970
FXUS65 KTFX 281107
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
507 AM MDT TUE APR 28 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- TODAY THROUGH WEDNESDAY THERE WILL BE ISOLATED SNOW/RAIN
SHOWERS IN THE AFTERNOON AND EVENING.
- THURSDAY AND FRIDAY IT WILL BE WARM AND DRY WITH PRECIPITATION
RETURNING FOR THE WEEKEND.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
TODAY NORTHWEST FLOW ALOFT REMAINS OVER NORTH-CENTRAL, CENTRAL, AND
SOUTHWESTERN MONTANA. THIS WILL ALLOW TEMPERATURES TO WARM UP TO
NEAR SEASONAL AVERAGES WITH MOUNTAIN SNOW SHOWERS AND ISOLATED
SNOW/RAIN SHOWERS IN LOWER-ELEVATION AREAS. WARMING TEMPERATURES
WILL ALLOW INSTABILITY TO BUILD THIS AFTERNOON. THIS WILL LEAD TO A
FEW RUMBLES OF THUNDER TUESDAY AFTERNOON IN CENTRAL MONTANA. ON
WEDNESDAY AN UPPER-LEVEL RIDGE BEGINS TO APPROACH MONTANA WITH
NORTHWEST FLOW ALOFT OVER NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN
MONTANA. THIS WILL KEEP TEMPERATURES AROUND SEASONAL AVERAGES. THERE
WILL BE ANOTHER DAY OF MOUNTAIN SHOWERS WITH ISOLATED LOWER-
ELEVATIONS SEEING RAIN/SNOW SHOWERS. WARMING TEMPERATURES WILL ALLOW
INSTABILITY TO BUILD THIS AFTERNOON. THIS WILL LEAD TO A FEW RUMBLES
OF THUNDER TUESDAY AFTERNOON IN CENTRAL MONTANA.
THURSDAY THROUGH FRIDAY AN UPPER-LEVEL RIDGE GRADUALLY MOVES OVER
NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. THIS WILL ALLOW
TEMPERATURES TO GRADUALLY WARM UP WITH MOSTLY DRY WEATHER. SATURDAY
THROUGH SUNDAY AN UPPER-LEVEL TROUGH BEGINS TO MOVE OVER CALIFORNIA
WITH NORTHWEST FLOW OVER MONTANA. THIS WILL BRING SLIGHTLY COOLER
TEMPERATURES AND MORE WIDESPREAD PRECIPITATION TO NORTH-CENTRAL,
CENTRAL, AND SOUTHWESTERN MONTANA. ON MONDAY AN UPPER-LEVEL RIDGE
BEGINS TO BUILD IN OVER NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN
MONTANA. THIS WILL ALLOW TEMPERATURES TO WARM UP WITH MOSTLY DRY
WEATHER. -IG
- FORECAST CONFIDENCE & SCENARIOS:
TODAY THERE IS A 15 - 20% FOR THUNDER IN CENTRAL MONTANA. ON
WEDNESDAY THERE IS A 15 - 25% CHANCE FOR THUNDER IN CENTRAL AND
SOUTHWESTERN MONTANA. DETERMINISTIC MODELS AND ENSEMBLE CLUSTERS ARE
IN GOOD AGREEMENT THAT THIS WEEKEND THERE WILL BE AN UPPER-LEVEL LOW
OFF THE COAST OF CALIFORNIA WITH NORTHWEST FLOW OVER MONTANA.
HOWEVER, THERE REMAINS SOME UNCERTAINTY WITH THE OVER ALL TRACK OF
THE UPPER-LEVEL PATTERN. THIS LEADS TO UNCERTAINTY IN HOW MUCH
COOLING WILL OCCUR AND HOW MUCH/WIDESPREAD PRECIPITATION OCCURS/IS
THIS WEEKEND. -IG
AVIATION
28/12Z TAF PERIOD
AN UNSTABLE NORTHWESTERLY FLOW ALOFT WILL RESIDE OVER THE CWA
THROUGH THE PERIOD. WITH COLD AIR ALOFT, THERE WILL BE A CHANCE
FOR SCATTERED RAIN OR SNOW SHOWERS ACROSS THE CWA. THE MOST
LIKELY TIME AT THE TERMINALS WILL BE LATE MORNING THROUGH THE
AFTERNOON. SINCE MOST OF THE SHOWERS WILL BE BRIEF, FOR NOW, I
CONFINED POPS TO JUST THE AFTERNOON HOURS AT THE TERMINAL SITES.
BUT KNOW THAT SHOWERS WILL BE POSSIBLE ACROSS THE CWA THROUGH THE
PERIOD. A LIGHTNING STRIKE IS ALSO POSSIBLE, MOSTLY THIS
AFTERNOON, BUT WITH THE PROBABILITY OF THUNDER ONLY AROUND 15
PERCENT, I KEPT IT OUT OF THE TERMINAL SITES AS WELL.
MOUNTAINS/PASSES WILL BE OBSCURED AT TIMES ACROSS THE CWA BY
SHOWERS/CLOUDS. BRUSDA
PRELIMINARY POINT TEMPS/POPS
GTF 56 33 58 32 / 40 20 30 10
CTB 54 29 56 29 / 20 40 20 0
HLN 57 33 58 32 / 40 30 50 10
BZN 54 30 56 28 / 50 30 50 20
WYS 46 22 49 21 / 40 30 50 10
DLN 54 31 56 29 / 50 20 30 20
HVR 58 29 59 29 / 30 20 10 0
LWT 52 28 53 28 / 50 30 40 10
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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