417
FXUS65 KTFX 061058
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
458 AM MDT TUE OCT 6 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- UNSEASONABLY WARM AND DRY WEATHER PERSISTS THROUGH FRIDAY.
- WINDY CONDITIONS FRIDAY LEAD TO ELEVATED FIRE WEATHER CONCERNS.
- CHANGE TO MUCH COOLER AND WETTER WEATHER THIS WEEKEND WITH
POTENTIAL FOR IMPACTFUL MOUNTAIN SNOW.
DISCUSSION
/ISSUED 253 AM MDT TUE OCT 6 2026/
- METEOROLOGICAL OVERVIEW:
LOW AMPLITUDE UPPER LEVEL RIDGING ACROSS THE WESTERN US WILL
MAINTAIN UNSEASONABLY WARM AND DRY CONDITIONS ACROSS THE AREA
THROUGH FRIDAY BENEATH A WEST-NORTHWEST FLOW ALOFT. AFTERNOON
TEMPERATURES WILL RUN SLIGHTLY LOWER THAN THOSE OF MONDAY BUT STILL
AROUND 15 DEGREES ABOVE EARLY OCTOBER CLIMATOLOGICAL AVERAGES.
AFTERNOON MIXING AND A MODERATE SURFACE PRESSURE GRADIENT ACROSS
THE ROCKIES WILL SUPPORT SOME BREEZINESS THIS AFTERNOON, MAINLY
ACROSS THE PLAINS, WITH OVERALL LIGHTER WINDS WED AND THU AS
SURFACE HIGH PRESSURE SLIDES EAST ACROSS THE CANADIAN PRAIRIES.
AN UPPER LEVEL TROUGH DIGGING SOUTHEAST THROUGH BC FRIDAY WILL BRING
A SIGNIFICANT WEATHER PATTERN CHANGE FOR THE WEEKEND WITH WINDY
CONDITIONS DEVELOPING FRIDAY AS SOUTHWESTERLY MID-LEVEL FLOW INCREASES
AHEAD OF THE APPROACHING TROUGH. WARM, WINDY AND DRY CONDITIONS
FRIDAY WILL BRING ELEVATED FIRE WEATHER CONCERNS AHEAD OF A COLD
FRONT FRIDAY NIGHT THAT BRINGS IN MUCH COOLER AND WETTER CONDITIONS
FOR THE WEEKEND. MODEL GUIDANCE IS IN REASONABLE AGREEMENT TO DIG
THE TROUGH SOUTHWARD INTO THE NW US SATURDAY WITH TYPICAL
DIFFERENCES AND SPREAD STILL AT THIS TIME RANGE AMONG
MODELS/ENSEMBLE MEMBERS IN THE EVENTUAL EVOLUTION OF THE TROUGH
THROUGH THE REST OF THE WEEKEND INTO EARLY NEXT WEEK.
- FORECAST CONFIDENCE & SCENARIOS:
FIRE WEATHER: WHILE WIND SPEEDS THROUGH THURSDAY WILL NOT BE
SIGNIFICANT, WARM AFTERNOON TEMPERATURES AND LOW AFTERNOON
HUMIDITY WILL PERSIST WITH ONLY MODERATE TO LOCALLY POOR OVERNIGHT
HUMIDLY RECOVERY, ESPECIALLY OVER THE CENTRAL MT MOUNTAINS AND
ADJACENT SLOPES. THESE CONDTIONS MAY ADVANCE THE CURING AND DRYING
OF LIGHTER (GRASS/SHRUB) FUELS THAT ARE ALREADY HEADED INTO
SEASONAL DORMANCY. INCREASED WINDS WITH POTENTIAL FOR GUSTS IN
EXCESS OF 40 MPH FRIDAY, ALONGSIDE THE CONTINUED WARMTH/DRYNESS
WILL BRING AN ELEVATED FIRE WEATHER RISK.
WEEKEND PATTERN CHANGE/IMPACTS: CONFIDENCE CONTINUES TO INCREASE IN
THE OVERALL INFLUX OF MUCH COOLER TEMPERATURES THIS WEEKEND, ALONG
WITH WIDESPREAD PRECIPITATION AND AT LEAST SOME IMPACTFUL
MOUNTIAN SNOWFALL. TEMPERATURES ON SATURDAY ARE LIKELY TO BE 25-30
DEGREES COLDER THAN FRIDAY WITH ADDITIONAL COOLING ARRIVING
SATURDAY NIGHT INTO SUNDAY. WHILE NOT UNUSUAL FOR EARLY OCTOBER,
THIS WILL BE THE FIRST OF SUCH DRASTIC SEASONAL SWINGS AND WILL
FOLLOW AN EXTENDED PERIOD OF MILD WEATHER. A MAJORITY OF MODEL
ENSEMBLE MEMBERS SUPPORT SNOW LEVELS FALLING TO BELOW 4000 FT BY
SUNDAY, WHICH BRINGS THE RISK FOR WET SNOWFALL DOWN TO LOWER
ELEVATIONS. HOWEVER, THERE IS STILL A VERY LARGE SPREAD IN
PRECIPITATION AMOUNTS/SCENARIOS AND TIMING DUE TO KEY DETAILS
THAT WILL CONTINUE TO BE RESOLVED OVER THE COMING DAYS. HOENISCH
AVIATION
06/12Z TAF PERIOD.
VFR CONDITIONS PREVAIL THROUGH THE TAF PERIOD WITH JUST SOME
PASSING HIGH CLOUDS. WESTERLY SURFACE WINDS INCREASE SOME ACROSS
THE PLAINS AND CENTRAL MT TERMINALS THIS AFTERNOON BEFORE
DIMINISHING AGAIN THIS EVENING. HOENISCH
PRELIMINARY POINT TEMPS/POPS
GTF 80 45 72 42 / 0 0 0 0
CTB 75 41 67 39 / 0 0 0 0
HLN 80 43 77 43 / 0 0 0 0
BZN 78 42 75 40 / 0 0 0 0
WYS 74 34 73 31 / 0 0 0 0
DLN 79 42 77 40 / 0 0 0 0
HVR 77 42 71 37 / 0 0 0 0
LWT 77 46 73 42 / 0 0 0 0
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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