731
FXUS65 KTFX 290603
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1203 AM MDT WED JUL 29 2026
KEY MESSAGES
- WILDFIRE SMOKE CONTINUES TO BRING HAZY SKIES AND AIR QUALITY
DEGRADATION THROUGH THE WEEK.
- HOT TEMPERATURES PERSIST THROUGH THE WEEK, WITH SATURDAY BEING
THE HOTTEST DAY.
- DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE ACROSS
SOUTHWEST AND CENTRAL MT THROUGH THURSDAY.
- GUSTY WINDS SATURDAY AND SUNDAY WITH THE STRONGEST WINDS ALONG
THE ROCKY MOUNTAIN FRONT WILL CREATE INCREASED FIRE WEATHER
CONCERNS.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
BEING ON THE PERIPHERY OF THE UPPER-LEVEL RIDGE, SOUTHWESTERLY
FLOW DOMINATES THE WEATHER PATTERN THROUGH FRIDAY. THIS PATTERN
ENTAILS HOT TEMPERATURES REGION WIDE AND DAILY CHANCES FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS FOR
SOUTHWEST/CENTRAL THROUGH AT LEAST THURSDAY. SEVERE THUNDERSTORM
CHANCES REMAIN LOW WEDNESDAY AND THURSDAY. HOWEVER, WITH A HOT AND
DRY SURFACE LAYER, WE CAN'T RULE OUT SOME GUSTY WINDS WITH
SHOWERS AND THUNDERSTORMS. THIS PATTERN ALSO CONTINUES TO ADVECT
IN WILDFIRE SMOKE FROM THE PACIFIC NORTHWEST, WHICH WILL KEEP
HAZY SKIES AND AIR QUALITY DEGRADATION.
HEADING INTO THE WEEKEND, THE UPPER-LEVEL RIDGE BEGINS TO BREAKDOWN.
INCREASING SOUTHWEST FLOW WILL HELP BRING IN THE HOTTEST
TEMPERATURES OF THE WEEK THE STATE. THE RIDGE BREAKDOWN WITH A
DRY COLD FRONT PASSAGE WILL BRING A RELIEF TO THE HEAT FOR THE
FIRST PART OF NEXT WEEK. HOWEVER, WITH THE RIDGE BREAKDOWN COMES
GUSTY TO STRONG WINDS LATE SATURDAY INTO SUNDAY, ESPECIALLY ALONG
THE ROCKY MOUNTAIN FRONT. COMBINED WITH LOW RELATIVE HUMIDITY,
THIS CAUSES CONCERNS FOR CRITICAL FIRE WEATHER. THIS TROUGHING
PATTERN WON'TLAST TOO LONG, AS ENSEMBLES HINT AT ANOTHER RIDGE
BUILDING IN MID WEEK.
- FORECAST CONFIDENCE & SCENARIOS:
HEAT THIS WEEKEND:
THERE IS GOOD CONFIDENCE IN IMPACTFUL HEAT SETTLING IN SATURDAY.
THE EUROPEAN MODEL EXTREME FORECAST INDEX SHOWS A 0.7 TO 0.95 EAST
OF THE CONTINENTAL DIVIDE SATURDAY, MEANING IT WILL BE UNUSUALLY
HOT FOR THIS TIME OF YEAR. THERE REMAINS SOME MODEL AND RUN TO RUN
INCONSISTENCY WITH HOW HOT IT WILL GET. ANOTHER BIG QUESTION MARK
IS THE WILDFIRE SMOKE AND IF AN INCREASE FIRE WEATHER BEHAVIOR
ACROSS THE PACIFIC NORTHWEST WILL PRODUCE MORE SMOKE AND DAMPEN
THE HIGH TEMPERATURES. REGARDLESS, THERE REMAINS GOOD CONFIDENCE
IN IMPACTFUL HEAT SATURDAY, ESPECIALLY ACROSS NORTH- CENTRAL MT.
