968
FXUS65 KTFX 031109
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
509 AM MDT SUN MAY 3 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- WIDELY SCATTERED SHOWER AND THUNDERSTORM ACTIVITY DEVELOPS
OVER SOUTHWEST MONTANA THIS AFTERNOON AND EVENING.
- A TROUGH AND ATTENDANT COLD FRONT DIVES SOUTHWARD TONIGHT INTO MONDAY
AND BRINGS A COOL AND SHOWERY START TO THE WORKWEEK.
- MILDER AND DRIER CONDITIONS RETURN FOR THE SECOND HALF OF THE
WEEK, BUT PASSING FRONTS MAY BRING SOME SHOWER AND THUNDERSTORM
ACTIVITY AND BRIEF COOL DOWNS, ESPECIALLY HEADING TOWARDS NEXT
WEEKEND.
DISCUSSION
/ISSUED 1203 AM MDT SUN MAY 3 2026/
- METEOROLOGICAL OVERVIEW:
DRY NORTHWESTERLY FLOW ALOFT WILL BRING ONE MORE DAY OF MILD AND
GENERALLY DRY CONDTIONS BEFORE A STRONGER TROUGH AND ATTENDANT
COLD FRONT DIVE SOUTHWARD TONIGHT INTO MONDAY. THE PRIMARY CONCERN
WILL BE DRY AND BREEZY CONDITIONS OVER THE PLAINS AND ISOLATED
SHOWER AND THUNDER ACTIVITY OVER SOUTHWEST MT.
THE COLD FRONT WILL CROSS THE CANADIAN BORDER THIS EVENING, CLEAR
MUCH OF CENTRAL MT BY DAWN, AND THEN MOVE INTO THE SOUTHWEST
MONDAY MORNING. WINDS WILL SHIFT NORTHERLY BEHIND THE FRONT AND
SHOWERS AND HIGHER MOUNTAIN SNOW WILL INCREASE IN A NORTH TO SOUTH
FASHION. COLDER AIR ALOFT MOVES IN ON MONDAY AND WILL SUPPORT
WIDELY SCATTERED RAIN, SNOW, AND GRAUPEL SHOWERS AT ALL
ELEVATIONS, ESPECIALLY OVER CENTRAL/NORTH-CENTRAL MT. A SECONDARY
SHORTWAVE DIVES SOUTHWARD ON TUESDAY AND DROPS H700/H500
TEMPERATURES AS LOW AS -15C/-30C OVER THE EASTERN PORTIONS OF THE
FORECAST AREA. THIS WILL REINFORCE THE WELL BELOW AVERAGE
TEMPERATURES AND OFFER ADDITIONAL SNOW SHOWER ACTIVITY.
THIS SYSTEM MOVES OUT BY THE MID-WEEK PERIOD WITH NORTHWESTERLY
FLOW ALOFT RETURNING FOR MUCH OF THE REMAINDER OF THE WEEK.
OVERALL, THIS WILL BRING DRIER AND MILDER CONDITIONS; HOWEVER,
WEAK TROUGHS WILL PERIODICALLY PASS THROUGH AND BRING SCATTERED
SHOWER AND THUNDERSTORM ACTIVITY, ESPECIALLY ON THURSDAY.
ENSEMBLES REMAIN IN AGREEMENT WITH A BROADER TROUGH MOVING IN NEXT
WEEKEND FOR COOLING TEMPERATURES AND INCREASED RAIN/MOUNTAIN
SNOW. SIMILAR TO SOME OF THE PREVIOUS STORMS THIS SPRING, LESSER
DEFINED AND SMALLER SCALE FORCING WITHIN THIS TROUGH ADD FORECAST
UNCERTAINTY IN TERMS OF PRECIPITATION AMOUNTS AND TIMING. - RCG
- FORECAST CONFIDENCE & SCENARIOS:
GUSTY NORTHERLY WINDS TONIGHT INTO MONDAY WITH SHOWERY AND COOL
CONDITIONS THROUGH TUESDAY...
