210
FXUS65 KTFX 111943
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
143 PM MDT TUE MAR 11 2025
KEY MESSAGES
- ABOVE AVERAGE TEMPERATURES THROUGH THURSDAY, WITH BREEZY
CONDITIONS AROUND AT TIMES.
- PACIFIC COLD FRONT BRINGS A MIX OF RAIN AND SNOW TO SOUTHWEST
AND CENTRAL MONTANA TERRAIN AND VICINITY THURSDAY INTO
THURSDAY NIGHT, WITH ACCUMULATING SNOW IN THE MADISONS,
GALLATINS, AND VICINITY.
- INCREASING CONFIDENCE IN INTENSE SNOW SHOWERS AT LOWER
ELEVATIONS ACROSS SOUTHWEST MONTANA THURSDAY AFTERNOON WITH
THE COLD FRONT.
- COOLER FOR FRIDAY AND THE WEEKEND, WITH AN ADDITIONAL BREEZY
PERIOD INCREASING IN LIKELIHOOD FOR SUNDAY AFTERNOON AND NIGHT.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
A LARGELY ZONAL FLOW ALOFT WILL BECOME INCREASINGLY SOUTHWESTERLY
WEDNESDAY AS THE NEXT LARGE SCALE TROUGH MOVES ONSHORE ACROSS THE
WESTERN CONUS. IN THE MEANTIME, DAYTIME MIXING HAS RESULTED IN A
BREEZY DAY ACROSS MUCH OF THE REGION, WITH WINDS FORECAST TO
DECREASE IN MAGNITUDE AROUND SUNSET. MOISTURE WITHIN THE ZONAL FLOW
WILL RESULT IN LIGHT PRECIPITATION AT TIMES, MOSTLY ALONG THE
CONTINENTAL DIVIDE NORTH OF LINCOLN OVER THE NEXT DAY OR SO. AS THE
FLOW ALOFT BECOMES MORE SOUTHWESTERLY WEDNESDAY AFTERNOON, BREEZY
WINDS WILL DEVELOP ACROSS SOUTHWEST MONTANA. FORECAST SOUNDINGS
AREN'T OVERLY OPTIMISTIC FOR WIDESPREAD HIGH WINDS, THOUGH WIND
PRONE AREAS LIKE NORRIS HILL DO LOOK TO HAVE A BETTER OPPORTUNITY
FOR STRONG WINDS/GUSTS INTO WEDNESDAY NIGHT.
MILD TEMPERATURES CONTINUE INTO THE DAY THURSDAY, THOUGH WILL BEGIN
TO TREND COOLER AS A PACIFIC COLD FRONT MOVES ACROSS THE AREA IN THE
AFTERNOON. PRECIPITATION INCREASES IN COVERAGE, MOSTLY ALONG THE
CONTINENTAL DIVIDE AND ACROSS SOUTHWEST MONTANA THROUGH THE DAY.
ACCUMULATING SNOWFALL WILL BE MOST FAVORED IN THE MADISONS,
GALLATINS, AND VICINITY THURSDAY INTO THURSDAY NIGHT. INSTABILITY
AHEAD OF AND ALONG THE COLD FRONT WILL BE CAPABLE OF A FEW RUMBLES
OF THUNDER, IN ADDITION TO AT LEAST A LOW-END CHANCE FOR INTENSE
SNOW SHOWERS AND PERHAPS SNOW SQUALLS ACROSS SOUTHWEST MONTANA IN
THE AFTERNOON AND EARLY EVENING THURSDAY. FURTHER NORTH OVER THE
PLAINS, THE MAIN IMPACTS FROM THIS SYSTEM WILL BE FOR A TREND
COOLER, WITH JUST A BRIEF OPPORTUNITY FOR RAIN OR SNOW AS THE FRONT
PROGRESSES THROUGH.
