627
FXUS65 KGGW 151849
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
1249 PM MDT FRI MAY 15 2026
KEY MESSAGES
- RED FLAG WARNING IN EFFECT UNTIL 9 PM THIS EVENING.
- LAKE WIND ADVISORY IN EFFECT UNTIL 9 PM THIS EVENING WITH WAVES
UP TO 5 FT. ISOLATED WAVE HEIGHTS UP TO 6 FT.
- POTENTIAL ACCUMULATING RAINFALL FROM SATURDAY NIGHT THROUGH
TUESDAY. OVERNIGHT TEMPERATURES MONDAY AND TUESDAY ARE EXPECTED
TO BE NEAR FREEZING.
DISCUSSION
WEATHER PATTERN OVERVIEW:
STRONG 500 MILLIBAR ZONAL FLOW AND COOL TEMPERATURES (BELOW -20
CELSIUS) WILL ALLOW SOME SCATTERED SHOWERS AND THUNDERSTORMS TO
OCCUR UNDER WINDY CONDITIONS. THERE IS POTENTIAL FOR SOME OF THESE
GUSTS TO EXCEED 50 MPH DURING PEAK HEATING. THE SURFACE LOW WILL
DRIFT INTO WESTERN ONTARIO WHILE A SLOW MOVING COLD FRONT DROPS
SOUTH CLOSE TO THE MONTANA/CANADA BORDER. WINDS ARE EXPECTED TO
COME DOWN AFTER SUNSET.
AN UPPER TROUGH WILL CONTINUE TO REMAIN OVER THE AREA FOR THE NEXT
5 DAYS BEFORE BREAKING DOWN A BIT. IN THAT TIME, A WAVE OF
MOISTURE IS EXPECTED TO REACH NORTHEAST MONTANA BY SATURDAY
NIGHT AND CONTINUE THROUGH TUESDAY. THE LATEST GFS ENSEMBLE
INDICATES THERE IS A 50 TO 100 PERCENT CHANCE OF RAIN EXCEEDING
ONE TENTH OF AN INCH ACROSS THE FAR WEST, EAST AND NORTHERN PARTS
OF THE AREA, WITH LESSER AMOUNTS IN THE CENTRAL PARTS. THERE IS A
30 TO 50 PERCENT PROBABILITY FOR HALF AN INCH OF RAIN OCCURRING.
SCATTERED THUNDERSTORMS HAVE THE BEST OPPORTUNITY FOR PRODUCING
HEAVY RAINFALL, SO HALF AN INCH OF RAIN IS POSSIBLE IN THESE
STORMS. AS THE LOW PRESSURE MOVES IN, SOME CAMS INDICATE WIND
GUSTS EXCEEDING 50 MPH IN THE FAR SOUTHEAST ON SATURDAY NIGHT. SOME
OF THE MODELS ARE SHOWING IT TO BE COLD ENOUGH FOR SNOW DURING THE
DAY AND NIGHT ON MONDAY FOR THE LITTLE ROCKIES. LITTLE
ACCUMULATION IS EXPECTED IN THIS TIME THOUGH.
THE UPPER TROUGH BEGINS TO LIFT OUT TUESDAY SO A RETURN TO MORE
NORMAL CONDITIONS FOR THIS TIME OF YEAR CAN BE EXPECTED.
FORECAST CONFIDENCE & DEVIATIONS:
INCREASED POPS MANUALLY TO REPRESENT THE LATEST CAM MODELS FOR
THIS AFTERNOON.
THERE IS MODERATE TO HIGH CONFIDENCE IN SCATTERED SHOWERS AND
STORMS OCCURRING ACROSS THE NORTHERN HALF OF THE AREA THIS
AFTERNOON.
THERE IS HIGH CONFIDENCE IN PRECIPITATION OCCURRING SATURDAY
EVENING THROUGH TUESDAY, BUT LOW TO MODERATE CONFIDENCE ON TOTAL
RAINFALL AMOUNTS.
THERE IS HIGH CONFIDENCE WIND GUSTS OVER 50 MPH WILL OCCUR ACROSS
VARIOUS PARTS OF THE AREA TODAY.
AVIATION
LAST UPDATED: 1850Z
FLIGHT CAT RANGE: VFR, MVFR POSSIBLE THIS AFTERNOON.
DISCUSSION:
GUSTY WEST WINDS ARE CONTINUING THROUGH THE DAY TODAY, SO PATCHY
BLOWING DUST, AND SCATTERED SHOWERS AND THUNDERSTORMS MAY
CONTRIBUTE TO MVFR CONDITIONS BETWEEN NOW AND 8 PM THIS EVENING.
THERE IS MODERATE CONFIDENCE (50 PERCENT) OF REDUCTIONS IN
VISIBILITY OCCURRING WITH THE WIND AND RAIN. VFR CONDITIONS ARE
EXPECTED AFTER 8 PM.
WINDS: WEST NORTHWEST AT 20 TO 30 KNOTS WITH GUSTS TO 40 KNOTS,
DECREASING TO LIGHT AND VARIABLE AFTER 05Z.
GGW WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR
DAWSON/MCCONE/PRAIRIE/RICHLAND/WIBAUX COUNTIES-FORT PECK
RESERVATION AND DANIELS/ROOSEVELT/SHERIDAN COUNTIES-NORTHERN
VALLEY AND NORTHERN PHILLIPS COUNTIES-SOUTHERN PETROLEUM AND
SOUTHERN GARFIELD COUNTIES-THE LITTLE ROCKIES-THE LOWER MISSOURI
RIVER BREAKS INCLUDING THE CHARLES M RUSSELL NATIONAL WILDLIFE
REFUGE.
LAKE WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR CENTRAL AND
SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY-GARFIELD-MCCONE-
PETROLEUM.
WEATHER.GOV/GLASGOW
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