811
FXUS65 KTFX 270538
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1138 PM MDT SUN APR 26 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- MUCH COOLER THAN AVERAGE TEMPERATURES AND UNSETTLED CONDITIONS
PERSIST THOUGH MONDAY WITH NEAR RECORD LOW TEMPERATURES IN SOME
LOCATIONS MONDAY MORNING.
- PERIODS OF LIGHT SNOW ACROSS SOUTHWEST MT TONIGHT WILL BRING SOME
MINOR ACCUMULATION, MAINLY TO MOUNTAIN PASSES.
- A GRADUAL WARMING TREND BEGINS TUESDAY WITH TEMPERATURES
RETURNING TO AROUND SEASONAL AVERAGES FOR MID TO LATE THIS
WEEK.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
A SPRAWLING CLOSED UPPER LEVEL LOW REMAINS CENTERED ACROSS SK WITH
TROUGHING EXTENDING TO ITS SOUTHWEST ACROSS THE WESTERN US. THE LOW
WILL SLOWLY LIFT OUT TO THE EAST/NORTHEAST EARLY THIS WEEK, BUT
TROUGHING WILL LINGER ACROSS THE NORTHERN ROCKIES AND MT THROUGH
THE THE FIRST HALF OF THE WORK WEEK.
MULTIPLE EMBEDDED SHORTWAVE DISTURBANCES CONTINUE TO ROTATE THROUGH
THE TROUGH, WITH ONE TRACKING EAST ACROSS CENTRAL/SOUTHERN MT TODAY
BEFORE ANOTHER DROPS SOUTH FROM BC AND TRACKS ACROSS SOUTHWEST MT
LATER TONIGHT THROUGH MONDAY MORNING. AREAS OF ENHANCED DAYTIME SNOW
SHOWER ACTIVITY AND OVERNIGHT LIGHT SNOW ACCOMPANY THESE
DISTURBANCES THROUGH MONDAY WHILE THE OVERALL COLD AIR ALOFT AND
UNSTABLE/CYCLONIC NORTHWESTERLY FLOW WILL CONTINUE TO SUPPORT MORE
SCATTERED SNOW SHOWERS/FLURRIES OUTSIDE OF THESE AREAS THROUGH
MONDAY AFTERNOON.
TEMPERATURES REMAIN WELL BELOW AVERAGE THROUGH MONDAY WITH A WARMING
TREND BEGINNING TUESDAY AND CONTINUING THROUGH FRIDAY. FLOW ALOFT
REMAINS CYCLONIC AND NORTHWESTERLY THROUGH WEDNESDAY BEHIND THE
DEPARTING UPPER LEVEL SYSTEM WITH ENOUGH MINOR DISTURBANCES,
LINGERING MOISTURE AND AFTERNOON INSTABILITY TO SUPPORT DIURNAL
SHOWER DEVELOPMENT AND EVEN THE POTENTIAL FOR A FEW ISOLATED
THUNDERSTORMS.
THE WARMEST/DRIEST DAYS OF THE UPCOMING WEEK WILL BE THURSDAY AND
FRIDAY AS RIDGING BRIEFLY DEVELOPS OVER THE WESTERN US. BY NEXT
WEEKEND, RIDGING SHIFTS WEST AND BUILDS OFFSHORE OF THE PACIFIC
NW WITH QUITE A BIT OF UNCERTAINTY IN THE DOWNSTREAM INTERACTION
OF TROUGHING REDEVELOPING ACROSS CANADA AND A SOUTHERN STREAM
SYSTEM LOCATED NEAR CA. HOENISCH
- FORECAST CONFIDENCE & SCENARIOS:
TONIGHT COULD BE THE COLDEST OF THE THIS STRETCH OF COOLER
WEATHER, PARTICULARLY ACROSS PARTS OF NORTH-CENTRAL MT, WHERE SOME
PARTIAL CLEARING IS EXPECTED. OVERNIGHT LOW TEMPERATURES MAY
REACH DAILY RECORDS AT SOME NORTH-CENTRAL MT LOCATIONS WITH THE
RISK FOR MINIMUM TEMPERATURES AT OR BELOW 15F RANGING FROM 25-35%
AT GREAT FALLS AND LEWISTOWN TO AROUND 50% NEAR HAVRE AND 90% OR
HIGHER ACROSS MOST OF GLACIER AND LIBERTY COUNTIES. WHILE MOST
AREAS HAVE SEEN SUB-FREEZING TEMPERATURES THE LAST FEW NIGHT, THE
ADDITIONAL DROP TONIGHT COULD HAVE A GREATER IMPACT ON
TENDER/EMERGING VEGETATION.
ADDITIONAL SNOW ACCUMULATION THROUGH MONDAY WILL BE MINOR (LESS
THAN 1") ACROSS MOST LOWER ELEVATION AREAS. THE DISTURBANCE MOVING
THROUGH SW MT TONIGHT THROUGH TOMORROW WILL BRING A PERIOD OF
STEADIER SNOW TO AREAS ALONG THE IDAHO BORDER AND ACROSS THE
MOUNTAINS AS FAR NORTH AS THE ELKHORN/BOULDER AND LITTLE/BIG BELT
RANGES WITH UP TO 3" AT THE HIGHEST ELEVATIONS BUT ACCUMULATIONS
CLOSER TO AROUND 1" AT PASS LEVELS. THE MAIN IMPACT FROM THIS
COULD BE SOME LOCALIZED SLUSHY/SLICK ROADS OVER MOUNTAIN PASSES
FOR THE MONDAY MORNING COMMUTE. HOENISCH
AVIATION
27/06Z TAF PERIOD
SCATTERED SNOW SHOWERS WILL CONTINUE TO AFFECT PORTIONS OF THE CWA
THROUGH THE PERIOD. THE MOST LIKELY AREA TODAY WILL BE FAR
SOUTHWEST MT ALONG THE ID/MT BORDER FROM MONIDA PASS TO WEST
YELLOWSTONE. AS YOU GO NORTH, THE CHANCES FOR SNOW SHOWERS
DECREASE. ALSO, CLOUDS WILL BEGIN TO THIN OUT ALONG THE HIGHWAY 2
CORRIDOR FROM CUT BANK TO HAVRE. MOUNTAINS/PASSES WILL BE OBSCURED
ACROSS THE CWA BY CLOUDS THROUGH THE PERIOD. BRUSDA
PRELIMINARY POINT TEMPS/POPS
GTF 18 50 28 57 / 20 10 10 20
CTB 12 47 23 55 / 0 10 0 10
HLN 24 50 28 57 / 20 40 10 30
BZN 24 47 24 54 / 40 50 20 30
WYS 20 42 18 46 / 60 70 40 40
DLN 25 48 26 54 / 50 60 10 10
HVR 17 50 24 59 / 0 0 0 0
LWT 18 44 23 53 / 30 30 10 40
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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