904
FXUS65 KBYZ 301920
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
120 PM MDT Sat Aug 30 2025

.KEY MESSAGES...

- Isolated showers and thunderstorms through this evening.
  Locally heavy rain is possible, mainly east of Billings.

- Warmer and mostly dry Sunday through Tuesday.

- Late Tuesday cold front brings cooler temps Wednesday and
  Thursday, but mostly dry weather continues.


&&

.DISCUSSION...
Through Monday Night...

The pesky low that has lingered across the region for the past
several days is finally forecast to be pushed out of the area late
today as a ridge continues to build across ID and MT. In the short
term though, scattered showers and storms will linger across the
eastern 2/3 of the CWA through this evening. CAMs have not been
picking up on the ongoing showers and convection well at all and
thus the models that want to dry out eastern MT cannot be
believed. A weak convergent boundary currently around Rosebud Co.
will likely be the focus of precipitation this afternoon as it
pivots with the parent low before being ushered out overnight
tonight. Some localized flooding remains possible today due to the
saturated ground, climatologically high PWATs, and slow moving
storms.

Sunday will be the start of the warm and dry period for much of
the area as the previously mentioned ridge continues to build.
High temps 5-10F above average seems to be the consensus amongst
the mid range models but keeping temps region-wide under 90F
across the CWA. A small vort max is progged to move along the jet
through far Eastern Montana saturday which could bring some
isolated to scattered showers and storms in the eastern zones of
the CWA in places such as Baker. Models do not seem to show any
precip with this feature, however, given the poor resolution of
the current precip, they could be a little too conservative.

Ridging will continue to dominate Monday with temps roughly 10F
above average across the CWA. It will also likely be the first
all dry day across the region in nearly a week! WMR


Tuesday through Saturday...

Upper ridge axis will be over the western CONUS on Tuesday
placing our CWA under a dry NW flow. Afternoon highs will be in
the mid to upper 80s for most locations. However, models still
indicate a backdoor cold front dropping south late in the day into
the high plains from Saskatchewan. Latest deterministic model
data shows the front into portions of east central Montana
(northern Rosebud, Custer, Fallon) late in the afternoon. So look
for winds shifting from westerly to north/northeast by evening.
Surface pressure rises are on order of 4 mb/6 hr...so some gusts
20-25 mph are possible. This does not seem like an overly wet
frontal passage, and we have PoPs 15-30% over the east through the
overnight hours.

Highs on Wednesday will be around 10 degrees cooler than Tuesday,
in the 70s for most locations. With this cooling trend, lows
Thursday morning will range from lower 40s east to lower 50s west.
Isolated showers are possible Wednesday, mainly along and over
the northeast facing mtn slopes due to upslope.

Upper level ridging gradually builds back into central and
eastern Montana the remainder of the week. This will mean dry
conditions with a gradual warming trend back into the mid to
upper 80s by Saturday. BT
&&

.AVIATION...

18z Discussion...

Scattered SHRA and TSRA will continue this afternoon and evening
for most sites with KMLS and KSHR having the highest chance of
seeing precipitation at the terminal (30-40%). After 00z expect
the entire forecast region to dry out. Some FG is possible in far
eastern MT (near KBHK) Sunday morning between 09z and 13z but
chances remain low (20-30%). Mountains will be partially obscured
for most of the period. The Bighorns near KSHR will be fully
obscured through 00z. WMR
&&

.PRELIMINARY POINT TEMP/POPS...

    Sun     Mon     Tue     Wed     Thu     Fri     Sat
-----------------------------------------------------------
BIL 056/088 058/088 057/088 055/075 051/082 052/084 055/088
    20/U    00/U    00/U    10/B    00/B    00/U    01/U
LVM 048/085 050/086 050/087 048/080 048/083 048/085 050/085
    00/U    00/U    00/U    01/U    00/U    01/U    12/W
HDN 052/088 053/089 053/088 052/075 045/081 048/084 050/088
    20/U    00/U    00/U    10/B    00/B    00/U    01/U
MLS 055/084 055/088 056/086 050/070 043/077 048/079 050/084
    22/W    00/U    00/U    10/B    00/B    00/U    00/U
4BQ 053/080 055/084 056/083 052/068 044/074 049/078 051/083
    20/U    00/U    00/U    20/B    00/B    00/U    00/U
BHK 052/079 052/086 053/080 044/067 038/074 044/077 046/081
    22/W    00/U    01/B    20/B    00/B    00/U    00/U
SHR 049/083 051/085 050/085 049/072 043/078 046/080 049/085
    20/U    00/U    00/U    11/B    00/B    00/U    01/U

&&

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

&&

$$
weather.gov/billings