Severe Thunderstorm Warning 33, NWS Glasgow, MT

NORTHEAST MONTANA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE GLASGOW MT
820 PM MDT FRI JUN 28 2002

CORRECTED FIRST PERIOD POP FOR GDV CCF.

.SHORT TERM...A VIGOROUS UPPER AIR LOW SPINNING OFF THE COAST OF
BRITISH COLUMBIA HAS INDUCED SOUTHWEST FLOW ALOFT OVER MONTANA. THIS
LOW ALONG WITH WEAK SHORTWAVES MOVING THROUGH THE SOUTHWEST FLOW
HAVE FORMED A WEAK SURFACE TROUGH OVER EASTERN MONTANA. STRONG
DAYTIME HEATING HAS CAUSED TEMPERATURES TO WARM BACK UP INTO THE 90S
AND LOWER 100S AGAIN THIS AFTERNOON AND EVENING...CAUSING THE
ATMOSPHERE TO BECOME UNSTABLE. 00Z KGGW SOUNDING SHOWS THIS
INSTABILITY WITH A CAPE VALUE OF 1875 J/KG...HOWEVER THERE IS ALSO A
CAP OF -125 J/KG. THUNDERSTORMS HAVE DEVELOPED OVER THE SOUTHWEST
MOUNTAINS OF MONTANA WITH MORE ISOLATED STORMS OVER SOUTH CENTRAL
AND SOUTHEASTERN MONTANA. DRY SOUNDING AT LOWER TO MID LEVELS
INDICATES MAIN THREAT FROM THESE STORMS WILL BE GUSTY TO DAMAGING
WINDS. BELIEVE SCENARIO IS MUCH LIKE YESTERDAY EVENING AND THAT
NEMONT MAY SEE SOME STORMS MOVE INTO THE WESTERN OR SOUTHERN PART OF
THE CWA OR DEVELOP ON AN OUTFLOW BOUNDARY. WILL INCREASE POPS IN
SOUTHEAST ZONES DUE TO CONVECTION DEVELOPING SOUTH OF THE AREA.
THUNDERSTORMS AND BLOW OFF FROM THUNDERSTORM ANVILS WILL KEEP SKIES
PARTLY CLOUDY TONIGHT...AND LIGHT WINDS ALONG WITH DEW POINTS IN THE
50S AND 60S WILL HELPS TEMPERATURES DROP TO THEIR FORECASTED LOWS
ACROSS MOST OF THE AREA. WINDS LOOK TO BE PROBLEMATIC WITH NO
COHERENT DIRECTION ACROSS THE CWA THE PAST FEW HOURS. CURRENT
CONDITIONS AND MODEL GUIDANCE INDICATE GENERAL DIRECTION OF THE WIND
WILL RANGE FROM THE WEST TO NORTH SO WILL GO WITH THAT SOLUTION.
BERDES

.LONG TERM...FLOW ALOFT IS SLOW TO SHIFT BACK TO THE SOUTHWEST...SO
WILL KEEP DRY CONDITIONS GOING TUESDAY. AN UPPER TROUGH ALONG THE
PACIFIC COAST FINALLY BACKS THE FLOW WEDNESDAY WHICH WILL BRING THE
CHANCE OF THUNDERSTORMS DAYS 5-7 AND A SLOW WARMING TREND.
WATERHOUSE

KGGW TBB 066/092 059/088 056/083 99344100
     BTTT 056/080 058/083 060/086 060/089 9901133333
KGDV TBB 064/098 061/090 058/085 99344100
     BTTT 058/081 058/084 060/087 060/090 9901133333

.GGW...NONE