548
FXUS65 KBYZ 020351
AFDBYZ
Area Forecast Discussion...Updated
National Weather Service Billings MT
951 PM MDT Sun Jun 1 2025
.KEY MESSAGES...
- Unsettled and cooler Monday through Wednesday.
- Winter Weather Advisory in effect beginning 9AM Monday for the
Beartooth Highway. Total accumulations of 1 to 4 inches, mainly
above 7,500 feet, will impact travel.
- Rivers and streams are running high and fast with snowmelt. No
flooding is forecast at this time, but additional rises are
expected through early week due to precipitation. Please use
extra caution near waterways and keep children a safe distance
away from the waters edge.
&&
.UPDATE...
The severe weather threat has come to an end across much of the
area with the loss of daytime instability. The one area to
continue to watch is over far south-eastern Montana (mainly Carter
County) where a strong storm or two could still occur this
evening. Otherwise, showers and isolated thunderstorms continue to
progress through the area late this evening and will continue to
do so into tonight. While there will likely be a break in the
precipitation tonight over south-central Montana and north-central
Wyoming, another round of precipitation looks to move into the
area Monday morning as the axis of an upper level trough
progresses through the region. The forecast for Monday onward
remains in good shape. Arends
&&
.DISCUSSION...
Rest of today through Monday night...
A surface cold front has swept through the region this morning,
shifting winds to the north-northwest and producing gusts in the
25-40 mph range. Locations in the northwestern zones have likely
seen their highest temperatures for the day, with Judith Gap
sitting at 58F now after reaching 68F earlier this morning.
Elsewhere, temps are in the 70s and 80s.
Isolated strong to severe thunderstorms are still forecast, mainly
west of Billings this afternoon. Convective initiation is
depicted around/after 2pm, over the ID/WY/MT borders. Some
environmental parameters are not very favorable such as MUCAPE
values around 500 J/kg and DCAPE around 800 J/kg in the west.
Favorable parameters include steep lapse rates (>7.5 C/km) and 40+
knots of bulk shear. With these conditions, the primary threats
are strong winds and hail as large as quarters. Heavy rainfall is
a secondary threat. Expect storms to decrease in strength going
into the evening hours, becoming more widespread across the area
as an upper trough slowly pushes east.
As the upper level trough moves east through Monday, a shortwave
is depicted dropping into the region, bringing another round of
showers and thunderstorms. Upslope flow will accompany this wave,
bringing favorable upslope flow to the mountains and foothills.
Storm total precipitation through Monday is greater than 0.25"
from Miles City to Fort Smith and west. Lower totals between 0.1
and 0.25" in the east. The mountains and western foothills are set
to receive the highest precipitation totals, greater than 0.75".
Precipitation will diminish Monday night, with a few lingering
showers and a weak thunderstorm or two.
Temperatures will be cooler than normal on Monday, with highs in
the 50s and 60s. Monday night lows will be in the 30s and 40s
across lower elevations and around to below 32F in the mountains.
Snow levels will drop to around 7,000ft by Tuesday morning but the
bulk of precipitation is set to fall overnight Monday.
Accumulating snowfall is forecast generally above 7,500ft
resulting in impacts to the Beartooth Pass. A Winter Weather
Advisory will go into effect at 9AM Monday and end at 6AM
Wednesday for the Beartooth Highway, with total accumulations of 2
to 4 inches of snow forecast.
Rivers and streams continue to run high with high elevation snow
melt from the past few days. Additional precipitation will
contribute to rises but flooding is not expected at this time.
Matos
Tuesday through Sunday...
Cyclonic flow over the region will keep shower chances in the
forecast on Tuesday, mainly over the southern mountains and
foothills (20-60% chance, highest over the mountains). An
additional shortwave is progged to drop through ID/western MT into
northern Wyoming, skirting across the MT/WY border Tuesday night
and Wednesday. This will bring more shower and thunderstorm
potential (20-70% chance, highest over the southern mountains and
far southeast MT. Guidance continues to struggle with how far
north the precipitation with this wave makes it into our area,
keeping it either over the southern mountains and foothills, or
lifting it farther north into southeast MT. Currently, the
probability of receiving 0.25 inches or more of liquid
precipitation for Tuesday and Wednesday is around 20-40%, highest
over the Bighorns and Sheridan County. A few inches of snow are
possible in the Bighorns above 8000 feet.
Beyond Wednesday, the weather pattern looks to remain unsettled,
as additional weak shortwaves are progged to pass through the
region at times bringing shower and thunderstorm chances (15-30%).
Temperatures are forecast to range from the 60s to around 70
degrees on Wednesday, warming into the 70s for Thursday, and 70s
to lower 80s through the remainder of the extended. STP
&&
.AVIATION...
03z Discussion...
A cold front is dropping through the region bringing a shift to
northerly winds with wind gusts of 25-35 kts. Periods of rain
showers will continue overnight tonight into Monday. SHRA will
linger for the entire period for most locations. Mountains will
be obscured at times.
Additionally, a G4 geomagnetic storm is forecast by the SWPC.
This could potentially have impacts on high altitude air traffic
as well as radio communications. More information can be found at
swpc.noaa.gov. STP/WMR
&&
.PRELIMINARY POINT TEMP/POPS...
Mon Tue Wed Thu Fri Sat Sun
-----------------------------------------------------------
BIL 050/059 042/066 046/070 048/074 052/079 055/081 054/079
68/T 11/B 23/T 12/T 12/T 23/T 32/T
LVM 047/060 036/063 039/067 043/071 046/075 049/077 048/077
76/T 23/W 33/T 13/T 23/T 22/T 22/T
HDN 051/059 042/067 045/070 046/075 050/079 053/082 052/079
67/T 11/B 23/T 12/T 12/T 23/T 32/T
MLS 051/059 043/069 046/071 048/075 051/082 055/082 054/078
58/T 11/U 13/T 11/B 11/U 22/T 31/B
4BQ 053/059 043/065 047/064 045/071 049/076 053/079 053/077
45/W 10/B 24/T 11/B 22/T 22/T 31/B
BHK 050/058 040/068 042/069 043/071 047/076 051/078 049/074
45/T 10/U 03/T 12/W 12/W 22/T 21/B
SHR 049/058 040/062 042/064 042/071 045/074 048/077 048/075
36/W 23/T 56/T 13/T 23/T 23/T 32/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings