635
FXUS65 KTFX 211101
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
501 AM MDT WED OCT 21 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- IT WILL BE MOSTLY DRY ACROSS NORTH-CENTRAL, CENTRAL, AND
SOUTHWESTERN MONTANA THROUGH THE DAY ON THURSDAY.
- IT WILL BE WINDY ACROSS NORTH-CENTRAL MONTANA ON FRIDAY.
- WIDESPREAD PRECIPITATION RETURNS LATE THURSDAY THROUGH FRIDAY.
- TEMPERATURES WILL BE WELL-ABOVE SEASONAL AVERAGES THROUGH THURSDAY
WITH TEMPERATURES COOLING DOWN FRIDAY THROUGH THIS WEEKEND.
DISCUSSION
/ISSUED 140 AM MDT WED OCT 21 2026/
- METEOROLOGICAL OVERVIEW:
TODAY OVER SOUTHWESTERN MONTANA THERE REMAINS SOUTHWEST FLOW ALOFT
WITH WEAK ZONAL FLOW (WEST-EAST) OVER NORTH-CENTRAL, AND CENTRAL
MONTANA. DUE TO SLIGHTLY STRONGER WARM AIR ADVECTION TODAY
TEMPERATURES WILL REBOUND TO ABOVE SEASONAL AVERAGES. ACROSS NORTH-
CENTRAL AND CENTRAL MONTANA IT WILL BE DRY WITH A LOW CHANCE FOR
SHOWERS ACROSS SOUTHWESTERN MONTANA TODAY. SEE THE FORECAST
CONFIDENCE & SCENARIOS SECTION FOR DETAILS. ON THURSDAY THERE
REMAINS SOUTHERLY FLOW ALOFT AND AN UPPER-LEVEL TROUGH ASSOCIATED
WITH A PACIFIC COLD FRONT BEGINS TO MOVE OVER NORTH-CENTRAL,
CENTRAL, AND SOUTHWESTERN MONTANA BY THURSDAY EVENING. THIS WILL
ALLOW TEMPERATURES TO REMAIN ABOVE SEASONAL AVERAGES WITH MOSTLY DRY
WEATHER UNTIL THURSDAY EVENING. THURSDAY EVENING INTO FRIDAY MORNING
PRECIPITATION WILL GRADUALLY SPREAD OVER NORTH-CENTRAL, CENTRAL, AND
SOUTHWESTERN MONTANA.
ON FRIDAY THE UPPER-LEVEL TROUGH MERGES WITH A SHORTWAVE TROUGH
MOVING SOUTH FROM CANADA. THIS COMBINED WITH THE COLD FRONT THAT
MOVED THROUGH WILL BRING WIDESPREAD PRECIPITATION AND COOLER
TEMPERATURES (BELOW SEASONAL AVERAGES) TO THE AREA. DUE TO THE
COLD FRONT THAT MOVED THROUGH THURSDAY EVENING INTO FRIDAY MORNING
SNOW-LEVELS WILL LOWER AND THE PRECIPITATION THAT FALLS IN
MOUNTAIN AREAS ON FRIDAY WILL TRANSITION FROM RAIN TO SNOW BY
FRIDAY EVENING. ON FRIDAY THERE IS AN INCREASING PRESSURE GRADIENT
AND STRONG LOW-LEVEL AND MID-LEVEL WINDS. THIS WILL BRING WINDY
CONDITIONS TO NORTH-CENTRAL MONTANA ON FRIDAY. ON SATURDAY AN
UPPER-LEVEL RIDGE BEGINS TO BUILD IN OVER NORTH-CENTRAL, CENTRAL,
AND SOUTHWESTERN MONTANA. THIS WILL ALLOW THE AREA TO DRY OUT WITH
COOL TEMPERATURES LINGERING.
