251
FXUS65 KTFX 272321
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
521 PM MDT WED MAY 27 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- DAILY CHANCES FOR ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH FRIDAY.
- HOTTER TEMPERATURES CONTINUE THROUGH FRIDAY.
- WETTER WIDESPREAD PRECIPITATION AND COOLER TEMPERATURES
ARRIVES SATURDAY THROUGH MONDAY
DISCUSSION
/ISSUED 137 PM MDT WED MAY 27 2026/
- METEOROLOGICAL OVERVIEW:
THE CLOSED LOW OVER CALIFORNIA AND NEVADA CONTINUES TO LINGER
THROUGH THE WEEKEND. THIS LOW WILL SLOWLY PHASE TOWARDS THE
INTERMOUNTAIN WEST THROUGH THE REST OF THE WEEK. THIS WILL GIVE A
DOMINANT SOUTHWEST FLOW ALOFT PATTERN THROUGH SATURDAY, WHICH
WILL KEEP ADVECTING IN WARM MOIST AIR FOR DAILY CONVECTION THROUGH
FRIDAY. STEEP LAPSE RATES AND A DRY SURFACE LAYER WILL KEEP THE
PRIMARY THREAT FOR STRONG TO SEVERE WIND GUSTS AND SMALLER HAIL
THIS AFTERNOON AND THURSDAY. FRIDAY LOOKS TO HAVE BETTER
INSTABILITY AND INCREASING SHEAR DURING THE DAY, WHICH RESULTS IN
A SLIGHTLY HIGHER CHANCE FOR SEVERE WIND AND HAIL. SOUTHERLY FLOW
WILL ALSO KEEP THE WELL ABOVE NORMAL TEMPERATURES THROUGH FRIDAY,
WITH THE HOTTEST TEMPS NEAR HILL AND BLAINE COUNTIES.
SATURDAY THROUGH THE BEGINNING OF NEXT WEEK, ANOTHER UPPER-LEVEL
TROUGH TRANSLATE EAST ACROSS THE WESTERN U.S AND INTERACTS WITH
THE REMNANTS OF THAT WEAKENED CLOSED LOW. A LOW PRESSURE
SYSTEM/COLD FRONT BRINGS WIDESPREAD PRECIPITATION TO THE REGION
AND THE COLD FRONT ALSO COOLS DOWN TEMPERATURES SATURDAY. THIS
TROUGH LINGERS INTO THE BEGINNING OF NEXT WEEK, WHICH KEEP
SCATTERED TO WIDESPREAD PRECIPITATION AND COOLER TEMPERATURES
THROUGH MONDAY. THERE ARE DIFFERENCES IN THE MODELS ON THE
INTERACTION OF THE NEW TROUGH AND HOW MUCH PRECIPITATION/WHERE
THE CORRIDOR OF BEST PRECIPITATION SETS UP. HOWEVER, THE MAIN
MESSAGE IS CONFIDENCE IS INCREASING FOR COOLER AND WETTER
CONDITIONS THIS WEEKEND AND MONDAY.
- FORECAST CONFIDENCE & SCENARIOS:
HEAT TODAY THROUGH FRIDAY:
WELL ABOVE NORMAL TEMPERATURES CONTINUE THROUGH FRIDAY, ESPECIALLY
ACROSS THE CENTRAL HI-LINE. THE CURRENT HEAT ADVISORY FOR HILL AND
BLAINE COUNTIES REMAIN IN EFFECT THROUGH 9PM TONIGHT. ALTHOUGH MID
TO UPPER 90S TEMPERATURES ARE FORECASTED FOR THAT AREA AGAIN
THURSDAY AND FRIDAY, OVERNIGHT LOWS WILL BE SLIGHTLY COOLER.
THEREFORE, I DID NOT MAKE ANY EXTENSIONS TO THE CURRENT HEAT
ADVISORY.
THUNDERSTORM RISK THROUGH THE WEEKEND:
CURRENT MESOANALYSIS SHOWS INSTABILITY HAS INCREASED TO 500 TO
1,000 J/KG ACROSS THE REGION WITH DOWNDRAFT CAPE AT 600 TO 1,000
J/KG. SHEAR IS LOW TODAY, WITH UP TO 25 TO 30KTS EFFECTIVE.
