022
FXUS65 KTFX 230959
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
359 AM MDT FRI OCT 23 2026
KEY MESSAGES
- WIDESPREAD RAIN AND SNOW TODAY, WITH SOME OF THE PRECIPITATION
BEING HEAVY AT TIMES.
- TEMPERATURES WILL BE MUCH COOLER TODAY, WITH THE COOLER
TEMPERATURES THEN CONTINUING INTO NEXT WEEK.
- THE NEXT STORM SYSTEM ARRIVES BY THE MIDDLE OF NEXT WEEK, WITH
MUCH OF THAT PRECIPITATION FALLING AS SNOW.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
TWO UPPER LEVEL DISTURBANCES ARE MOVING TOWARD CENTRAL MT THIS
MORNING, ONE FROM THE SOUTH AND ONE FROM THE NORTH. THERE IS AMPLE
AMOUNTS OF PRECIPITATION COMING UP WITH THE DISTURBANCE FROM THE
SOUTH THIS MORNING. THIS WILL BE A QUICK MOVING SYSTEM, WITH MUCH
OF THE PRECIPITATION EXITING THE REGION BY EARLY SATURDAY MORNING.
SOME OF THE PRECIPITATION COULD BE HEAVY AT TIMES THIS AFTERNOON.
OVERALL, QPF IS EXPECTED TO RANGE FROM ABOUT 1/2 INCH TO 3/4 OF AN
INCH OVER CENTRAL AND SOUTHWEST MT, WITH LIGHTER AMOUNTS AS YOU
GO NORTHWARD TOWARDS THE US/CANADIAN BORDER.
THERE ARE TWO MAIN CONCERNS WITH THIS EVENT.
ONE, STRONG WINDS. EXPECT STRONG WIND GUSTS LATER THIS MORNING AND
THROUGH EARLY THIS EVENING OVER PORTIONS OF NORTH CENTRAL MT.
THUS, NO CHANGES TO THE HIGH WIND WARNING AREA.
THE SECOND CONCERN IS WHEN DOES THE RAIN CHANGE TO SNOW. THE
FREEZING LEVEL WAS OVER 11,000 FEET ON THURSDAY EVENING. THE
FORECAST MODELS HAVE THIS FREEZING LEVEL LOWERING VERY QUICKLY
THIS AFTERNOON, AS THE HEAVY PRECIPITATION BRINGS DOWN THE COLDER
AIR FROM ALOFT. THIS IS POSSIBLE, BUT ALSO THE AIRMASS MIGHT BE SO
SATURATED AT LOWER LEVELS, IT DOESN'T ADIABATICALLY COOL AS
EFFICIENTLY AS THE FORECAST MODELS HAVE PROGGED. THUS, THE ONLY
CHANGE TO THE WINTER WEATHER ADVISORY WAS TO ADD A FEW MORE
MOUNTAIN RANGES OVER SOUTHWEST MT. OTHERWISE, FOR MOST LOWER
ELEVATION LOCATIONS, THE RAIN SHOULD CHANGE TO SNOW BY THIS
EVENING, BUT WITH THE MAJORITY OF THE PRECIPITATION THROUGH BY
THIS TIME, SNOW ACCUMULATIONS AT LOWER ELEVATIONS WILL BE ON THE
LOW SIDE FOR THIS EVENT.
TEMPERATURES TODAY WILL BE MUCH COOLER THAN THEY HAVE BEEN, WITH
MOST AREAS HAVING HIGH TEMPERATURES THIS MORNING, AND FALLING
TEMPERATURES THIS AFTERNOON.
AFTER THIS EVENT, EXPECT RATHER DRY CONDITIONS FOR SUN/MON, WITH
THE COOL TEMPERATURES CONTINUING. FOR TUE/WED, THE NEXT WEATHER
SYSTEM APPROACHES THE CWA, WITH THE BEST CHANCE FOR PRECIPITATION
OVER THE CENTRAL AND SOUTHWEST PORTIONS OF THE CWA. THE AIRMASS
WILL BE QUITE A BIT COLDER BY THE MIDDLE OF NEXT WEEK, THAT MUCH
OF THE PRECIPITATION WILL FALL AS SNOW, WITH SOME RAIN MIXING IN
AT LOWER ELEVATIONS.
