540
FXUS65 KTFX 072026
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
226 PM MDT THU AUG 7 2025
KEY MESSAGES
- SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE LATE TONIGHT, WITH
A FEW STORMS CAPABLE OF PRODUCING GUSTY WINDS AND HAIL.
- SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE THROUGH FRIDAY, WITH
COOLER TEMPERATURES.
- WARMER AND DRIER FOR THE WEEKEND.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
THERE LOOKS TO BE TWO DIFFERENT WAVES OF PRECIPITATION TODAY. A
SHORTWAVE THIS AFTERNOON HAS PRODUCED THE FIRST WAVE OF SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS THE REGION. LATER IN THE EVENING,
THE CORE OF THE UPPER-LEVEL TROUGH MOVES THROUGH. CAPE BETWEEN
500-1,000 J/KG AND MODEST SHEAR OF 40-50KTS WILL BRING AN ISOLATED
RISK FOR STRONG TO SEVERE THUNDERSTORMS THROUGH THE EVENING. THE
UPPER-LEVEL LOW BRINGING IN COOLER AIR ALOFT LATER THIS EVENING
WILL KEEP A LITTLE BIT OF ELEVATED INSTABILITY AND ISOLATED STORMS INTO
THE OVERNIGHT HOURS.
HEADING INTO THE OVERNIGHT HOURS, THIS OCCLUDING LOW ALOFT LOOKS
TO TRANSVERSE OVER NORTH-CENTRAL MT. THIS WILL BRING A WIDESPREAD
BAND OF WETTING RAIN TO PORTIONS OF NORTH-CENTRAL MT THROUGH
FRIDAY MORNING. THAT MAIN WAVE WILL EXIT OFF TO THE EST IN THE
AFTERNOON, BUT MOISTURE WRAPPING AROUND THAT LOW PRESSURE SYSTEM
WILL KEEP SHOWERS AND THUNDERSTORMS ACROSS THE REGION (MAINLY
NORTH OF I-90) THROUGHOUT FRIDAY AND OVERNIGHT INTO SATURDAY
MORNING. THE LOW PRESSURE SYSTEM WILL MOVE OFF TO THE EAST BY
SATURDAY AFTERNOON. WE THEN TRANSITION TO NORTHWEST FLOW ALOFT FOR
THE WEEKEND AS AN UPPER- LEVEL RIDGE BUILDS OFF THE PACIFIC
NORTHWEST COAST. ALTHOUGH THE WEEKEND WILL STAY ON THE DRIER SIDE
OVERALL, AS FEW DISTURBANCES TRIES TO "ROUND OUT THE RIDGE" AND
DIVE SOUTH FROM CANADA INTO MONTANA. THIS WILL KEEP LOW END
CHANCES FOR PRECIPITATION THIS WEEKEND, PARTICULARLY ON SATURDAY.
FRIDAY LOOKS TO BE THE COOLEST DAY OF THE FORECAST PERIOD WITH
HIGH TEMPERATURES FORECASTED TO REACH ONLY THE 60S TO LOW 70S AT
LOWER ELEVATIONS. A WARMUP TREND IS EXPECTED THROUGH THE BEGINNING
OF NEXT WEEK, BUT STILL TEMPERATURES DON'T LOOK IMPRESSIVE. IT'LL
REMAIN NEAR TO SLIGHTLY BELOW AVERAGE.
MODELS NEXT WEEK ARE UNCERTAIN HOW LONG THIS NORTHWEST FLOW ALOFT
PATTERN LASTS. ENSEMBLES INDICATE A SMALL SHORTWAVE TROUGH
DEVELOPING IN BRITISH COLUMBIA, BUT ARE UNSURE HOW TO PROGRESS
THIS TROUGH. SOME HAVE THIS TROUGH DIGGING INTO THE PACIFIC
NORTHWEST, BRINGING BETTER CHANCES FOR PRECIPITATION, WHILE SOME
KEEP IT CONFINED TO CANADA WHICH WILL KEEP THINGS ON THE DRIER
SIDE. TIMING OF THIS WAVE IS ALSO INCONSISTENT, WHICH LOWERS THE
CONFIDENCE OF THE FORECAST FOR NEXT WEEK.
- FORECAST CONFIDENCE & SCENARIOS:
MORNING CLOUD COVER HAS LIMITED INSTABILITY ACROSS THE REGION THIS
AFTERNOON TO GENERALLY 1,000 J/KG OR LESS. THIS WILL KEEP THE
THREAT FOR STRONG TO SEVERE THUNDERSTORMS ISOLATED, TO MAINLY
AREAS EAST OF THE LITTLE BELTS REGION THIS AFTERNOON. LATER THIS
EVENING WITH THE ARRIVAL OF THE UPPER-LEVEL CLOSED LOW, ANOTHER
CORRIDOR ALONG THE BOULDER HILL, BROADWATER COUNTY, AND THE
MISSOURI HEADWATERS AREA, WHERE GOOD DEEP LAYER SHEAR AND LOWER
AMOUNTS OF HELICITY WILL BRING AN ISOLATED CHANCE FOR A FEW STRONG
TO SEVERE STORMS.
FOR FRIDAY, THERE ARE SUBTLE DIFFERENCES IN THE LOCATION OF THE
WIDESPREAD OF PRECIPITATION OVERNIGHT. AREAS THAT DO GET THIS
STEADY, CONSISTENT RAIN CAN SEE AMOUNTS HIGHER END AMOUNTS OF 0.75"-
1". BEING ON THE WESTERN SIDE OF THE LOW PRESSURE SYSTEM NOW, THE
SYNOPTICS AND MESOSCALE DYNAMICS LOOK TO KEEP THUNDERSTORMS
RELATIVELY WEAK ON FRIDAY. AN INCREASE IN THE LOW LEVEL JET
HOWEVER, WILL BRING BREEZY WEST TO NORTHWEST WINDS TO THE REGION
FOR FRIDAY. -WILSON
AVIATION
07/18Z TAF PERIOD
SHOWERS/THUNDERSTORMS WILL CONTINUE TO IMPACT MOST TERMINALS
THROUGH THE PERIOD, AS A SLOW MOVING UPPER LEVEL TROF MOVES FROM
WEST TO EAST ACROSS FAR SOUTHERN CANADA. THE PRECIPITATION WILL BE
MOST WIDESPREAD AND LAST LONGER OVER NORTH CENTRAL MT. VISIBILITY
COULD BE BELOW 6SM AT TIMES DURING HEAVIER RAINFALL. SOME GUSTY
WINDS ALSO POSSIBLE WITH STORMS THIS AFTERNOON OVER THE EASTERN
PORTIONS OF THE CWA. MOUNTAIN TOPS WILL BE OBSCURED IN SOME AREAS,
AS CEILINGS WILL BE BELOW 7000 FEET AT TIMES. BRUSDA
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION
WEATHER AND HAZARD INFORMATION.
PRELIMINARY POINT TEMPS/POPS
GTF 50 72 53 77 / 80 50 20 10
CTB 50 67 51 73 / 30 60 30 10
HLN 49 73 52 79 / 60 30 10 10
BZN 44 73 45 78 / 80 10 10 0
WYS 34 67 32 71 / 20 10 0 0
DLN 39 70 40 75 / 60 0 0 0
HVR 52 70 54 76 / 60 70 60 30
LWT 47 67 49 70 / 40 60 40 20
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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