335
FXUS65 KBYZ 050803
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
203 AM MDT TUE AUG 5 2025
KEY MESSAGES
- ISOLATED TO SCATTERED SHOWERS AND THUNDERSHOWERS EARLY TODAY OVER
EAST CENTRAL SECTIONS OUT TO THE DAKOTA BORDERS.
- SEASONAL TEMPERATURES IN THE 80S TO LOWER 90S THROUGH
THURSDAY.
- COOLER (HIGHS IN THE 70S) AND AN INCREASED CHANCE OF SHOWERS
AND THUNDERSTORMS THURSDAY NIGHT INTO FRIDAY.
DISCUSSION
THROUGH WEDNESDAY NIGHT...
UPPER TROUGH OVER IDAHO/WESTERN MT AT THIS TIME. MESOANALYSIS
INDICATES STRONG UPPER DIVERGENCE AND 500 JET-LETS AHEAD OF THE
TROUGH WAS DRIVING STRONG FORCING ACROSS PORTIONS OF EAST CENTRAL
AND SOUTHEAST MT OVERNIGHT. NUMEROUS SHOWERS AND SCATTERED
THUNDERSTORMS HAVE CONVERGED OVER THE AREA AND WILL PUSH SLOWLY
NORTHEAST THROUGH THE MORNING HOURS. STRONG WIND GUSTS TO 45 MPH
ARE POSSIBLE AND EVEN A SLIGHT CHANCE OF SMALL HAIL WITH STRONGER
CELLS. THE UPPER TROUGH WILL TRACK NORTHEAST THROUGH CENTRAL AND
NORTHERN MONTANA THROUGH THE DAY. WE ANTICIPATE SOME LINGERING
CONVECTIVE ACTIVITY ALONG THE NORTHERN PERIPHERY OF OUR CWA IN
EAST CENTRAL MT THROUGH AT LEAST MIDDAY. ONCE THE POSITIVELY
TILTED TROUGH AXIS PUSHES INTO NORTHEAST MT LATER TODAY...WE
SHOULD SEE A PUSH OF DRIER MORE STABLE CONDITIONS SPREAD OVER OUR
ENTIRE FORECAST AREA. HIGHS TODAY WILL BE A LITTLE COOLER THAN
MONDAYS WITH READINGS MAINLY IN THE 80S.
TONIGHT INTO WEDNESDAY MORNING LOOK FOR CALM AND MOSTLY CLEAR
SKIES WITH LOWS RANGING FROM NEAR 50 IN THE WESTERN FOOTHILLS TO
AROUND 60 FURTHER EAST. WEDNESDAY WILL BE A DRY DAY AS A LOW
AMPLITUDE RIDGE BUILDS INTO THE REGION. HIGHS WILL BE IN THE UPPER
80S TO LOWER 90S.
WILDFIRE SMOKE...SMOKE MODELS SUGGEST SOME MODEST OCCASIONAL
INFLUX OF SMOKE ALOFT FROM WILDFIRES, BOTH NEARBY AND ALSO FROM
FURTHER OUT WEST/SOUTHWEST OF OUR REGION. WHILE NOTHING
SIGNIFICANT IS EXPECTED, PEOPLE SHOULD ANTICIPATE HAZY SKIES. BT
THURSDAY THROUGH MONDAY...
THERE CONTINUES TO BE VERY GOOD CONSISTENCY IN THE ENSEMBLES AND
CLUSTER ANALYSIS THAT A POWERFUL UPPER TROUGH WILL TRACK THROUGH
THE NORTHERN ROCKIES THURSDAY AND THROUGH MONTANA AND THE HIGH
PLAINS FRIDAY. THERE IS STILL SOME UNCERTAINTY JUST HOW FAR SOUTH
THIS TROUGH DIGS WITH MAIN UPPER LOW REMAINING OVER SOUTHERN
SASKATCHEWAN/NORTHERN MONTANA. HOWEVER, EXCELLENT UPPER JET
DYNAMICS ROUNDING THE BOTTOM OF THE TROUGH SHOULD BE IN PLACE OVER
OUR AREA LATE THURSDAY NIGHT THROUGH FRIDAY. WHILE INITIAL PWAT
VALUES ARE HIGH, ESPECIALLY OVER THE PLAINS THURSDAY NIGHT INTO
EARLY FRIDAY (>1.00 INCHES), MODELS SHOW MOISTURE IS PUSHED
QUICKLY EAST BY FRIDAY AFTERNOON AS WESTERLY FLOW SHOOTS ACROSS
THE REGION AS UPPER TROUGH AXIS MOVES ACROSS. SO THERE REMAINS
UNCERTAINTY ON OUR PRECIPITATION COVERAGE AND OVERALL RAINFALL AS
CURRENT NBM POPS (30-60%) MAY BE OVERDONE FOR THE LATTER PART OF
FRIDAY IN OUR WESTERN CWA DUE TO A LACK OF DOWNSLOPE DRYING
IMPACTS BEING TAKEN INTO ACCOUNT. SOMETHING TO KEEP AN EYE ON.
