331
FXUS65 KTFX 031942
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
142 PM MDT SAT MAY 3 2025
KEY MESSAGES
- QUIET CONDITIONS THROUGH MUCH OF TONIGHT, BEFORE THE NEXT SPRING
STORM ARRIVES ON SUNDAY.
- SHOWERS, THUNDERSTORMS AND HIGH MOUNTAIN SNOW DEVELOP ON SUNDAY,
AS COOLER TEMPERATURES SLOWLY MOVE SOUTHWARD INTO THE CWA.
- SCATTERED SHOWERS WILL CONTINUE INTO TUESDAY FOR THE EASTERN
PORTIONS OF THE CWA.
- TURNING WARMER, WITH ONLY SLIGHT CHANCES FOR PRECIPITATION BY
LATE NEXT WEEK.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
WITH AN UPPER LEVEL RIDGE OF HIGH PRESSURE OVER THE CWA, QUIET AND
NICE WEATHER CONDITIONS CAN BE EXPECTED THROUGH THIS EVENING. BY
SUNDAY MORNING, THE NEXT UPPER LEVEL DISTURBANCE WILL BEGIN TO
APPROACH THE GLACIER PARK REGION, ALLOWING FOR SOME SHOWERS TO
DEVELOP IN THAT AREA BY SUNDAY MORNING.
ON SUNDAY, A CANADIAN COLD FRONT WILL GENERALLY MOVE SOUTHWARD
THROUGH THE CWA, WHILE A WIND SHIFT TO THE NORTHWEST BEHIND THE
FRONT, WILL ALSO BRING IN COOLER AIR. PRECIPITATION STARTS TO
DEVELOP BY SUNDAY AFTERNOON, IN THE FORM OF SCATTERED
SHOWERS/THUNDERSTORMS. SOME STORMS COULD BE A BIT STRONG OVER
SOUTHWEST MT IF THEY DEVELOP EARLY ENOUGH. OTHERWISE, THE MAIN
CONCERN ON SUNDAY EVENING WILL BE THE TIME THE RAIN CHANGES TO
SNOW AT HIGHER ELEVATIONS. THE CHANGE OVER TIME WILL AFFECT TOTAL
SNOWFALL AMOUNTS. THE STEADIER PRECIPITATION ENDS BY MID DAY
MONDAY, WITH SCATTERED SHOWERS CONTINUING INTO TUESDAY MORNING
OVER THE EASTERN PORTIONS OF THE CWA, AS THE UPPER LEVEL TROF WILL
BE SLOW TO MOVE THROUGH THE CWA.
FOR WEDNESDAY INTO NEXT WEEKEND, A NEW UPPER LEVEL RIDGE OF HIGH
PRESSURE WILL BEGIN TO BUILD OVER THE CWA BY LATE NEXT WEEK. SOME
FORECAST MODELS PROG WEAK UPPER LEVEL DISTURBANCES MOVING THROUGH
THE CWA FROM THE SOUTHWEST LATER NEXT WEEK. THIS COULD RESULT IN
A FEW SCATTERED SHOWERS/THUNDERSTORMS FROM THU THRU SAT. HOWEVER,
MOST MODELS AGREE THAT AFTERNOON TEMPERATURES WILL RETURN TO ABOVE
NORMAL READINGS, WITH AFTERNOON TEMPERATURES IN THE 70S FOR MANY
AREAS. DO EXPECT THE WINDS TO INCREASE A BIT ON THURSDAY ALONG THE
FRONT RANGE OF THE ROCKIES AND IN THE CUT BANK AREA, BUT AS OF
NOW, WIND SPEEDS SHOULD REMAIN BELOW WARNING CRITERIA.
- FORECAST CONFIDENCE & SCENARIOS:
THERE IS NOW A 75 PERCENT CHANCE FOR LIQUID PRECIPITATION AMOUNTS
OF AROUND A HALF INCH FROM HELENA TO GREAT FALLS TO HAVRE FROM
SUNDAY NIGHT INTO MONDAY, WITH SOME AREAS RECEIVING UP TO ABOUT
0.75 INCHES. THE OTHER CONCERN WILL BE THE RAIN CHANGING TO SNOW
IN THE MOUNTAINS. OVERALL THE KINGS HILL AREAS WILL HAVE A
SNOWFALL RANGING FROM 2 TO 5 INCHES, BUT THERE IS STILL A LOW
PROBABILITY OF AROUND A 30 PERCENT CHANCE SNOW AMOUNTS COULD
EXCEED 8 INCHES. THE EARLIER THE SNOW CHANGES TO SNOW, THE
PROBABILITY OF HIGHER SNOWFALL AMOUNTS INCREASE. BRUSDA
AVIATION
03/18Z TAF PERIOD
VFR CONDITIONS WILL PREVAIL ACROSS ALL TERMINALS DURING THIS TAF
PERIOD EXCEPT FOR THE LAST THREE HOURS AT THE KCTB TERMINAL. AT ALL
TERMINALS EXCEPT FOR THE KGTF AND KCTB TERMINALS WINDS WILL BE LIGHT
AND VARIABLE DURING THE DURATION OF THIS TAF PERIOD. AT THE KBZN
TERMINAL THERE IS A 20% CHANCE FOR THUNDERSTORMS AND A 50% CHANCE
FOR RAIN SHOWERS FROM 04/18Z TO 05/00Z. AT THE KCTB TERMINAL THERE
IS A 20 - 40% CHANCE FOR RAIN SHOWERS BETWEEN 04/05Z AND 04/18Z. -IG
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION
WEATHER AND HAZARD INFORMATION.
PRELIMINARY POINT TEMPS/POPS
GTF 47 70 39 49 / 0 30 100 80
CTB 46 57 37 54 / 20 50 90 40
HLN 48 70 41 52 / 10 70 100 80
BZN 41 72 39 48 / 0 60 90 80
WYS 29 70 35 51 / 0 30 70 50
DLN 41 71 37 49 / 10 70 90 50
HVR 46 73 39 57 / 0 10 90 70
LWT 48 70 37 43 / 0 20 70 90
TFX WATCHES/WARNINGS/ADVISORIES
WINTER WEATHER ADVISORY FROM 9 PM SUNDAY TO NOON MDT MONDAY FOR
LITTLE BELT AND HIGHWOOD MOUNTAINS.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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