[MCD] SWOMCD

Sat Aug 12 08:12:03 UTC 2006

ACUS11 KWNS 120813
SWOMCD
SPC MCD 120813 
MNZ000-SDZ000-NDZ000-120915-

MESOSCALE DISCUSSION 1803
NWS STORM PREDICTION CENTER NORMAN OK
0313 AM CDT SAT AUG 12 2006

AREAS AFFECTED...CENTRAL-ERN ND/PARTS OF CENTRAL-ERN SD

CONCERNING...SEVERE THUNDERSTORM WATCH 712...

VALID 120813Z - 120915Z

THREAT FOR ISOLATED HAIL AND STRONG WIND GUSTS SHOULD CONTINUE
MAINLY ACROSS NERN ND INTO ADJACENT PORTIONS OF NWRN MN.  ALTHOUGH
POTENTIAL EXISTS FOR A FEW SEVERE STORMS TO MOVE EAST OF WW 712 INTO
NWRN MN BY 09Z...LIMITED AREAL COVERAGE PRECLUDES ISSUANCE OF NEW WW
AT THIS TIME.

EARLY MORNING WATER VAPOR IMAGERY SHOWED LARGE SCALE UPPER TROUGH
CONTINUING TO MOVE EWD INTO SASKATCHEWAN AND THE NRN HIGH
PLAINS...WHILE SEVERAL VORTICITY MAXIMA TRAVERSED SWLY FLOW REGIME
ACROSS ERN MT AND THE DAKOTAS. FORCING FOR ASCENT AHEAD OF THESE
VORTICITY MAXIMA APPEAR TO BE AIDING ONGOING STORM CLUSTERS OVER ERN
SD...NERN MT INTO NWRN ND AND THE LARGER MCS LOCATED OVER SRN
MANITOBA INTO NERN ND.

...NERN ND/NWRN MN...
IN ADDITION TO ASCENT AHEAD OF NERN ND SHORT WAVE TROUGH...30-35 KT
SWLY LLJ OVER THE DAKOTAS WILL MAINTAIN INFLOW OF MODERATE
INSTABILITY RESERVOIR LOCATED OVER ERN ND/CENTRAL SD TO SUSTAIN NEW
THUNDERSTORM DEVELOPMENT ALONG SRN FLANK OF THIS MCS.  STORMS
ASSOCIATED WITH THIS COMPLEX SHOULD MOVE INTO NWRN MN BETWEEN
08-09Z...BUT AREAL COVERAGE FOR A SEVERE THREAT SHOULD BE LOW...
ESPECIALLY AS ACTIVITY MOVES EAST OF INSTABILITY AXIS.

...ERN SD...
OUTFLOW BOUNDARY ASSOCIATED WITH ERN SD CLUSTER OF STORMS EXTENDED
FROM NEAR HON TO 9V9 AND THEN GENERALLY WWD INTO SWRN SD.  40-45 KT
SSWLY LLJ EXTENDING FROM WRN NEB INTO CENTRAL SD IS RESULTING IN
ISENTROPIC ASCENT NORTH OF OUTFLOW BOUNDARY AND SUPPORTING WAA
REGIME GIVEN 850 MB N-S ORIENTED THERMAL GRADIENT OVER ERN SD. 
THUS...THUNDERSTORMS SHOULD CONTINUE WITH THIS COMPLEX...BUT
GENERALLY REMAIN WEAK AS ACTIVITY MOVES ESE OF INSTABILITY AXIS.

...NWRN ND...
ISENTROPIC ASCENT NORTH OF OUTFLOW BOUNDARY ASSOCIATED WITH SRN
MANITOBA/NERN ND MCS WILL CONTINUE TO SUPPORT THUNDERSTORM
DEVELOPMENT ACROSS NWRN ND EARLY THIS MORNING. HOWEVER... GENERALLY
WEAK EFFECTIVE BULK SHEAR IS EXPECTED TO PRECLUDE AN ORGANIZED
SEVERE THREAT.

..PETERS.. 08/12/2006

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

ATTN...WFO...FGF...FSD...ABR...BIS...

49009579 46539647 45709726 44179718 43879739 43869911
44380050 44880052 45640037 46850081 47160167 47820232
48580100 49030017 

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