175
FXUS65 KTFX 230810
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
210 AM MDT THU JUL 23 2026
KEY MESSAGES
- DAILY ROUNDS OF SHOWER AND THUNDERSTORM ACTIVITY CONTINUES
THROUGH THE WEEKEND, ALTHOUGH STORM COVERAGE DROPS OFF SOMEWHAT
FRIDAY AND SATURDAY.
- THUNDERSTORM HAZARDS WILL INCLUDE STRONG, GUSTY WINDS, HAIL,
AND DOWNPOURS IN ADDITION TO CLOUD TO GROUND LIGHTNING.
- DRY, HOT, AND BREEZY TO WINDY CONDITIONS WILL RAISE ELEVATED
TO CRITICAL FIRE WEATHER CONCERNS FOR THE WEEKEND, ESPECIALLY
FRIDAY AND SATURDAY.
- THE SUMMER HEAT WILL CONTINUE THROUGH THE WEEKEND INTO NEXT
WEEK, BUT WILL BE MOST INTENSE FRIDAY AND SATURDAY.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
SLIGHTLY DRIER AIR MOVES IN TODAY BEHIND THE EXITING SHORTWAVE;
HOWEVER, ANOTHER SHORTWAVE MOVES IN FROM THE SOUTHWEST AND BRINGS
MORE WIDELY SCATTERED SHOWERS AND STORMS TO MUCH OF THE FORECAST
AREA. FORECAST SOUNDINGS CONTINUE TO SHOW INVERTED V PROFILES,
WHICH WILL RESULT IN STRONGER THUNDERSTORM OUTFLOW WINDS THAN THE
LAST COUPLE OF DAYS. ML CAPE VALUES GENERALLY RUNNING BETWEEN 800
AND 1200 J/KG WILL ALSO BE SUFFICIENT FOR HAIL, BRIEF HEAVY
DOWNPOURS, AND CLOUD TO GROUND LIGHTNING. THE COMBINATION OF THE
THINNING MOISTURE AND THE BUILDING RIDGE WILL ALSO WARM AFTERNOON
TEMPERATURES WELL INTO THE 90S AND EVEN 100S FOR MOST LOWER
ELEVATION LOCATIONS.
A DRIER SOUTHWESTERLY FLOW ALOFT WILL CONTINUE TO THIN THE
MOISTURE PROFILE FROM WEST TO EAST ON FRIDAY AND SATURDAY FOR
MOSTLY DRY CONDITIONS AND INTENSIFYING HEAT, BUT THERE WILL BE
ENOUGH LINGERING INSTABILITY AND MOISTURE FOR AT LEAST SOME
SHOWERS AND STORMS. MODEL GUIDANCE HAS STEADILY INCREASED
SATURDAY'S THUNDERSTORM ACTIVITY OVER CENTRAL AND SOUTHWEST MT
WITH A MORE DEFINED SHORTWAVE PASSAGE DURING PEAK DIURNAL HEATING.
OTHERWISE, STRENGTHENING DRY SOUTHWESTERLY FLOW WILL INCREASE
SURFACE WINDS FOR AT LEAST THE FIRST HALF OF THE WEEKEND AND
INTRODUCE ELEVATED TO CRITICAL FIRE WEATHER CONCERNS, ESPECIALLY
FOR NORTHERN AREAS.
SOUTHWESTERLY FLOW ALOFT CONTINUES OVER THE NORTHERN ROCKIES
HEADING INTO NEXT WEEK. THIS WILL MAINTAIN THE SUMMER HEAT WHILE
PASSING SHORTWAVES INTERACT WITH DIURNAL INSTABILITY FOR AT LEAST
DAILY ISOLATED SHOWER AND THUNDERSTORM ACTIVITY. THERE WILL ALSO
BE PERIODIC BREEZINESS TO GO ALONG WITH THE HOT AND MOSTLY DRY
CONDITIONS, BUT THERE'S NO CLEAR SIGNAL FOR WIND SPEEDS STRONG
ENOUGH TO WARRANT FIRE WEATHER CONCERNS JUST QUITE YET. - RCG
- FORECAST CONFIDENCE & SCENARIOS:
SHOWER AND THUNDERSTORM ACTIVITY WILL BE FAR MORE SCATTERED IN
NATURE THAN YESTERDAY, BUT THE RISK AREA WILL COVER VIRTUALLY THE
ENTIRE FORECAST AREA, NOT JUST CENTRAL AND SOUTHWEST MT. THINNING
MOISTURE PROFILES WILL BEGIN TO REDUCE THE THREAT FOR LOCALIZED
FLOODING WHILE INCREASING INSTANCES OF STRONG WIND GUSTS NEAR
SHOWERS AND STORMS. IN ADDITION TO THE STRONG WIND GUST THREAT
STORMS WILL ALSO BE CAPABLE OF HAIL, BRIEF DOWNPOURS, AND CLOUD TO
GROUND LIGHTNING. PEAK TIMING WILL GENERALLY RUN BETWEEN 3 PM AND
MIDNIGHT.
EVEN DRIER AIR MOVES IN ON FRIDAY WHILE THE HEAT INTENSIFIES.
ISOLATED SHOWERS AND STORMS WILL MOSTLY BE CONFINED TO THE CENTRAL
AND SOUTHWEST MOUNTAINS. A MORE DEFINED SHORTWAVE LOOKS TO BRING
A SLIGHT UPTICK IN SHOWER AND THUNDERSTORM ACTIVITY ON SATURDAY.
