236
FXUS65 KTFX 220948
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
348 AM MDT TUE OCT 22 2024
SYNOPSIS
SEASONABLY COOL AND MAINLY DRY CONDITIONS ARE EXPECTED THROUGH
WEDNESDAY WITH SOME PATCHY LOW CLOUDS AND FOG DISSIPATING THIS
MORNING. A QUICK MOVING WEATHER SYSTEM BRINGS SOME LIGHT
PRECIPITATION AND MOUNTAIN SNOW TO SOUTHWEST MT WEDNESDAY NIGHT
WITH WARMER AND DRY CONDITIONS DEVELOPING AGAIN LATE IN THE WORK-
WEEK INTO THE UPCOMING WEEKEND.
DISCUSSION
KEY MESSAGES...
-SEASONABLY COOL TODAY WITH SOME PATCHY EARLY MORNING LOW CLOUDS AND
FOG
-QUICK MOVING WEATHER SYSTEM TAKES A MORE FAVORABLE TRACK TO BRING SW
MT SOME LIGHT PRECIPITATION AND MOUNTAIN SNOW WEDNESDAY NIGHT
AN UPPER LEVEL TROUGH EXTENDING FROM CENTRAL CANADA SOUTHWEST AND
WEST OFF THE PACIFIC NW COAST CONTINUES TO SHEAR/ELONGATE E-W TODAY
AS UPPER LEVEL RIDGING SHIFTS INTO NW CANADA. WESTERLY FLOW ALOFT
PERSISTS ACROSS THE NORTHERN ROCKIES AND MT TODAY WITH SOME RESIDUAL
CLOUDS AND MOISTURE MOVING ACROSS THE REGION THIS MORNING BEFORE
OVERALL DRIER CONDITIONS AND LESS CLOUD-COVER DEVELOPS THIS
AFTERNOON THROUGH WEDNESDAY. ENOUGH LOW LEVEL MOISTURE LINGERS
ACROSS N-CENTRAL MT EARLY THIS MORNING HOWEVER FOR SOME LOW CLOUDS
AND PATCHY FOG IN AREAS WHICH SHOULD ERODE FROM WEST TO EAST BY LATE
THIS MORNING. THE COOLER AIRMASS THAT MOVED SOUTH INTO THE AREA LATE
YESTERDAY WILL SLIDE ACROSS EASTERN MT INTO THE DAKOTAS TONIGHT WITH
TEMPERATURES ACROSS THE AREA FLUCTUATING CLOSE TO SEASONABLY COOL
VALUES THROUGH THURSDAY.
AN UPPER LEVEL WAVE DEVELOPING OUT OF THE OFFSHORE PORTION OF THE
UPPER TROUGH MOVES INTO THE PACIFIC NW WEDNESDAY AND QUICKLY
TRANSLATES EAST ACROSS ID INTO WY WEDNESDAY NIGHT. MODELS ARE IN
FAIRLY DECENT AGREEMENT FOCUSING PRECIPITATION PRIMARILY ACROSS SW MT,
WITH PROBABILITIES FOR AMOUNTS OF 0.10" OR MORE RANGING FROM AROUND
15% NEAR HELENA TO 30-50% FROM DILLON TO BOZEMAN TO AROUND 80% NEAR
THE ID/WY BORDER. HIGHEST AMOUNTS ARE LIKELY TO OCCUR IN THE
GALLATIN/MADISON/CENTENNIAL RANGES, WHERE THERE IS 50-70%
PROBABILITY OF AMOUNTS EXCEEDING 0.25". SNOW LEVELS LOOK TO
INITIALLY BEGIN AT OR ABOVE 7000FT WEDNESDAY EVENING BUT LOWER TO
AROUND 5000FT BY THURSDAY MORNING FOR SOME MINOR SNOW ACCUMULATION
AT AND BELOW PASSES WEDNESDAY NIGHT AND A 30-50% RISK FOR SNOW
ACCUMULATIONS OF 2" OR MORE MAINLY ABOVE 7000FT IN THE GALLATIN
AND MADISON RANGES.
MEDIUM RANGE MODEL ENSEMBLES ARE IN FAIR AGREEMENT IN THE DEPICTION
OF A PERIOD OF UPPER LEVEL RIDGING AND WARMER/DRY CONDITIONS FROM
FRIDAY THROUGH AT LEAST THE FIRST HALF OF THE UPCOMING WEEKEND.
THERE ALSO IS GOOD AGREEMENT ON THE DEVELOPMENT OF LARGER SCALE
UPPER LEVEL TROUGHING ACROSS THE WESTERN US BY EARLY NEXT WEEK,
IMPLYING A SHIFT TO COOLER/WETTER AND MORE ACTIVE CONDITIONS.
CLUSTER ANALYSIS HOWEVER REVEALS THERE ARE STILL SOME SIGNIFICANT
DIFFERENCES IN THE TIMING AND DEPTH OF THE UPPER LEVEL TROUGHING
EARLY NEXT WEEK, SO MORE SPECIFIC DETAILS REMAIN UNCERTAIN FOR
NOW. HOENISCH
AVIATION
22/06Z TAF PERIOD
SOME LINGERING SHOWERS FOR THE NEXT FEW HOURS ACROSS NORTH CENTRAL
MT. CLOUDS WILL SLOWLY CLEAR OUT THROUGH THE NIGHT AND EARLY MORNING
HOURS. MVFR/IFR CLOUDS WILL LIKELY LINGER THROUGH THE MORNING FOR
KHVR, KCTB, AND KLWT. DEPENDING ON HOW MUCH CLOUDS CLEAR, WE WILL
HAVE TO MONITOR FOR FOG DEVELOPMENT. HOWEVER DUE TO SCATTERED CLOUD
COVER EXPECTED THROUGHOUT THE NIGHT, I'VE OPTED OUT OF THE TAFS FOR
NOW. BY TUESDAY AFTERNOON, ALL TERMINALS ARE EXPECTED TO BE VFR FOR
THE REST OF THE TAF PERIOD. -WILSON
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION WEATHER
AND HAZARD INFORMATION.
PRELIMINARY POINT TEMPS/POPS
GTF 56 30 60 32 / 0 0 0 10
CTB 51 25 54 28 / 10 0 0 0
HLN 57 29 59 32 / 0 0 20 40
BZN 57 27 60 27 / 10 0 10 80
WYS 50 18 52 22 / 10 0 20 90
DLN 55 28 58 26 / 0 0 20 80
HVR 53 28 59 28 / 20 0 0 0
LWT 53 30 61 29 / 0 0 0 40
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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