448
FXUS65 KTFX 041104
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
504 AM MDT MON MAY 4 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- COOLER TEMPERATURES AND BREEZY NORTH WINDS WITH A FEW SHOWERS
THROUGH TUESDAY.
- OVERNIGHT LOW TEMPERATURES IN THE UPPER 20S TUESDAY NIGHT.
- WARMER BUT WITH A CONTINUED CHANCE FOR SHOWERS AND A FEW
THUNDERSTORMS LATER THIS WEEK INTO THE WEEKEND.
DISCUSSION
/ISSUED 146 AM MDT MON MAY 4 2026/
- METEOROLOGICAL OVERVIEW:
A HIGHLY AMPLIFIED UPPER LEVEL PATTERN IS IN PLACE WITH RIDGING IN
THE NE PACIFIC AND DEEP TROUGHING ACROSS CENTRAL/EASTERN CANADA.
ENERGY DIVING SOUTH AROUND THE CANADIAN TROUGH WILL MAINTAIN A
CYCLONIC NORTHERLY FLOW ACROSS MT THROUGH TUESDAY WITH A COOLER
AIRMASS AND SURFACE HIGH PRESSURE BUILDING SOUTHWARD INTO THE AREA
TODAY AND MAINTAINING BELOW AVERAGE TEMPERATURES THROUGH TUESDAY.
GUSTY NORTH WINDS WITH THE INITIAL COLD FRONT AND SURGE OF HIGHER
PRESSURE ACROSS CENTRAL AND SOUTHWEST MT THIS MORNING WILL DECREASE
SOME BY LATE MORNING BUT EXPECT BREEZY TO WINDY CONDITIONS TO BE
FAIRLY WIDESPREAD ACROSS NORTH-CENTRAL MT THIS AFTERNOON AND AGAIN
TUESDAY AFTERNOON BENEATH MODERATE NORTHERLY MID LEVEL FLOW. MOISTURE
IN THIS CYCLONIC NORTHERLY FLOW IS FAIRLY SHALLOW AND LARGELY BELOW
600MB BUT IS SUPPORTING AN AREA OF SHOWERS MOVING SOUTH ACROSS NORTH-
CENTRAL MT THIS MORNING WITH WEAK AFTERNOON INSTABILITY AND NORTHERLY
USPSLOPE FLOW SUPPORTING WIDELY SCATTERED SHOWERS THIS AFTERNOON AND
AGAIN TUESDAY. DAYTIME TEMPERATURES WILL BE AROUND 10 DEGREES BELOW
SEASONAL AVERAGES TODAY AND TOMORROW WITH THE COLDEST TEMPERATURES
LIKELY TUESDAY NIGHT/EARLY WEDNESDAY MORNING AS CLOUDS AND WINDS
DECREASE, ALLOWING OVERNIGHT MINIMUM TEMPERATURES TO REACH THE
UPPER 20S ACROSS MUCH OF THE AREA.
THE LARGER SCALE UPPER LEVEL PATTERN DE-AMPLIFIES LATER THIS WEEK
WITH MODEL ENSEMBLES SHOWING BROAD UPPER LEVEL RIDGING SHIFTING
INLAND AND SUPPORTING A RETURN TO NEAR AND ABOVE AVERAGE TEMPERATURES
THROUGH NEXT WEEKEND. THERE ARE HOWEVER SEVERAL EMBEDDED DISTURBANCES
INCLUDING A SHORTWAVE TRACKING THROUGH NW FLOW AROUND THURSDAY
AND ANOTHER CROSSING THE REGION NEXT WEEKEND. THERE IS UNCERTAINTY
STILL WITH THE TIMING AND STRENGTH OF EACH OF THESE DISTURBANCES
BUT EACH WILL BRING AN INCREASED RISK OF SHOWERS AND POTENTIALLY
SOME THUNDERSTORMS. HOENISCH
- FORECAST CONFIDENCE & SCENARIOS:
WIND GUSTS IN EXCESS OF 40 MPH ARE MOST LIKELY (>50% PROBABILITY)
THIS MORNING THROUGH THE N-S ORIENTED VALLEYS OF SOUTHWEST MT
AS SURFACE HIGH PRESSURE SURGES SOUTH FROM CANADA WITH WIND GUSTS
PEAKING AGAIN IN THESE AREAS TONIGHT AS ADDITIONAL PRESSURE RISES
OCCUR. SIMILAR PROBABILITIES FOR GUSTS IN EXCESS OF 40MPH EXIST
TODAY ACROSS PORTIONS OF HILL, BLAINE AND FERGUS COUNTIES AS WELL
AS THE JUDITH GAP AREA BENEATH STRONGER MID LEVEL NORTHWESTERLY
FLOW WHERE WINDS WILL PEAK THIS AFTERNOON.
AVIATION
04/12Z TAF PERIOD
COLD FRONT CONTINUES TO PUSH SOUTH THROUGH SW MT EARLY THIS
MORNING, SHIFTING WINDS TO THE NORTH AT KBZN AND KEKS BY 14Z.
BROKEN MID LEVEL CLOUD-COVER AND AREAS OF MOUNTAIN OBSCURATION ARE
LIKELY TO EXIST THROUGH THE TAF PERIOD. AN AREA OF LIGHT RAIN/SHOWERS
AFFECTS SOME NORTH-CENTRAL MT TERMINALS THIS MORNING WITH LOW
VFR/MVFR CLOUD CEILINGS. BY THIS AFTERNOON VFR CONDITIONS PREVAIL
AGAIN THOUGH A FEW LIGHT SHOWERS MAY LINGER OVER THE MOUNTAINS.
GUSTY NORTHERLY SURFACE WINDS BECOME WIDESPREAD AGAIN THIS AFTERNOON
WITH GUSTS IN EXCESS OF 30KTS MOST LIKELY ACROSS EASTERN PORTIONS
OF NORTH-CENTRAL MT AND THROUGH N-S ORIENTED VALLEYS OF SOUTHWEST
MT. HOENISCH
PRELIMINARY POINT TEMPS/POPS
GTF 57 34 53 30 / 40 10 20 0
CTB 55 30 51 27 / 20 0 10 0
HLN 58 34 54 30 / 30 10 20 0
BZN 60 30 51 25 / 20 20 30 10
WYS 60 29 48 20 / 10 10 20 10
DLN 63 32 54 27 / 10 10 10 0
HVR 58 27 54 26 / 10 0 10 0
LWT 52 28 48 25 / 50 10 40 10
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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