766
FXUS65 KGGW 122006
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
206 PM MDT FRI SEP 12 2025
DISCUSSION
KEY MESSAGES:
1) SPC HAS UPGRADED PARTS OF NORTHEAST MONTANA TO A SLIGHT RISK
FOR SEVERE WEATHER THIS AFTERNOON AND EVENING
2) STRONG THUNDERSTORMS WITH A HAIL RISK MORE LIKELY LATE
AFTERNOON AND EARLY EVENING, WITH WIND TAKING OVER AS MAIN RISK
LATER TONIGHT
3) SATURDAY-SUNDAY AND THEN TUESDAY-WEDNESDAY WILL BE THE MAIN TWO
WIDESPREAD PRECIPITATION ACCUMULATING DAYS THIS COMING WEEK, WITH
MANY AREAS SEEING HIGH PROBABILITY (>80%) OF 0.10" AND LOW
PROBABILITY (<20%) OF 1" OR MORE
WEATHER PATTERN OVERVIEW:
SHOWERS AND THUNDERSTORMS ARE BLOOMING ACROSS EASTERN MONTANA AS
TEMPERATURES HEAT UP AND THE ATMOSPHERE BECOMES MORE UNSTABLE.
WITH THE SLIGHT RISK FOR SEVERE WEATHER FROM SPC THIS EVENING,
EARLY STORMS COULD PRODUCE A HAIL RISK, THEN TRANSITION TO STRONG
WINDS LATER TONIGHT. STORM MOTIONS WILL BE SLOW, MEANING ANY AREAS
CAUGHT UNDER STORMS COULD SEE HEAVY RAINFALL IN A SHORT AMOUNT OF
TIME.
BEGINNING SATURDAY, A STRONG LOW PRESSURE MOVES UP INTO THE REGION
AND WILL BRING WIDESPREAD ACCUMULATING RAINFALL AND COOLER
TEMPERATURES. THERE IS A HIGH LIKELIHOOD (>80%) OF RAINFALL
EXCEEDING 0.10" FOR MANY AREAS, BUT A LOW PROBABILITY (<20%) OF
AREAS RECEIVING IN EXCESS OF 1". THE BEST CHANCES FOR THIS LOW
PROBABILITY EVENT TO OCCUR WILL BE ALONG THE ND BORDER AND INTO
NORTH DAKOTA. A BACKSIDE EVENT WITH ACCUMULATING RAINFALL IS
EXPECTED TUESDAY INTO WEDNESDAY, WITH HIGHER RAINFALL EXPECTED IN
WESTERN AREAS OUT TOWARDS GREAT FALLS AND LESS AMOUNTS TO THE
EAST. TEMPERATURES FOR MUCH OF THE COMING WEEK WILL BE SEASONABLE.
FORECAST CONFIDENCE & DEVIATIONS:
NBM MOSTLY LEFT IN PLACE THIS FORECAST CYCLE AS IT CAPTURED
OVERALL EXPECTED TRENDS WELL AND MATCHED FOR COLLABORATION. CONFIDENCE
THUS REMAINS MODERATE TO HIGH ON AN ACTIVE PATTERN THROUGH THE WEEKEND,
BUT BELOW AVERAGE ON THE TIMING, PLACEMENT, AND EXACT PRECIPITATION
AMOUNTS GIVEN ENSEMBLE SHIFTS RUN TO RUN.
CLIFF
AVIATION
UPDATED: 2000Z ON 9/12/2025
EXPECTED FLIGHT CATEGORY: VFR TRANSITIONING TO IFR TOMORROW
SYNOPSIS: ANOTHER ROUND OF ISOLATED AND SCATTERED SHOWERS AND
STORMS WILL PUSH THROUGH NORTHEAST MONTANA THIS EVENING AND
TONIGHT, WITH SOME POSSIBLY STRONG STORMS IN THE VICINITY OF LOCAL
AIRFIELDS. MORE WIDESPREAD RAIN MOVES INTO THE REGION SATURDAY
AND SUNDAY, ALONG WITH CEILINGS DEGRADING DOWN TO IFR RANGE WITH
THE APPROACHING LOW PRESSURE SYSTEM.
WINDS: GENERALLY LIGHT AND VARIABLE, BECOMING ERRATIC AND GUSTY
NEAR THE STRONGER STORMS.
EQUIPMENT: COMMS ISSUES WITH THE KSDY OBSERVATION REMAIN. AMD NOT
SKED WILL REMAIN WITH THE TAF THERE UNTIL TRANSMISSION OF OBS
BECOMES MORE STABLE.
CLIFF
GGW WATCHES/WARNINGS/ADVISORIES
NONE.
WEATHER.GOV/GLASGOW
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