152
FXUS65 KBYZ 261938
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
138 PM MDT MON MAY 26 2025
KEY MESSAGES
- SCATTERED SHOWERS AND T-STORMS MAINLY WEST OF ROSEBUD COUNTY
TUESDAY AFTERNOON AND EVENING (30-70% CHANCE); STORMS COULD
PRODUCE BRIEF HEAVY RAIN, SMALL HAIL AND ERRATIC WIND GUSTS.
- DRIER AND WARMER THURSDAY THOUGH THE WEEKEND; TEMPS PUSHING 80
DEGREES THURSDAY THROUGH SATURDAY; 90F IS POSSIBLE BY SUNDAY.
- A RETURN TO UNSETTLED WEATHER AND A COOLING TREND EXPECTED EARLY
NEXT WEEK; MONITOR THE FORECAST.
DISCUSSION
THROUGH TUESDAY NIGHT...
SATELLITE IMAGERY SHOWS A THIN RIDGE AXIS EXTENDING FROM CENTRAL
MT TO SASKATCHEWAN BREAKING DOWN, WITH CYCLONIC NORTHERLY FLOW
OVER THE NORTHERN HIGH PLAINS AND AN UPSTREAM SPLITTING TROF
MOVING FROM WA/OR INTO ID. SCATTERED TO BROKEN CLOUD COVER REMAINS
OVER THE EAST BUT THIS IS SLOWLY ERODING. TO THE WEST, A T-STORM
HAS RECENTLY DEVELOPED NEAR GARDINER AND SCATTERED CUMULUS EXISTS
OVER THE MOUNTAINS. FROM NOW THRU SUNSET, EXPECT MAINLY ISOLATED
WEAK CONVECTION OVER AREA MOUNTAINS, AND CONTINUED DRY CONDITIONS
AND EAST WINDS ELSEWHERE.
LATER TONIGHT, WE WILL SEE WEAK ASCENT ARRIVE FROM THE WEST, WHICH
WITH MODEST MID LEVEL INSTABILITY AND MOISTURE MAY BRING A FEW
LIGHT SHOWERS OR SPRINKLES INITIALLY ALONG THE WESTERN FOOTHILLS
BUT EVENTUALLY DRIFTING EASTWARD OVER THE LOWER ELEVATIONS LATE
TONIGHT AND TUESDAY MORNING. FOR BILLINGS, THERE COULD BE SOME
SPRINKLES/VIRGA AROUND TOMORROW MORNING. BEGINNING AROUND MIDDAY
TOMORROW, AS THE SPLITTING ENERGY ARRIVES IN EASTERN MT/WY AND
TRIES TO PHASE WITH THE CYCLONIC FLOW OVER THE NORTHERN PLAINS, WE
WILL SEE SCATTERED SHOWERS & T-STORMS DEVELOP OVER THE WEST HALF
OF OUR FORECAST AREA. THIS ACTIVITY WILL PERSIST THROUGH THE
EVENING. CAPES OF 250-750 J/KG ARE HIGH ENOUGH FOR T-STORMS, AND
PWATS UP TO 0.80-0.90" ARE ABOVE NORMAL FOR LATE MAY, BUT BULK
SHEAR IS EXPECTED TO REMAIN QUITE WEAK (15 KNOTS OR LESS PER THE
HREF). THUS, STORMS WILL BE NON-SEVERE BUT COULD PRODUCE BRIEF
HEAVY RAIN, SMALL HAIL AND ERRATIC SURFACE WINDS. SOMETHING TO
KEEP IN MIND IF YOU HAVE OUTDOOR PLANS TOMORROW. LOCATIONS EAST OF
MILES CITY & BROADUS ARE EXPECTED TO REMAIN DRY. NORTHERLY
UPSLOPE FLOW WILL LIKELY KEEP SOME ACTIVITY LINGERING BEYOND
SUNSET IN OUR SOUTH, OTHERWISE THE NORTH WILL SEE SUBSIDENCE/
DRYING TUESDAY NIGHT. TEMPS TOMORROW WILL BE SEASONABLE WITH HIGHS
RANGING FROM THE UPPER 60S FAR EAST TO LOWER-MID 70S ELSEWHERE.
ONE FINAL ITEM TO NOTE. LOW LEVEL FLOW WILL REMAIN SOUTHEASTERLY
IN OUR FAR EAST THRU TONIGHT. BOUNDARY LAYER MOISTURE SHOULD
REMAIN ELEVATED ENOUGH TO PRODUCE ANOTHER ROUND OF STRATUS/FOG
OVER OUR EASTERN ZONES LATE TONIGHT INTO EARLY TUESDAY. GREATEST
POTENTIAL FOR VISIBILITY REDUCTIONS DUE TO FOG IS IN CARTER
COUNTY (40% CHANCE).
JKL
WEDNESDAY THROUGH MONDAY...
WE WILL REMAIN UNDER CYCLONIC NORTHERLY FLOW ON WEDNESDAY (BEHIND
TUESDAY'S WAVE), AND THIS SHOULD YIELD SOME MOSTLY DIURNAL SHOWERS
AND WEAK T-STORMS OVER THE SOUTHERN MOUNTAINS AND FOOTHILLS.
