633
FXUS65 KTFX 092045
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
245 PM MDT WED SEP 9 2026
KEY MESSAGES
- IT WILL BE DRY AND BREEZY THROUGH THURSDAY.
- PRECIPITATION AND COOLER TEMPERATURES WITH MOUNTAIN SNOW IS
EXPECTED FRIDAY THROUGH THIS WEEKEND.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
THIS AFTERNOON THERE IS AN UPPER-LEVEL RIDGE OVER NORTH-CENTRAL,
CENTRAL, AND SOUTHWESTERN MONTANA. THIS WILL BRING DRY AND WARM
TEMPERATURES (NEAR SEASONAL AVERAGES) TO THE AREA ON WEDNESDAY.
THIS AFTERNOON THE PRESSURE GRADIENT INCREASES WHICH WILL BRING
BREEZY CONDITIONS TO THE ROCKY MOUNTAIN FRONT. ON THURSDAY THE
UPPER-LEVEL RIDGE BEGINS TO BREAK DOWN. THIS WILL KEEP WARMER
TEMPERATURES WITH MOSTLY DRY WEATHER FOR THE AREA ON THURSDAY.
THURSDAY EVENING A COLD FRONT WILL MOVE THROUGH NORTH-CENTRAL,
CENTRAL, AND SOUTHWESTERN MONTANA.
ON FRIDAY ZONAL FLOW IS OVER NORTH-CENTRAL, CENTRAL, AND
SOUTHWESTERN MONTANA. THIS COMBINED WITH THE COLD FRONT THAT MOVED
THROUGH WILL BRING COOLER TEMPERATURES (WELL-BELOW SEASONAL
AVERAGES). ON FRIDAY THERE WILL BE RAIN SHOWERS ACROSS NORTH-
CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. ON SATURDAY AN UPPER-
LEVEL RIDGE BUILDS IN BRIEFLY OVER NORTH-CENTRAL, CENTRAL, AND
SOUTHWESTERN MONTANA. THIS WILL BRIEFLY BRING DRY CONDITIONS TO
ALL BUT THE ROCKY MOUNTAIN FRONT AND STATUS QUO TEMPERATURES TO
THE AREA. SUNDAY THROUGH MONDAY THERE WILL BE UPPER-LEVEL CLOSED
LOW THAT WILL BRING COOLER TEMPERATURES AND WIDESPREAD
PRECIPITATION TO THE AREA. HIGHER ELEVATIONS LOCATIONS HAVE THE
POTENTIAL TO RECEIVE SNOW FRIDAY THROUGH SUNDAY. SEE THE FORECAST
CONFIDENCE & SCENARIOS SECTION FOR DETAILS. -IG
- FORECAST CONFIDENCE & SCENARIOS:
ON THURSDAY THERE IS GREATER THAN A 60% CHANCE FOR WIND GUSTS OF
45 MPH OR GREATER ACROSS THE ROCKY MOUNTAIN FRONT AND PLAINS WEST
OF 1- 15, THE HI-LINE, AND CASCADE TO JUDITH BASIN COUNTY. ON
THURSDAY ALONG THE ROCKY MOUNTAIN FRONT THERE IS A 60 - 80% CHANCE
FOR WIND GUSTS OF 55 MPH OR GREATER.
SATURDAY THROUGH SUNDAY THERE IS A 40 - 60% CHANCE FOR 4 INCHES OF
SNOW OR GREATER ALONG THE ROCKY MOUNTAIN FRONT. SATURDAY THROUGH
SUNDAY THERE IS A 30 - 60% CHANCE FOR 2 INCHES OF SNOW OR GREATER
ACROSS THE LITTLE BELTS AND MOUNTAINS OF SOUTHWESTERN MONTANA.
SUNDAY MORNING THERE IS A 20 - 40% CHANCE FOR LOW TEMPERATURES OF
36 DEGREES OR LESS ACROSS THE PLAINS OF NORTH-CENTRAL MONTANA. ON
MONDAY THERE IS A 60 - 80% CHANCE FOR LOW TEMPERATURES OF 36
DEGREES OR LOWER ACROSS THE LOWER-ELEVATIONS OF NORTH-CENTRAL,
CENTRAL, AND SOUTHWESTERN MONTANA. ON MONDAY THERE IS A 30 - 50%
CHANCE FOR LOW TEMPERATURES OF 34 DEGREES OR LOWER ACROSS THE
LOWER-ELEVATIONS OF NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN
MONTANA.
ON FRIDAY THERE IS A 50 - 70% CHANCE FOR A QUARTER INCH OF
PRECIPITATION ACROSS THE MAJORITY OF NORTH-CENTRAL MONTANA. ON
SATURDAY THERE IS A 50% CHANCE FOR A QUARTER INCH OF
PRECIPITATION OR GREATER ALONG THE ROCKY MOUNTAIN FRONT. ON SUNDAY
ACROSS CENTRAL AND NORTH-CENTRAL MONTANA THERE IS A 50 - 70%
CHANCE FOR HALF AN INCH OF RAIN OR GREATER. ON SUNDAY THERE IS 30
- 60% CHANCE FOR A QUARTER INCH OF RAIN OR GREATER ACROSS
SOUTHWESTERN MONTANA. -IG
AVIATION
09/18Z TAF PERIOD
VFR CONDITIONS WILL DOMINATE THE REGION THROUGH THE PERIOD. WINDS
WILL PREVAIL OUT OF THE WEST-SOUTHWEST THIS AFTERNOON WITH GUSTS
UP TO 25 KT TO 30 KT THROUGHOUT THE REGION. THERE IS A 60%
PROBABILITY FOR WIND SHEAR CONDITIONS AT KCTB, KHVR, AND KLWT
TONIGHT FROM 10/02Z TO 10/11Z AS BOUNDARY LAYER DECOUPLING IS
POSSIBLE FOR SOME AREAS WITH STRONGER SYNOPTIC FORCING INFLUENCE
ABOVE. THURSDAY MORNING INTO AFTERNOON WILL SEE GUSTY WINDS AGAIN
AS THE MIXED LAYER SETS BACK UP.
FOR KGTF: VFR CONDITIONS WILL PERSIST WITH SOUTHWESTERLY WINDS
GUSTING TO 25 KT WHICH WILL YIELD 15 KT CROSSWIND EXCEEDANCE AT
TIMES UNTIL TONIGHT AFTER SUNSET. THERE IS A 30% CHANCE FOR WIND
SHEAR CONDITIONS TO SET UP OVERNIGHT HOWEVER BOUNDARY LAYER MIXING
IS PRIMARILY EXPECTED TO CONTINUE. A STRONG INVERSION SETUP WITH
TEMPERATURES COOLING BELOW EXPECTED WILL BE THE DIFFERENCE FOR
WIND SHEAR. - AKINS
PRELIMINARY POINT TEMPS/POPS
GTF 55 80 48 60 / 0 10 80 70
CTB 51 72 42 54 / 0 0 60 70
HLN 49 84 50 69 / 0 0 60 30
BZN 45 84 48 73 / 0 0 0 20
WYS 33 72 37 72 / 0 0 0 0
DLN 43 82 46 76 / 0 0 0 0
HVR 50 81 44 64 / 0 0 50 60
LWT 50 83 47 61 / 0 0 70 80
TFX WATCHES/WARNINGS/ADVISORIES
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