SPC AC 161600
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1100 AM CDT WED AUG 16 2006
VALID 161630Z - 171200Z
...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF NRN/CENTRAL ID AND
WRN MT...
...THERE IS A SLGT RISK OF SVR TSTMS ERN ND AND NWRN MN...
...WRN MT AND NRN/CENTRAL ID...
TROUGH THAT DEEPENED SEWD INTO PAC NW PAST 24 HOURS IS NOW SHIFTING
EWD SPREADING STRONGER FLOW...LARGE SCALE UPWARD MOTION FIELD AND
COOLING ALOFT ACROSS NRN ROCKIES TODAY/TONIGHT. SURFACE HIGH
DROPPING SEWD SRN PRAIRIE PROVINCES WILL PROVIDE UPSLOPE COMPONENT
TO THE LOW LEVEL FLOW ENHANCING THE DEEP LAYER SHEAR PROFILES ACROSS
WRN MT. ALTHOUGH THE AVAILABLE MOISTURE AND INSTABILITY WILL BE
SOMEWHAT LIMITED AHEAD OF THE TROUGH...COMBINATION OF 40-50 KT OF
SHEAR AND STEEP LAPSE RATES SUFFICIENT TO UPGRADE MUCH OF NRN
ROCKIES TO A SLIGHT RISK FOR THIS AFTERNOON AND EVENING. WITH
OVERNIGHT CONVECTION AND CLOUD COVER CURRENTLY CLEARING OUT OF THE
NRN ROCKIES...FULL HEATING WILL RAPIDLY STEEPEN LOW LEVEL LAPSE
RATES DURING AFTERNOON WITH THUNDERSTORMS FORMING OVER HIGHER
TERRAIN FROM NERN ORE MTNS ACROSS CENTRAL ID INTO WRN MT.
THE THREAT OF LARGE HAIL AND DAMAGING DOWNBURSTS WINDS WILL INCREASE
BY MID/LATE AFTERNOON WITH MLCAPES UPWARDS TO 1000 J/KG DEVELOPING
GIVEN THE STRONG SURFACE HEATING AND COLD ADVECTION ALOFT.
...ND/MN...
WATER VAPOR IMAGERY SHOWS RELATIVELY FAST-MOVING SHORTWAVE TROUGH
MOVING INTO WRN DAKOTAS. THIS FEATURE WILL MOVE EASTWARD ACROSS ND
TODAY...WITH ACCOMPANYING COLD FRONT EXTENDING FROM ERN ND TO SWRN
SD BY 00Z. THE LOW LEVEL AIR MASS AHEAD OF THE COLD FRONT IS
EXPECTED TO BECOME MODERATELY UNSTABLE THIS AFTERNOON WITH DEWPOINTS
CLIMBING INTO THE 60S AND POCKETS OF HEATING. SCATTERED
THUNDERSTORMS WILL DEVELOP BY MID/LATE AFTERNOON ALONG THE FRONT
OVER EASTERN ND AND SPREAD INTO MN THIS EVENING. VERTICAL SHEAR
PROFILES IN THIS REGION WILL BE FAVORABLE FOR SUPERCELLS CAPABLE OF
HAIL AND DAMAGING WINDS. ACTIVITY WILL LIKELY WEAKEN RAPIDLY
OVERNIGHT AS STORMS MOVE INTO MN DUE TO MORE STABLE AIRMASS.
...KS/NE/SD...
SLY FLOW RETURNING A MOIST AND POTENTIALLY MODERATELY UNSTABLE AIR
MASS NWD THRU THE PLAINS. STRONG HEATING WILL STEEPEN LOW LEVEL
LAPSE RATES ACROSS PLAINS THIS AFTERNOON. WITH MLCAPES UPWARDS TO
2000 J/KG...WET MICRO BURSTS ARE POSSIBLE MOST ANYWHERE IN THIS AREA
WHERE STRONG STORMS DEVELOP. GENERALLY DEEP LAYER SHEAR LESS THAN
15KTS MUCH OF PLAINS SUPPORT A PULSE MODE FOR CONVECTIVE
DEVELOPMENT.
..HALES/GUYER.. 08/16/2006
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
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