526
FXUS65 KTFX 151118
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
518 AM MDT FRI MAY 15 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- STRONG AND GUSTY WINDS CONTINUE TODAY, ESPECIALLY ALONG THE
ROCKY MOUNTAIN FRONT.
- BELOW NORMAL TEMPERATURES THROUGH TUESDAY, ESPECIALLY OVER THE
WEEKEND AND MONDAY WHEN HIGHS WILL STRUGGLE TO RISE INTO THE
40S AND 50S.
- MOUNTAIN SNOW AND LOWER ELEVATION RAIN AND SNOW MIX THIS
WEEKEND.
UPDATE
/ISSUED 417 AM MDT FRI MAY 15 2026/
EARLY MORNING UPDATE HAS BEEN PUBLISHED, WITH THE PRIMARY
ADJUSTMENT BEING TO RAISE POPS ALONG THE CONTINENTAL DIVIDE AND
SPREAD LOW CHANCE POPS FURTHER EAST OVER THE ADJACENT PLAINS OF
CENTRAL AND NORTH CENTRAL MONTANA.. OTHERWISE THE REMAINDER OF THE
FORECAST REMAINS ON TRACK, WITH STRONG AND GUSTY WEST WINDS
EXPECTED ACROSS THE NORTHERN ROCKIES TODAY. - MOLDAN
DISCUSSION
/ISSUED 417 AM MDT FRI MAY 15 2026/
- METEOROLOGICAL OVERVIEW:
MONTANA WILL BE UNDER ZONAL FLOW TODAY, KEEPING TEMPERATURES
SEASONABLE AND CONDITIONS DRY. BREEZY CONDITIONS WILL CONTINUE, BUT
WILL DISSIPATE TOWARDS THE EVENING. THE GUSTY WINDS MAY CREATE
AREAS OF BLOWING DUST, REDUCING VISIBILITIES AT TIMES. ON
SATURDAY, AN UPPER LEVEL TROUGH BEGINS TO MOVE OVER THE NORTHERN
ROCKIES FROM THE WEST, ALONG WITH A SURFACE COLD FRONT. THIS
COMBINATION WILL BRING INCREASED CHANCES OF PRECIPITATION AND
COOLER TEMPERATURES. THE TROUGH DEEPENS OVER THE GREAT BASIN ON
SUNDAY, RESULTING IN WELL- BELOW SEASONAL AVERAGE TEMPERATURES
ACROSS NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. INCREASED
MOISTURE ALOFT WITH THE TROUGH WILL BRING CHANCES OF
PRECIPITATION ON SATURDAY, BECOMING WIDESPREAD ACROSS THE AREA ON
SUNDAY. THE PRECIPITATION WILL PRIMARILY TAKE THE FORM OF SNOW IN
THE MOUNTAINS, WHILE THE COOLER TEMPERATURES WILL RESULT IN A
RAIN/SNOW MIX AT THE LOWER ELEVATIONS. THERE IS ENOUGH INSTABILITY
ON SUNDAY AFTERNOON THAT A RUMBLE OF THUNDER MAY BE HEARD, MAINLY
OVER SOUTHWESTERN MONTANA.
ON MONDAY, THE TROUGH DEEPENS EASTWARD THROUGH THE FOUR CORNERS OF
THE SOUTHWESTERN U.S., KEEPING NORTH-CENTRAL, CENTRAL AND
SOUTHWESTERN MONTANA UNDER ITS INFLUENCE. THIS WILL CAUSE
PRECIPITATION CHANCES TO LINGER AND WELL-BELOW SEASONAL AVERAGE
TEMPERATURES TO CONTINUE. A RUMBLE OF THUNDER MAY ALSO BE HEARD
MONDAY AFTERNOON, ONCE AGAIN MAINLY IN SOUTHWESTERN MONTANA. BY THE
MIDDLE OF NEXT WEEK AN UPPER LEVEL RIDGE BEGINS TO BUILD IN FROM THE
WEST, ALLOWING TEMPERATURES TO WARM WITH MOSTLY DRY WEATHER. -IG AND
DZOMBA
- FORECAST CONFIDENCE & SCENARIOS:
ON SATURDAY THERE IS A 10 - 20% CHANCE FOR THUNDER ACROSS
SOUTHWESTERN MONTANA. ON SUNDAY THESE CHANCES BECOME MORE
WIDESPREAD, WITH THERE BEING A 10 - 20% CHANCE FOR THUNDER ACROSS
MOST OF NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA, WITH THE
HIGHER CHANCES BEING IN SOUTHWESTERN MONTANA.
