Livingston, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

024
FXUS65 KBYZ 172018
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
218 PM MDT Sat May 17 2025

.KEY MESSAGES...

- Scattered showers and a few thunderstorms over the west half of
  our forecast area this evening.

- Showers and thunderstorms become more numerous on Sunday.
  Stronger storms could produce localized heavy rain. Southeast
  winds will gust 40-50 mph from Baker to Ekalaka Sunday.

- Areas of moderate precipitation will become more widespread
  Sunday night into Monday. Precipitation will come to an end from
  west to east later Monday into Tuesday.

- Significant rainfall totals Sunday into Monday may cause
  localized flooding over recent burn scars and areas with
  saturated ground. Increased flows on area waterways can also be
  expected.

&&

.DISCUSSION...
Through Monday Night...

Satellite imagery shows a deepening trof over the Pacific coastal
states with mid level flow backing to the southwest across the
Rockies. This pattern is inducing easterly low level winds across
the plains which may be producing some capping effect, but some
weak forcing from diffluence and height falls is developing in SW
Montana with some showers popping up in our far western zones.
This trend will continue with any convection tracking north as
southerly flow strengthens this evening, thus keeping the bulk of
any precipitation over the western half of our CWA, mainly from
Yellowstone County westward this evening. CAPE is modest (<500
J/kg) and shear weak, so we are not expecting any strong strong
thunderstorms within this activity.

Surface low develops overnight into Sunday across north central
Wyoming with an inverted surface trough extending north (Sheridan
to east of Roundup). Expect to see showers/some thunder with
cooler conditions on west side of this inverted trough, and a warm
sector under it over the Big Horns into south central Montana.
MUCAPE values push 750-1000 J/kg across the Big Horns into SE MT
by early afternoon. As heights falls and cooler air slowly push
east, there are hints of some stronger convection developing in
this warm unstable sector with strong low level convergence.
Convective feedback with PWATS around 0.80 inches suggest heavy
rain (and possibly some small hail) is possible with some of the
scattered to numerous storms that develop. Thus, the Flood Watch
over the Big Horns region, where saturated ground is likely to be
found, still looks prudent for tomorrow.

As a complex pattern evolves over the region Sunday night into
Monday (deep cyclonic flow with two lows pin-wheeling around from
the Great Basin to the Nebraska panhandle). This will produce
areas of moderate to heavy rainfall over our CWA, and possibly
some periods where areas get dry slotted. Ensembles continue to
show a great deal of spread in placement and amounts of
precipitation, but are consistently hitting the Big Horns north
to the Snowies with 1 to 1.5 inches of rainfall through the
event. The Big Horns area has the best chance (30%) of seeing up
to 2 inches of liquid through Monday. Thus, the Flood Watch looks
good to go through Monday in this area.

The upper trough complex eventually moves out into the central
plains by Monday evening with rainfall decreasing from west to
east over our forecast area.

A few other items...Pressure falls in our central zones on
Sunday will allow for increasing SE winds over our east, strongest
near the Dakotas line. Current indications are for 40-50 mph
gusts from Baker to Ekalaka. There is a 50-70% chance of gusts
reaching 50 mph in this area. Snow levels will initially be over
9000 ft Sunday, but fall to around 6500 ft in the Beartooths by
Monday and to around 7000 ft in the Big Horns by Monday
afternoon. Thus, the high country may see some decent wet
snowfall with 5-10 inches possible over the higher Beartooths,
and 4-8 inches possible in the higher Big Horns. Next couple of
shifts will monitor for winter highlights, but for now there is
much uncertainty with snowfall (ensembles range from 1 to 7
inches for Burgess Junction).

Temps on Sunday will max out in the mid 50s west to lower 70s
central and east, warmest in an area from Billings-Sheridan to
Miles City-Broadus. BT

Tuesday through Saturday...

Into Tuesday, the upper level low will depart to the east,
bringing precip chances to eastern MT. Ensembles have the next
shortwave coming into the west Tuesday evening through Wednesday.
There is still disagreement in precip amounts, but there is a low
to moderate chance for a quarter inch of precip through Wednesday
night. Additional disturbances will pass through Thursday and for
the weekend with the weekend system looking more promising as far
as moisture. In short, conditions will remain unsettled through
next week with daily precipitation chances. High temperatures will
be around average with highs in the upper 50s to low 70s. TS

&&

.AVIATION...

Scattered showers with a few thunderstorms will develop this
afternoon and evening. A small chance (20%) of thunderstorms is
mainly for KLVM. Breezy SW winds will ramp up late this evening
for SE MT (KMLS) with gusts of 25-35 kts through Sunday. TS

&&

.PRELIMINARY POINT TEMP/POPS...

    Sun     Mon     Tue     Wed     Thu     Fri     Sat
-----------------------------------------------------------
BIL 050/065 045/052 042/066 043/066 046/070 047/069 048/069
    29/T    97/W    45/W    53/T    25/T    43/T    34/T
LVM 045/054 035/058 038/061 037/064 041/067 041/068 043/064
    5+/T    64/W    26/W    62/T    25/T    33/T    34/T
HDN 050/070 043/050 040/064 041/066 044/071 045/070 046/070
    29/T    +8/W    55/W    54/T    25/W    44/T    44/T
MLS 048/068 044/050 041/059 040/065 043/071 047/068 047/071
    25/T    +9/W    75/W    34/W    24/W    43/W    43/W
4BQ 047/069 043/046 040/058 039/063 043/071 046/068 047/070
    16/T    99/W    74/W    33/T    13/W    43/T    33/T
BHK 041/056 038/046 035/052 035/061 037/068 043/066 043/067
    24/T    99/W    86/W    43/W    23/W    43/W    32/W
SHR 044/069 038/047 037/062 036/062 039/072 041/069 043/070
    18/T    +9/W    55/W    55/T    14/T    34/T    34/T

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Flood Watch in effect from Sunday afternoon through Monday
      afternoon FOR ZONES 138-169-171.
WY...Flood Watch in effect from Sunday afternoon through Monday
      afternoon FOR ZONES 198-199.

&&

$$
weather.gov/billings