[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 202053
SWOMCD
SPC MCD 202053 
MTZ000-WYZ000-202300-

MESOSCALE DISCUSSION 0908
NWS STORM PREDICTION CENTER NORMAN OK
0353 PM CDT SAT MAY 20 2006

AREAS AFFECTED...WESTERN/CENTRAL MT AND NORTHERN WY

CONCERNING...SEVERE THUNDERSTORM WATCH 367...

VALID 202053Z - 202300Z

SEVERE THUNDERSTORM WATCH 367 CONTINUES UNTIL 02Z...WITH CONTINUED
THREAT FOR LARGE HAIL/STRONG WIND GUSTS ACROSS WESTERN/CENTRAL MT
AND NORTHERN WY. MONITORING FOR AN ADDITIONAL WATCH ISSUANCE ACROSS
FAR SOUTHEAST MT/NORTHEAST WY AND PERHAPS EAST CENTRAL WY.

THE STRONGEST STORMS IN/NEAR WW 367 ARE OCCURRING AT THIS TIME
ACROSS SOUTHEAST MT BETWEEN BILLINGS AND MILES CITY...WITH A
RELATIVELY WELL ORGANIZED MCS ABOUT 70 MILES SE OF BILLINGS AS OF
2045Z. IN ADDITION TO LARGE HAIL...DAMAGING WIND THREAT MAY INCREASE
IN THE SHORT TERM ACROSS SOUTHEAST MT GIVEN THE APPARENT COLD
POOL/MCS ORGANIZATION. ADDITIONAL STRONG/SEVERE STORMS HAVE
DEVELOPED IN THE BIGHORN BASIN OF NORTH CENTRAL WY NEAR
GREYBULL/WORLAND. THESE STORMS...AS WELL AS ADDITIONAL STORMS ACROSS
SOUTHWEST MT...WILL CONTINUE TO SPREAD EAST-NORTHEAST DURING THE
REMAINDER OF THE AFTERNOON AIDED BY WESTERN MT SHORTWAVE TROUGH PER
WATER VAPOR IMAGERY. A RATHER MOIST/MODERATELY UNSTABLE AIRMASS WITH
UPPER 40S/LOWER 50S F DEWPOINTS IN PRESENCE OF 35-40 KTS OF VERTICAL
SHEAR WILL CONTINUE TO SUPPORT A LARGE HAIL/STRONG WIND GUST THREAT.

SOUTH OF WW 367...MONITORING FOR AN ADDITIONAL WATCH ISSUANCE ACROSS
FAR SOUTHEAST MT/NORTHEAST WY AND PERHAPS EAST CENTRAL WY. STORMS
WILL LIKELY POSE AT LEAST AN ISOLATED SEVERE THREAT AS THEY DEVELOP
EASTWARD INTO THE EASTERN WY PLAINS WHERE AN UNSTABLE AIRMASS
EXISTS.

..GUYER.. 05/20/2006

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

ATTN...WFO...UNR...CYS...BYZ...GGW...RIW...TFX...

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