692
FXUS65 KBYZ 302313
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
513 PM MDT FRI MAY 30 2025
KEY MESSAGES
- WARM THROUGH THE WEEKEND WITH HIGHS IN THE 80S SATURDAY,
APPROACHING 90 DEGREES SUNDAY.
- COLD FRONT DROPPING INTO THE REGION BRINGS A CHANCE FOR STRONG
TO SEVERE THUNDERSTORMS SUNDAY.
- UNSETTLED AND COOLER MONDAY THROUGH WEDNESDAY. UNCERTAINTY
REMAINS WITH JUST HOW MUCH PRECIPITATION WILL FALL.
- SNOW IS FORECAST IN THE HIGHER ELEVATIONS OF THE
BEARTOOTH/ABSAROKA MOUNTAINS WHICH MAY IMPACT TRAVEL OVER THE
BEARTOOTH PASS BEGINNING MONDAY NIGHT.
- RIVERS AND STREAMS ARE RUNNING HIGH AND FAST WITH SNOWMELT. NO
FLOODING IS FORECAST AT THIS TIME, BUT ADDITIONAL RISES ARE
EXPECTED THROUGH EARLY NEXT WEEK. PLEASE USE EXTRA CAUTION NEAR
WATERWAYS AND KEEP CHILDREN AWAY FROM THE WATERS EDGE.
DISCUSSION
THROUGH SATURDAY NIGHT...
A COMPACT AREA OF LOW PRESSURE WAS DROPPING SOUTH AND EAST THROUGH
WESTERN NORTH DAKOTA THIS AFTERNOON BRINGING GUSTY NORTH TO
NORTHWEST WINDS TO THE AREA. THE LOW MAY BRING AN ISOLATED SHOWER
OR THUNDERSTORM TO FAR NORTHEAST AREAS INCLUDING BAKER THROUGH
THE EVENING, THOUGH MOST CONVECTION WILL STAY EAST INTO THE
DAKOTAS. SMOKE FROM CANADIAN WILDFIRES WILL MOVE BACK INTO AREAS
NEAR THE DAKOTAS BORDER TONIGHT INTO SATURDAY. RIDGING AMPLIFIES
OVER THE REGION ON SATURDAY, CONTINUING TO BRING WARM AND DRY
CONDITIONS, WITH HIGHS IN THE UPPER 70S TO MIDDLE 80S, WARMEST
OVER WESTERN AND CENTRAL AREAS.
HYDROLOGY...SNOWMELT IS GOING STRONG IN THE MOUNTAINS WITH RIVER
LEVELS CONTINUING TO RISE ACROSS THE AREA. PEAK SPRING FLOWS
USUALLY ARRIVE BETWEEN NOW AND THE SECOND WEEK OF JUNE ON OUR
STREAMS. AT THIS TIME THERE IS NO INDICATION OF A FLOOD THREAT
OVER THE NEXT 5 DAYS THOUGH WATER LEVELS ARE EXPECTED TO CONTINUE
TO RISE DURING THIS PERIOD. HOWEVER, EXTRA CAUTION SHOULD BE
EXERCISED NEAR WATERWAYS AT THIS TIME. BANK EROSION IS A BIG
CONCERN WITH RIVERS AND STREAMS AT THESE LEVELS. UNDERCUT BANKS
CAN FALL INTO THE WATER TAKING ANYONE STANDING THERE INTO THE
COLD, HIGH, AND FAST MOVING WATER. MURKY FAST MOVING WATER
CONTAINS LARGE PIECES OF DEBRIS AND CAN HIDE OBSTRUCTIONS, BOTH
CAN BE DANGEROUS FOR BOATERS. CONSIDER STAYING OFF THE WATER
DURING THIS PERIOD OF HIGH FLOWS, KEEP AWAY FROM THE WATERS EDGE,
ESPECIALLY CHILDREN. CHAMBERS/STP
SUNDAY THROUGH THURSDAY...
WARM AND MOSTLY DRY CONDITIONS ARE FORECAST SUNDAY AHEAD OF A
PACIFIC TROUGH. HIGH TEMPERATURES WILL BE IN THE 80S TO 90F.
