308
FXUS65 KTFX 091724
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1124 AM MDT SUN AUG 9 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- HAZY, VERY WARM, AND DRY CONDITIONS GENERALLY CONTINUE FOR
THE NEXT FEW DAYS.
- A PASSING WEATHER SYSTEM AND INCREASED MOISTURE WILL INTRODUCE SHOWER
AND THUNDERSTORM ACTIVITY AND COOL TEMPERATURES DOWN WEDNESDAY
THROUGH FRIDAY, PARTICULARLY FOR NORTHERN AREAS.
- THERE WILL BE DAILY SCATTERED SHOWER AND THUNDERSTORM
ACTIVITY AND WARMING TEMPERATURES NEXT WEEKEND.
DISCUSSION
/ISSUED 233 AM MDT SUN AUG 9 2026/
- METEOROLOGICAL OVERVIEW:
RIDGING ALOFT WILL MAINTAIN THE HAZY, VERY WARM, AND DRY
CONDITIONS FOR AT LEAST THE NEXT FEW DAYS. THE MAIN AREA OF
INSTABILITY AND ASSOCIATED SHOWER AND THUNDERSTORM ACTIVITY WILL
GENERALLY STAY NORTH OF THE CANADIAN BORDER DURING THIS PERIOD.
SEASONABLY BREEZY CONDITIONS WILL CONTINUE WITH SURFACE BOUNDARIES
BRINGING TRANSIENT GUSTY NORTHERLY WIND SHIFTS, MOSTLY OVER
CENTRAL/NORTH-CENTRAL MT.
A TROUGH BEGINS TO MOVE SOUTHEASTWARD THROUGH BC/AB AND INTO THE
NORTHERN ROCKIES SOMETIME WEDNESDAY INTO THURSDAY. THERE ARE SOME
DISAGREEMENTS WITH THE EVOLUTION OF THIS SYSTEM, BUT PWATS LOOK TO
RISE TOWARDS THE THREE QUARTER TO ONE INCH RANGE BY LATE
WEDNESDAY INTO THURSDAY ACCORDING TO THE NORTH AMERICAN ENSEMBLE
FORECAST SYSTEM (NAEFS). SHOWER AND THUNDERSTORM ACTIVITY LOOKS TO
INCREASE FROM NORTH TO SOUTH WITH AREAS ALONG THE HI-LINE SEEING
SCATTERED SHOWERS AND STORMS AS EARLY AS TUESDAY EVENING. THE
WEDNESDAY NIGHT THROUGH THURSDAY TIME PERIOD IS GENERALLY FAVORED
TO SEE THE MOST WIDESPREAD RAINFALL, ESPECIALLY FOR NORTH-CENTRAL
AREAS. WHILE SOME AREAS MAY SEE BENEFICIAL RAINS AND COOLING
TEMPERATURES, THE CONVECTIVE NATURE OF THIS ACTIVITY MAY ALSO
BRING SOME STRONG TO SEVERE STORMS WITH LOCALIZED STRONG GUSTY
WINDS, HAIL, AND HEAVY DOWNPOURS. WITH THAT BEING SAID, ML CAPE
DOESN'T LOOKS OVERLY IMPRESSIVE AT THIS POINT WITH VALUES
GENERALLY MAXING OUT BETWEEN 300 AND 800 J/KG.
THE RIDGING ALOFT BEGINS TO BUILD BACK IN HEADING INTO NEXT
WEEKEND, BUT ANOTHER TROUGH APPROACHING THE PACIFIC NW COAST WILL
BRING SOUTHWESTERLY FLOW ALOFT WITHIN STRIKING DISTANCE OF THE
NORTHERN ROCKIES. THIS WILL RESULT IN TEMPERATURES WARMING BACK
UP, ALONG WITH DAILY SHOWER AND THUNDERSTORM ACTIVITY. - RCG
- FORECAST CONFIDENCE & SCENARIOS:
BREEZY CONDITIONS, SHIFTING WINDS, AND LOCALIZED ELEVATED FIRE
CONCERNS...