THE INITIAL CONCERN FOLLOWING TONIGHT'S COLD FRONTAL PASSAGE WILL
BE GUSTY NORTHERLY WINDS, ESPECIALLY OVER THE PLAINS AND THEN THE
NARROW NORTH TO SOUTH ORIENTED VALLEYS OF CENTRAL AND SOUTHWEST
MONTANA. THESE AREAS WILL HAVE THE GREATEST RISK (50 TO 70%) FOR
WIND GUSTS OVER 40 MPH, HIGHEST IN THE TOWNSEND AREA SOUTHWARD TO
THREE FORKS FOLLOWED BY JUDITH GAP, AND THE DILLON/ENNIS AREAS.
THE FRONT WILL CROSS THE CANADIAN BORDER BY 8 PM THIS EVENING,
CLEAR MUCH OF CENTRAL MT BY THE PRE-DAWN HOURS, AND THEN MOVE INTO
THE SOUTHWEST MONDAY MORNING. THE WINDS WILL BEGIN DIMINISHING BY
MONDAY EVENING FOR NORTHERN AREAS, BUT WILL CONTINUE THROUGH
TUESDAY IN SOUTHWEST MONTANA.
PRECIPITATION WILL BE SCATTERED IN NATURE WITH SNOW AND GRAUPEL
SHOWERS DOWN TO THE VALLEY/PLAINS BY MONDAY AFTERNOON. IMPACTFUL
ACCUMULATIONS ARE GENERALLY NOT EXPECTED ASIDE FROM A DUSTING TO
AROUND AN INCH OVER THE HIGHER TERRAIN OF CENTRAL AND SOUTHWEST
MT. OF COURSE THERE WILL BE INSTANCES WITH HEAVIER SHOWERS
REDUCING VISIBILITY AND TEMPORARILY LEAVING LOCALIZED SLUSHY
ACCUMULATIONS. INCREASED INSTABILITY WILL ALSO BRING A FEW
THUNDERSTORMS, MOSTLY IN THE AFTERNOON AND EARLY EVENING.
TEMPERATURES WILL GENERALLY RUN AROUND 10 TO 15 DEGREES BELOW
AVERAGE WITH FREEZING OVERNIGHT TEMPERATURES. A SECONDARY TROUGH
PASSAGE WITH COLD AIR LOFT WILL MAINTAIN THE COOL SHOWERY
CONDITIONS THROUGH TUESDAY EVENING AND NEAR TO BELOW FREEZING AM
TEMPERATURES THROUGH WEDNESDAY. - RCG
AVIATION
03/12Z TAF PERIOD.
VFR CONDITIONS PREVAIL TODAY UNDER A NORTHWEST FLOW ALOFT WITH
PRIMARILY HIGH LEVEL CLOUDS AND JUST A SMALL CHANCE FOR A FEW
ISOLATED SHOWERS TO DEVELOP ACROSS FAR SW MT LATE THIS AFTERNOON
IN THE KWYS VICINITY. BREEZY NORTHWEST SURFACE WINDS WITH GUSTS
20-25KTS DEVELOP ACROSS MOST OF THE AREA THIS AFTERNOON. A
CANADIAN COLD FRONT MOVES SOUTH THROUGH THE REGION TONIGHT,
SHIFTING SURFACE WINDS TO NORTHERLY WITH INCREASING CLOUDS AND
MOUNTAIN OBSCURATION ALONG WITH THE DEVELOPMENT OF SHOWERS ACROSS
NORTH-CENTRAL MT BY 12Z MONDAY. HOENISCH
PRELIMINARY POINT TEMPS/POPS
GTF 74 43 54 33 / 0 30 30 10
CTB 73 40 53 30 / 0 10 20 0
HLN 75 43 57 33 / 0 10 30 10
BZN 71 39 57 28 / 10 10 30 20
WYS 64 31 59 26 / 30 30 30 20
DLN 70 40 61 31 / 10 10 20 10
HVR 76 40 56 28 / 0 30 30 0
LWT 69 38 50 28 / 0 30 50 20
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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