991
FXUS65 KGGW 160912
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
212 AM MST TUE DEC 16 2025
DISCUSSION
KEY MESSAGES:
- HIGH WIND WARNINGS AND WATCHES REMAINS IN EFFECT. WARNING FOR
PHILLIPS COUNTY CONTINUES THROUGH 11 AM THIS MORNING, WATCH FOR
THE ENTIRE AREA IS IN EFFECT FOR WEDNESDAY AND WEDNESDAY NIGHT.
- WARM TEMPERATURES AND MOSTLY DRIER WEATHER EXPECTED THROUGH
WEDNESDAY.
- WINTRY PRECIPITATION IS LIKELY IN THE NE WEDNESDAY NIGHT THAT
COULD BRING BLIZZARD CONDITIONS AT TIMES TO VALLEY, ROOSEVELT,
DANIELS AND SHERIDAN COUNTIES.
WEATHER PATTERN OVERVIEW:
ARCTIC AIRMASS OVER CANADA WILL CONTINUE TO STAY NORTH WITH THE
ZONAL FLOW KEEPING THE MILD PACIFIC AIRMASS OVER MONTANA. BUT A
COLD FRONT WILL DROP IN THIS MORNING AND HELP MIX IN HIGHER LEVEL
WINDS TO THE SURFACE OVER THE CWA THIS MORNING. WIND GUSTS TO 75
MPH HAVE OCCURRED OVERNIGHT IN PHILLIPS COUNTY, WHERE A HIGH WIND
WARNING REMAINS IN EFFECT.
A STRONGER COLD FRONT THEN DROPS IN WEDNESDAY AFTERNOON AND
EVENING WITH 850 MB WINDS AS HIGH AS 70 KTS OVER THE AREA. IT
ALSO HAS A VERY STRONG PRESSURE GRADIENT AND HIGH LAPSE RATES. A
HIGH WIND WATCH REMAINS IN EFFECT FOR THE ENTIRE CWA. ABOUT AN
INCH OR TWO OF SNOW IS POSSIBLE ACROSS PARTS OF VALLEY, DANIELS,
SHERIDAN, AND ROOSEVELT COUNTIES AND WITH 40+ MPH SUSTAINED WINDS
AND SNOW THAT FALLS WILL LIKELY CREATE BLIZZARD OR NEAR BLIZZARD
CONDITIONS. THE QUESTION MARK IS WHETHER OR NOT IT ENDS UP BEING A
SHORT DURATION SNOW SQUALL OR WILL THE SNOW LAST 3+ HOURS TO MEET
THE CRITERIA FOR A BLIZZARD WARNING. ANY SNOW COVER THAT REMAINS
FROM THE CURRENT WARM WEATHER WILL BE CRUSTED AND NOT BLOW. SO,
ANY BLOWING SNOW THAT OCCURS WILL HAVE TO COME FROM NEW SNOW.
STRONG WINDS WILL QUICKLY DIMINISH EARLY THURSDAY MORNING.
LOW WEDNESDAY NIGHT WILL BE SIGNIFICANTLY COLDER WITH LOWS FROM BELOW
ZERO NORTH TO THE TEENS SW.
ANOTHER DISTURBANCE WILL MOVE EAST THROUGH THE AREA THURSDAY NIGHT
AND FRIDAY, WITH A BRIEF WARM UP AND A CHANCE OF A RAIN/SNOW MIX.
COLDER TEMPERATURES WILL RETURN FRIDAY NIGHT AND SATURDAY.
FORECAST CONFIDENCE & DEVIATIONS:
BLENDED NBM AND NBM90 FOR THE WINDS FOR WEDNESDAY AND WEDNESDAY
NIGHT.
CONFIDENCE IS HIGH FOR THE STRONG WINDS WEDNESDAY AFTERNOON AND
NIGHT. CONFIDENCE IS MODERATE FOR SNOW AND BLOWING SNOW WEDNESDAY
NIGHT BUT LOW ON WHETHER OR NOT IT WILL LAST LONG ENOUGH TO MEET
BLIZZARD CONDITIONS.
AVIATION
UPDATED: 0900Z/200 AM
FLIGHT CATEGORY: VFR.
DISCUSSION: WEST TO SW WINDS 15 TO 30 KNOTS WITH HIGHER GUSTS
EARLY THIS MORNING WILL SHIFT TO WNW AROUND 12Z THIS MORNING WITH
THE PASSAGE OF A COLD FRONT. GUSTS TO 40 KTS CAN BE EXPECTED. WNW
WINDS WILL DIMINISH TO 10 TO 20 KNOTS THIS AFTERNOON AND BACK TO
THE SOUTH TO SW 5 TO 10 KNOTS THIS EVENING AND REMAIN THAT WAY
OVERNIGHT.
SKIES WILL BE MOSTLY CLEAR WITH SOME MID AND HIGH CLOUDS AT TIMES.
MID LEVEL CLOUDS ARE EXPECTED TONIGHT.
LLWS: THERE WILL BE LLWS AT TIMES THIS MORNING.
GGW WATCHES/WARNINGS/ADVISORIES
HIGH WIND WARNING UNTIL 11 AM MST THIS MORNING FOR CENTRAL AND
SOUTHEAST PHILLIPS-NORTHERN PHILLIPS-SOUTHWEST PHILLIPS.
HIGH WIND WATCH FROM WEDNESDAY MORNING THROUGH LATE WEDNESDAY
NIGHT FOR CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN
VALLEY-DANIELS-DAWSON-EASTERN ROOSEVELT-GARFIELD-MCCONE-NORTHERN
PHILLIPS-NORTHERN VALLEY-PETROLEUM-PRAIRIE-RICHLAND-SHERIDAN-
WESTERN ROOSEVELT-WIBAUX.
HIGH WIND WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING
FOR SOUTHWEST PHILLIPS.
WEATHER.GOV/GLASGOW
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