071
FXUS65 KTFX 281946
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
146 PM MDT FRI AUG 28 2026
KEY MESSAGES
- DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS WITH HIGHER
RAINFALL AMOUNTS THROUGH THE WEEKEND, WITH THE POTENTIAL FOR
SOME MINOR MOUNTAIN SNOW ON SUNDAY.
- BREEZY AND GUSTY WINDS ON SUNDAY, ESPECIALLY ALONG THE ROCKY
MOUNTAIN FRONT AND CRAZY MTNS.
- BELOW NORMAL TEMPERATURES FOR SUNDAY AND MONDAY MORNING.
DISCUSSION
/ISSUED 146 PM MDT FRI AUG 28 2026/
- METEOROLOGICAL OVERVIEW:
CLOSED UPPER LEVEL LOW OFF THE COAST OF BRITISH COLUMBIA AND
ASSOCIATED UPPER LEVEL TROUGH WILL DIG SOUTH OVER THE PACIFIC
NORTHWEST BY SATURDAY MORNING BEFORE TRACKING EAST ALONG THE
CANADIAN BORDER THROUGH THE DAY ON SUNDAY. SOUTHWESTERLY FLOW
ALOFT AHEAD OF THE APPROACHING UPPER LEVEL TROUGH WILL CONTINUE TO
TRANSPORT PACIFIC MOISTURE NORTH AND EAST OVER THE NORTHERN
ROCKIES THROUGH THE TIMEFRAME. STRATIFORM RAIN AND SHOWERS ARE THE
PREDOMINANT PRECIPITATION DRIVERS CURRENTLY HOWEVER ISOLATED
EMBEDDED AND AIR MASS THUNDERSTORMS COULD DEVELOP THIS AFTERNOON
AS MID LEVEL STRATIFORM DRIES OUT AND DAYTIME HEATING REACHES ITS
MAX. HIGH TEMPERATURES IN THE UPPER 70S TO UPPER 80S TODAY WILL
FALL TO THE 60S TO LOW 70S BY SUNDAY AS THE TROUGH PROPOGATES
THROUGH THE CWA AND EXITS MONDAY MORNING. MID LEVEL WINDS WILL
SHIFT WESTERLY BY SUNDAY AFTERNOON AND CREATE STRONG AND GUSTY
SURFACE WINDS FOR MOST OF THE CWA AS THE LOW TRACKS EASTWARD.
AREAS ALONG THE NORTHERN ROCKY MOUNTAIN FRONT WILL SEE THE HIGHEST
WINDS DUE TO PRESSURE GRADIENT FORCING AND CROSS-BARRIER
DOWNSLOPING.
SYNOPTIC PATTERN NEXT WEEK WILL BE PRIMARILY UNDER THE INFLUENCE
OF LONGWAVE TROUGHING OVER THE PACIFIC COAST KEEPING SOUTHWESTERLY
FLOW OVER THE CWA BRINGING ABOVE NORMAL PWAT'S AND WARMER
TEMPERATURES UNTIL FRIDAY WHEN THE LONG WAVE TROUGH PROPOGATES
EASTWARD. - AKINS
- FORECAST CONFIDENCE & SCENARIOS:
EFI'S INDICATE ELEVATED WINDS ABOVE CLIMATE NORMS FOR THE NORTHERN
ROCKY MOUNTAIN FRONT AS WELL AS HIGHER THAN NORMAL QPF'S FOR THE
SOUTHWEST OF MONTANA FOR SATURDAY AND SUNDAY. NBM SIGNALS OF 80%+
PROBABILITIES FOR WIND GUSTS OVER 35 KT FOR NORTHERN RMF AND
LEESIDE OF CRAZY MTNS ALONG HWY 191. CONFIDENCE IS LOWER BUT STILL
WORTH MENTIONING FOR GUSTS OVER 50 KT WITH NBM SIGNALING 30%
PROBABILITY IN THE SAME AREAS. PROBABILITIES COULD INCREASE OR
DECREASE DEPENDING ON LATITUDINAL POSITION OF THE UPPER LOW'S
TRACK AS WELL AS TIMING OF THE JET STREAK POSITION DURING MAXIMUM
MIXED LAYER TIMES ON SUNDAY. FOR QPF'S ON SATURDAY, NBM IS
INDICATING A 40% PROBABILITY FOR RAINFALL OVER 1" FOR THE WEST
YELLOWSTONE AREA FROM NOON SATURDAY UNTIL 6PM SUNDAY AS WELL AS
30% PROBABILITIES OF OVER 1" IN THE LITTLE BELTS AND BRIDGER MTNS.
