624
FXUS65 KBYZ 222338
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
538 PM MDT Thu May 22 2025

.KEY MESSAGES...

- Periodic showers, a few afternoon and evening thunderstorms, and
  seasonable temps from late Thursday to Sunday.

- Memorial Day Forecast: Mostly sunny with a slight (20%) chance
  of showers/thunderstorms in the afternoon and evening; high
  temps in the lower 60s to mid 70s (coolest east).

- Temps back to near 80 degrees toward the middle of next week.

&&

.DISCUSSION...
Through Saturday Night...

A shortwave trough will approach the region this evening bringing
showers and thunderstorms to southeast Montana. High pressure to
our east and low pressure to the west will bring winds out of the
southeast advecting in moisture. The ECMWF Ensemble indicates PWAT
values near 0.75 inches, or 100-130% of normal for much of the
region today and throughout the weekend. Soundings indicate
instability will be limited today as peak heating and associated
lapse rates may not overlap with increased surface moisture. An
upper level jet will provide shear values of 40-50 kts bringing
the potential for strong thunderstorms. Widespread severe storms
are not expected. Showers and thunderstorms are expected to come
to an end Friday morning. The NBM is giving the best chances for
0.25 inches of precipitation to locations east of a line from
Ingomar to Broadus where there is a 30-50% chance. Locations
elsewhere generally have a 10-20% chance.

Another 500 mb wave will quickly follow bringing more
precipitation chances for the weekend. This wave will be deeper
but have weaker upper level flow allowing it to linger over the
region longer. Easterly upslope flow will continue to create
showers Saturday with 50-80% Pops across the region. The expected
weak upper level flow also indicates that strong thunderstorms
will be less of a risk Saturday with only general thunderstorms
expected. The best chances for precipitation will be locations
in Sheridan county where there is a 50% chance for an additional
0.25 inches of precipitation.

High temperatures will be in the 60s F for most of southeast
Montana with 50s F along the Dakotas border Friday and Saturday.

Torgerson




Sunday through Thursday...

Into Sunday, troughing over SE MT and north-central WY will
continue to provide showers over that area through Monday morning.
Additional accumulations of one to two tenths of precipitation can
be expected. Ensembles then look to bring in above average heights
and ridging for Monday through the remainder of the period. This
will allow for temperatures to warm through the week from the 60s
and 70s to the 70s and low 80s by mid week. There is still some
uncertainty in the track of the next low Tuesday and Wednesday,
but ensembles generally keep it off to the southwest to where is
wouldn`t affect the region. Weak energy under ridging could
provide small chances of daily showers, but nothing strong is
expected. Precipitation chances (20-40%) return late Thursday as
the next shortwave trough approaches. TS

&&

.AVIATION...

00z Discussion...

Scattered SHRA moving through the area this evening. The precip
should be out of most sites by 07z with but lingering near
KMLS/KBHK through 12-13z. Some TSRA are possible SW of Billings
near KLVM and K6S0. Gusty winds will die down with these showers
before returning Friday afternoon. Gusts should stay under 30kts
at all sites. Mountains will be obscured through 10z. WMR
&&

.PRELIMINARY POINT TEMP/POPS...

    Fri     Sat     Sun     Mon     Tue     Wed     Thu
-----------------------------------------------------------
BIL 046/066 045/066 046/070 046/075 049/075 050/077 052/081
    53/W    36/W    22/W    01/U    12/W    12/W    13/T
LVM 040/066 043/066 042/070 044/075 048/075 047/076 049/080
    75/W    46/T    11/U    01/U    23/T    22/W    24/T
HDN 045/066 044/066 044/069 045/076 048/076 048/079 050/082
    42/W    36/W    23/W    11/U    12/W    22/W    22/W
MLS 048/058 044/064 046/066 046/069 047/072 049/076 050/081
    63/T    25/W    23/W    11/U    11/U    11/U    12/W
4BQ 045/063 046/061 047/062 046/067 046/071 048/073 049/077
    71/B    26/W    34/W    11/B    11/U    12/W    12/W
BHK 042/053 040/057 042/060 042/063 043/066 043/071 046/074
    64/W    24/W    33/W    11/B    11/B    11/U    11/U
SHR 040/066 042/060 041/065 041/071 043/072 044/074 046/078
    53/W    49/T    45/W    12/T    12/T    23/W    13/W

&&

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

&&

$$
weather.gov/billings