[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 270258
SWOMCD
SPC MCD 270258 
MNZ000-SDZ000-NDZ000-270430-

MESOSCALE DISCUSSION 1494
NWS STORM PREDICTION CENTER NORMAN OK
0958 PM CDT SUN JUN 26 2005

AREAS AFFECTED...PORTIONS CENTRAL/ERN ND...N-CENTRAL/EXTREME NERN
SD...

CONCERNING...HEAVY RAINFALL...SEVERE THUNDERSTORM WATCH 533...

VALID 270258Z - 270430Z

MAINTAIN WW ALONG/AHEAD OF PRIMARY CONVECTIVE BAND...EVIDENT AT 230Z
FROM CORSON COUNTY SD NNEWD THROUGH ROLETTE COUNTY ND AND INTO SWRN
MB.  ADDITIONALLY...PORTIONS NWRN MN E OF WW 533 ARE BEING MONITORED
FOR WW IN ADVANCE OF SEVERE CONVECTION MOVING NEWD FROM
SARGENT/RANSOM COUNTIES IN SERN ND.

SQUALL LINE THAT HAD DEVELOPED OVER SERN MT/NWRN SD HAS MERGED WITH
EARLIER SUPERCELLS ACROSS GRANT COUNTY ND...FORMING BOW ECHO THAT
SHOULD CROSS SRN PORTIONS BIS AREA MOVING 40-45 KT.  ASSOCIATED
DAMAGING WIND THREAT MAY EXTEND DOWNSHEAR ACROSS A CORRIDOR
EXTENDING ENEWD TOWARD JMS...DURING NEXT 3-4 HOURS.  AIR MASS OVER
ERN ND IS GRADUALLY BECOMING DECOUPLED AT SFC BECAUSE OF DIABATIC
COOLING...BUT STABLE LAYER WILL REMAIN SUFFICIENTLY SHALLOW TO ALLOW
DAMAGING DOWNDRAFTS TO REACH SFC RELATIVELY UNIMPEDED. MODIFIED RUC
SOUNDINGS OVER PRE-STORM AIR MASS IN ND...NERN SD AND NWRN MN
INDICATE 30-40 KT EFFECTIVE SHEAR...AND MUCAPES 2000-2500 J/KG
SUPPORTED BY RICH MOISTURE IN SFC 850 MB LAYER.

..EDWARDS.. 06/27/2005

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

ATTN...WFO...FGF...ABR...BIS...UNR...

45309641 44660148 48430154 49049641 

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