MESOSCALE DISCUSSION 0844
NWS STORM PREDICTION CENTER NORMAN OK
0602 PM CDT FRI MAY 09 2008
AREAS AFFECTED...ERN WY...SWRN SD...WRN NEB...NERN CO AND NWRN KS
CONCERNING...SEVERE THUNDERSTORM WATCH 287...288...
VALID 092302Z - 100100Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
287...288...CONTINUES.
THREAT FOR SVR TSTMS WILL REMAIN GREATEST OVER ERN HALF OF WW 287
AND MOST OF WW 288 THROUGH THE NEXT FEW HOURS. ALTHOUGH LARGE
HAIL/DMGG WINDS WILL BE THE PRIMARY THREAT...A BRIEF/WEAK TORNADO
WILL BE POSSIBLE WITH ANY LONG LIVED/DISCRETE SUPERCELLS.
LATEST SFC ANALYSIS SHOWS STRONGLY BACKED SFC WINDS AND AN AREA OF
CONCENTRATED PRESSURE FALLS OVER SWRN NEB/NERN CO AND FAR NWRN KS. A
DISCRETE SUPERCELL OVER THE NERN CO/SWRN NEB CORNER WILL LIKELY BE
SUSTAINED GIVEN STRONG S-R INFLOW INTO THIS STORM. THIS SVR TSTM
WILL LIKELY MOVE OUT OF WW 287/288 BY 00Z...AND A LOCAL EXTENSION OF
WW 287/288 MAY BE NEEDED BEFORE THEN. HOWEVER...THE INSTABILITY
GRADIENT OVER WRN NEB/SWRN SD SHOULD ONLY SLOWLY MOVE EWD THIS
EVENING AS THE LOW LEVEL JET AXIS REMAINS CENTERED OVER THE REGION.
THUS THE SVR THREAT SHOULD REMAIN WITHIN 2 ROWS OF COUNTIES EAST OF
WW 288/287 THROUGH 03Z. FURTHER WEST...CONVECTION MOVING OUT OF
CENTRAL WY HAS NOT STRENGTHENED AS PREVIOUSLY ANTICIPATED ONCE
MOVING INTO WRN PORTIONS OF WW 287. THIS IS MOST LIKELY ATTRIBUTED
TO STABILIZATION BY EARLIER CONVECTION...AND MAY BE REMOVED FROM WW
287 BY 00Z IF CURRENT TRENDS CONTINUE.
OVER THE SRN 2/3RDS OF WW 288...SATELLITE TRENDS INDICATE ADDITIONAL
SVR TSTM DEVELOPMENT REMAINS POSSIBLE THROUGH 00Z GIVEN FOCUSED
CONVERGENCE INVOF A SFC DRYLINE EXTENDING FROM JUST WEST OF GLD TO
NORTH OF AKO AND INCREASING LARGE SCALE ASCENT/MINIMAL CINH.
..CROSBIE.. 05/09/2008
ATTN...WFO...LBF...UNR...GLD...BOU...CYS...
41080514 43120517 44150506 43830298 43440229 43310102
40300055 39230041 38850031 38760274 41020356
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