815
FXUS65 KBYZ 042002
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
202 PM MDT Wed Jun 4 2025

.KEY MESSAGES...

- Scattered showers and isolated weak thunderstorms expected late
  this afternoon and evening, and again Thursday.

- Warming trend through the remainder of the week, with above
  normal temps returning Friday through the first half of next
  week.

- Rivers and streams are running high and fast, but recent cooler
  temps have slowed mountain snowmelt, resulting in decreasing
  flows through the middle of the week.

- The chance for showers and thunderstorms increases next Tuesday
  and Wednesday.

&&

.DISCUSSION...

Through Thursday night...

Satellite imagery shows broad troffing/cyclonic flow over the
region, with one shortwave exiting southeast MT into the Dakotas
and an upstream wave on the back side of the trof dropping thru
ID. As expected, weak diurnal convection has developed over the
past couple hours. Showers are most widespread (at this time) in
our east where mid level lapse rates are steepest (~7.5C/km), and
in fact the Baker airport reported a gust of 42 mph last hour.
Would expect greater shower coverage to shift to the west in
response to ascent from the next shortwave, but overall we are
looking at isolated to scattered showers and weak t-storms from
now through sunset. As the upstream wave reaches WY tonight,
precip will become enhanced along a mid level baroclinic zone
draped from WY to western SD/NE. Will keep low pops going thru the
night and into early Thursday in Sheridan County and along the
southeast MT/WY border...but in reality the much wetter conditions
will remain to our south.

On Thursday, yet another shortwave in the NW flow aloft will help
to produce another day of scattered showers and isolated t-storms
in the afternoon/evening. There is no chance of severe wx, but any
outdoor activities this evening and again tomorrow could be
impacted by brief moderate rain and breezy wind gusts. Late
Thursday night will be dry as this wave exits.

Temperatures will slowly moderate but remain a little cooler than
normal. Look for lows in the upper 30s and 40s, and highs Thursday
in the mid 60s to lower 70s.

Finally, there should be another push or two of lofted wildfire
smoke from the NW-N late tonight and Thursday and again Thursday
night. Do not expect any surface impacts, but occasionally hazy
skies (especially up in northeast MT).

JKL

Friday through Wednesday...

The long term forecast brings calm conditions and above average
temperatures. Temperatures Friday and Saturday are expected to be
in the high 70s to mid 80s F across southeast Montana. Sunday, a
500 mb trough will slide south to our east bringing cold air
advection. This will drop temperatures about 5 degrees across the
region with the largest drop near the Dakotas border.

Starting Monday, upper level ridging is expected to move back into
the region increasing temperatures into the low to mid 80s F.
The NBM is giving a 20-50% chance for high temperatures over 90 F
for locations east of Billings Monday and Tuesday. The next
chance for widespread precipitation will be next
Wednesday/Thursday as ensemble systems indicate an upper level
wave moving through. Little is known about this system at this
time. This potential system also brings more uncertainty in the
high temperature forecast, though a slight cooldown is currently
favored. Torgerson

&&

.AVIATION...

Scattered showers and isolated weak t-storms are expected over
the region late this afternoon and evening. The chance of a TS
directly impacting a TAF site is low (<20%) but winds could be
somewhat erratic at times. While VFR conditions will prevail, any
moderate shower or thunderstorm could produce brief MVFR
conditions. This shower activity will also obscure the mountains
at times. Scattered showers and a few weak t-storms are expected
again on Thursday, mainly in the afternoon and evening. JKL

&&

.PRELIMINARY POINT TEMP/POPS...

    Thu     Fri     Sat     Sun     Mon     Tue     Wed
-----------------------------------------------------------
BIL 046/071 048/079 055/081 054/079 053/085 057/088 059/084
    22/T    20/U    01/U    10/B    00/U    12/T    34/T
LVM 037/069 039/076 049/079 049/079 050/084 053/085 053/081
    23/T    10/U    00/U    10/U    01/U    13/T    45/T
HDN 045/072 045/079 053/081 053/078 049/084 051/088 057/086
    22/T    20/U    01/U    20/B    00/U    11/U    34/T
MLS 048/073 048/080 056/081 053/077 050/082 053/089 058/087
    22/T    10/U    01/B    20/U    00/U    11/U    33/W
4BQ 047/068 046/076 054/079 053/075 048/078 051/085 057/085
    23/T    20/U    01/B    20/B    00/U    11/U    22/T
BHK 042/070 042/076 051/079 046/073 043/076 048/084 052/083
    23/T    10/U    01/B    10/N    00/U    11/U    22/W
SHR 043/066 041/073 049/078 048/074 046/079 049/084 053/083
    26/T    21/U    01/U    21/B    01/U    12/T    35/T

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.

&&

$$
weather.gov/billings