972
FXUS65 KTFX 080929
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
329 AM MDT THU OCT 8 2026
KEY MESSAGES
- WARM AND DRY WEATHER PERSISTS THROUGH FRIDAY WITH WINDY
CONDITIONS FRIDAY AFTERNOON BRINGING ELEVATED TO CRITICAL FIRE
WEATHER CONDITIONS.
- A DRASTIC CHANGE TO MUCH COLDER TEMPERATURES OCCURS SATURDAY
WITH WIDESPREAD PRECIPITATION DEVELOPING AND CHANGING TO SNOW
FOR MOST LOCATIONS BY LATE SATURDAY.
- IMPACTFUL WINTER WEATHER AND SNOW ACCUMULATION IS POSSIBLE OVER SOME
MOUNTAIN PASSES THIS WEEKEND, ESPECIALLY SATURDAY NIGHT
THROUGH SUNDAY MORNING.
DISCUSSION
A BROAD UPPER LEVEL RIDGE SOUTH OF THE AREA AND ZONAL/WESTERLY FLOW
ALOFT MAINTAINS WARM AND DRY CONDITIONS ACROSS THE AREA TODAY WITH
GENERALLY LIGHT WINDS. MEANWHILE, UPPER LEVEL TROUGHING IN THE
GULF OF AK WILL DEEPEN TODAY AS ADDITIONAL ENERGY ARRIVES FROM
THE WEST, SETTING THE STAGE FOR A SIGNIFICANT PATTERN CHANGE AS
THE THE LARGE SCALE FLOW AMPLIFIES AND THE TROUGH DIGS SOUTHWARD
INTO THE WESTERN US THIS WEEKEND. INCREASING WEST-SOUTHWEST MID-
UPPER LEVEL FLOW AHEAD OF THE APPROACHING TROUGH ALONG WITH SURFACE
LOW DEVELOPMENT IN SOUTHERN AB WILL LEAD TO WINDY CONDITIONS
FRIDAY AS WELL AS A FEW ADDITIONAL DEGREES OF WARMING AND
INCREASED FIRE WEATHER CONCERNS THROUGH FRIDAY EVENING. AN INITIAL
PACIFIC COLD FRONT LOOKS TO MOVE EAST ACROSS CENTRAL/NORTH-
CENTRAL MT FRIDAY NIGHT WITH STRONGER COOLING FROM NORTH TO SOUTH
ON SATURDAY AS AN AIRMASS FROM CANADA SURGES SOUTH THROUGH THE
AREA.
PRECIPITATION DEVELOPS SATURDAY NIGHT ALONG THE CONTINENTAL DIVIDE
WITH THE INITIAL PACIFIC FRONT WITH MORE WIDESPREAD PRECIPITATION
DEVELOPING ACROSS CENTRAL MT SATURDAY, BOTH ALONG AND FOLLOWING THE
SURGE OF COLDER AIR AND IN ASSOCIATION WITH A PLUME OF DEEPER
MOISTURE AND FRONTOGENIC FORCING. MODELS ARE IN REASONABLE
AGREEMENT WITH THE EVOLUTION OF THE TROUGH THIS WEEKEND AS IT
SPLITS/ELONGATES WITH MUCH OF THE ENERGY DIGGING SOUTH ALONG THE
WEST COAST THROUGH SUNDAY. THIS MAINTAINS A FLOW OF DEEP MOISTURE
ACROSS THE AREA IN SW FLOW ALOFT, WHILE THE LOWER LEVEL COLD AIR
CONTINUES TO DEEPEN AND SPREAD SOUTH THROUGH SUNDAY. THE FOCUS FOR
STEADY PRECIPITATION WILL LIKELY CONTINUE ACROSS CENTRAL MT INTO
SATURDAY NIGHT THEN SHIFT SOUTHWARD THROUGH SW MT LATER SATURDAY
NIGHT THROUGH SUNDAY. BEYOND THIS, MODELS DIVERGE WITH HOW LONG
PRECIPITATION MAY LINGER BUT AN OVERALL DECREASE FROM NW TO SE IS
LIKELY LATER SUNDAY THROUGH EARLY MONDAY.
THE COMBINATION OF COOLING ALOFT WITH THE UPPER TROUGH AND SURGE
OF LOWER LEVEL COLD AIR FROM THE NORTH WILL RAPIDLY COOL
TEMPERATURES AND LOWER SNOW LEVELS ACROSS WESTERN PORTIONS OF
NORTH-CENTRAL/CENTRAL MT ON SATURDAY WITH DAYTIME TEMPERATURES
LIKELY IN THE UPPER 30S TO AROUND 40 BY SATURDAY AFTERNOON AS SNOW
LEVELS LOWER TO AROUND 3000-4000 FT. WHILE SNOW LEVELS ARE ALSO
LIKELY TO LOWER TO NEAR THE VALLEYS IN SW MT SATURDAY NIGHT,
CONFIDENCE IN TIMING IS LOWER. POTENTIAL EXISTS FOR SIGNIFICANT
SNOWFALL AMOUNTS OVER SOME MOUNTAIN PASSES THIS WEEKEND WITH MAIN
IMPACTS LIKELY IN THE SATURDAY NIGHT THROUGH SUNDAY MORNING PERIOD
WHEN SNOW IS MOST LIKELY TO ACCUMULATE ON SURFACES THAT WILL TAKE
TIME TO COOL AFTER THE RECENT WARMTH. A FEW INCHES OF SNOW ARE
ALSO LIKELY AT LOWER ELEVATION LOCATIONS INCLUDING HELENA AND
GREAT FALLS. THE DRASTIC CHANGE TO COLDER TEMPERATURES THIS
WEEKEND WILL BE AN IMPACT TO ANYONE WITH OUTDOOR PLANS, ESPECIALLY
AFTER THE RECENT EXTENDED PERIOD OF MILD WEATHER. WINTER WEATHER
STATEMENTS ARE LIKELY FOR PORTIONS OF THE AREA THIS WEEKEND AS
CONFIDENCE IN SNOWFALL AMOUNTS AND TIMING INCREASES. HOENISCH
AVIATION
08/06Z TAF PERIOD.
VFR AND DRY CONDITIONS PREVAIL THROUGH THE TAF PERIOD. WINDS
REMAIN ON THE LIGHTER SIDE THROUGHOUT THE TAF PERIOD. HIGH CLOUDS
BEGIN TO INCREASE TOWARDS THE END OF THE TAF PERIOD. -WILSON
FIRE WEATHER
CONSECUTIVE DAYS OF UNSEASONABLY MILD TEMPERATURES, LOW AFTERNOON
HUMIDITY AND POOR OVERNIGHT RECOVERY HAVE LEAD TO INCREASED FIRE
DANGER INDICES, PARTICULARLY ACROSS CENTRAL MT WHERE OVERNIGHT
MOISTURE RECOVERY HAS BEEN LOWEST. UNSEASONABLE WARMTH AND
CONTINUED DRYNESS ON FRIDAY WILL COMBINE WITH INCREASING SOUTHWEST
WINDS WITH GUSTS AS HIGH AS 30-40 MPH TO CREATE ELEVATED FIRE
WEATHER CONDITIONS ACROSS MUCH OF THE AREA WITH THE MOST CRITICAL
COMBINATION OF WINDS AND DRYNESS ACROSS CENTRAL MT, WHERE A FIRE
WEATHER WATCH IS IN EFFECT. HOENISCH
PRELIMINARY POINT TEMPS/POPS
GTF 78 54 80 38 / 0 0 0 30
CTB 74 52 72 31 / 0 0 0 30
HLN 77 47 82 42 / 0 0 0 20
BZN 76 43 81 43 / 0 0 0 10
WYS 72 31 70 37 / 0 0 0 10
DLN 77 41 80 43 / 0 0 0 0
HVR 73 47 82 34 / 0 0 0 10
LWT 75 51 82 38 / 0 0 0 10
TFX WATCHES/WARNINGS/ADVISORIES
FIRE WEATHER WATCH FRIDAY AFTERNOON FOR CENTRAL AND EASTERN
LEWIS AND CLARK NATIONAL FOREST AREAS-HELENA AND TOWNSEND RANGER
DISTRICTS OF THE HELENA NATIONAL FOREST.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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