534
FXUS65 KTFX 260824
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
224 AM MDT MON MAY 26 2025
KEY MESSAGES
- SCATTERED SHOWERS AND THUNDERSTORMS DEVELOP LATE THIS
AFTERNOON AND EVENING, FEW STORMS WILL BE ON THE STRONGER SIDE
WITH LOCALIZED GUSTY WINDS, BRIEF DOWNPOURS, AND SMALL HAIL.
- ANOTHER PASSING WEATHER SYSTEM WILL BRING BREEZY TO
WINDY CONDITIONS AND MORE SCATTERED SHOWERS AND THUNDERSTORMS
THURSDAY INTO FRIDAY.
- TEMPERATURES WILL TREND ABOVE AVERAGE FOR MOST OF THE WEEK.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
RIDGING ALOFT WILL MAINTAIN WARM AND DRY CONDITIONS THROUGH THIS
AFTERNOON BEFORE SHOWER AND THUNDERSTORM ACTIVITY INCREASES BY THE
EVENING HOURS IN RESPONSE TO A PASSING SHORTWAVE. MOST OF THE
FORCING IS EXPECTED TO REMAIN NORTHWEST OF THE FORECAST AREA;
HOWEVER, THE WEAKLY SHEARED ENVIRONMENT WILL BE COMPLIMENTED BY ML
CAPE LEVELS AROUND AND ABOVE 500 J/KG AND PWATS OVER A HALF INCH.
SHOWERS AND STORMS WILL INITIALLY FIRE OVER THE HIGHER TERRAIN OF
WESTERN/SOUTHWESTERN MONTANA LATE IN THE AFTERNOON AND THEN
SPREAD EASTWARD WHILE WEAKENING DURING THE EVENING AND EARLY
OVERNIGHT HOURS. THE STRONGEST STORMS WILL BE CAPABLE OF LOCALIZED
GUSTY WINDS IN EXCESS OF 40 MPH, BRIEF DOWNPOURS, AND SMALL HAIL.
A WEAK CLOSED LOW IS STILL EXPECTED TO SPLIT OFF OF THE MAIN
SHORTWAVE AND MOVE SOUTHWARD INTO MONTANA ON TUESDAY. SLIGHTLY
COOLER TEMPERATURES AND ANOTHER ROUND OF SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED ON TUESDAY WITH THE FOCUS OF ACTIVITY
GENERALLY EAST OF I15.
RIDGING ALOFT WILL CONTINUE TO BE THE PRIMARY WEATHER INFLUENCER
HEADING INTO THE WEEKEND WITH MOSTLY DRY CONDITIONS AND AFTERNOON
TEMPERATURES RUNNING 10 TO 20 DEGREES ABOVE AVERAGE; HOWEVER A
SHORTWAVE WILL BRUSH THE NORTHERN ROCKIES LATE THURSDAY INTO
FRIDAY AND BRING BREEZY TO WINDY CONDITIONS AND ANOTHER INCREASE
IN SHOWER AND THUNDERSTORM ACTIVITY. - RCG
- FORECAST CONFIDENCE & SCENARIOS:
SHOWERS AND THUNDERSTORMS TODAY AND TUESDAY...
THE FORCING AND INSTABILITY WITH THIS SYSTEM AREN'T IDEALLY
ALIGNED, BUT STEEP LAPSE RATES AND INITIALLY DRY SUB-CLOUD LAYERS
ELEVATE DCAPE VALUES ABOVE 1,000 J/KG PRIOR TO THE STORMS ARRIVAL.
THIS IS INDICATIVE OF POTENTIAL STRONG AND GUSTY THUNDERSTORM
WINDS. THE LATEST HREF GUIDANCE SHOWS A 30 TO 50% CHANCE FOR
CONVECTIVE WIND GUSTS EXCEEDING 35 MPH, HIGHEST OVER THE
SOUTHWEST. MOISTURE WITH SYSTEM IS ALSO NOT VERY IMPRESSIVE, BUT
PRECIPITABLE WATER VALUES DO ECLIPSE THE HALF INCH MARK BY THIS
EVENING, SO BRIEF HEAVY DOWNPOURS ARE ALSO NOT OUT OF THE
QUESTION. THE MOST AGGRESSIVE STORMS SHOULD OCCUR LATE THIS
AFTERNOON AND EVENING NEAR THE CONTINENTAL DIVIDE AND SOUTHWEST
MONTANA WITH WEAKER ACTIVITY FARTHER EAST LATER IN THE EVENING AND
EARLY OVERNIGHT HOURS. THE STRONGEST STORMS WILL BE CAPABLE OF
LOCALIZED STRONG, GUSTY WINDS IN EXCESS OF 40 MPH, BRIEF
DOWNPOURS, AND SMALL HAIL. A MORE MODEST BRAND OF SCATTERED
SHOWERS AND THUNDERSTORMS ARE EXPECTED ON TUESDAY, MOSTLY EAST OF
I15. - RCG
AVIATION
26/06Z TAF PERIOD
VFR CONDITIONS ARE EXPECTED TO PREVAIL OVER THE NEXT 24 HOURS.
MOSTLY CLEAR SKIES WILL CONTINUE THROUGH THE MORNING WITH
INCREASING MID AND HIGH-LEVEL CLOUDINESS EXPECTED TO DEVELOP AFTER
26/18Z.
ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS MUCH OF
REGION, PARTICULARLY CENTRAL AND SOUTHWEST MONTANA, BETWEEN
27/00Z AND 27/06Z. THE MAIN CONCERNS WILL BE GUSTY, ERRATIC WINDS
AS WELL AS THE POTENTIAL FOR BRIEF, HEAVY RAIN FROM STRONGER
STORMS. MOUNTAIN OBSCURATION WILL BE A CONCERN WHERE SHOWERS AND
THUNDERSTORMS FORM. -THOR
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION
WEATHER AND HAZARD INFORMATION.
PRELIMINARY POINT TEMPS/POPS
GTF 82 52 75 50 / 10 40 10 0
CTB 80 48 75 48 / 20 40 0 0
HLN 83 52 77 52 / 20 50 20 0
BZN 80 47 73 46 / 10 30 50 10
WYS 72 38 69 37 / 30 40 60 10
DLN 78 47 73 46 / 30 40 30 0
HVR 80 50 78 49 / 0 10 10 0
LWT 74 48 70 48 / 0 10 40 10
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
HTTP://WWW.WEATHER.GOV/GREATFALLS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page