801
FXUS65 KTFX 271917
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
117 PM MDT SUN SEP 27 2026
KEY MESSAGES
- THERE WILL BE ISOLATED SHOWERS THIS AFTERNOON AND EVENING WITH
SHOWERS AND THUNDERSTORMS IN SOUTHWESTERN MONTANA MONDAY
AFTERNOON/EVENING.
- IT WILL BE WINDY ON TUESDAY ACROSS NORTH-CENTRAL MONTANA.
- MONDAY THROUGH FRIDAY IT WILL WARM UP TO AROUND SEASONAL
AVERAGES WITH MOSTLY DRY WEATHER.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
THIS AFTERNOON AN UPPER-LEVEL RIDGE BEGINS TO BUILD IN OVER NORTH-
CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. THIS WILL KEEP COOL
TEMPERATURES OVER THE AREA. AN UPPER-LEVEL SHORTWAVE WILL MOVE
THROUGH THE UPPER-LEVEL FLOW THIS AFTERNOON AND EVENING AND BRING
SHOWERS AND THUNDERSTORMS TO SOUTHWESTERN MONTANA. THIS EVENING
ISOLATED SHOWERS WILL SPREAD TO NORTH-CENTRAL MONTANA. ON MONDAY A
WEAK UPPER-LEVEL TROUGH MOVES OVER NORTH-CENTRAL, CENTRAL, AND
SOUTHWESTERN MONTANA. THIS WILL BRING SHOWERS AND THUNDERSTORMS TO
SOUTHWESTERN MONTANA ON MONDAY. IT WILL WARM UP ACROSS THE AREA WITH
MOSTLY DRY WEATHER NORTH OF I-90 ON MONDAY.
ON TUESDAY THERE WILL BE ZONAL (WEST TO EAST) FLOW OVER NORTH-
CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. THIS WILL ALLOW WARM
TEMPERATURES TO REMAIN WITH DRY WEATHER. ON TUESDAY THERE WILL BE
STRONG LOW-LEVEL AND MID-LEVEL WINDS. THIS WILL BRING WINDY
CONDITIONS TO NORTH-CENTRAL MONTANA WITH THE STRONGEST WINDS ALONG
THE ROCKY MOUNTAIN FRONT. ON WEDNESDAY ZONAL FLOW REMAINS OVER
NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA WITH STRONG LOW-
LEVEL AND MID-LEVEL WINDS. THIS WILL BRING WARM AND MOSTLY DRY
WEATHER TO THE AREA WITH WINDY CONDITONS ACROSS NORTH-CENTRAL
MONTANA. ON THURSDAY AND FRIDAY AN UPPER-LEVEL RIDGE BUILDS IN
OVER NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. THIS WILL
ALLOW TEMPERATURES TO WARM UP WITH MOSTLY DRY WEATHER ACROSS THE
AREA. -IG
- FORECAST CONFIDENCE & SCENARIOS:
ON MONDAY THERE IS A 20 - 30% CHANCE FOR THUNDERSTORMS ACROSS
SOUTHERN GALLATIN AND MADISON COUNTIES. ON MONDAY THERE IS A 40 -
60% CHANCE FOR A QUARTER INCH OF RAIN OR GREATER IN THE WEST
YELLOWSTONE AREA. ON TUESDAY ACROSS THE NORTHERN ROCKY MOUNTAIN
FRONT THERE IS A 40 - 70% CHANCE FOR WIND GUSTS OF 75 MPH OR
GREATER. ON TUESDAY ACROSS THE PLAINS WEST OF I-15 THERE IS A A 20 -
50% CHANCE FOR WIND GUSTS OF 55 MPH OR GREATER. AS A RESULT A HIGH
WIND WATCH WAS ISSUED FOR THE NORTHERN ROCKY MOUNTAIN FRONT AND
NORTHERN HIGH PLAINS FROM 12 AM TUESDAY TO 12 AM WEDNESDAY. -IG
AVIATION
27/18Z TAF PERIOD.
INITIAL CONCERN WILL BE FOR SOME ISOLATED POCKETS OF RAIN THROUGH
THE AFTERNOON AND EVENING ACROSS MOST AREAS. THIS PROBABILITY IS TOO
LOW TO WARRANT MENTION IN ANY TAFS, HOWEVER. CONFIDENCE IS A BIT
HIGHER IN SHOWERS AND PERHAPS A FEW THUNDERSTORMS NEAR KWYS LATE
TONIGHT INTO MONDAY MORNING. VFR CONDITIONS PREVAIL OVERALL, WITH
SOME BRIEF MVFR NEAR ANY PRECIPITATION THAT DEVELOPS. -AM
PRELIMINARY POINT TEMPS/POPS
GTF 45 73 45 73 / 30 0 0 0
CTB 36 67 42 65 / 10 0 0 0
HLN 42 71 40 74 / 20 0 0 0
BZN 38 68 37 74 / 10 20 0 0
WYS 37 60 28 66 / 70 50 20 0
DLN 40 68 36 75 / 10 0 0 0
HVR 41 72 42 75 / 20 0 0 0
LWT 41 70 41 76 / 10 10 0 0
TFX WATCHES/WARNINGS/ADVISORIES
HIGH WIND WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY EVENING
FOR EAST GLACIER PARK REGION-NORTHERN HIGH PLAINS.
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