Hail and Damaging Winds in Montana, August 6, 2002

SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
252 PM MDT TUE AUG 06 2002

.SHORT TERM...VALID FOR WED...THU...FRI...

JET LOCATED NORTHWEST OF THE CWA WILL REMAIN NEARLY STATIONARY AND
PROVIDE SOME LIFT FOR THE CWA.  HOWEVER...18Z ACARS STILL INDICATES
THE CWA IS WELL CAPPED.  SOME COOLING WILL TAKE PLACE IN THE MID LEVELS
THIS EVENING OVER NORTHWESTERN SECTIONS...BUT FEEL ONLY ISOLATED
CONVECTION WILL GET GOING.  MORE CONVECTION MAY DEVELOP OVER WY AND
SPREAD INTO EASTERN SECTIONS LATER TONIGHT...SO WILL GO WITH CHANCE
POPS THERE.  CONDITIONS LOOK MORE FAVORABLE FOR CONVECTION ON
WEDNESDAY AS THE UPPER TROF OVER THE PACNW APPROACHES. A GREATER MID
LEVEL MOISTURE WILL BE PRESENT WITH A WEAKER CAP AND STRONGER JET
FORCING. STORMS SHOULD HAVE GOOD STRUCTURE CONSIDERING THE FORECAST
SHEAR.  WILL GO WITH HIGH CHANCE POPS FOR WEDNESDAY AND WEDNESDAY NIGHT.
THE TROUGH WILL BE SITUATED OVER THE STATE ON THURSDAY...LEAVING THE CWA
IN FAVORABLE POSITION FOR COOLER TEMPERATURES AND THUNDERSTORMS. WILL
KEEP CHANCE POPS GOING. MOORE

.LONG TERM...VALID FOR SAT...SUN...MON...TUE...

SAT...EXTENDED TEMPS WILL BE MORE LIKE TEMPS FOR EARLY SEPTEMBER THAN
EARLY AUGUST. ALL MODELS INDICATE A TROUGH IN THE VICINITY OF SOUTHERN
BRITISH COLUMBIA AND ALBERTA SATURDAY RESULTING IN A ZONAL FLOW ALOFT
ACROSS OUR FORECAST AREA. IN ADDITION...AN ELONGATED AREA OF HIGH
PRESSURE WILL STRETCH FROM WESTERN MONTANA DOWN INTO COLORADO. PRESSURE
FIELDS IN THE MODELS DIVERGE AT THIS POINT. THE MRF PLACES A STRONG AREA
OF LOW PRESSURE ACROSS EASTERN NORTH DAKOTA. THIS COMBINED WITH THE AREA
OF HIGH PRESSURE OVER THE NORTHERN ROCKIES WOULD RESULT IN WINDY
CONDITIONS.
SUN...TROUGH ACROSS SOUTHERN CANADA STRENGTHENS AND SLIDES JUST TO THE
NORTH OF THE BORDER MAKING FOR A NORTHWEST FLOW ALOFT. BOTH MRF
AND ECMWF ARE IN AGREEMENT THAT A LEE SIDE TROUGH WILL DEVELOP
WITH PRESSURE GRADIENTS TIGHTENING ACROSS THE WESTERN HALF OF OUR
FORECAST AREA. UKMET IS THE ONE IN DISAGREEMENT AND DOES NOT HINT AT
MUCH OF A TROUGH. SUNDAY SHOULD HAVE BREEZY NORTH WINDS BUT NOT AS
BREEZY AS SATURDAY.
MON & TUE...TROUGH CONTINUES TO MOVE ACROSS SOUTHERN CANADA WHICH WILL
CONTINUE OUR NORTHWEST FLOW ALOFT. COOLER AIR ALOFT COUPLED WITH
NORTHWEST FLOW SHOULD HELP TO PRODUCE MOSTLY CLOUDY SKIES ACROSS THE
FORECAST AREA. BEST CHANCES FOR PRECIP WILL BE ACROSS THE FAR EAST AS
MOST OF THE PRECIP FROM THE TROUGH IN CANADA MOVES ACROSS THE DAKOTAS.
HOOLEY

    WED     THU     FRI     FRI     SAT     SUN     MON
-----------------------------------------------------------
BIL 060/084 056/075 050/075 053/081 053/077 050/075 049/075
    03/T    44/T    43/T    20/B    00/E    00/B    00/E
LVM 049/079 048/071 045/073 048/079 049/076 049/073 045/073
    04/T    44/T    42/T    00/B    00/E    00/B    00/E
HDN 057/086 053/077 048/075 048/083 053/079 049/077 047/077
    03/T    44/T    43/T    22/T    00/E    02/T    20/E
MLS 067/087 061/078 053/073 052/081 054/079 053/077 050/077
    22/T    44/T    43/T    03/T    00/E    23/T    32/T
4BQ 064/086 059/077 052/071 052/081 053/078 053/076 051/076
    22/T    44/T    43/T    23/T    00/E    22/T    22/T
BHK 063/085 058/078 051/072 051/080 051/079 052/075 049/075
    32/T    44/T    43/T    03/T    00/E    33/T    33/T
SHR 057/087 056/077 047/074 047/080 048/078 049/073 045/073
    23/T    44/T    43/T    30/U    00/E    02/T    20/E

.BYZ...
MT...NONE.
WY...NONE.