CENTRAL AND SOUTHWESTERN AREAS LOOK TO SEE THE MOST WIDESPREAD
ACTIVITY WITH STORM HAZARDS INCLUDING LOCALIZED STRONG WIND GUSTS,
HAIL, AND DOWNPOURS IN ADDITION TO LIGHTNING. - RCG
AVIATION
23/06Z TAF PERIOD
LINGERING SHOWERS ACROSS CENTRAL AND SOUTHWEST MONTANA WILL
DIMINISH BY AROUND 23/09Z. IMPACTS ARE GENERALLY NOT EXPECTED AT
ANY OF THE TERMINALS OUTSIDE OF KWYS WHICH WILL HAVE CONTINUE TO
RECEIVE SOME LIGHT RAIN BEFORE TAPERING OFF.
THERE IS A HIGH CHANCE FOR FOG DEVELOPING AT KWYS OVERNIGHT WITH
SLIGHTLY LESSER CONFIDENCE IN KEKS THAT WILL DEPEND ON WHETHER THE
CLOUDS ARE ABLE TO FULLY CLEAR OUT. THE FOG WILL START TO LIFT
AFTER 23/15Z AS THE NEXT SHORTWAVE TROUGH STARTS TO MOVE INTO THE
REGION BRINGING ANOTHER MID-LEVEL CLOUD DECK AND A CHANCE FOR
PRECIPITATION.
ANOTHER ROUND OF ISOLATED TO SCATTERED THUNDERSTORMS ARE POSSIBLE
THURSDAY AFTERNOON ALTHOUGH CONFIDENCE IN IMPACTS TO ANY ONE
TERMINAL REMAINS RATHER LOW. THE HIGHEST CONFIDENCE FOR IMPACT
WILL BE ACROSS SOUTHWEST MONTANA INCLUDING KBZN, KEKS, AND KWYS
WHICH ALL HAVE PROB30 GROUPS FOR THE CONVECTIVE TIMEFRAME. FOR ALL
OTHER TERMINALS, CONFIDENCE WAS LESS THAN 10% AND THUS TOO LOW TO
INCLUDE IN THE TAF AT THIS TIME. THE MAIN CONCERNS FOR ANY
THUNDERSTORM THAT DEVELOPS WILL BE MOUNTAIN OBSCURATION,
LIGHTNING, AND GUSTY WINDS.
WILDFIRE SMOKE WILL CONTINUE TO IMPACT SLANTWISE VISIBILITY
THROUGH THE PERIOD. THERE ARE SOME HINTS IN THE HI-RES MODELS THAT
CONDITIONS MIGHT WORSEN THURSDAY AFTERNOON/EVENING TOWARDS THE END
OF THE TAF PERIOD BUT THERE IS STILL DISAGREEMENT IN THE MODELS AS
TO HOW MUCH SURFACE VISIBILITY AND CEILINGS WILL BE IMPACTED.
-THOR
FIRE WEATHER
INTENSIFYING HEAT, CRITICALLY LOW MINIMUM HUMIDITY, AND WESTERLY
WINDS ROUTINELY GUSTING IN THE 20 TO 30 MPH RANGE WILL RAISE DAILY
ELEVATED TO CRITICAL FIRE WEATHER CONCERNS THIS WEEKEND INTO NEXT
WEEK. IN THE NEAR TERM, THE WORST FIRE WEATHER CONDITIONS WILL BE
OVER THE NORTH-CENTRAL PLAINS FRIDAY AND SATURDAY. ADDITIONALLY,
ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS MAY PRODUCE
LOCALIZED STRONG WIND GUSTS AND CLOUD TO GROUND LIGHTNING, MOSTLY
FOR CENTRAL AND SOUTHWEST MONTANA SATURDAY AFTERNOON AND EVENING.
A FIRE WEATHER WATCH HAS BEEN ISSUED FOR ZONES 112, 113, 114,
115, AND 117 FOR FRIDAY AND SATURDAY TO ADDRESS THE ELEVATED TO
CRITICAL FIRE WEATHER CONDITIONS THAT MAY DEVELOP IN THIS SETUP.
- RCG
PRELIMINARY POINT TEMPS/POPS
GTF 96 64 99 63 / 20 20 10 0
CTB 93 61 92 58 / 20 20 0 0
HLN 94 63 98 63 / 20 20 10 10
BZN 90 60 97 61 / 30 20 0 20
WYS 80 50 87 51 / 50 30 0 10
DLN 87 57 93 57 / 20 20 0 10
HVR 99 65 102 63 / 20 20 0 0
LWT 90 61 95 61 / 20 20 10 10
TFX WATCHES/WARNINGS/ADVISORIES
FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH SATURDAY EVENING
FOR CENTRAL AND EASTERN LEWIS AND CLARK NATIONAL FOREST AREAS-
CHOUTEAU AND FERGUS COUNTIES-EASTERN
GLACIER/TOOLE/CENTRAL/EASTERN PONDERA/LIBERTY-HILL AND BLAINE
COUNTIES-LEWIS AND CLARK NATIONAL FOREST ROCKY MOUNTAIN DISTRICT-
ROCKY MOUNTAIN FRONT.
EXTREME HEAT WATCH FROM FRIDAY MORNING THROUGH SUNDAY EVENING
FOR BEARS PAW MOUNTAINS AND SOUTHERN BLAINE-CASCADE COUNTY BELOW
5000FT-FERGUS COUNTY BELOW 4500FT-HILL COUNTY-JUDITH BASIN
COUNTY AND JUDITH GAP-NORTHERN BLAINE COUNTY-WESTERN AND CENTRAL
CHOUTEAU COUNTY.
HTTP://WWW.WEATHER.GOV/GREATFALLS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page