970
FXUS65 KTFX 301724 CCA
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1021 AM MST SUN NOV 30 2025
AVIATION SECTION UPDATED.
KEY MESSAGES
- FREEZING FOG WILL RESULT IN SOME ICY ROADS THIS MORNING ACROSS
THE GOLDEN TRIANGLE.
- AREAS OF BLOWING SNOW WILL BE POSSIBLE ON MONDAY AS WESTERLY
WINDS INCREASE.
- TWO MORE ROUNDS OF WIDESPREAD SNOWFALL ARE EXPECTED THIS WEEK,
THE FIRST ON TUESDAY AND THE SECOND FRIDAY AND SATURDAY.
UPDATE
AREAS OF LOCALLY DENSE FOG ARE THE PRIMARY CONCERN ACROSS NORTH-
CENTRAL MT THIS MORNING WHERE A SHALLOW COLD/MOIST AIRMASS REMAINS
IN PLACE. SUNRISE HAS BROUGHT SOME IMPROVEMENT, WITH MOST FOG
DISSIPATING BY NOON AND THE ADVISORY FOR FOG WILL BE ALLOWED TO
EXPIRE LATER THIS MORNING. MID TO HIGHER LEVEL CLOUDS ARE CROSSING
SW MT THIS MORNING IN ASSOCIATION WITH A WEATHER DISTURBANCE MOVING
THROUGH SOUTHERN ID. AFTER A COLD START THIS MORNING, TEMPERATURES
APPEAR TO BE ON TRACK FROM PREVIOUS FORECASTS WTIH AFTERNOON
TEMPERATURES RANGING FROM THE SINGLE DIGITS AND LOW TEENS ACROSS
ACROSS THE PLAINS TO MAINLY THE 20S ACROSS CENTRAL AND SOUTHWEST MT.
HOENISCH
DISCUSSION
- METEOROLOGICAL OVERVIEW:
AN AREA OF HIGH PRESSURE CENTERED OVER NORTHEASTERN MONTANA THIS
MORNING WILL CONTINUE TO SHIFT TO THE SOUTHEAST TODAY. THIS WILL
ALLOW, AFTER A COLD AND FOGGY MORNING (PARTICULARLY ACROSS THE
GOLDEN TRIANGLE), WARMER AIR TO BEGIN TO WORK ITS WAY INTO THE
AREA FROM THE SOUTHWEST. WHILE AREAS NORTH AND EAST OF A LINE FROM
CUT BANK TO FORT BENTON TO THE MISSOURI RIVER BREAKS WILL REMAIN
TRAPPED IN THE COLD AIR TODAY, EVEN THESE AREAS WILL SEE
TEMPERATURES MODERATE ON MONDAY.
SPEAKING OF MONDAY, UPPER LEVEL RIDGING WILL BEGIN TO PUSH INTO
THE AREA ON MONDAY, WHICH WILL RESULT IN SOME GUSTY WINDS ACROSS
THE PLAINS AND A FEW SNOW SHOWERS OVER THE HIGHER TERRAIN OF
SOUTHWESTERN MONTANA AS WARMER AIR PUSHES INTO THE AREA. HOWEVER,
THIS RIDGING WILL NOT LAST LONG AS A SHORTWAVE TROUGH WILL PUSH IN
FROM THE NORTHWEST ON TUESDAY, BRINGING SOME MORE WIDESPREAD
SNOWFALL TO THE AREA FOLLOWED BY ANOTHER SURGE OF COLDER AIR,
THOUGH NOT NEARLY AS COLD AS THE AIR MASS CURRENTLY OVER THE AREA.
THE SECOND HALF OF THE WEEK WILL BE SIMILAR TO THE FIRST HALF,
WITH A DAY OR TWO OF QUIETER WEATHER CONDITIONS AS A WEAK UPPER
LEVEL RIDGE BUILDS INTO THE AREA BEFORE A DISTURBANCE PUSHES IN
FROM THE NORTHWEST ON FRIDAY. HOWEVER, THIS FRIDAY SYSTEM DOES
HAVE THE CHANCE TO BE A LITTLE MORE DISRUPTIVE THAN THE TUESDAY
SYSTEM SINCE IT MIGHT HAVE SOME MORE MOISTURE TO WORK WITH, BUT
THERE STILL SEEMS TO BE SOME DISAGREEMENT ON JUST HOW MUCH
MOISTURE THIS SYSTEM WILL BRING TO THE AREA. BEYOND FRIDAY AND
SATURDAY, MODELS CONTINUE TO HINT TOWARDS A LARGER SCALE PATTERN
CHANGE, WHICH IS LIKELY TO RESULT IN A PERIOD OF COOLER AND
UNSETTLED WEATHER NEXT WEEK.
