044
FXUS65 KTFX 121445
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
845 AM MDT FRI SEP 12 2025
KEY MESSAGES
- THERE WILL BE RAIN SHOWERS THIS MORNING ACROSS NORTH-CENTRAL
MONTANA AND ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON
ACROSS THE REGION.
- AN ACTIVE PERIOD CONTINUE THROUGH THE WEEKEND AND INTO NEXT
WEEK.
UPDATE
SLIGHT ADJUSTMENTS WERE MADE BASED ON TRENDING OBSERVATIONS AND
UPDATED MODEL GUIDANCE BUT OTHERWISE NO MAJOR CHANGES WERE MADE TO
THE GOING FORECAST. -THOR
DISCUSSION
/ISSUED 452 AM MDT FRI SEP 12 2025/
- METEOROLOGICAL OVERVIEW:
WITH THIS TROUGH AXIS COMING CLOSER TO BEING OVERHEAD, LOTS OF
VORTICITY MAXIMUMS ALOFT WILL INCREASE COVERAGE IN PRECIPITATION
TO SCATTERED THIS MORNING ACROSS NORTH-CENTRAL MT. HIGH PRESSURE
TO THE SOUTH IN SOUTHWEST MT WILL KEEP THINGS DRY THROUGHOUT THE
MORNING. THIS AFTERNOON, ISOLATED SHOWERS AND THUNDERSTORMS
DEVELOP ACROSS THE REGION. THIS MORNING, THERE SHOULD BE BREAKS
IN THE CLOUD COVER TO WHERE INSTABILITY CAN DEVELOP. A FEW
STRONGER STORMS CAN BE CAPABLE OF PRODUCING ERRATIC GUSTY WINDS,
HAIL, AND LOCALLY HEAVY RAINFALL. THE BEST CHANCES FOR THIS
EXTENDS FROM CENTRAL MT TO ALONG THE HI-LINE WHERE THE BOUNDARY
LIFTS NORTHWARD THROUGHOUT THE AFTERNOON. A LOW PRESSURE SYSTEM
DEVELOPING WILL KEEP PRECIPITATION CHANCES THROUGH THE WEEKEND.
BEGINNING OF NEXT WEEK, ANOTHER TROUGH COMES THROUGH. MODELS TRY
TO FORM A CLOSED LOW FROM THIS. THIS WILL KEEP THE ACTIVE PATTERN
AND GIVE A BRIEF COOL DOWN FOR THE FIRST PART OF THE WEEK.
HOWEVER, THERE IS UNCERTAINTY IN THE AMPLITUDE AND TIMING OF THE
TROUGH, SO DETAILS REMAIN A LITTLE MURKY AT THIS. MODELS STILL;L
HAVE DIVERGING SOLUTIONS TOWARDS THE END OF THE WORK WEEK NEXT
WEEK. SOME BRING ANOTHER TROUGH FROM THE PACIFIC, KEEPING THIS
ACTIVE PATTERN. WHILE SOME KEEPS A BRIEF DRY PERIOD BEFORE
PRECIPITATION RETURNS.
- FORECAST CONFIDENCE & SCENARIOS:
FOR THUNDERSTORMS TODAY, AREAS THAT HAVE LESS CLOUD COVER FROM
PRECIPITATION THIS MORNING WILL BUILD IN BETTER INSTABILITY.
STORMS THAT DO FORM WILL BE MORE LIKE PULSE THUNDERSTORMS DUE TO
LOW WIND SHEAR. MEANING, STORMS THAT FORM WILL GO UP AND WILL BE
SHORTER LIVED. GOOD LAPSE RATES AND DEPENDING ON HOW MUCH
INSTABILITY BUILDS IN, A FEW STRONGER STORMS WILL DEVELOP. THESE
STORMS WILL BE CAPABLE OF PRODUCING GUSTY WINDS, HAIL, AND
LOCALLY HEAVY RAIN.
THERE REMAINS A LITTLE BIT OF UNCERTAINTY WITH THE POSITION AND
PRECIPITATION AMOUNTS WITH THIS LOW MORNING ACROSS CENTRAL MT
SATURDAY AND SUNDAY. WITH THAT CUT OFF LOW THE BEGINNING OF NEXT
WEEK, DEPENDING ON WHERE IT SETS UP, THERE IS A LOW CHANCE ENOUGH
COLD AIR MOVES INTO SOUTHWEST MT WHERE THE HIGHEST PEAKS CAN SEE A
DUSTING OF SNOW. -WILSON
AVIATION
12/12Z TAF PERIOD
VFR CONDITIONS WILL PREDOMINATELY PREVAIL THROUGHOUT THE 1212/1312
TAF PERIOD; HOWEVER, BRIEF PERIODS OF MVFR/LOW-VFR CONDITIONS ARE
POSSIBLE BENEATH SHOWER AND THUNDERSTORM ACTIVITY IN ADDITION TO
GUSTY AND ERRATIC WINDS. SHOWER AND THUNDERSTORM COVERAGE WILL
LARGELY BE ISOLATED TO WIDELY SCATTERED OVER THE NEXT 18-24 HOURS,
WITH THE GREATEST AREAL COVERAGE OCCURRING BETWEEN 21-24Z THIS
AFTERNOON. WHILE WIDESPREAD MOUNTAIN OBSCURATION IS NOT EXPECTED
THERE WILL BE PERIODS OF OBSCURATION BENEATH/NEAR PRECIPITATION.
- MOLDAN
HYDROLOGY
A FEW HEAVY SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY. WHILE
UNLIKELY, SHOULD ONE OF THE HEAVIEST RAIN SHOWERS HIT A BURN SCAR
SOME FLASH FLOODING MAY BE POSSIBLE. LUDWIG
PRELIMINARY POINT TEMPS/POPS
GTF 78 48 78 51 / 40 20 20 10
CTB 76 45 77 48 / 40 20 10 10
HLN 76 49 76 51 / 40 20 30 10
BZN 75 44 73 45 / 20 20 40 10
WYS 69 35 65 33 / 30 10 50 10
DLN 73 41 71 42 / 20 10 20 10
HVR 78 49 77 52 / 40 30 30 20
LWT 74 48 69 48 / 60 40 60 30
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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