SUNDAY THROUGH MONDAY THERE IS A 10 - 50% CHANCE FOR GREATER THAN A
TENTH OF AN INCH OF SNOW ACROSS THE LOWER-ELEVATIONS OF NORTH-
CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. ACROSS THE MOUNTAINS OF
NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA THERE IS A 50 - 80%
CHANCE FOR 4 INCHES OF SNOW OR GREATER. ONE AREA OF UNCERTAINTY WITH
THIS SNOWFALL IS WHEN IT FALLS WILL HAVE DRASTIC DIFFERENCES ON
IMPACTS. IF SNOW FALLS DURING DAYLIGHT HOURS THERE WILL BE MINIMAL
IMPACTS. HOWEVER, IF SNOWFALL FALLS OVERNIGHT THIS HAS THE POTENTIAL
TO BE MORE IMPACTFUL. ANOTHER AREA OF UNCERTAINTY WITH THE
PRECIPITATION TYPES OF THIS SYSTEM IS WHEN THE COLD AIR MOVES IN, AS
THIS WILL DETERMINE WHEN PRECIPITATION TRANSITIONS FROM RAIN TO
SNOW AT AT THE LOWER-ELEVATIONS.
SUNDAY MORNING ACROSS THE LOWER-ELEVATIONS OF SOUTHWESTERN MONTANA
THERE IS GREATER THAN A 40% CHANCE FOR LOW TEMPERATURES OF 28
DEGREES OR COLDER. ON SUNDAY, THERE IS A 50 -70% CHANCE FOR HIGH
TEMPERATURES OF 45 DEGREES OR COLDER ACROSS MOST OF THE LOWER-
ELEVATIONS OF NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA.
MONDAY MORNING THERE IS A 30 - 50% CHANCE FOR LOW TEMPERATURES OF 28
DEGREES OR COLDER ACROSS THE LOWER-ELEVATIONS OF NORTH-CENTRAL,
CENTRAL, AND SOUTHWESTERN MONTANA. -IG AND DZOMBA
AVIATION
15/12Z TAF PERIOD
DESPITE MID- TO UPPER LEVEL CLOUDINESS MOVING OVER THE NORTHERN
ROCKIES VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE
1512/1612 TAF PERIOD; HOWEVER, MOUNTAIN OBSCURATION WILL OCCUR
THROUGH 18-21Z THIS AFTERNOON, ESPECIALLY FOR PEAKS ABOVE 9KFT.
OTHERWISE STRONG AND GUSTY WEST WINDS WILL BE EXPERIENCED WITH
FREQUENT GUSTS UP TO 35 KTS ACROSS MOST TERMINALS, WITH GUSTS
EVEN APPROACHING 45 KTS AT THE KCTB TERMINAL THROUGH 21-24Z THIS
AFTERNOON. MOUNTAIN WAVE TURBULENCE WILL REMAIN A CONCERN ACROSS
THE NORTHERN ROCKIES THROUGH 03-09Z SATURDAY BEFORE MID-LEVEL WIND
GRADUALLY DECREASE. - MOLDAN
PRELIMINARY POINT TEMPS/POPS
GTF 62 41 57 34 / 0 10 30 60
CTB 57 34 55 29 / 10 10 10 50
HLN 63 39 55 34 / 0 10 60 50
BZN 65 37 59 29 / 10 10 70 100
WYS 63 31 56 26 / 0 0 10 50
DLN 65 38 58 28 / 0 10 30 70
HVR 65 39 63 33 / 20 0 20 60
LWT 61 38 56 30 / 10 10 80 90
TFX WATCHES/WARNINGS/ADVISORIES
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