[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 082345
SWOMCD
SPC MCD 082344 
IAZ000-MNZ000-090145-

MESOSCALE DISCUSSION 1146
NWS STORM PREDICTION CENTER NORMAN OK
0644 PM CDT TUE JUN 08 2004

AREAS AFFECTED...NRN IA

CONCERNING...SEVERE THUNDERSTORM WATCH 411...

VALID 082344Z - 090145Z

CONTINUE WW.

SATELLITE/RADAR IMAGERY HAVE SUGGESTED ONGOING CONVECTIVE
DEVELOPMENT EAST NORTHEAST OF SIOUX CITY IA HAS BEEN SUPPORTED BY
FOCUSED AREA OF ENHANCED UPPER DIVERGENCE AND WEAK MID-LEVEL
CIRCULATION.  THIS FEATURE...PERHAPS ASSOCIATED WITH PRIOR
CONVECTIVE CLUSTER...IS EMBEDDED WITHIN MOIST PLUME TO THE SOUTH OF
STRONGER WESTERLIES...ABOVE LOW/MID-LEVEL DEFORMATION ZONE ACROSS
NORTHERN IOWA.

GIVEN FAVORABLE FORCING...VIGOROUS THUNDERSTORM ACTIVITY LIKELY WILL
CONTINUE NORTHWEST THROUGH NORTH OF FORT DODGE INTO THE MASON CITY 
AREA NEXT FEW HOURS...SLOWLY MERGING INTO LARGER CONVECTIVE CLUSTER.
 ROOTED IN VERY MOIST UNSTABLE BOUNDARY LAYER WITH 70F SURFACE DEW
POINTS/MEAN MIXED LAYER CAPE ON THE ORDER OF 3000 J/KG...STRONG
UPDRAFTS ARE LIKELY...CAPABLE OF SUPPORTING VERY HEAVY
RAIN...PERHAPS SOME MARGINALLY SEVERE HAIL DESPITE WEAK SHEAR
PROFILES.  THOUGH LOW-LEVEL LAPSE RATES ARE NOT PARTICULARLY
STEEP...MID-LEVELS ARE RELATIVELY DRY...AND EVAPORATIVE COOLING MAY
CONTRIBUTE TO SLOW EVOLUTION OF SURFACE COLD POOL/GUST FRONT.

..KERR.. 06/08/2004

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

ATTN...WFO...ARX...MPX...DMX...FSD...

43239516 43599375 43609314 43029267 42369292 42019380
41849454 41899528 42589543 

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