019
FXUS65 KBYZ 150203
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
803 PM MDT Wed May 14 2025

.KEY MESSAGES...

- Midweek precipitation may add to elevated water levels on rivers
  and streams along the foothills, although rises due to snowmelt
  will end.

- Widespread precipitation and normal to below normal temperatures
  will continue through Thursday. Additional heavy snowfall (10 to
  20 inches) in the western mountains and an additional 0.25 to 1
  inch of liquid precipitation over the western foothills is
  expected.

- Potential cool and wet system late this weekend/early next
  week.

&&

.DISCUSSION...
.8pm UPDATE...
Overall there is no major changes to the forecast. There have
been a few reports of cold air funnels in the mountain foothills
associated with some of the storms. Single cell "pulse like"
storms continue to pop up acros the western 2/3 of the CWA. This
is expected to die down as the upper low pushes off to the east
and more widespread synoptic precipitation moves into the region.

Tomorrow morning, as the low continues eastwards, some steady
moderate rain could occur in Carter and Fallon counties and
linger into the afternoon. Scattered showers and storms will
continue across much of the region throughout the day Thursday as
well. WMR

&& Rest of Today through Thursday night...

.DISCUSSION...

Upper low is over south-central Montana currently. Showers and
weak thunderstorms are wrapping around the low across the area.
Additional precipitation accumulations are forecast across the
area through Thursday. Amounts are in the range of 0.10 to over an
inch, with the highest amounts in the western mountains and
foothills. The upper low begins to shift east and phase with
another low over the northern Midwest tonight, this will bring an
increased chance for precipitation to the far east into Friday.
The current forecast has 0.20 to 0.70 inches of liquid
precipitation with the highest totals near Baker.

Periods of heavy snow will continue above 7,000ft in the western
mountains into Thursday morning. The Winter Storm Warning has been
extended to 6am Thursday, with additional accumulations of 10 to
20 inches forecast. The greatest totals will fall on north-facing
slopes. As for the Winter Weather Advisory in the Pryor/Bighorn
mountains, snow will resume tonight, with additional accumulations
of 2-5 inches, with locally greater amounts on the highest peaks.
Those with recreation or travel plans across any of the mountain
ranges should be prepared for adverse conditions.

As the upper low departs the region, increasing WNW winds will
spread across the area, with gusts of 20-40 mph. The highest
gusts are forecast in Carter and Fallon counties tomorrow
afternoon, in the 40-50s mph.

Brief shortwave ridge approaches Friday, high temperatures will be
near to below normal, 50s to mid 60s.

In the short-term forecast period, hydrological concerns remain in
check, for further information please view the latest ESF.

Matos



Friday through Tuesday...

Shortwave ridging building into the region will bring drier
conditions for western and central areas for the first part of the
day on Friday, while the east could see wrap around precipitation
from the low continuing to slide east through the upper Plains
(30-50% chance). Gusty northwest winds of 30-45 mph are possible
over the far east. The next shortwave moving into the west will
bring showers and isolated thunderstorms to western areas Friday
afternoon/evening (30-60% chance). Overall drier conditions are
forecast for Saturday, while showers are possible over the
southwest mountains during the afternoon and evening (30-60%
chance) as diffluent southwest flow works over the area, ahead of
the next approaching system.

Sunday into Tuesday, model ensemble solutions largely agree on
the large-scale pattern of an upper trough and associated upper
low moving from the Pacific Northwest to the central Rockies. What
is unknown is the track and evolution of the low thereafter. Either
taking the track of the low through the region, or remaining
farther to the south with more of a split flow to the north.
Regardless, this pattern would bring periods of showers and weak
thunderstorms to the lower elevations, and snow to the higher
terrain. Precipitation amounts and snow amounts, including snow
levels (varying between 5000-8000 feet) remain uncertain.
There remains a high (70-100%) chance of precipitation over the
area, highest near the mountains and foothills. The latest NBM
gives a 60-90% chance at exceeding a half an inch of liquid
precipitation from Sunday through Monday, with an inch or more at
30-60%, highest over the Bighorns and into southeast Montana.
Several inches of snow are possible in the mountains. Given recent
moisture, and another period of potentially significant
precipitation on the horizon, area waterways may continue to run
high, with additional rises possible. Will be monitoring for any
potential flood products over the coming days.

Temperatures are forecast to range from the 50s to lower 60s
Friday, warming into the 60s for Saturday and Sunday, dropping
into the 50s to lower 60s for Monday and Tuesday. Low
temperatures in the upper 30s to 40s are forecast most
nights/mornings. STP

&&

.AVIATION...


Widespread rain showers will continue to fill in across all
terminals tonight. Isolated to scattered thunderstorms are
possible west of KMLS through 04z. Showers and thunderstorms may
briefly reduce flight conditions down to MVFR-IFR through the
period. Gusty WNW winds between 20-45 knots will spread across
the region before sunrise tomorrow, with the highest gusts around
KBHK and K97M. As the winds increase, precipitation coverage will
decrease, but not end. Chambers

&&

.PRELIMINARY POINT TEMP/POPS...

    Thu     Fri     Sat     Sun     Mon     Tue     Wed
-----------------------------------------------------------
BIL 045/062 043/063 045/066 048/065 047/057 044/063 045/063
    64/T    24/W    45/T    48/T    98/W    66/T    55/T
LVM 039/057 034/060 040/064 043/057 041/056 039/060 037/059
    73/T    26/T    66/T    69/T    97/W    56/T    44/T
HDN 044/062 042/063 043/068 047/068 046/057 042/063 043/063
    44/T    24/W    35/T    37/T    99/W    77/W    66/T
MLS 045/062 046/060 042/064 045/064 046/057 042/062 043/063
    32/T    34/W    13/W    36/W    89/W    77/W    55/W
4BQ 045/059 045/058 041/064 045/065 046/056 042/058 043/059
    32/T    34/W    13/T    46/T    99/W    77/W    45/T
BHK 042/053 040/056 035/062 040/060 041/058 039/058 038/062
    47/T    55/W    21/B    34/W    89/W    87/W    44/W
SHR 039/060 039/060 037/066 042/068 043/056 039/061 038/059
    34/T    25/W    25/T    48/T    99/W    77/T    56/T

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Storm Warning in effect until 6 AM MDT Thursday FOR
      ZONES 67-68.
     Winter Weather Advisory in effect until 6 AM MDT Friday FOR
      ZONE 171.
WY...Winter Weather Advisory in effect until 6 AM MDT Friday FOR
      ZONE 198.

&&

$$
weather.gov/billings