247
FXUS65 KTFX 261946
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
146 PM MDT MON MAY 26 2025
KEY MESSAGES
- SCATTERED SHOWERS AND THUNDERSTORMS DEVELOP IN THIS AFTERNOON
AND EARLY EVENING, WITH A FEW STORMS CAPABLE OF PRODUCING GUSTY
WINDS, SMALL HAIL, AND BRIEF DOWNPOURS.
- ADDITIONAL WEATHER SYSTEMS PASSING THROUGH WILL BRING ANOTHER ROUND
OF SHOWERS AND THUNDERSTORMS TUESDAY, AND THURSDAY INTO FRIDAY.
- TEMPERATURES CONTINUE TO TREND ABOVE AVERAGE THROUGH THE
FORECAST PERIOD.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
A SMALL SHORTWAVE TROUGH MOVING THROUGH TODAY AND TOMORROW WILL
BRING SCATTERED SHOWERS AND THUNDERSTORMS. FOR TODAY, INCREASING
MOISTURE AND AFTERNOON TEMPERATURES HAS BEGUN PRODUCING SHOWERS
AND THUNDERSTORMS ALONG THE HIGHER TERRAIN ALONG THE CONTINENTAL
DIVIDE AND SOUTHWEST MT. ADDITIONAL DEVELOPMENT WILL BE ALONG THE
SHORTWAVE COMING THROUGH DURING THE LATE AFTERNOON. BY EARLY
EVENING, STORMS WILL TRAVERSE OFF THE TERRAIN INTO THE NORTH-
CENTRAL MT PLAINS. WEAKER SHEAR AND CAPE SHOULD KEEP STORMS SUB-
SEVERE. HOWEVER, DEEP INVERTED V VERTICAL PROFILE SOUNDINGS AND
TALL, SKINNY CAPE WILL ALLOW FOR SOME STORMS TO PRODUCE GUSTY
WINDS (40-50 MPH), SMALL HAIL, AND BRIEF HEAVY DOWNPOURS. ALTHOUGH
CHANCES FOR STORMS RAPIDLY DROP OFF AFTER SUNSET, A FEW STORMS
MAY STILL GO INTO THE LATE NIGHT. COVERAGE FOR SHOWERS AND STORMS
TUESDAY WILL BE LESS THAN TODAY, WITH IT BEING CONCENTRATED MAINLY
EAST OF THE MONIDA TO HAVRE LINE.
RIDGING ALOFT MOVES IN AFTER, AND WILL BE THE DOMINANT PATTERN
FOR THE WEEK. THOUGH, ANOTHER SMALL SHORTWAVE TROUGH WILL BRING
SLIGHT CHANCES FOR PRECIPITATION THURSDAY INTO FRIDAY.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGHOUT THE WEEK, WITH
THURSDAY AND SATURDAY BEING THE WARMEST. FOR THE BEGINNING OF NEXT
WEEK, MODELS ARE STARTING TO HINT ON ANOTHER WIDESPREAD SYSTEM
MOVING IN.
- FORECAST CONFIDENCE & SCENARIOS:
CONVECTION HAS HAD AN EARLY START THIS AFTERNOON FROM SURFACE
HEATING, BUT THE BEST WINDOW FOR SHOWERS AND THUNDERSTORMS WILL BE
LATE AFTERNOON THROUGH EVENING. HREF GUIDANCE SHOWS THE STRONGEST
STORMS ARE CAPABLE TO PRODUCE 40-50 MPH WIND GUSTS. GIVEN THE
HIGH BASED STORMS AND "INVERTED V'S", THIS SEEMS REASONABLE AS
STORMS MOVE OFF OF THE CONTINENTAL DIVIDE AND TO THE PLAINS. PWATS
OF 0.5" WILL ALLOW FOR BRIEF HEAVY DOWNPOURS AS WELL. WEAK SHEAR
WILL GIVE SLOWER STORM MOTIONS AND SHORTER-LIVED STORMS ("PULSE"
TYPE). A CLOSED LOW SPLITTING OFF THIS WAVE WILL BRING ADDITIONAL
CHANCES FOR SHOWER AND THUNDERSTORMS FOR TUESDAY, BUT FORCING
BEING MORE TO THE EAST WILL KEEP PRECIPITATION MAINLY CONFINED TO
EAST OF THE MONIDA TO HAVRE LINE.
THE RIDGE DOMINATING THE PATTERN MID TO LATE WEEK WILL KEEP
TEMPERATURES ABOVE AVERAGE, EVEN TO WELL ABOVE AVERAGE SOME DAYS.
THURSDAY AND SATURDAY ARE CURRENTLY TRENDING THE WARMEST, WITH
MOST LOWER ELEVATION LOCATIONS REACHING INTO THE 80S. THERE'S A
20-40% CHANCE FOR PARTS OF THE NORTH-CENTRAL MT PLAINS TO REACH
90 DEGREES BOTH DAYS. -WILSON
AVIATION
26/18Z TAF PERIOD
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE 2618/2718 TAF PERIOD;
HOWEVER, SHOWERS AND THUNDERSTORMS DEVELOPING AFTER 21Z THIS
AFTERNOON AND PERSISTING THROUGH 06-12Z TUESDAY WILL BE CAPABLE
OF PRODUCING GUSTY AND ERRATIC WINDS. THESE SHOWERS AND
THUNDERSTORMS WILL INITIALLY DEVELOP OVER NORTHEAST IDAHO AND
ALONG THE CONTINENTAL DIVIDE IN MONTANA BEFORE SLOWLY MOVING
NORTHEAST AND OVER LOWER ELEVATIONS OF SOUTHWEST THROUGH NORTH
CENTRAL MONTANA, GENERALLY ALONG AND WEST OF A KLVM, TO KLWT, TO
KHVR LINE. SOME MOUNTAIN OBSCURATION IS POSSIBLE BEYOND 21Z THIS
AFTERNOON, BUT WITH CLOUD BASES GENERALLY AROUND 9KFT WIDESPREAD
OBSCURATION IN NOT EXPECTED.- MOLDAN
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL
AVIATION WEATHER AND HAZARD INFORMATION.
PRELIMINARY POINT TEMPS/POPS
GTF 52 75 48 78 / 50 10 0 0
CTB 47 74 46 79 / 40 10 0 0
HLN 52 76 51 81 / 50 20 0 0
BZN 47 73 46 78 / 30 40 10 10
WYS 38 69 38 72 / 30 50 10 20
DLN 45 72 45 76 / 30 20 0 10
HVR 50 78 48 83 / 10 10 0 0
LWT 48 69 46 73 / 20 40 10 10
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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