199
FXUS65 KBYZ 220845
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
245 AM MDT Tue Apr 22 2025

.KEY MESSAGES...

- Fairly quiet today, with only a few isolated showers outside of
  the mountains.

- Chance of scattered showers/mtn snow Wednesday, increasing
  Thursday.

- Temperatures in the 50s through mid-week, maybe near 60 Friday
  and peaking near 70 Saturday.

- Another storm system taking shape for the weekend. Stay Tuned.

&&

.DISCUSSION...

Today through Wednesday night...

A few weak showers are lingering over the south and may persist
through the morning. Then, today will be fairly quiet ahead of
the next trough bringing an increased chance of precipitation to
the region Wednesday into Thursday.

Enough instability will be present for isolated (10-20% chance)
showers this afternoon from a line from near and north of
Harlowton to Roundup to Miles City. Moisture moving in will bring
scattered snow showers (20-40%) over the mountains by late
afternoon/early evening. As more moisture and more energy enters
the region, the chance for precip will gradually increase
Wednesday into Thursday. See the extended for more information on
precip for Thursday.

Currently, through Wednesday night, there is a 60% chance of at
least 4 inches of snow over the Beartooth/Absarokas and a 30%
chance over the Bighorns. Ahead of Thursday, the best chance for
accumulating precip over the plains will be south of US-12,
ranging from 30%(over the north) to 50% (over the south) chance
of at least 0.1" of moisture. Precip is expected to fall mostly as
rain below 6000 feet, although there will be brief windows during
the overnight hours to see light snow accumulate on grassy
surfaces over the foothills and higher hills, with a less than 20%
chance of seeing more than 1 inch of snow.

Conditions will be breezy today, with gusts in the 20s to low 30s
mph. High temperatures will be in the 50s to near 60 today and
Wednesday. Archer

Thursday through Monday...

Short wave trough within a mid level SW flow will track
over the our region Thursday. Ensemble means suggest best chance
of at least 0.25 of an inch is in the SE corner of the state
(78%),decreasing to the north/northwest where its only 6% chance
for Harlowton. Billings has about a 20% chance of at least a
quarter inch of rainfall. Look for a few inches of snowfall in
the high country with this system. Current model scenarios suggest
showers will lift north/northeast by Friday morning. An upper
ridge axis strengthens over the high plains Friday as an upper
trough digs into the west coast. Some weak perturbations will
continue to track across our southwest mountains, so a few
rain/snow showers are possible, but mainly over the high country.

As the aforementioned upper trough digs into the Great Basin of
Nevada and slides slowly east, we should see an increasing chance
of precipitation again Saturday through Sunday. Warm air advection
ahead of this system will boost temps to the 60s and lower 70s
Saturday. Diurnal instability combined with directional shear may
produce a few thunderstorms Saturday as well.

By Sunday, models agree the upper trough will be moving through
the central Rockies, with the trough axis moving across our CWA
Monday. As a result, the forecast for overall precipitation early
next week (Sun-Mon) has increased. Probability of at least 0.50
inch of precip is currently 40-60% across our region, which is
double from just 24 hrs ago. So anticipate a wet start to next
week, but keep an eye on the forecast for changes and details.

Temperatures will be on the cool-side Thursday with readings in
the 40s to lower 50s. Friday will be seasonal in the 50s to near
60. Readings range from lower 60s west to around 70 east on
Saturday before cooling up to 10 degrees Sunday into Monday. BT

&&

.AVIATION...

Localized fog is possible over eastern portions of the area early
this morning including the KMLS and KBHK areas. Otherwise, VFR
conditions will prevail over the plains today with occasional
mountain obscurations possible due to snow showers. BT
&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Wed     Thu     Fri     Sat     Sun     Mon
-------------------------------------------------------
BIL 057 038/053 040/049 038/057 039/068 046/062 045/057
    1/B 13/W    47/W    41/E    12/T    36/T    65/W
LVM 053 033/050 035/049 034/053 039/063 040/057 038/051
    2/U 23/W    36/W    42/W    23/T    37/T    66/W
HDN 058 035/056 039/050 037/058 039/071 044/063 044/057
    1/U 23/W    67/W    41/E    12/T    36/W    76/W
MLS 055 031/054 038/050 036/054 042/067 046/066 045/057
    2/W 01/E    46/W    32/W    22/T    34/T    65/W
4BQ 056 036/055 040/047 037/052 043/068 047/068 046/056
    0/B 11/E    68/W    32/W    12/T    24/W    55/W
BHK 055 026/054 033/047 032/051 037/064 043/066 042/057
    1/N 01/B    36/W    33/W    22/W    24/W    54/W
SHR 054 029/057 035/047 034/055 037/068 039/062 039/054
    2/W 23/W    78/W    51/E    22/T    25/T    66/W

&&

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

&&

$$
weather.gov/billings