THE COMBINATION OF VERY WARM, DRY, AND BREEZY CONDITIONS WILL
CAUSE LOCALIZED FIRE WEATHER CONDITIONS FOR THE NEXT COUPLE OF
DAYS. WHILE WIND GUSTS WILL GENERALLY BE BELOW THE 20 TO 25 MPH
THRESHOLD, SURFACE BOUNDARIES WILL BRING DAILY NORTHERLY WIND
SHIFTS, MOST NOTABLY OVER CENTRAL AND NORTH-CENTRAL MT. AFTERNOON
HUMIDITY WILL FALL TO OR NEAR CRITICALLY LOW LEVELS WITH ONLY
MODERATE TO POOR OVERNIGHT RECOVERIES, DRIEST OVER SOUTHWEST
MONTANA. THERE ARE NO PLANS FOR FIRE WEATHER HIGHLIGHTS AT THIS
TIME; HOWEVER, THOSE WORKING TO CONTAIN ONGOING FIRES SHOULD
BEWARE OF DRY CONDITIONS AND BREEZY, SHIFTING WINDS.
INCREASED SHOWER AND THUNDERSTORM ACTIVITY AND COOLER
TEMPERATURES WEDNESDAY THROUGH FRIDAY...
THERE HAS BEEN ENSEMBLE DISAGREEMENTS AND POOR RUN TO RUN
CONSISTENCY FOR THIS TIME PERIOD. THE PRIMARY QUESTION IS HOW FAR
SOUTH THIS TROUGH WILL GO, WHICH WILL DETERMINE HOW WIDESPREAD THE
SHOWERS WILL BE AND WHETHER TEMPERATURES COOL BELOW AVERAGE. IN
ADDITION TO THIS UNCERTAINTY, THERE ARE ALSO TIMING DISCREPANCIES
WITH A GROWING NUMBER OF MEMBERS SHIFTING THE MOST WIDESPREAD
PRECIPITATION TO THURSDAY INTO FRIDAY RATHER THAN WEDNESDAY INTO
THURSDAY. THE COOLER SOLUTION WOULD SUPPORT MORE BENEFICIAL
WETTING RAINS OVER CENTRAL AND NORTH-CENTRAL MT WHILE THE WARMER
SOLUTION WOULD SUPPORT MORE SCATTERED PRECIPITATION, BUT WITH
INCREASED INSTANCES OF STRONGER STORMS CAPABLE OF LOCALIZED STRONG
WIND GUSTS, HAIL, AND HEAVY DOWNPOURS. - RCG
AVIATION
09/18Z TAF PERIOD
VFR CONDITIONS WILL PREVAIL ACROSS ALL TERMINALS DURING THIS TAF
PERIOD OUTSIDE OF THE KBZN TERMINAL. THROUGH AT LEAST 09/22Z SMOKE
FROM WILDFIRES WILL PERIDICALLY REDUCE VISIBILITY TO MVFR LEVELS AT
THE KBZN TERMINAL. AT ALL OF THE TAF SITES DURING THIS TAF PERIOD
THERE WILL BE MULTIPLE WIND SHIFTS. ACROSS MOST OF THE TAF SITES
SMOKE FROM WILDFIRES WILL REDUCE SLANTWISE VISIBILITY DURING THE
MAJORITY OF THIS TAF PERIOD. -IG
KGTF: WINDS WILL BE LIGHT AND VARIABLE OVER THE NEXT 24 HOURS.
MAIN IMPACTS WILL BE THE SHIFTING WINDS FROM TIME TO TIME.
BRUSDA
PRELIMINARY POINT TEMPS/POPS
GTF 86 55 89 55 / 0 0 0 0
CTB 79 51 82 50 / 0 0 0 0
HLN 88 55 88 55 / 0 0 0 0
BZN 87 52 91 53 / 0 0 0 0
WYS 85 44 86 42 / 0 0 0 0
DLN 85 52 89 51 / 0 0 0 0
HVR 86 52 88 53 / 10 0 0 0
LWT 83 51 86 52 / 0 0 10 0
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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