863
FXUS65 KGGW 301841
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
1241 PM MDT MON MAR 30 2026
KEY MESSAGES
- A SLOW-MOVING SURFACE TROUGH WILL BRING SCATTERED RAIN AND
SHOWERS THROUGH AROUND MIDNIGHT TONIGHT. A LAKE WIND ADVISORY IS
IN EFFECT THROUGH 3 AM TUESDAY FOR FORT PECK LAKE.
- BELOW FREEZING LOW TEMPERATURES THROUGH THE END OF THE WEEK.
ANOTHER SURFACE TROUGH BRINGS POTENTIAL FOR PRECIPITATION
TUESDAY NIGHT INTO WEDNESDAY.
- NEXT CHANCE FOR WIDESPREAD RAIN AND SNOW IS LINING UP AROUND
THURSDAY THROUGH FRIDAY.
DISCUSSION
WEATHER PATTERN OVERVIEW:
A BROAD UPPER TROUGH AND SURFACE TROUGH ARE HELPING RAIN SHOWERS,
AND A SLIGHT CHANCE OF SNOW SHOWERS MOVE THE AREA THROUGH ABOUT
MIDNIGHT TONIGHT BEFORE MOVING EAST. STRONG WINDS ARE ALSO
EXPECTED WITH THIS DISTURBANCE. RAIN AND SNOW ACCUMULATIONS WILL
DEPEND ON THE LOCATION OF THE JET OVERHEAD IN COMBINATION WITH THE
SURFACE TROUGH. ENOUGH COLDER AIR HAS MIXED IN BEHIND THE TROUGH
TO ALLOW SNOW ALONG THE HI- LINE. THIS AFTERNOON, A COLD FRONT
ACCELERATES SOUTH AND OPENS THE WAY FOR COLDER TEMPERATURES AND A
HARD FREEZE BOTH TONIGHT AND TUESDAY NIGHT. THERE IS A DECENT
LIKELIHOOD OF STRESS OCCURING TO NEWBORN LIVESTOCK.
ON TUESDAY NIGHT INTO WEDNESDAY, ANOTHER PUSH OF A SURFACE TROUGH
HAS ANOTHER OPPORTUNITY FOR RAIN AND SNOW OCCURRING ACROSS THE
SOUTHEASTERN TWO THIRDS OF THE AREA. OVERALL PRECIPITATION
ACCUMULATIONS ARE SUGGESTED TO BE BELOW 0.05 INCHES FOR THIS
PERIOD.
ON WEDNESDAY NIGHT THROUGH FRIDAY NIGHT, THERE IS AGREEMENT
BETWEEN THE GFS AND ECMWF ENSEMBLES OF A POTENT, SLOW MOVING
SHORTWAVE TROUGH MOVING THROUGH THE AREA. SOUTHEAST WINDS ARE
EXPECTED TO COME UP AHEAD OF AND DURING THIS SYSTEM, SO THERE IS
DECENT POTENTIAL FOR A LAKE WIND ADVISORY TO BE ISSUED IN THIS
TIME. THERE IS ALSO A STRONG SUGGESTION OF RAIN AND SNOW
OCCURRING, WITH A HIGH LIKELIHOOD OF ACCUMULATIONS OF
PRECIPITATION BETWEEN ONE TENTH OF AN INCH UP TO SEVEN TENTHS OF
AN INCH, AS WELL AS A TRACE OF SNOW UP TO 7 INCHES OF SNOW.
TEMPERATURES BETWEEN TUESDAY AND FRIDAY ARE LIKELY TO BE BELOW THE
AVERAGE HIGH TEMPERATURE FOR THIS TIME OF YEAR, WITH A TREND
TOWARD NORMAL FROM SATURDAY ONWARD. THERE IS SOME MODEL AGREEMENT
BETWEEN THE ECMWF AND GFS ENSEMBLES ON DRIER WEATHER AND A RIDGE FROM
SATURDAY THROUGH MONDAY.
FORECAST CONFIDENCE & DEVIATIONS:
MAIN DEVIATIONS ARE WINDS AND POPS. USED A MIX OF NBM AND NBM 90
FOR WINDS FOR TODAY, AND USED GFS1HR FOR POPS FOR TODAY.
THERE IS MODERATE TO HIGH CONFIDENCE IN RAIN AND SNOW OCCURRING
THROUGH MIDNIGHT TONIGHT, WITH MODERATE CONFIDENCE ON
ACCUMULATIONS.
THERE IS MODERATE CONFIDENCE A LAKE WIND ADVISORY WILL BE NEEDED
AGAIN SOMETIME BETWEEN TUESDAY NIGHT AND FRIDAY.
THERE IS MODERATE CONFIDENCE IN PRECIPITATION OCCURRING TUESDAY
NIGHT INTO WEDNESDAY FOR THE SOUTHEASTERN TWO THIRDS OF THE AREA,
AND IN ACCUMULATIONS STAYING BELOW 0.05 INCHES.
THERE IS HIGH CONFIDENCE IN RAIN AND SNOW OCCURRING FROM THURSDAY
INTO FRIDAY EVENING FOR THE ENTIRE AREA, WITH LOW TO MODERATE
CONFIDENCE ON SNOWFALL AND PRECIPITATION AMOUNTS. THERE IS
MODERATE TO HIGH CONFIDENCE ON THE PRECIPITATION BEING WIND
DRIVEN, WHICH HAS POTENTIAL TO REDUCE VISIBILITY IN THIS PERIOD.
AVIATION
LAST UPDATE: 1900Z
FLIGHT CATEGORY: VFR - MVFR
DISCUSSION: A BROAD UPPER TROUGH AND SURFACE TROUGH ARE EXPECTED
TO HELP RAIN SHOWERS AND A SLIGHT CHANCE OF SNOW SHOWERS MOVE
THROUGH TAF SITES THROUGH 06Z BEFORE COMING TO AN END. THERE IS
MODERATE TO HIGH (40 TO 60 PERCENT) CONFIDENCE OF MVFR CONDITIONS
OCCURING THROUGH 06Z BEFORE A TRANSITION TO VFR. THE NEXT
OPPORTUNITY FOR MVFR CONDITIONS LOOKS TO BE TOMORROW NIGHT AS
ANOTHER CHANCE FOR PRECIPITATION MOVES THROUGH THE SOUTHEAST PART
OF THE AREA.
WIND: NORTHWEST AT 15 TO 25 KNOTS WITH GUSTS TO 34 KNOTS,
DECREASING TO 10 TO 16 KNOTS AFTER 08Z, BECOMING LIGHT AND
VARIABLE AFTER 13Z, BECOMING SOUTHEAST 6 TO 15 KNOTS AFTER 18Z
TUESDAY.
GGW WATCHES/WARNINGS/ADVISORIES
LAKE WIND ADVISORY UNTIL 3 AM MDT TUESDAY FOR CENTRAL AND
SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY-GARFIELD-MCCONE-
PETROLEUM.
WEATHER.GOV/GLASGOW
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page