DISORGANIZED UPPER LEVEL TROUGHING WITH WEAK EMBEDDED WAVES WILL
STICK AROUND INTO SATURDAY, KEEPING LOW END OPPORTUNITIES FOR
PRECIPITATION AROUND, MOSTLY IN THE MOUNTAINS IN THE AFTERNOON AND
EARLY EVENING TIMEFRAME. BRIEF RIDGING MOVES IN FOR SUNDAY BUT IS
QUICKLY BROKEN DOWN HEADING INTO SUNDAY NIGHT BY AN UPPER LEVEL
TROUGH APPROACHING FROM THE PACIFIC NORTHWEST. SOUTHWEST FLOW ALOFT
IN ADVANCE OF THIS SYSTEM SUNDAY AFTERNOON AND NIGHT LOOKS TO BRING
ANOTHER BREEZY PERIOD TO SOUTHWEST MONTANA BEFORE PRECIPITATION
CHANCES INCREASE HEADING INTO MONDAY. THERE ARE DISCREPANCIES IN
TIMING AND NORTH-SOUTH POSITIONING OF THIS SYSTEM HEADING INTO NEXT
WEEK, WHICH LEADS TO A LOW CONFIDENCE PRECIPITATION FORECAST. -AM
- FORECAST CONFIDENCE & SCENARIOS:
WIND WEDNESDAY IN SOUTHWEST MONTANA:
PROBABILISTIC GUIDANCE GIVES AROUND A 30 TO 50% CHANCE FOR A 58 MPH
GUST IN THE DILLON TO TWIN BRIDGES AREA DURING THE AFTERNOON HOURS
WEDNESDAY. PROBABILITIES ARE SIMILAR FOR THE ENNIS AND NORRIS HILL
AREAS FROM THE AFTERNOON WEDNESDAY INTO WEDNESDAY NIGHT. GIVEN THESE
PROBABILITIES ARE JUST BARELY TOUCHING 50% IN SPOTS, I WILL HOLD OFF
ON A HIGH WIND WATCH FOR NOW, BUT THIS WILL BE WORTH MONITORING OVER
THE NEXT 24 HOURS FOR TRENDS.
INTENSE SNOW SHOWERS ACROSS SOUTHWEST MONTANA THURSDAY AFTERNOON:
HIGH RESOLUTION GUIDANCE THAT IS IN RANGE OF THURSDAY AFTERNOON IS
BEGINNING TO PAINT A PICTURE THAT THERE WILL BE A PERIOD OF AT LEAST
ISOLATED INTENSE SNOW SHOWERS NEAR A PACIFIC COLD FRONT THAT WILL
PROGRESS ACROSS THE REGION FROM WEST TO EAST. TEMPERATURES AT THE
SURFACE WILL BE MARGINAL FOR THE SNOW HOWEVER, WHICH GIVES LOW
CONFIDENCE FOR ACCUMULATIONS AT LOWER ELEVATIONS. A MORE ORGANIZED
AND SLIGHTLY COOLER SCENARIO WOULD INCLUDE MORE ORGANIZED SNOW
SHOWERS ALONG THE COLD FRONT THAT HAVE THE ABILITY TO CONSOLIDATE
INTO A SNOW SQUALL. TRENDS WILL NEED TO BE MONITORED OVER THE NEXT
24-36 HOURS OR SO.
SOUTHWEST MONTANA MOUNTAIN SNOW THURSDAY INTO FRIDAY:
HIGH TERRAIN EAST OF I-15 IN SOUTHWEST MONTANA HAS BETWEEN A 50 AND
80% CHANCE FOR SNOW IN EXCESS OF 9 INCHES OVER THIS TIMEFRAME. AT
PASS LEVEL THESE PROBABILITIES LOWER SIGNIFICANTLY, ONLY GETTING UP
TO 20% OR SO OVER TARGHEE AND RAYNOLDS PASSES. GIVEN THIS LOWER
CONFIDENCE AT PASS LEVEL, I AM HOLDING OFF ON A WINTER STORM WATCH
AT THIS TIME.
SOUTHWEST MONTANA WIND LATE SUNDAY INTO SUNDAY NIGHT:
PROBABILISTIC GUIDANCE IS A BIT MORE OPTIMISTIC IN STRONG WINDS
OVER THIS TIMEFRAME, GIVING A 50-70% CHANCE FOR A 58 MPH GUST OVER
MANY LOWER ELEVATION LOCATIONS SOUTH OF THE US-12 CORRIDOR. TIMING
OF THE BEST WINDS ALOFT TWILL BE IMPORTANT IN DETERMINING HOW WELL
THE GUSTS WILL BE ABLE TO MIX TO THE SURFACE. -AM
AVIATION
11/18Z TAF PERIOD
VFR CONDITIONS PREVAIL AT AREA TERMINALS THROUGH THE PERIOD.
SOMEWHAT MOIST WESTERLY FLOW ACROSS THE REGION WILL MAINTAIN
BROKEN MID-HIGH LEVEL CLOUDS THROUGH MUCH OF THE TAF PERIOD WITH
CLOUDS DECREASING FROM SOUTH TO NORTH TONIGHT. BREEZY SURFACE
WINDS DEVELOP AT MOST TERMINALS THIS AFTERNOON AND DIMINISH THIS
EVENING. HOENISCH/LUDWIG
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION
WEATHER AND HAZARD INFORMATION.
PRELIMINARY POINT TEMPS/POPS
GTF 38 61 40 57 / 10 10 10 30
CTB 32 54 31 51 / 10 10 0 10
HLN 34 58 36 52 / 20 10 10 50
BZN 29 55 32 49 / 10 0 0 60
WYS 19 45 30 41 / 10 10 70 80
DLN 30 54 34 47 / 0 0 20 70
HVR 32 57 34 60 / 10 10 0 10
LWT 31 55 36 55 / 10 10 0 40
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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