDT TUE MAY 18 2004

AREAS AFFECTED...PORTIONS OF NRN/ERN WY AND SCENTRAL MT

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 181917Z - 182115Z

ISOLATED THUNDERSTORMS ARE ANTICIPATED TO DEVELOP OVER THE HIGHER
TERRAIN AND ALONG A LEE TROUGH FROM NCENTRAL INTO SERN WY OVER THE
NEXT HOUR. CONVECTION IS ANTICIPATED TO BEGIN POSING A SEVERE THREAT
WITHIN 1-2 HOURS OF DEVELOPMENT. MARGINAL INSTABILITY IS THE MAIN
LIMITING FACTOR FOR A MORE ORGANIZED SEVERE THREAT...BUT TRENDS WILL
CONTINUE TO BE MONITORED FOR A POSSIBLE WW AFTER 21Z. 

LATEST VIS SAT IMAGERY INDICATES SUBSTANTIAL INHIBITION OVER LOWER
ELEVATIONS OF NERN WY/SERN MT...WHERE WAVE CLOUDS WERE NOTED. AREAS
ALONG AND JUST EAST OF THE BIG HORN/WIND RIVER AND LARAMIE MTNS HAVE
HAD SEVERAL HOURS OF HEATING. THIS HAS LED TO MINIMAL CIN NOW
OBSERVED ALONG WITH TOWERING CU SUGGESTING THAT THUNDERSTORM
DEVELOPMENT IS IMMINENT IN THESE AREAS. MODIFIED RUC SOUNDINGS
INDICATE AROUND 500 J/KG OF MLCAPE. AS STRONGER DEEP LAYER SHEAR
GRADUALLY INCREASES OVER WRN WY BEGINS TO MOVE INTO THE
REGION...STORM ROTATION WILL LEAD TO GREATER THREAT FOR SEVERE HAIL.
 HOWEVER UNLESS MARGINAL INSTABILITY CAN IMPROVE THE OVERALL
MAGNITUDE OF THE SEVERE THREAT MAY BE INSUFFICIENT FOR A WW.

..CROSBIE.. 05/18/2004

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

ATTN...WFO...UNR...CYS...BYZ...RIW...

42650782 43520901 44350932 45360842 45320616 43450442
41620400 41370518 

WWWW