- FORECAST CONFIDENCE & SCENARIOS:
THE MAIN CONCERN WITH THE RAIN/SNOW TODAY IS WHAT TIME DOES THE
RAIN CHANGE TO SNOW? THE QUICKER IT CHANGES TO SNOW, THE HIGHER
PROBABILITY OF A BIT HIGHER SNOW ACCUMULATIONS. SINCE THIS WILL BE
A QUICK MOVING SYSTEM, IMPACTS FROM THE SNOWFALL WILL SHORT. THAT
BEING SAID, SOME SNOWFALL RATES COULD APPROACH 1 INCH PER HOUR
THIS AFTERNOON/EVENING...WHICH COULD AFFECT THE EVENING COMMUTE.
ALSO, I CAN'T RULE OUT A LIGHTNING STRIKE HERE/THERE...BUT THE
PROBABILITY IS TO LOW TO INCLUDE THUNDER FOR MOST AREAS RIGHT NOW.
BRUSDA
AVIATION
23/12Z TAF PERIOD
MAIN CONCERN WILL BE RAIN/SNOW DEVELOPING OVER THE CWA THIS
MORNING AND THEN SPREADING EASTWARD THIS AFTERNOON/EVENING. SOME
PRECIP COULD BE HEAVY AT TIMES LATE MORNING THROUGH THIS
AFTERNOON. THE RAIN SHOULD CHANGE TO SNOW FOR MOST
AREAS/ELEVATIONS BY THIS EVENING. IFR/LIFR CONDITIONS ARE POSSIBLE
AT TIMES IN AREAS OF SNOW. AN ISOLATED LIGHTNING STRIKE IS
POSSIBLE, BUT THE PROBABILITY IS TOO LOW TO INCLUDE AT A TERMINAL
SITE RIGHT NOW. MUCH OF THE PRECIPITATION ENDS BY 06Z SAT. SOME
PATCHY FOG POSSIBLE ON SAT MORNING. MOUNTAINS/PASSES WILL BE
OBSCURED THROUGH 06Z SAT. BRUSDA
PRELIMINARY POINT TEMPS/POPS
GTF 51 27 47 26 / 100 50 0 0
CTB 48 22 44 22 / 90 0 0 0
HLN 52 23 47 26 / 100 60 0 0
BZN 52 22 45 21 / 100 100 0 0
WYS 45 14 46 14 / 100 90 0 0
DLN 51 26 46 25 / 100 90 0 0
HVR 57 24 46 22 / 100 80 0 0
LWT 57 22 43 21 / 100 100 0 0
TFX WATCHES/WARNINGS/ADVISORIES
HIGH WIND WARNING FROM 11 AM THIS MORNING TO 3 PM MDT THIS
AFTERNOON FOR EASTERN GLACIER, WESTERN TOOLE, AND CENTRAL
PONDERA-EASTERN TOOLE AND LIBERTY-HILL COUNTY.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 3 AM MDT
SATURDAY FOR BEARS PAW MOUNTAINS AND SOUTHERN BLAINE-FERGUS
COUNTY BELOW 4500FT-JUDITH BASIN COUNTY AND JUDITH GAP-SNOWY AND
JUDITH MOUNTAINS.
HIGH WIND WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
FERGUS COUNTY BELOW 4500FT.
WINTER WEATHER ADVISORY FROM NOON TODAY TO MIDNIGHT MDT TONIGHT
FOR BIG BELT, BRIDGER AND CASTLE MOUNTAINS-ELKHORN AND BOULDER
MOUNTAINS-GALLATIN AND MADISON COUNTY MOUNTAINS AND CENTENNIAL
MOUNTAINS-LITTLE BELT AND HIGHWOOD MOUNTAINS-NORTHWEST
BEAVERHEAD COUNTY-RUBY MOUNTAINS AND SOUTHERN BEAVERHEAD
MOUNTAINS-UPPER BLACKFOOT AND MACDONALD PASS.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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