Saturday, June 9, 2007

MESO: Mesoscale Discussion 1076

ACUS11 KWNS 092034
SWOMCD
SPC MCD 092034
MNZ000-NDZ000-092230-

MESOSCALE DISCUSSION 1076
NWS STORM PREDICTION CENTER NORMAN OK
0334 PM CDT SAT JUN 09 2007

AREAS AFFECTED...NORTHERN ND/NORTHWEST MN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 092034Z - 092230Z

POTENTIAL FOR ISOLATED DAMAGING WIND GUSTS AND MARGINALLY SEVERE
HAIL MAY INCREASE THROUGH LATE AFTERNOON ACROSS NORTHERN
ND/NORTHWEST MN. EXPECTED MARGINAL/ISOLATED NATURE OF THE RISK WILL
LIKELY PRECLUDE A SEVERE THUNDERSTORM WATCH ISSUANCE...ALTHOUGH
CONVECTIVE TRENDS WILL BE MONITORED.

IN WAKE OF EARLIER IMPULSE MOVING ACROSS CENTRAL MN...WATER VAPOR
IMAGERY FEATURES A LOW AMPLITUDE SHORTWAVE TROUGH MOVING EASTWARD
OVER SOUTHERN SASKATCHEWAN/NORTHEAST MN. AS THE SURFACE...A WEAK
COLD FRONT WAS SAGGING SOUTHWARD ACROSS SOUTHEAST SASKATCHEWAN/FAR
SOUTHERN MANITOBA AT MID AFTERNOON...WITH A WARM/MODESTLY MOIST
AIRMASS IN THE AMBIENT WARM SECTOR ACROSS ND. OWING TO THE SHALLOW
NATURE OF THE BOUNDARY LAYER MOISTURE...DEWPOINTS HAVE ALREADY BEGAN
TO MIX OUT TO A DEGREE AT MID AFTERNOON...ALTHOUGH GENERALLY REMAIN
IN THE UPPER 40S TO MIDDLE 50S AS OF 20Z.

ALTHOUGH BOUNDARY LAYER CONVERGENCE IS LIMITED...SOME ADDITIONAL
HEATING/MODEST BACKGROUND FORCING FOR ASCENT WILL LEAD TO INCREASING
COVERAGE OF THUNDERSTORMS THROUGH LATE AFTERNOON. EVEN WITH SOME
ADDITIONAL MIXING...LATEST RUC SOUNDINGS SUPPORT MLCAPE VALUES OF
500-750 J/KG. MODEST COMBINATION OF CONVECTIVE INSTABILITY AND
EFFECTIVE BULK SHEAR AROUND 30 KT WILL LEAD TO THE POSSIBILITY OF
ISOLATED SEVERE STORMS/SEMI-ORGANIZED MULTICELLS THROUGH EARLY
EVENING. IN ADDITION TO MARGINALLY SEVERE HAIL...STEEP LOW LEVEL
LAPSE RATES/LARGELY UNIDIRECTIONAL WIND PROFILES WILL FAVOR DAMAGING
WIND GUSTS WITH THE STRONGEST STORMS. OVERALL STORM INTENSITY SHOULD
DECREASE BY AROUND SUNSET.

.GUYER.. 06/09/2007

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

ATTN...WFO...FGF...BIS...

49020146 49059964 49079779 48969654 48729605 47929607
47169683 46929886 46940135 47520254 48530278 48860244

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