796
FXUS65 KTFX 072019
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
219 PM MDT WED MAY 7 2025
KEY MESSAGES
- A WARMING TREND CONTINUES THROUGH THE UPCOMING WEEKEND WITH MAINLY
DRY AND LOCALLY BREEZY CONDITIONS THROUGH THE REST OF THE WORK
WEEK.
- ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS MAINLY CONFINED TO
CENTRAL AND SOUTHWEST MONTANA INITIALLY, BECOME MORE
WIDESPREAD THIS WEEKEND WITH AN INCREASED RISK FOR STRONG
THUNDERSTORMS BY SUNDAY.
- AN ACTIVE WEATHER PATTERN DEVELOPING NEXT WEEK WILL BRING COOLER
TEMPERATURES AND OPPORTUNITIES FOR PRECIPITATION.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
BROAD UPPER LEVEL RIDGING REMAINS IN PLACE ACROSS THE NORTHERN TIER
OF THE US WITH UPPER-LEVEL JET AND MID-LEVEL SHORTWAVE ENERGY
EJECTING OUT OF A TROUGH IN THE PACIFIC AND LARGELY TRACKING WELL TO
THE NORTH AND NORTHWEST OF THE REGION THROUGH THE REST OF THE WEEK.
RISING HEIGHTS BENEATH THE RIDGE WILL SUPPORT A GRADUAL WARMING
TREND THROUGH THE NEXT SEVERAL DAYS WITH TEMPERATURES PEAKING ON
SATURDAY BEFORE THE RIDGE MOVES OFF TO THE EAST.
WHILE THE UPPER LEVEL RIDGE WILL MAINTAIN OVERALL DRY CONDITIONS
INTO THE FIRST PART OF THIS WEEKEND, THERE IS ENOUGH SURFACE
MOISTURE PRESENT AND SOME INFLUX OF MID LEVEL MOISTURE FOR DAILY
CUMULUS DEVELOPMENT AND AT LEAST AN ISOLATED CHANCE OF
SHOWER/THUNDERSTORM DEVELOPMENT EACH AFTERNOON ACROSS PRIMARILY THE
TERRAIN OF SOUTHWEST AND CENTRAL MT. SHORTWAVE AND UPPER JET ENERGY
TRACKING ACROSS BC/AB ON THURSDAY WILL SUPPORT A SOMEWHAT BETTER
CHANCE FOR SHOWER/THUNDERSTORM DEVELOPMENT LATE THURSDAY AS A WEAK
FRONTAL BOUNDARY AND SURFACE TROUGH SHIFT EAST ACROSS THE AREA.
BREEZY SOUTHWEST WINDS PERSIST ACROSS MUCH OF THE AREA THROUGH
THURSDAY AS WELL WITH LIGHTER WINDS FRIDAY AS SURFACE HIGH PRESSURE
MOVES ACROSS THE CANADIAN PRAIRIES.
A MORE ACTIVE PERIOD OF WEATHER BEGINS THIS WEEKEND AS UPPER LEVEL
TROUGHING SHIFTS INLAND WITH CONSIDERABLE INSTABILITY DEVELOPING
UNDER INCREASING SOUTHWEST FLOW ALOFT BY LATE SATURDAY WITH AN
INITIAL WAVE AND UPPER LEVEL JET ENERGY EJECTING OUT OF THE TROUGH
ACROSS THE NORTHERN ROCKIES LATE SUNDAY. THIS WILL SUPPORT THE
POTENTIAL FOR SOME STRONG THUNDERSTORMS LATE SATURDAY WITH A MORE
WIDESPREAD RISK OF STRONG THUNDERSTORM DEVELOPMENT ON SUNDAY.
- FORECAST CONFIDENCE & SCENARIOS:
SATURDAYS MAX TEMPERATURES ARE LIKELY TO BE THE WARMEST OF THE
SEASON SO FAR WITH MANY LOWER ELEVATION LOCATIONS REACHING THE MID
80S. DAILY TEMPERATURE RECORDS FOR SATURDAY ARE STILL A FEW DEGREES
WARMER THAN CURRENT FORECAST GUIDANCE.
THE COVERAGE AND INTENSITY OF THUNDERSTORMS THIS WEEKEND WILL
LARGELY DEPEND ON THE DEPTH OF AVAILABLE MOISTURE AND THE TIMING OF
THE INITIAL WAVE EJECTING OUT OF THE TROUGH, BOTH OF WHICH THERE IS
STILL SOME UNCERTAINTY (DEWPOINTS IN THE LOW 40S VS AROUND 50F). IN
ANY CASE, THERE WILL BE AT LEAST SOME RISK FOR BOTH STRONG WINDS AND
HAIL WITH ANY MORE ORGANIZED THUNDERSTORMS THAT DEVELOP LATER THIS
WEEKEND, SO THOSE WITH OUTDOOR PLANS SHOULD MONITOR FORECASTS AND
HAVE A PLAN FOR ALTERNATIVES, ESPECIALLY ON SUNDAY.
MEDIUM RANGE MODELS/ENSEMBLES AGREE TO SHIFT THE LARGER SCALE TROUGH
ACROSS THE INTERIOR WESTERN US EARLY NEXT WEEK, EMERGING IN THE
NORTHERN US PLAINS BY WEDNESDAY. THERE IS STILL A FAIR AMOUNT OF
UNCERTAINTY IN SPECIFIC DETAILS, ESPECIALLY BY TUESDAY AND
WEDNESDAY, BUT MODERATE CONFIDENCE IN A SHIFT TO COOLER TEMPERATURES
AND A MORE WIDESPREAD CHANGE FOR PRECIPITATION.
AVIATION
07/18Z TAF
VFR WITH MOSTLY SKC AND P6SM EXPECTED THROUGHOUT THE PERIOD AS AN
UPPER LEVEL RIDGE OF HIGH PRESSURE CONTINUES TO DOMINATE THE
REGION. A DISTANT, WEAK LOW CROSSING ALBERTA OFFERS SOME PASSING
10+ KFT DECKS OVERNIGHT INTO TOMORROW AND VARIABLE FLOW, OTHERWISE
RELATIVELY TRANQUIL SKIES ARE EXPECTED.
FOR WINDS, WE ARE SEEING OCCASIONALLY GUSTY FLOW OUT OF THE SOUTH
AND SOUTHWEST ACROSS PLAINS SITES TODAY. SOUTHWESTERLY LLWS ON
THE ORDER OF 30-40 KTS IS BRIEFLY POSSIBLE AT KCTB DURING THE LATE
NIGHT/EARLY MORNING HOURS SHOULD SURFACE FLOW DROP BELOW 10 KTS
OR SO. TOMORROW, PRESSURE RISES FROM THE WEST WILL OFFER A MORE
WESTERLY COMPONENT TO WIND DIRECTION WITH SIMILAR SPEEDS AS TODAY.
-CASEY
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION
WEATHER AND HAZARD INFORMATION.
PRELIMINARY POINT TEMPS/POPS
GTF 47 74 42 80 / 0 0 0 0
CTB 46 68 37 77 / 0 0 0 0
HLN 48 76 46 81 / 0 20 20 10
BZN 43 74 41 77 / 10 30 20 10
WYS 32 67 32 70 / 0 30 20 0
DLN 42 73 41 77 / 10 30 20 0
HVR 47 78 39 81 / 0 0 0 0
LWT 46 71 43 75 / 0 30 30 10
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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