207
FXUS65 KTFX 200553
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1153 PM MDT SAT SEP 19 2026
KEY MESSAGES
- RAIN CONTINUES TO SLOWLY EXIT CENTRAL MT THROUGHOUT THE MORNING.
- DRY CONDITIONS AND WARM TEMPERATURES SETTLE IN FOR MOST OF THE
WEEK.
- UNSETTLED WEATHER AND A COOL DOWN IN TEMPERATURES POSSIBLE NEXT
WEEKEND.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
THE VERTICALLY STACKED LOW PRESSURE SYSTEM WILL CONTINUE TO SLIDE
EASTWARDS THROUGHOUT THE DAY. WITH IT WILL ALSO PULL THE
PRECIPITATION OVER CENTRAL MT. HOWEVER, EXPECT LIGHT RAIN TO
CONTINUE OVER CENTRAL MT THROUGH AT LEAST THE MORNING HOURS.
ISOLATED SHOWERS MAY LINGER IN EASTERN FERGUS COUNTY THROUGH
SUNDAY AFTERNOON. AS THIS STORM SYSTEM EXITS, HIGH PRESSURE MOVES
INTO THE REGION, CREATING LOW LEVEL STABILITY. THE CALM
CONDITIONS WITH BREAKING IN THE CLOUDS OVERNIGHT TONIGHT WILL
BRING THE POTENTIAL FOR FOG TO DEVELOP MAINLY IN SOUTHWEST MT THIS
MORNING. SIMILAR CONDITIONS SET UP MONDAY MORNING, WITH THE
POTENTIAL FOR FOG DEVELOPMENT TO SHIFT INTO NORTH-CENTRAL MT AS
WELL.
A DRIER WEATHER PATTERN SETS UP FOR MOST OF THE WEEK AS THE CURRENT
STORM SYSTEM MOVES EAST AND ANOTHER SHORTWAVE SLIDES SOUTH OF
MONTANA ACROSS THE GREAT BASIN. AS THIS SHORTWAVE SLIDES ACROSS THE
GREAT BASIN REGION, AREAS NEAR THE MT/ID BORDER MIGHT GET CLIPPED
WITH A FEW RAIN SHOWERS LATE TUESDAY NIGHT. FOR THE SECOND HALF OF
THE WEEK, SOUTHWEST FLOW DOMINATES AS THE NEXT INCOMING TROUGH
BUILDS OFF OF THE WESTERN U.S. COAST. ABOVE NORMAL TEMPERATURES
ARE EXPECTED THROUGH FRIDAY.
ENSEMBLES HINT AT THIS UPPER-LEVEL TROUGH MOVING THROUGH NEXT
WEEKEND, BRINGING BACK CHANCES FOR PRECIPITATION. THIS TROUGH
ALSO PUSHES TEMPERATURES DOWN CLOSER TO NORMAL, AND MAY LOWER
SNOW LEVELS TO THE HIGHER MOUNTAIN PEAKS. -WILSON
- FORECAST CONFIDENCE & SCENARIOS:
THERE STILL REMAINS SOME UNCERTAINTY IN FOG DEVELOPMENT ACROSS THE
SOUTHWEST MT VALLEYS THIS MORNING. THE MAIN UNCERTAINTY IS FORECAST
SOUNDINGS ALSO SHOWING LOW STRATUS ALSO DEVELOPING, WHICH COULD
PROHIBIT FOG POTENTIAL. THE BEST CHANCES FOR FOG DEVELOPMENT WILL BE
IN THE HIGHER SOUTHWEST MT VALLEYS. THERE'S A 10-20% CHANCE FOR FOG
DEVELOPMENT THIS MORNING. MONDAY MORNING, HI-RES GUIDANCE SHOWS
GREATER PROBABILITIES, WITH A 30-60% CHANCE FOR FOG WITH LESS THAN A
MILE OF VISIBILITY ALONG US HIGHWAY 2 FROM HAVRE TO CUT BANK.
-WILSON
AVIATION
20/06Z TAF PERIOD
MOISTURE WRAPPING AROUND THE UPPER LEVEL LOW TRACKING ACROSS WY
WILL MAINTAIN LOW TO MID CLOUDS AND MOUNTAIN OBSCURATION ACROSS
EASTERN PORTIONS OF SOUTHWEST AND CENTRAL MT TONIGHT WITH SOME
LIGHT PRECIPITATION LINGERING NEAR KLWT. MID LEVEL CLOUD-COVER
THINS FROM WEST TO EAST ACROSS THESE AREAS OVERNIGHT, WHICH IS
LIKELY TO ALLOW FOR LOW STRATUS AND/OR PATCHY FOG DEVELOPMENT.
VFR CONDITIONS PREVAIL FURTHER NORTH WITH MAINLY HIGH CLOUD-
COVER, HOWEVER SURFACE WINDS REMAIN FAIRLY LIGHT AND CANNOT RULE
OUT SOME PATCHY FOG DEVELOPMENT NEAR KHVR OR KCTB EARLY SUNDAY
MORNING. EXPECT IMPROVEMENT AT ALL SITES BY 16Z SUNDAY. HOENISCH
PRELIMINARY POINT TEMPS/POPS
GTF 65 46 74 47 / 20 10 0 0
CTB 68 43 73 43 / 0 0 0 0
HLN 61 45 72 44 / 90 10 0 0
BZN 57 44 66 40 / 90 40 10 0
WYS 57 34 63 29 / 60 60 10 10
DLN 60 42 67 40 / 70 20 0 0
HVR 70 46 74 46 / 10 10 10 0
LWT 60 46 65 44 / 90 80 30 0
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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