National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS65 KBYZ 240918
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
318 AM MDT Wed Apr 24 2024

.DISCUSSION...

Today through Thursday night...

Flat ridging in place over the central and northern Rockies at
the moment, with a slowly deepening trough over British Columbia.
As the ridge gives way to the approaching trough, the weather will
transition from quiet today, to more active Thursday and Thursday
night.

Temperatures will be above seasonal values today with highs in
the lower to mid 70s. Humidity values will fall into the teens to
lower 20s. Winds will be generally light, with the strongest winds
(10-20 mph gusts to 25 mph) over the far southeast zones (Carter
and Fallon counties). Given the lack of prolonged strong winds,
will not mention any fire weather concerns, despite above normal
temperatures and low humidities.

Backing flow over western zones will allow weak energy and mid
level moisture to creep in. Elevated cape (albeit weak) slides
into the west at the time of moisture and energy influx. This
takes place this evening and tonight and have a low chance (20% or
less) of showers over the far western zones (with most of the
activity in the higher terrain).

Flow continues to back on Thursday. This will allow deeper
moisture to move into all zones (as evidenced by precipitable
water values increasing to 0.60 over western zones, 0.70 over
central zones and around 0.80 over the east. Cape values will rise
to around around 200 j/kg over central and west, with much larger
values (700-900 j/kg) over the east. An ejecting low from the
Desert Southwest will trigger ascent over eastern Wyoming, the
western Dakotas and eastern Montana, Thursday afternoon and night.
Cape values would support stronger storms but weak shear should
prevent organized strong storms. Could see stronger pulse type
storms over Carter and Fallon counties Thursday afternoon and
evening. Models have focused over the western Dakotas as the
strongest storm potential but storms could certainly initiate over
the far southeast zones of southern Montana (especially with an
inverted surface trough poking into Carter and Fallon counties).
SPC keeps the marginal risk just southeast of the area, but bears
watching.

Western and central zones have weaker cape but better shear, so
expect more organized showers, with a few thundestorms forming.
Expect showers to form easily Thursday afternoon with tall and
skinny cape, with a slow eastward progression. Showers will
eventually translate into central zones (including Billings)
Thursday evening and overnight. Increasing PWATs will give the
potential for locally heavy rain with any shower. Snow levels will
be around 8 thousand feet to start the day, but fall to around 7
thousand feet overnight. Mountains above 7 thousand feet should
get a quick 2-4 inches of wet accumulation. TWH

Friday through Wednesday...

If you have outdoor plans Friday, Saturday, or Sunday, make sure
to stay weather aware and up-to-date with the most recent
forecasts. Wet conditions with rain over the lower elevations and
snow over the mountains is in the forecast.

The best chance for more persistent precipitation Friday into
Sunday is over south-central MT (mainly the mountains and
foothills, not including Billings) and far southeast MT (mainly
Carter County). At this time, these areas continue to have a
50-90% chance of seeing at least half an inch of liquid
precipitation (rain/melted snow) Friday into Sunday. Between these
areas, think Yellowstone County through Custer County, a drier
slot is likely, especially during the day Friday. This dry slot is
where the most uncertainty in total precipitation amounts remains
though, with a multi- day QPF spread anywhere from zero
precipitation to nearly a half inch. In the end, the precipitation
that does fall over the lower elevations looks to be more
beneficial than hazardous, with the main threat just being
periods of heavier rain. Carter and Fallon counties could have a
rumble of thunder Friday afternoon and evening, but the chance
remains low with only weak instability in place.

As far as the mountains go, all snow is expected above 7000 to
8000 feet. From Friday through Sunday, there is a 50-90% chance to
see 8 or more inches of snow above these areas. Therefore, if you
have plans in the high country this weekend, plan for winter
weather conditions. With this event, we are also not looking at a
rain on snow scenario, but rises in small streams is possible with
the persistent stream of moisture into the region.

Monday through Wednesday next week will be drier, but chances of
precipitation will remain each day with troughing over the west
coast allowing waves of energy and moisture to move through.

High temperatures are forecast to range from the 50s to upper 60s
Friday, 50s to lower 60s Saturday and Sunday, and 60s to lower
70s Monday through Wednesday. Arends

&&

.AVIATION...

VFR conditions will prevail across the area today. Expect mid to
high clouds to increase from the southwest this evening. With the
increasing cloud cover, low chances of precipitation are forecast
over KLVM and the Beartooth/Absarokas this evening through
tonight. Expect chances of precipitation, and weak thunderstorms,
to increase Thursday. Arends

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Thu     Fri     Sat     Sun     Mon     Tue
-------------------------------------------------------
BIL 074 046/069 048/060 043/056 041/061 042/067 041/064
    0/U 13/W    46/R    67/R    44/R    13/R    33/R
LVM 074 042/064 043/053 040/050 036/059 038/060 036/058
    0/B 17/T    79/R    88/R    54/T    14/R    44/R
HDN 076 044/073 046/065 043/058 040/062 040/070 040/066
    0/U 02/W    45/R    56/R    44/R    13/R    43/R
MLS 075 044/074 047/069 044/058 039/057 037/068 041/064
    0/U 02/W    24/R    43/R    22/R    01/B    31/B
4BQ 075 046/075 048/066 044/053 039/054 037/067 041/066
    0/U 03/T    35/R    55/R    43/R    01/U    21/B
BHK 074 040/074 045/063 040/053 034/052 033/065 039/064
    0/U 04/T    47/T    54/R    33/R    11/B    21/B
SHR 075 042/069 044/060 041/051 036/057 035/065 037/065
    0/U 14/T    57/R    78/R    55/R    12/R    33/R

&&

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

&&

$$
weather.gov/billings