THEREFORE, THUNDERSTORMS ARE LESS LIKELY TO BE WELL
ORGANIZED/SUSTAINING, MEANING CHANCES FOR SEVERE THUNDERSTORMS IS
LOW. HOWEVER, WITH DEEP INVERTED V PROFILES FROM A DRY SURFACE
LAYER, WE CAN'T RULE OUT A FEW STRONG TO AN ISOLATED SEVERE WIND
GUST. THURSDAY'S THUNDERSTORMS LOOK SIMILAR TO TODAY IN HAZARDS,
BUT STORM MOTIONS MAY BE A LITTLE BIT SLOWER TOWARDS CENTRAL MT
WHICH CAN INCREASE THE RISK SLIGHTLY FOR LOCALIZED FLASH FLOODING
OVER BURN SCARS.
BETTER INSTABILITY AND SHEAR INCREASES FRIDAY, WHICH WILL INCREASE
CHANCES FOR MARGINAL SEVERE WIND GUSTS AND LARGE HAIL. PWATS
NEARING AN INCH WILL BRING A MINOR THREAT FOR LOCALIZED FLASH
FLOODING PARTICULAR IN BURN SCAR AREAS/URBAN AREAS.
SATURDAY'S THUNDERSTORM THREAT WILL MOSTLY BE FOCUSED TO THE
HILL/BLAINE/FERGUS COUNTY AREAS.
WEEKEND SYSTEM BRINGING BETTER CHANCES FOR PRECIPITATION:
THERE ARE STILL SOME DIFFERENCES FOR HOW THIS CLOSED LOW PHASES
WITH THE NEW INCOMING TROUGH, THEREFORE, THERE REMAINS A GOOD
SPREAD IN PRECIPITATION AMOUNTS. SATURDAY THROUGH SUNDAY, THERE
IS AN 80 TO 90% CHANCE FOR 0.25" OF PRECIPITATION, 60 TO 80%
CHANCE OF 0.5" AND A 40 TO 70% CHANCE FOR AN 1", AND AN UP TO 15%
TO 30% CHANCE FOR 2" INCHES. SNOW LEVELS LOOK TO DROP TO ABOVE
PASS LEVEL, WHICH CAN BRING LIGHT, SLUSHY SNOW ACCUMULATIONS TO
THE HIGHER PEAKS. -WILSON
AVIATION
28/00Z TAF PERIOD
VFR CONDITIONS WILL LARGELY PREVAIL THROUGHOUT THE 2800/2900 TAF
PERIOD, WITH ONLY TEMPORARY REDUCTIONS TO MVFR/LOW-VFR BEING
POSSIBLE THROUGH 03-06Z THIS EVENING. ISOLATED TO WIDELY SCATTERED
THUNDERSTORMS HAVE DEVELOPED OVER THE HIGHER TERRAIN THIS
AFTERNOON, WITH THE EXPECTATION FOR THESE STORMS TO SLOWLY DRIFT
NORTH TO NORTHWEST OVER THE ADJACENT PLAINS BEFORE SLOWLY
DISSIPATING THROUGH THE MID- TO LATE EVENING HOURS. MAIN IMPACT
FROM THESE THUNDERSTORMS WILL BE ERRATIC WINDS IN ADDITION TO THE
TEMPORARY REDUCTION IN CIGS AND/VIS. - MOLDAN
PRELIMINARY POINT TEMPS/POPS
GTF 55 91 57 90 / 20 20 30 20
CTB 52 88 53 86 / 30 20 40 30
HLN 53 90 54 87 / 20 20 20 20
BZN 47 89 48 86 / 20 20 20 20
WYS 39 82 40 78 / 20 10 0 10
DLN 45 84 46 80 / 20 10 0 10
HVR 55 97 57 96 / 30 20 20 10
LWT 52 89 53 88 / 20 20 20 20
TFX WATCHES/WARNINGS/ADVISORIES
HEAT ADVISORY UNTIL 9 PM MDT THIS EVENING FOR HILL COUNTY-
NORTHERN BLAINE COUNTY.
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