AT THIS TIME, WE ANTICIPATE GOOD DYNAMICS MOVING ACROSS OUR
WESTERN ZONES THURSDAY NIGHT INTO FRIDAY MORNING WITH THE
POTENTIAL OF POCKETS OF HEAVY RAIN AND SOME STRONG
THUNDERSTORMS...DECREASING FRIDAY AFTERNOON AS DOWNSLOPE EFFECTS
KICK IN. THE NORTHERN TIER OF THE CWA STILL HAS A >50% CHANCE OF
PICKING UP AT LEAST 0.1" OF PRECIPITATION THURSDAY NIGHT INTO
FRIDAY WITH PROBABILITIES GRADUALLY TAPERING OFF TO UNDER 25% IN
THE SOUTHEAST CORNER.
THIS SYSTEM WILL ALSO BRING WITH IT COME COOLER THAN AVERAGE
TEMPERATURES. THURSDAY WILL LIKELY STILL BE WARM FOR MUCH OF THE
REGION BEFORE A COLD FRONT DROPS IN DURING THE EVENING. MUCH OF
THE AREA WILL SEE HIGHS ON FRIDAY 10+ DEGREES BELOW AVERAGE WITH
BILLINGS CURRENTLY SITTING AT A 38% CHANCE OF A HIGH BELOW 75F ON
FRIDAY.
MOVING INTO THE WEEKEND, 500 MB FLOW REMAINS CYCLONIC, BUT DRY,
WITH A GRADUAL TRANSITION TO RIDGING BY EARLY NEXT WEEK. SO EXPECT
MAINLY DRY CONDITIONS WITH A WARMING TREND. BT
AVIATION
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
CONTINUE THROUGH THE EARLY MORNING HOURS (THRU 12Z) OVER PORTIONS
OF EAST CENTRAL AND SOUTHEAST MT AS THE ACTIVITY SLOWLY SHIFTS
NORTHEAST. WITHIN THESE SHOWERS/STORMS MVFR CONDITIONS WITH GUSTS
TO 35KTS IS POSSIBLE. LOCATIONS MOST LIKELY IMPACTED INCLUDE
KMLS/KBHK. ISOLATED SHOWERS/THUNDERSHOWERS MAY LINGER OVER EAST
CENTRAL SECTIONS OF MONTANA THROUGH MIDDAY. OTHERWISE, EXPECT VFR
CONDITIONS TO DOMINATE. SOME HAZE FROM WILDFIRE SMOKE MAY
OCCASIONALLY AND MODESTLY REDUCE SLANT-WISE VISIBILITY. BT
PRELIMINARY POINT TEMP/POPS
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 086 059/091 062/089 058/078 055/081 057/085 058/086
1/U 00/U 12/T 54/T 11/U 10/B 00/U
LVM 083 050/090 052/086 047/075 045/080 049/084 051/086
1/U 00/U 14/T 64/T 11/U 00/U 00/U
HDN 086 056/092 059/090 058/079 052/082 055/086 056/087
1/U 00/U 01/U 44/T 21/U 10/B 00/U
MLS 085 060/092 064/093 062/078 056/081 057/085 058/086
3/T 00/U 11/U 44/T 21/B 10/B 10/U
4BQ 085 062/092 064/094 062/079 056/080 058/083 059/084
1/U 00/U 00/U 33/T 31/U 10/U 10/U
BHK 084 058/091 062/094 060/078 053/078 055/081 055/082
4/T 10/U 11/U 43/T 31/B 10/B 10/U
SHR 085 054/092 058/093 055/077 049/080 051/083 053/084
0/U 00/U 01/U 24/T 21/U 11/U 10/U
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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