- AKINS
AVIATION
28/18Z TAF PERIOD
WHILE VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH MOST OF THE
18Z TAF PERIOD (THROUGH 29/18Z) -RA WITH EMBEDDED TSRA WILL
CONTINUE TO PERSIST ACROSS SOUTHERN MONTANA THROUGH THE REMAINDER
OF THE DAYLIGHT HOURS TODAY, BRINGING SOME PERIODS OF MVFR
VISIBILITIES TO SOME TERMINALS, MAINLY SOUTH OF A KHLN TO KLWT
LINE. FURTHER NORTH, A STRAY SHOWER CANNOT BE ENTIRELY RULED OUT
AROUND KGTF, BUT THIS PROBABILITY IS AROUND 10% AND THEREFORE NOT
MENTIONED IN THE TAF. ADDITIONAL -RA WILL WORK BACK INTO THE AREA
FROM THE SOUTHWEST TOMORROW, BUT SHOULD ONLY REACH KWYS/KEKS/KBZN
BY 18Z. LUDWIG
FOR KGTF: SOUTHWEST WINDS THROUGHOUT THE TAF PERIOD WILL YIELD
NEARLY A NON-ZERO CHANCE FOR CROSSWINDS TO EXCEED 15KTS; HOWEVER,
SHOWER AND THUNDERSTORM ACTIVITY MOVING SOUTH AND EAST OF THE
TERMINAL BEYOND 21Z THIS AFTERNOON COULD PRODUCE GUSTY OUTFLOW
BOUNDARIES THAT COULD MOVE NORTH AND WEST ACROSS THE TERMINAL. THE
GREATEST AREAL COVERAGE (WITHIN 50NM OF THE TERMINAL) OF THESE
SHOWERS AND STORMS LOOKS TO OCCUR BETWEEN 21-03Z THIS
AFTERNOON/EVENING, BUT ISOLATED COVERAGE WILL LINGER INTO THE
EVENING AND OVERNIGHT HOURS TONIGHT. EVEN DURING THIS PERIOD OF
GREATEST ACTIVITY, THE RISK FOR IMPACTS TO THE AIRFIELD FROM RAIN
OR OUTFLOWS REMAINS LOW (10% FOR RAIN, ~20% FOR WINDS) AND ANY
IMPACTS SHOULD BE TRANSIENT.
- MOLDAN/LUDWIG
FIRE WEATHER
ELEVATED FIRE WEATHER CONDITIONS WILL EXIST ACROSS PORTIONS OF
FIRE WEATHER ZONE 112 TODAY AS SOUTHWEST WINDS PEAK BETWEEN 15-20
MPH DURING THE AFTERNOON AND EVENING HOURS, WITH GUSTS NEAR 30
MPH. THE BREEZY WINDS COMBINED WITH MINIMUM RELATIVE HUMIDLY
VALUES OF 15-20% WEST OF THE I-15 CORRIDOR RAISES CONCERNS FOR THE
POTENTIAL OF NEW FIRES TO SPREAD RAPIDLY; HOWEVER, WITH LESS THAN
HALF OF THE FIRE WEATHER ZONE EXPECTED TO SEE WIND GUSTS NEAR 30
MPH WE WILL CONTINUE TO HOLD OFF ON ANY FIRE WEATHER PRODUCTS. -
MOLDAN
PRELIMINARY POINT TEMPS/POPS
GTF 58 79 50 67 / 20 60 80 60
CTB 50 74 46 62 / 10 40 60 30
HLN 54 78 48 70 / 10 90 80 50
BZN 52 77 46 69 / 20 60 80 70
WYS 40 65 35 65 / 60 90 90 80
DLN 51 75 43 71 / 50 70 70 40
HVR 56 86 50 70 / 20 40 70 60
LWT 55 79 47 67 / 20 70 60 80
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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