853
FXUS65 KTFX 261630
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1030 AM MDT THU JUN 26 2025
KEY MESSAGES
- ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED
EACH AFTERNOON AND EVENING THROUGH SATURDAY.
- SOME THUNDERSTORMS WILL PRODUCE STRONG WIND GUSTS TODAY.
- TEMPERATURES TREND ABOVE SEASONAL AVERAGES EARLY NEXT WEEK
WITH A RETURN TO TO DAILY THUNDERSTORM CHANCES BY THE MIDDLE OF
NEXT WEEK.
UPDATE
AN AREA OF CLOUDS AND LIGHT RAIN SHOWERS CONTINUES TO PUSH THROUGH
THE AREA THIS MORNING, MOSTLY IN LINE WITH THE FORECAST IF NOT
SLIGHTLY MORE WIDESPREAD AND LONGER LASTING THAN FORECAST. THE
IMPACT OF THESE LINGERING CLOUDS ON THIS AFTERNOON'S CLOUDS IS A
BIT UNCERTAIN, SO WE WILL SEE HOW THINGS DEVELOP THIS AFTERNOON.
LUDWIG
DISCUSSION
/ISSUED 459 AM MDT THU JUN 26 2025/
- METEOROLOGICAL OVERVIEW:
THE NORTHERN ROCKIES AND MT REMAIN UNDER AN OVERALL
ZONAL/WESTERLY FLOW ALOFT INTO THE UPCOMING WEEKEND WITH
PERSISTENT UPPER TROUGHING CENTERED IN THE GULF OF AK SENDING A
SERIES MAINLY WEAK SHORTWAVE AND UPPER LEVEL JET IMPULSES FROM
THE PACIFIC EASTWARD ALONG THE US/CANADIAN BORDER. A WEAK FRONTAL
BOUNDARY ALOFT PUSHING EAST ACROSS THE ROCKIES EARLY THIS MORNING
WILL SPREAD CLOUDS AND A FEW LIGHT SHOWERS ACROSS CENTRAL AND
NORTH-CENTRAL MT THIS MORNING WITH THUNDERSTORM DEVELOPMENT ACROSS
CENTRAL ID AND WEST-CENTRAL MT DEVELOPING EARLY THIS AFTERNOON
AND TRACKING EAST ACROSS NORTH-CENTRAL AND SOUTHWEST MT LATER
THIS AFTERNOON THROUGH EARLY THIS EVENING. THERE IS A MARGINAL
(5-10%) RISK FOR SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS
CENTRAL/NORTH-CENTRAL MT, MAINLY DUE TO STRONG WIND GUST
POTENTIAL. WEAKER DISTURBANCES MOVING THROUGH THE WESTERLY FLOW
WILL BRING ADDITIONAL CHANCES FOR WIDELY SCATTERED AFTERNOON
SHOWERS AND THUNDERSTORMS AGAIN FRIDAY WITH MORE ISOLATED COVERAGE
OF ANY SHOWERS/STORMS ON SATURDAY. IN THE WAKE OF THIS SERIES OF
DISTURBANCES UPPER LEVEL RIDGING WILL BUILD ACROSS THE INTERIOR
WESTERN US LATER THIS WEEKEND INTO EARLY NEXT WEEK, SENDING
TEMPERATURES ABOVE SEASONAL AVERAGES WITH AFTERNOON MAXIMUMS
REACHING THE UPPER 80S TO AROUND 90S ACROSS LOWER ELEVATION
LOCATIONS BY MONDAY AND TUESDAY. MAINLY DRY CONDITIONS ARE ALSO
EXPECTED THROUGH AT LEAST MONDAY WITH SOME MOISTURE RETURN
BRINGING AN INCREASE IN DAILY SHOWER/THUNDERSTORM CHANCES AGAIN BY
THE MIDDLE OF NEXT WEEK.
- FORECAST CONFIDENCE & SCENARIOS:
PRIMARY CONCERN WITH THUNDERSTORM ACTIVITY THIS AFTERNOON WILL BE
STRONG WINDS, NOTING A RELATIVELY DEEP/ELEVATED MIX LAYER STILL
IN PLACE PER THE 06Z KTFX UPPER AIR SOUNDING AND MID-LEVEL FLOW
INCREASING TODAY, SUPPORTING THE IDEA OF CONVECTION WITH ENHANCED
OUTFLOW OR A MORE ORGANIZED COLD POOL DESPITE ONLY MODEST
INSTABILITY. SOME UNCERTAINTY EXISTS RELATED TO HOW MUCH OF THIS
DEEPLY MIXED BOUNDARY LAYER WILL REMAIN GOING INTO THIS AFTERNOON
FOLLOWING MID-LEVEL MOISTURE INCREASES AND EVEN SOME LIGHT SHOWERS
MOVING ACROSS THE AREA THIS MORNING. HI-RESOLUTION/CONVECTION
ALLOWING MODEL GUIDANCE CONTINUES TO KEY ON STRONGER STORMS WITHIN
A CORRIDOR OF CAPE IN THE 500-1000 J/KG RANGE FROM ROUGHLY
SOUTHERN LEWIS AND CLARK COUNTY EAST THROUGH FERGUS COUNTY THIS
AFTERNOON WITH SOME HIGHER CAPE POTENTIALLY POOLING EAST OF THE
LITTLE BELTS, GIVING THE GREATEST RISK FOR STRONGER THUNDERSTORMS
ACROSS JUDITH BASIN AND FERGUS COUNTIES. HOENISCH
AVIATION
26/12Z TAF PERIOD
MID-LEVEL CLOUDS INCREASE THIS MORNING WITH A FEW LIGHT SHOWERS
BUT VFR CONDITIONS PREVAILING AT ALL TERMINALS. SCATTERED SHOWERS
AND THUNDERSTORMS DEVELOP THIS AFTERNOON WITH POTENTIAL FOR LOCAL
MVFR AND MOUNTAIN OBSCURATION NEAR STRONGER STORMS BUT PRIMARY
IMPACT TO AVIATION WILL BE STRONGER AND SHIFTING WINDS NEAR
STORMS, PARTICULARLY ACROSS CENTRAL MT. HOENISCH
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION
WEATHER AND HAZARD INFORMATION.
PRELIMINARY POINT TEMPS/POPS
GTF 81 55 80 52 / 40 30 30 0
CTB 76 55 74 50 / 20 10 10 0
HLN 80 54 80 52 / 70 30 40 10
BZN 85 50 85 50 / 30 20 30 10
WYS 74 39 75 39 / 10 10 20 10
DLN 79 48 80 47 / 30 10 10 0
HVR 84 55 83 53 / 20 30 10 0
LWT 79 52 75 51 / 40 40 50 20
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
HTTP://WWW.WEATHER.GOV/GREATFALLS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page