ON SUNDAY THE UPPER-LEVEL RIDGE REMAINS OVER NORTH-CENTRAL, CENTRAL,
AND SOUTHWESTERN MONTANA. THIS WILL KEEP DRY AND COOL (BELOW
SEASONAL AVERAGES) WEATHER FOR THE AREA ON SUNDAY. MONDAY THROUGH
TUESDAY AN UPPER-LEVEL TROUGH MOVES OVER NORTH-CENTRAL, CENTRAL,
AND SOUTHWESTERN MONTANA. THIS WILL BRING COOLER TEMPERATURES AND
WIDESPREAD PRECIPITATION TO THE AREA ON MONDAY AND TUESDAY. -IG
- FORECAST CONFIDENCE & SCENARIOS:
TODAY ACROSS SOUTHWESTERN MONTANA ALONG THE IDAHO/MONTANA BORDER
THERE IS A 10% CHANCE FOR A TENTH OF RAIN OR GREATER. ON FRIDAY
THERE IS A 40 - 65% CHANCE FOR WIND GUSTS OF 45 MPH OR GREATER
ACROSS MUCH OF NORTH-CENTRAL MONTANA. ON FRIDAY ALONG THE ROCKY
MOUNTAIN FRONT AND PLAINS WEST OF I-15 THERE IS A 30 - 50% CHANCE
FOR WIND GUSTS OF 55 MPH OR GREATER.
FOR TOTAL LIQUID PRECIPITATION THURSDAY NIGHT THROUGH FRIDAY NIGHT
THERE IS GREATER THAN AN 80% CHANCE FOR ONE HALF INCH OF LIQUID
PRECIPITATION OR GREATER ALONG AND SOUTH OF THE MONTANA HIGHWAY
200/US HIGHWAY 87 CORRIDOR BETWEEN GREAT FALLS AND LEWISTOWN. FOR
TOTAL LIQUID PRECIPITATION THURSDAY NIGHT THROUGH FRIDAY NIGHT THERE
IS A 30 - 60% CHANCE FOR ONE HALF INCH OF LIQUID PRECIPITATION
ACROSS NORTH-CENTRAL MONTANA NORTH OF THE MONTANA HIGHWAY 200/US
HIGHWAY 87 CORRIDOR BETWEEN GREAT FALLS AND LEWISTOWN. FOR TOTAL
LIQUID PRECIPITATION THURSDAY NIGHT THROUGH FRIDAY NIGHT THERE IS A
60 - 90% CHANCE FOR ONE INCH OF LIQUID PRECIPITATION OR GREATER
ACROSS CENTRAL AND SOUTHWESTERN MONTANA. ACROSS MOST OF THE
MOUNTAINS OF NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA THERE
IS GREATER THAN A 60% CHANCE FOR 2 INCHES OF SNOW OR GREATER FROM
THURSDAY NIGHT THROUGH FRIDAY NIGHT. THURSDAY NIGHT THROUGH
FRIDAY NIGHT THERE IS A 50 - 80% CHANCE FOR 4 INCHES OF SNOW OR
GREATER ACROSS THE MADISON AND GALLATIN RANGES AND THE LITTLE
BELTS. FRIDAY AFTERNOON INTO EARLY SATURDAY MORNING THERE IS A
HIGH CHANCE THAT AT LEAST SOME LOWER-ELEVATION LOCATIONS ACROSS
NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA WILL SEE A FEW
FLAKES OF SNOW. -IG
AVIATION
21/12Z TAF PERIOD
VFR CONDITIONS WILL PREVAIL AT ALL TERMINALS DURING THIS TAF PERIOD
WITH PRIMARILY LIGHT WINDS AND HIGH-LEVEL CLOUDS AROUND. AT THE KWYS
TERMINAL BETWEEN 21/15Z AND 21/22Z THERE IS A 15 - 30% CHANCE FOR
RAIN SHOWERS. -IG
PRELIMINARY POINT TEMPS/POPS
GTF 73 45 74 42 / 0 0 0 30
CTB 68 39 70 38 / 0 0 0 60
HLN 69 39 71 43 / 10 10 0 40
BZN 67 38 70 40 / 10 0 0 30
WYS 60 29 62 32 / 30 10 10 70
DLN 65 38 66 41 / 20 10 0 80
HVR 69 37 73 40 / 0 0 0 20
LWT 71 45 75 43 / 0 0 0 20
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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