566
FXUS65 KTFX 032351
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
551 PM MDT SAT MAY 3 2025
AVIATION SECTION UPDATED.
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
/ISSUED 142 PM MDT SAT MAY 3 2025/
- 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
04/00Z TAF PERIOD
VFR CONDITIONS WILL PREVAIL THROUGH THE START OF THE PERIOD BEFORE
A ROUND OF WIDESPREAD SHOWERS (MOUNTAIN SNOW/LOWER ELEVATION RAIN)
ARRIVES ON SUNDAY. PRECIPITATION WILL START ALONG THE CONTINENTAL
DIVIDE BY 04/14Z AND SPREAD EASTWARD IMPACTING THE REST OF THE
AREA BY 04/20Z. MVFR CIGS ARE MOST LIKELY TO LINGER AT KCTB WITH
PERIODS OF MVFR POSSIBLE AT ALL OTHER TERMINALS AS SHOWERS MOVE
THROUGH. MOUNTAIN OBSCURATION WILL BE A CONCERN PRIMARILY AFTER
04/21Z.
CURRENTLY THERE IS AROUND A 30% CHANCE OF THUNDERSTORMS WITHIN THE
VICINITY OF KBZN BETWEEN 04/21Z AND 05/04Z AND A 20% CHANCE OF
THUNDERSTORMS NEAR KEKS, KWYS, AND KHLN. THE MAIN CONCERNS WILL BE
LIGHTNING, PERIODS OF HEAVY RAIN, GUSTY/ERRATIC WINDS, AND THE
POTENTIAL FOR SMALL HAIL (LESS THAN HALF AN INCH). -THOR
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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