185
FXUS65 KTFX 261130
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
430 AM MST SUN JAN 26 2025
AVIATION SECTION UPDATED.
KEY MESSAGES
- DENSE FOG AND COLD TEMPERATURES THROUGH THIS MORNING.
- GENERALLY QUIET WEATHER CONDITIONS WITH A SLOW WARMING TREND
EXPECTED FOR MUCH OF NEXT WEEK.
- POTENTIAL FOR LIGHT SNOW NEXT WEEKEND.
DISCUSSION
/ISSUED 405 AM MST SUN JAN 26 2025/
- METEOROLOGICAL OVERVIEW:
CLEAR SKIES OVER SOUTHWEST MT THIS MORNING IS ALLOWING FOR A VERY
COLD MORNING, ALONG WITH SOME PATCHY DENSE FOG IN THE VALLEYS.
MOST OF THE FOG WILL DIMINISH BY LATE MORNING, AND WITH WARMING
TEMPERATURES BY LATE MORNING AS WELL, THE COLD AIR PRODUCTS
SHOULD BE ALLOWED TO EXPIRE BY THEN. OTHERWISE EXPECT INCREASING
CLOUDS THIS MORNING FROM THE NORTH, AS HIGH CLOUDS MOVE SOUTHWARD
FROM CANADA.
FOR MUCH OF THE WORK WEEK, EXPECT QUIET WEATHER CONDITIONS, AS AN
UPPER LEVEL RIDGE BUILDS ALONG THE WEST COAST. THIS WILL RESULT
IN SLOWLY WARMING TEMPERATURES OVER THE CWA THROUGH THE WEEK. THE
ONE EXCEPTION WILL BE THE VALLEYS OF SOUTHWEST MT. WITH MOSTLY
CLEAR SKIES AT NIGHT AND LIGHT WINDS DURING THE DAY, SOME VALLEY
LOCATIONS MIGHT NOT WARM AS QUICKLY AS PROGGED. THUS SOME
ADJUSTMENTS MIGHT NEED TO MADE TO HIGH TEMPERATURES OVER THE
SOUTHWEST MT THIS WEEK TO LOWER THEM A BIT.
THE NEXT CHANCE FOR SNOW LOOKS TO ARRIVE LATE ON FRIDAY, BUT MOST
LIKELY OVER THE WEEKEND. THE GFS/EC WERE IN PRETTY GOOD AGREEMENT
A FEW DAYS AGO, BUT NOW HAVE DIVERGED A BIT, WITH THE GFS
BECOMING A BIT WARMER AND SLOWER WITH THE INCREASED CHANCES FOR
SNOW. SO SOME ADJUSTMENTS TO SNOWFALL/TEMPERATURES MIGHT OCCUR
OVER THE NEXT FEW DAYS BECAUSE OF THE DIFFERENCE.
- FORECAST CONFIDENCE & SCENARIOS:
THE MAIN CONCERN OVER THE NEXT SEVERAL DAYS WILL BE DAYTIME HIGH
TEMPERATURES IN THE VALLEYS OF SOUTHWEST MT. WITH A COLD START
AND LIGHT WINDS, THE VALLEYS OF SOUTHWEST MT WILL BE SLOW TO
WARM, AND HIGH TEMPERATURES MIGHT BE A FEW DEGREES COOLER THAN
CURRENTLY FORECASTED.
FOR NEXT WEEKEND, SNOW AMOUNTS LOOK TO BE ON THE LIGHT SIDE, WITH
A GENERAL 1 TO 3 INCHES AT LOWER ELEVATIONS AND 4 TO 8 INCHES IN
THE MOUNTAINS, EXPECT GLACIER PARK WHERE SNOW AMOUNTS COULD
EXCEED A FOOT. HOWEVER, PROBABILITIES ARE LOW NOW, BECAUSE OF
MODEL DIFFERENCES, THUS THE LOW CONFIDENCE IN THESE SNOW AMOUNTS.
BRUSDA
AVIATION
26/12Z TAF PERIOD
OVERALL, MAINLY VFR CONDITIONS ARE FORECAST FOR NORTH CENTRAL,
CENTRAL, AND SOUTHWEST MONTANA THROUGH AT LEAST 27/12Z WITH AREAS
OF HIGH CLOUDINESS MOVING THROUGH A HIGH PRESSURE RIDGE. SOUTHWEST
TO WEST WINDS WILL ALSO REMAIN BREEZY OVER THE PLAINS OF NORTH
CENTRAL AND CENTRAL MONTANA THROUGH THE PERIOD, CAUSING SOME
MOUNTAIN WAVE TURBULENCE. A WEAK DISTURBANCE IN THE NORTHWESTERLY
FLOW ALOFT WILL ALSO BRING A PERIOD OF LOW-LEVEL WIND SHEAR TO THE
PLAINS AFTER 06Z.
HOWEVER, AREAS OF FOG AND LOW CLOUDS HAVE FORMED OVERNIGHT IN THE
VALLEYS FROM KHLN THROUGH THE CANYON FERRY LAKE AREA INTO THE
KBZN AREA. THIS WILL CONTINUE TERRAIN-OBSCURING IFR/LIFR
CONDITIONS THROUGH AT LEAST 16Z. DAYTIME HEATING SHOULD HELP
DISSIPATE THE FOG AND LOW CLOUDS. -COULSTON
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION
WEATHER AND HAZARD INFORMATION.
PRELIMINARY POINT TEMPS/POPS
GTF 29 18 37 18 / 0 0 0 0
CTB 33 21 37 20 / 0 0 0 0
HLN 21 9 31 10 / 0 0 0 0
BZN 17 3 30 7 / 0 0 0 0
WYS 22 -12 32 -6 / 0 0 0 0
DLN 19 5 29 9 / 0 0 0 0
HVR 30 18 37 18 / 0 0 0 0
LWT 32 19 40 20 / 0 0 0 0
TFX WATCHES/WARNINGS/ADVISORIES
COLD WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR
BEAVERHEAD AND WESTERN MADISON BELOW 6000FT-ELKHORN AND BOULDER
MOUNTAINS-GALLATIN VALLEY-GALLATIN AND MADISON COUNTY MOUNTAINS
AND CENTENNIAL MOUNTAINS-MADISON RIVER VALLEY-MEAGHER COUNTY
VALLEYS-MISSOURI HEADWATERS-NORTHWEST BEAVERHEAD COUNTY-RUBY
MOUNTAINS AND SOUTHERN BEAVERHEAD MOUNTAINS-UPPER BLACKFOOT AND
MACDONALD PASS.
DENSE FOG ADVISORY UNTIL 11 AM MST THIS MORNING FOR CANYON FERRY
AREA-GALLATIN VALLEY-HELENA VALLEY-MISSOURI HEADWATERS.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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