701
FXUS65 KTFX 021056
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
456 AM MDT FRI MAY 2 2025
AVIATION SECTION UPDATED.
KEY MESSAGES
- ABOVE AVERAGE TEMPERATURES EXPECTED FRIDAY AND SATURDAY.
- COOL AND WET CONDITIONS ARE EXPECTED SUNDAY AND MONDAY, WITH
MAINLY MOUNTAIN SNOW AND LOWER ELEVATION RAIN.
- NEAR TO ABOVE AVERAGE TEMPERATURES RETURN FOR MID TO LATE NEXT
WEEK.
DISCUSSION
/ISSUED 424 AM MDT FRI MAY 2 2025/
- METEOROLOGICAL OVERVIEW:
UPPER LEVEL RIDGING OVER THE WESTERN CONUS WILL REMAIN OVERHEAD
TODAY AND SATURDAY, WHICH WILL RESULT IN WARM AND DRY CONDITIONS
TO CLOSE OUT THE WEEK. HOWEVER, THIS RIDGE WILL NOT HANG AROUND
VERY LONG, AS AN UPPER LEVEL TROUGH WILL PUSH INTO THE PACIFIC
NORTHWEST ON SUNDAY, BRINGING COOLER TEMPERATURES, WIDESPREAD
PRECIPITATION, AND EVEN SOME MOUNTAIN SNOWFALL TO THE AREA SUNDAY
AND MONDAY. WHILE TUESDAY WILL SEE PRECIPITATION CLEAR OUT, A
LINGERING UPPER LEVEL LOW OVER THE FOUR CORNERS MAY HELP SPUR THE
DEVELOPMENT OF A FEW ADDITIONAL RAIN SHOWERS AS LATE AS TUESDAY
BEFORE WEAK UPPER LEVEL RIDGING BEGINS TO BUILD BACK INTO THE AREA
FOR THE END OF THE WORK WEEK.
- FORECAST CONFIDENCE & SCENARIOS:
WHILE THE BOOKENDS OF THIS FORECAST PERIOD BOTH HAVE RELATIVELY
HIGH CONFIDENCE IN THE OVERALL WEATHER PATTERN (WARM AND DRY UNDER
UPPER LEVEL RIDGES), THE MAIN AREA OF UNCERTAINTY WILL BE WITH THE
COOLER AND WETTER PERIOD EARLY NEXT WEEK, IN PARTICULAR
PRECIPITATION TYPE AND AMOUNTS. FOR PRECIPITATION TYPE, MOST
MODELS ARE IN GOOD AGREEMENT THAT PRECIPITATION AT ALL BUT THE
HIGHEST TERRAIN WILL BE MOSTLY RAIN, THOUGH A FEW OF THE MOUNTAIN
PASSES ARE LIABLE TO GET A SLUSHY COATING OF SNOW OVER THE COURSE
OF THE EVENT. HOWEVER, THE GFS AND THE NAM OPERATIONAL MODELS BOTH
WANT TO BRING SNOW LEVELS DOWN CLOSER TO 3000 FEET, WHICH COULD
BRING SNOW TO SOME VALLEY AND PLAINS LOCATIONS SHOULD THIS OCCUR.
AS OF NOW, HOWEVER, I SUSPECT THAT THESE MODELS ARE RUNNING A BIT
COOL AND THIS SOLUTION IS LESS LIKELY, AND EVEN IF SOME SNOWFLAKES
DO MIX IN IMPACTS ARE UNLIKELY TO BE WIDESPREAD OR SIGNIFICANT
GIVEN THAT GROUND TEMPERATURES HAVE BEEN WARMING UP THANKS TO
RECENT WARM WEATHER. AS FAR AS AMOUNTS GO, THERE HAS BEEN SOME
HINTING TOWARDS LOCALIZED AMOUNTS OVER AN INCH ALONG THE SOUTHERN
ROCKY MOUNTAIN FRONT, THOUGH CURRENT PROBABILISTIC DATA SUGGESTS
AROUND A 30% - 40% CHANCE AT MOST OVER A 3 DAY PERIOD. WHILE THIS
IS LIKELY TO CAUSE SOME RISES ON RIVERS AND STREAMS, GIVEN THE
DRAWN OUT NATURE OF THIS EVENT FLOODING IS NOT EXPECTED AT THIS
TIME. LUDWIG
AVIATION
02/12Z TAF PERIOD
THE ONLY CONCERN THIS TAF PERIOD WILL BE FOR LOCALIZED DENSITY
ALTITUDE IMPACTS TOWARD THIS AFTERNOON. BENIGN CONDITIONS ARE
FORECAST OTHERWISE. -AM
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION
WEATHER AND HAZARD INFORMATION.
PRELIMINARY POINT TEMPS/POPS
GTF 78 44 81 48 / 0 0 0 10
CTB 76 41 80 47 / 0 0 0 20
HLN 79 46 83 49 / 0 0 0 10
BZN 73 39 78 42 / 0 0 0 0
WYS 65 26 70 30 / 0 0 0 0
DLN 73 40 76 42 / 0 0 0 0
HVR 78 42 84 46 / 0 0 0 0
LWT 72 44 77 48 / 0 0 0 0
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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