454
FXUS65 KGGW 140829
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
229 AM MDT MON JUL 14 2025
DISCUSSION
KEY MESSAGES:
1) LOOK FOR SHOWERS AND THUNDERSTORMS AT TIMES TODAY MAINLY ALONG
THE CANADIAN BORDER. THE SHOWERS AND THUNDERSTORMS WILL BECOME
WIDESPREAD ACROSS NE MONTANA TONIGHT. ISOLATED STRONG TO SEVERE
THUNDERSTORMS ARE POSSIBLE TODAY AND TONIGHT WITH THE BEST CHANCE
THIS EVENING.
2) GUSTY NORTHEAST WINDS ARE EXPECTED STARTING THIS EVENING WITH
A COLD FRONTAL PASSAGE. THE GUSTY NE WIND WILL CONTINUE OVERNIGHT
AND TUESDAY. A LAKE WIND ADVISORY WILL BE ISSUED FOR FORT PECK
LAKE
3) WIDESPREAD WET WEATHER AND COOLER TEMPERATURES LOOK TO BE IN
PLACE AREA WIDE LATE TONIGHT THROUGH WEDNESDAY. TOTAL RAINFALL
ACROSS THE REGION WILL RANGE BETWEEN 0.50" AND 1.00" FOR MOST
LOCATIONS WITH ISOLATED HIGHER TOTALS.
WEATHER PATTERN OVERVIEW:
A FRONTAL BOUNDARY LOOKS TO KEEP SHOWERS AND THUNDERSTORMS
CONFINED TO THE CANADIAN BORDER MOST OF TODAY. IT WILL ALSO
PROVIDE A LARGE TEMPERATURE RANGE BETWEEN THE UPPER 70S NORTH AND
MID TO UPPER 90S SOUTH FOR HIGHS TODAY. THE FRONT WILL MOVE SOUTH
AS A COLD FRONT STATING IN THE LATE AFTERNOON AND SPREAD THE
SHOWERS AND THUNDERSTORMS TO THE ENTIRE REGION THIS EVENING AND
TONIGHT. GUSTY NE WINDS ARE EXPECTED BEHIND THE FRONT AND A LAKE
WIND ADVISORY FOR FORT PECK LAKE WILL BE ISSUED BETWEEN 6 PM TODAY
AND 6 PM TUESDAY.
THIS EVENING, HREF MAX ENSEMBLE WIND GUST AND MAX UPDRAFT
HELICITY LEND SUPPORT FOR AN ISOLATED SEVERE THUNDERSTORM THREAT.
LARGE HAIL AND DAMAGING WINDS WOULD BE PRIMARY CONCERNS WITH THE
TIMING MAINLY AFTER 4PM. OTHERWISE SHOWERS AND THUNDERSTORMS WILL
BECOME WIDESPREAD TONIGHT THROUGH EITHER TUESDAY NIGHT OR
WEDNESDAY. HEAVY RAINFALL IS POSSIBLE IN SOME AREAS. MOST AREAS
ARE LOOKING AT BETWEEN 0.50 INCH AND ONE INCH OF RAINFALL FROM
THIS EVENING. TUESDAY AND WEDNESDAY WILL HAVE MUCH COOLER
TEMPERATURES.
AN EARLY LOOK AT ENSEMBLES SUPPORT A RETURN TO NEAR NORMAL
TEMPERATURES BY THE END OF THE WEEK BUT WITH ACTIVE WEATHER
CONTINUING AT TIMES.
FORECAST CONFIDENCE & DEVIATIONS:
CONFIDENCE IS MODERATE TO HIGH THAT THUNDERSTORM CHANCES WILL
INCREASE ACROSS NE MONTANA TODAY INTO TUESDAY WITH WIDESPREAD
STEADY RAINFALL AMOUNTS. HOWEVER, SOMEWHAT LOWER CONFIDENCE EXISTS
ON A SEVERE WEATHER POTENTIAL DUE TO THE ISOLATED NATURE OF
EXPECTED RISK.
INCREASED WINDS SPEEDS SOMEWHAT TONIGHT AS MODELS FREQUENTLY UNDER
FORECAST WINDS BEHIND COLD FRONTS. NBM WAS OTHERWISE LARGELY
USED FOR THE FORECAST PERIOD WHICH CAPTURED EXPECTED OVERALL
TRENDS WELL FOR THIS CYCLE.
AVIATION
LAST UPDATED: 0815Z ON JULY 14, 2025
FLIGHT CAT RANGE: VFR TODAY AND THIS EVENING TRANSITIONING TO MVFR
AND IFR LATE TONIGHT.
DISCUSSION: VFR CONDITIONS WILL CONTINUE TODAY WITH MID AND HIGH
LEVEL CLOUDS AT TIMES. MOST SHOWERS AND THUNDERSTORMS TODAY WILL
REMAIN NORTH OF THE TAF SITES ALTHOUGH KGGW AND KOLF COULD SEE AN
ISOLATED SHOWER OR THUNDERSTORM. A COLD FRONT THAT WILL QUASI-
STATIONARY NEAR THE CANADIAN BORDER MOST OF TODAY WILL MOVE SOUTH
STARTING IN THE LATE AFTERNOON AND BRING FREQUENT SHOWERS AND
THUNDERSTORMS STARTING THIS EVENING AND CONTINUING INTO TUESDAY.
LOW CLOUDS WILL MOVE INTO THE AREA TONIGHT BEHIND THE COLD FRONT
WITH A MIX OF MVFR AND IFR CEILINGS LIKELY AFTER 06Z.
WINDS: LOOK FOR EAST TO NE WINDS AT 5 TO 15 KNOTS THIS MORNING,
BECOMING NORTH AT 5 TO 15 KTS THIS AFTERNOON AT KGDV WHILE
REMAINING NE AT THE OTHER TAF SITES. NE WINDS WILL INCREASE TO 15
TO 25 KNOTS AFTER 00Z AT ALL TAF SITES.
GGW WATCHES/WARNINGS/ADVISORIES
LAKE WIND ADVISORY FROM 6 PM THIS EVENING TO 6 PM MDT TUESDAY
FOR CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY-
GARFIELD-MCCONE-PETROLEUM.
WEATHER.GOV/GLASGOW
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