[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 172320
SWOMCD
SPC MCD 172320 
SDZ000-NDZ000-MTZ000-180045-

MESOSCALE DISCUSSION 0898
NWS STORM PREDICTION CENTER NORMAN OK
0620 PM CDT TUE MAY 17 2005

AREAS AFFECTED...ERN MT...WRN ND THROUGH NW SD

CONCERNING...SEVERE THUNDERSTORM WATCH 284...

VALID 172320Z - 180045Z

THREAT OF ISOLATED HAIL AND STRONG WIND GUSTS CONTINUES FROM ERN MT
THROUGH SWRN ND INTO NWRN SD...BUT OVERALL THREAT APPEARS MARGINAL.
IF CURRENT TRENDS CONTINUE...WW 284 MIGHT BE CANCELLED BEFORE ITS
EXPIRATION TIME OF 03Z.

EARLY THIS EVENING A COLD FRONT EXTENDS THROUGH SERN MT INTO NWRN SD
FROM A SURFACE LOW IN ERN MT. A WARM FRONT EXTENDS SEWD FROM THE LOW
THROUGH NRN SD WITH AN OCCLUDED BOUNDARY FROM NERN MT NWWD INTO
SASKATCHEWAN. AN AXIS OF MODEST INSTABILITY EXISTS FROM ERN MT SEWD
THROUGH WRN ND AND NWRN SD IN VICINITY OF AND E OF THE COLD FRONT
WITH MLCAPE FROM 800 TO 1200 J/KG. LARGE SCALE ASCENT DOWNSTREAM
FROM NEGATIVELY TILTED SHORTWAVE TROUGH MOVING NEWD THROUGH WY WILL
MAINTAIN A FAVORABLE ENVIRONMENT FOR STORMS TO CONTINUE DEVELOPING
NEXT SEVERAL HOURS ALONG THE COLD FRONT. OTHER STORMS MAY DEVELOP
FARTHER EAST INTO ND WITHIN THE ZONE OF WARM ADVECTION ASSOCIATED
WITH THE INTENSIFYING LOW LEVEL JET. THE PRIMARY MID LEVEL JET AXIS
REMAINS S OF THE REGION. AS A RESULT... DEEP LAYER VERTICAL SHEAR IS
NOT PARTICULARLY STRONG AND GENERALLY SUPPORTIVE OF MULTICELL
STORMS. GIVEN ONLY MODEST VERTICAL SHEAR AND INSTABILITY...THE ONSET
OF NOCTURNAL COOLING AND CHARACTER OF THE ONGOING STORMS...OVERALL
THREAT APPEARS SOMEWHAT LIMITED.

..DIAL.. 05/17/2005

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

ATTN...WFO...BIS...UNR...BYZ...GGW...

45410377 46830534 48750620 49000399 48380309 46580239
45390253 

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