OTHERWISE, MOST OF THE FORECAST AREA WILL BE DRY W/ EAST WINDS
KEEPING TEMPS IN CHECK (HIGHS UPPER 60S TO MID 70S). THURSDAY WILL
NO DOUBT BE WARMER W/ A SHIFT TO DOWNSLOPE WINDS PUSHING TEMPS TO
THE MID 70S TO MID 80S. THERE MAY BE ISOLATED LATE DAY WEAK
CONVECTION IN OUR WEST AS HEIGHT FALLS INITIATE W/ A PACIFIC TROF,
BUT THE BETTER CHANCE OF SHOWERS WILL BE THURSDAY NIGHT AND FRIDAY
AS THIS ENERGY SKIRTS ACROSS NORTHERN MT AND FLATTENS THE RIDGE.
NOT MUCH TO SAY HERE. CHANCE OF MEASURABLE PRECIP WILL BE MODEST
(10-20%) AND FRIDAY WILL BE JUST A FEW DEGREES COOLER THAN
THURSDAY...AND IN FACT A LITTLE WARMER IN THE FAR EAST.
CONFIDENCE IS HIGH FOR ANOTHER PERIOD OF RIDGING AND WARMER TEMPS
NEXT WEEKEND. LOOK FOR HIGHS BACK TO THE 80S SATURDAY AND PERHAPS
90F SUNDAY...THOUGH THERE IS INCREASING MODEL SPREAD IN THE LATER
STAGES OF THIS RIDGING AND WHEN THE NEXT COLD FRONT ARRIVES. IF
THE RIDGE BEGINS TO BREAK DOWN SUNDAY WE COULD SEE AFTERNOON AND
EVENING THUNDERSTORMS ON THIS DAY, ESPECIALLY IN THE WEST, BUT IT
IS TOO SOON TO TELL. SOMETHING TO MONITOR IF YOU HAVE OUTDOOR
PLANS NEXT SUNDAY, AS A RIDGE BREAK DOWN AND COLD FRONT COULD
YIELD SOME STRONG T-STORMS. IF THE COLD FRONT HOLDS OFF UNTIL THAT
NIGHT OR MONDAY, WHICH IS THE MOST LIKELY SCENARIO PER CLUSTER
ANALYSES, SUNDAY COULD SEE THE HOTTEST TEMPS WE'VE SEEN SO FAR
THIS YEAR.
THINGS LOOK TO GET MUCH MORE INTERESTING THE FIRST PART OF NEXT
WEEK AS A POTENTIALLY DEEP PACIFIC TROF MOVES INLAND. DETAILS ARE
IMPOSSIBLE TO SAY NOW, BUT WITH CONFIDENCE EXPECT A COOLING TREND
TO START AND MUCH GREATER PRECIP CHANCES BY NEXT MONDAY. HEAVY
RAIN AND STRONG TO SEVERE T-STORMS ARE ALL ON THE TABLE EARLY NEXT
WEEK IF WE DO SEE IMPACTS FROM A DEEP TROF. STAY TUNED.
JKL
AVIATION
SCATTERED TO BROKEN STRATUS WITH 3.5-4.5KFT AGL BASES EAST OF
ROSEBUD COUNTY WILL SLOWLY DISSIPATE THROUGH THE AFTERNOON. AFTER
A PERIOD OF CLEARING, LOW CEILINGS MAY SPREAD BACK INTO SOUTHEAST
MT LATE TONIGHT INTO EARLY TUESDAY, WITH MVFR POSSIBLE, AND
LOCALIZED FOG IN CARTER COUNTY. THIS WILL BE SOMETHING TO MONITOR
TONIGHT. LOOK FOR ISOLATED SHOWERS AND WEAK T-STORMS OVER THE
ABSAROKA/BEARTOOTH AND BIGHORN MOUNTAINS THRU 04Z THIS EVENING.
MOUNTAIN TOPS MAY BE OBSCURED AT TIMES. LIGHT SHOWERS WILL SPREAD
TO WESTERN LOWER ELEVATIONS LATE TONIGHT, WITH VFR PREVAILING. BY
TUESDAY AFTERNOON, LOOK FOR SCATTERED SHOWERS & T-STORMS WEST OF
ROSEBUD COUNTY (POTENTIALLY IMPACTING KLVM, KBIL & KSHR). THESE
STORMS WILL BE CAPABLE OF PRODUCING BRIEF MVFR IN HEAVY RAIN,
SMALL HAIL AND ERRATIC WIND GUSTS. JKL
PRELIMINARY POINT TEMP/POPS
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 051/074 053/076 051/082 057/079 053/085 058/090 058/080
14/T 20/U 00/U 22/W 00/U 01/U 35/T
LVM 050/072 047/074 048/082 054/077 049/084 055/088 054/075
26/T 21/U 01/U 21/U 00/U 02/T 36/T
HDN 048/075 051/076 050/082 054/079 050/085 055/091 057/083
02/T 21/U 00/U 22/W 10/U 01/U 34/T
MLS 047/075 051/076 050/080 054/081 052/085 056/090 059/085
01/B 10/U 00/U 12/W 00/U 00/U 23/T
4BQ 046/072 049/072 047/078 052/079 052/082 055/090 060/085
01/B 20/U 00/U 12/T 00/U 00/U 22/T
BHK 043/070 043/072 043/076 047/079 049/080 051/084 054/081
00/B 10/U 00/U 02/T 00/U 00/U 22/T
SHR 044/071 047/071 046/077 051/076 048/082 052/090 054/083
05/T 73/T 00/U 13/T 10/U 01/U 24/T
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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