- FORECAST CONFIDENCE & SCENARIOS:
BLOWING SNOW MONDAY: AS UPPER LEVEL RIDGING BUILDS INTO THE AREA
ON MONDAY, WINDS ACROSS THE PLAINS ARE VERY LIKELY TO INCREASE,
WHICH COULD RESULT IN SOME BLOWING AND DRIFTING OF THE SNOWPACK
ACROSS THE AREA. HOWEVER, THERE ARE A FEW AREAS OF UNCERTAINTY AT
THIS POINT WITH REGARDS TO HOW BIG OF AN ISSUE ANY BLOWING OR
DRIFTING COULD BE, INCLUDING HOW MUCH THE SNOWPACK COMPACTS AND
SETTLES TODAY AND HOW QUICKLY (OR IF) TEMPERATURES RISE ABOVE
FREEZING, WHICH WOULD ALSO PUT AN END TO ANY BLOWING OR DRIFTING
SNOW. HOWEVER, AS IT STANDS THE SNOWPACK IS NOT OVERLY DEEP, SO
ANY BLOWING SNOW IS UNLIKELY TO BE AN ISSUE FOR MORE THAN A FEW
HOURS BEFORE MOST OF THE SNOW IS DEPOSITED INTO DRIFTS.
LATE WEEK SNOW: WHILE THE ARRIVAL OF SOME SNOWFALL FRIDAY AND
SATURDAY IS APPEARING MORE AND MORE LIKELY, THERE REMAINS SOME
UNCERTAINTY AS TO HOW MUCH SNOW WILL FALL AND HOW WIDESPREAD AN
AREA THE SNOW WILL AFFECT. RIGHT NOW THE MOST LIKELY SCENARIO
APPEARS TO BE A QUICK HITTING SNOWFALL THAT DROPS ANYWHERE BETWEEN 1
TO 4 INCHES ACROSS THE LOWER ELEVATIONS, BUT I CAN’T RULE OUT A
SCENARIO WHERE NORTHERLY WINDS BEHIND THIS SYSTEM BRING SOME MORE
SNOW TO THE NORTHERLY UPSLOPE AREAS. LUDWIG
AVIATION
30/18Z TAF PERIOD
VFR CONDITIONS WILL PREVAIL ACROSS ALL BUT THE KHVR AND KHLN
TERMINALS. FOR THE FIRST THREE HOURS OF THIS TAF PERIOD THERE BE
LIFR-LEVEL CEILINGS AT THE KHVR AND KHLN TERMINALS. AFTER THAT VFR
CONDITIONS WILL PREVAIL AT THE KHVR AND KHLN TERMINALS. ACROSS THE
REST OF THE TERMINALS DURING THIS TAF PERIOD THERE WILL BE MOSTLY
LIGHT WINDS WITH HI-LEVEL CLOUDS AROUND. FROM 01/15Z ON THROUGH THE
END OF THE TAF PERIOD THERE WILL BE ISOLATED INSTANCES OF LOW-LEVEL
WIND SHEAR AND MOUNTAIN WAVE TURBULENCE ACROSS NORTH-CENTRAL
MONTANA. -IG
PRELIMINARY POINT TEMPS/POPS
GTF 24 10 34 27 / 0 0 0 30
CTB 20 8 31 22 / 0 0 0 30
HLN 26 12 35 25 / 0 0 0 30
BZN 24 5 32 21 / 0 0 0 30
WYS 29 2 25 14 / 20 0 10 50
DLN 29 12 36 23 / 20 0 0 20
HVR 6 -6 28 18 / 0 0 0 30
LWT 26 8 35 22 / 0 0 0 20
TFX WATCHES/WARNINGS/ADVISORIES
COLD WEATHER ADVISORY UNTIL 10 AM MST MONDAY FOR HILL COUNTY-
NORTHERN BLAINE COUNTY.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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