THE TROUGH WILL BRING A SURFACE COLD FRONT THROUGH THE REGION
SUNDAY EVENING. STRONG TO POTENTIALLY SEVERE THUNDERSTORMS ARE
POSSIBLE AS WELL. THERE IS STILL UNCERTAINTY AS TO WHERE AND WHEN
THESE STORMS WOULD OCCUR, WITH THE GFS DEPICTING STORM DEVELOPMENT
WITH THE COLD FRONT AND THE ECMWF SHOWING STORMS AHEAD OF THE
FRONT IN THE FAR EAST. CURRENTLY, THE STORM PREDICTION CENTER HAS
A MARGINAL RISK FOR ISOLATED SEVERE THUNDERSTORMS OVER
SOUTHWESTERN AND SOUTH-CENTRAL MT. THE MAIN THREATS WILL BE STRONG
WIND GUSTS AND HAIL. LOCALLY HEAVY RAINFALL IS A SECONDARY
THREAT. ENVIRONMENTAL PARAMETERS AND PATTERN RECOGNITION WOULD
INDICATE THAT STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE,
ESPECIALLY WITH AMPLE FORCING WITH THE FRONT. LATEST MODEL
SOUNDINGS DEPICT 500-1500 JOULES OF MUCAPE AND STEEP LAPSE RATES
(>7.0C/KM). THERE IS SPORADIC SHEAR THOUGH, WITH THE HIGHEST
VALUES SHOWN OVER THE WESTERN ZONES. THE ECMWF HAS CONSISTENTLY
SHOWN A THETA-E TONGUE LIFTING INTO THE FAR EAST ON SUNDAY. LACK
OF SHEAR AND LOWER CAPE VALUES APPEAR TO BE INHIBITING FACTORS IN
THE EAST THOUGH.
THE LATEST FORECAST SAW A CONTINUATION IN THE DOWNWARD TREND OF
TOTAL PRECIPITATION AMOUNTS WITH THE TROUGH, SUNDAY THROUGH
WEDNESDAY. INSTEAD OF A WIDESPREAD RAIN EVENT, THIS LOOKS TO BE
MORE OF AN UNSETTLED START TO NEXT WEEK WITH COOLER TEMPERATURES
(60S-70S), WITH A DAILY CHANCE FOR SHOWERS. THE CURRENT FORECAST
HAS STORM TOTAL PRECIPITATION AMOUNTS OF 0.10" TO MORE THAN AN
INCH, WITH LOWEST AMOUNTS IN THE FAR EAST AND HIGHEST AMOUNTS IN
THE MOUNTAINS AND NORTHWESTERN ZONES. ENSEMBLES ARE TRYING TO SHOW
A WEAK UPPER LOW TRYING TO FORM OVER THE ROCKIES NEXT WEDNESDAY.
THE RESULT OF THIS COULD BE UPSLOPE FLOW AND ENHANCED
PRECIPITATION AMOUNTS IN THE MOUNTAINS AND FOOTHILLS, THOUGH THERE
IS STILL HIGH UNCERTAINTY.
SNOW LEVELS WILL DROP TO AROUND 8,000FT MONDAY NIGHT THROUGH
TUESDAY MORNING. THIS WILL ALLOW FOR ANY PRECIPITATION OVER THE
WESTERN MOUNTAINS TO BECOME SNOW. THE CURRENT FORECAST HAS LIGHT
ACCUMULATIONS UP TO A FEW INCHES MONDAY NIGHT THROUGH WEDNESDAY.
THIS MAY RESULT IN ADVERSE TRAVEL CONDITIONS ALONG THE BEARTOOTH
PASS AND US 212.
ANOTHER WARMING TREND IS SHOWN BY ENSEMBLES, NEXT THURSDAY WITH
TEMPERATURES CLIMBING BACK INTO THE 70S TO LOW 80S.
MATOS
AVIATION
00Z DISCUSSION...
A STRAY SHOWER IS POSSIBLE IN FAR EASTERN MT OVER THE NEXT 2-3
HOURS. (MAINLY NEAR KBHK). WINDS WILL GRADUALLY DIE DOWN OVERNIGHT
WITH ALL SITES SEEING LIGHT WINDS (<10KTS) BY 10Z. SKIES WILL
REMAIN MOSTLY CLEAR THROUGH THE PERIOD. WMR
PRELIMINARY POINT TEMP/POPS
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 052/086 059/086 055/065 046/065 046/072 050/077 053/079
00/U 02/T 76/T 44/T 23/T 11/B 12/T
LVM 048/086 057/082 050/064 041/062 040/068 045/072 047/076
00/U 06/T 97/T 45/T 23/T 12/T 13/T
HDN 049/085 054/086 054/064 046/066 044/072 047/077 051/080
00/U 01/U 66/T 44/W 33/W 12/T 22/T
MLS 050/084 054/090 056/067 047/069 047/073 050/079 053/081
00/U 00/U 56/T 32/W 12/W 11/B 11/B
4BQ 052/080 053/089 056/067 046/064 046/070 048/075 052/078
00/U 00/U 34/T 42/W 22/T 11/B 11/U
BHK 047/080 051/090 053/066 043/066 043/070 046/074 049/077
20/K 00/U 34/T 31/B 12/W 11/B 11/B
SHR 047/079 052/086 051/064 041/060 039/068 043/073 046/077
00/U 01/U 46/T 76/T 44/T 12/T 12/T
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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