940
FXUS65 KMSO 090857
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
257 AM MDT SUN AUG 9 2020
DISCUSSION
THE NORTHERN ROCKIES WILL REMAIN UNDER A DRY
WESTERLY FLOW THROUGH AT LEAST TUESDAY. A LONGWAVE TROUGH WILL
REMAIN ANCHORED ACROSS ALASKA AND PORTIONS OF WESTERN CANADA TODAY
THROUGH EARLY NEXT WEEK. SHORTWAVE TROUGHS WILL PROGRESS EASTWARD
ACROSS BRITISH COLUMBIA AND ALBERTA MONDAY INTO TUESDAY. THIS
WILL RESULT IN THE FOUR CORNERS HIGH REMAINING SUPPRESSED ACROSS
THE DESERT SOUTHWEST, LEAVING THE WESTERN U.S. IN A DRY WESTERLY
FLOW. TEMPERATURES WILL MODERATE BACK TO SEASONAL AVERAGES BY
TUESDAY, WITH HIGHS WARMING INTO THE MID TO UPPER 80S ACROSS
MONTANA VALLEY LOCATIONS AND INTO THE 90S ACROSS LOWER ELEVATIONS
OF CENTRAL IDAHO.
A DRY COLD FRONT ASSOCIATED WITH A SHORTWAVE TROUGH MOVING
EASTWARD ACROSS ALBERTA WILL MOVE ACROSS THE NORTHERN ROCKIES
TUESDAY INTO WEDNESDAY MORNING. THE PRIMARY CONCERN TUESDAY IS THE
POTENTIAL FOR AREAS OF CRITICAL FIRE WEATHER CONDITIONS,
PARTICULARLY ACROSS SOUTHWEST MONTANA, DUE TO THE COMBINATION OF
LOW HUMIDITY AND GUSTY WINDS WITH THE FRONT.
MODEL ENSEMBLE GUIDANCE HAS COME INTO BETTER AGREEMENT WITH THE
EVOLUTION OF THE WEATHER PATTERN WEDNESDAY THROUGH FRIDAY NEXT
WEEK. A SHORTWAVE TROUGH WILL DIG SOUTHWARD ACROSS BRITISH
COLUMBIA AND WILL MOVE EASTWARD ACROSS ALBERTA AND NORTHWEST
MONTANA. ENSEMBLE GUIDANCE HAVE BACKED OFF ON THE DEPICTION OF A
DEEPER SHORTWAVE TROUGH DIGGING SOUTHWARD INTO WESTERN MONTANA.
INSTEAD, GUIDANCE IS FAVORING THE BULK OF PRECIPITATION AND COOLER
TEMPERATURES STAYING NORTHWARD IN CANADIAN. NONETHELESS,
TEMPERATURES WILL REMAIN SLIGHTLY BELOW NORMAL DURING THIS TIME
PERIOD; HOWEVER, A WIDESPREAD PRECIPITATION EVENT ACROSS THE
NORTHERN ROCKIES LOOKS FAR LESS LIKELY.
AVIATION
VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS THE
NORTHERN ROCKIES TODAY. BREEZY WEST TO NORTHWESTERLY WINDS WILL
DEVELOP THIS AFTERNOON WITH GUSTS UP TO 20 KNOTS BEING COMMON AS
AN UPPER-LEVEL JET NOSES INTO NORTHWEST MONTANA NEAR THE
CONTINENTAL DIVIDE. SCATTERED FAIR WEATHER CUMULUS CLOUDS ARE
EXPECTED ACROSS WESTERN MONTANA THIS AFTERNOON. SKIES WILL
GRADUALLY BEGIN TO CLEAR OUT LATER THIS EVENING AS DRIER MID-LEVEL
AIR MOVES INTO THE REGION.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page