WINDS THIS WEEKEND:
MODELS STILL HINT AT THE INCREASING POTENTIAL FOR GUSTY TO STRONG
WINDS DEVELOP ALONG THE ROCKY MOUNTAIN FRONT AND NORTH-CENTRAL MT
LATE SATURDAY INTO SUNDAY. MODELS HAVE BEEN CONSISTENTLY SHOWING
A 50-70KT 700MB JET DEVELOPING ALONG THE ROCKY MOUNTAIN FRONT AND
NORTH-CENTRAL MT PLAINS LATE SATURDAY NIGHT INTO MID SUNDAY
MORNING. THE TIMING OF THIS JET IS NOT THE MOST IDEAL FOR HIGH
WINDS, BUT GOOD RIDGETOP STABILITY SUGGESTS MOUNTAIN WAVE ACTIVITY
WILL BE POSSIBLE. ANOTHER CONCERN IS IMPACT ON RECREATION ALONG
THE ROCKY MOUNTAIN FRONT/BACK COUNTRY DUE TO FALLING TREES. RIGHT
NOW, THERE'S A 20-60% CHANCE FOR 55 MPH WINDS ALONG THE IMMEDIATE
NORTHERN ROCKY MOUNTAIN FRONT FOOTHILLS. ANOTHER CONCERN WITH
WINDS IS INCREASED FIRE WEATHER BEHAVIOR SATURDAY AND SUNDAY WITH
THE COMBINATION OF CRITICALLY LOW RELATIVE HUMIDITY. -WILSON
AVIATION
29/06Z TAF PERIOD
REGIONAL WILDFIRE SMOKE WILL CONTINUE TO BE PRESENT ACROSS THE
NORTHERN ROCKIES THROUGH THE 2906/3006 TAF PERIOD, WITH
PREDOMINATELY LOW-VFR/VFR CONDITIONS EXPECTED. THE ONE EXCEPTION
WILL BE THE KCTB TERMINAL WHERE MVFR CONDITIONS ARE POSSIBLE
BETWEEN 29/21Z AND 30/03Z DUE SMOKE SPREADING NORTHEAST FROM THE
SILVERTIP FIRE. SLANTWISE VISIBILITY WILL BE REDUCED UPON ASCENT
AND DESCENT ACROSS ALL TERMINALS OVER THE NEXT 24 HOURS. OTHERWISE
THE ONLY OTHER CONCERN WILL BE SCATTERED SHOWERS AND THUNDERSTORMS
DEVELOPING ACROSS SOUTHWEST MONTANA BEYOND 18Z WEDNESDAY AND
PERSISTING THROUGH 03Z THURSDAY. MAIN IMPACT FROM THESE SHOWERS
AND STORMS WILL BE GUSTY AND ERRATIC WINDS AT THE KBZN, KEKS, AND
KWYS TERMINALS THROUGH THIS TIMEFRAME.
FOR KGTF: LIGHT AND VARIABLE WINDS WILL BACK TO THE EAST DURING
THE LATE AFTERNOON HOURS; INCREASING THEREAFTER AND BECOMING GUSTY
DUE TO DEEP, DIURNAL MIXING. THE PROBABILITY OF THIS EAST WIND
EXCEEDING A 15KT CROSSWIND IS 30% BETWEEN 30/00Z AND 30/04Z. -
MOLDAN
PRELIMINARY POINT TEMPS/POPS
GTF 93 59 95 59 / 0 0 10 30
CTB 89 54 90 55 / 0 0 0 10
HLN 93 59 93 59 / 10 10 10 20
BZN 92 56 93 56 / 20 20 10 20
WYS 84 46 86 47 / 40 30 10 0
DLN 87 53 89 54 / 20 10 20 10
HVR 95 59 98 59 / 0 0 10 20
LWT 90 56 91 57 / 0 20 20 30
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
HTTP://WWW.WEATHER.GOV/GREATFALLS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page