639
FXUS65 KBYZ 042008
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
208 PM MDT Fri Jul 4 2025

.KEY MESSAGES...

- Cooler temperatures Today into Sunday.

- 30-60 percent chance of showers and thunderstorms this afternoon
  and evening. Severe thunderstorm chances are low. Not a wash
  out for fireworks activities.

- Scattered strong to severe thunderstorms possible Saturday
  afternoon and evening. Be weather aware and have plans to seek
  shelter if storms approach.

- Hot and mainly Dry next week, 90s to near 100 Tuesday through
  Thursday.

&&

.DISCUSSION...

Through Saturday night...

Isolated showers were lingering over eastern areas early this
afternoon as one wave lifted into the Dakotas, and another
shortwave lifted into the region from the southwest. Energy from
the shortwave and upper diffluence was spreading into the area,
bringing showers and thunderstorms to the southern mountains.
Scattered showers and thunderstorms (30-60% chance) will spread
southwest to northeast over the area this afternoon and evening.
Convection looks to wind down by 10pm for most areas, lingering
over northern areas into the overnight hours. Strongest
thunderstorms will be capable of gusty winds, small hail and brief
heavy rain. If storms approach please postpone outdoor activities
and head indoors until storms pass.

A stronger Pacific trough is expected to move through the region
on Saturday, bringing scattered to numerous showers and
thunderstorms (40-80% chance) to the area during the afternoon and
evening hours. Thunderstorms will decrease into Saturday night.
MUCAPE will increase towards 1000 J/kg Saturday afternoon with
deep layer shear of 30-50 kts. This, combined with the forcing
from the trough will bring the potential for strong to severe
thunderstorms during the afternoon and evening. Greatest threats
are large hail and strong wind gusts. SPC currently has a slight
risk for severe thunderstorms Saturday afternoon and evening. Those
with outdoor plans Saturday should pay close attention to the
weather and have a plan to seek shelter if storms approach.

Cooler Pacific air will keep temperatures in the 70s over the
west, to lower 80s over the east on Saturday. STP

Sunday through Friday...

The upper level trough will exit the region Sunday, giving way to
weak westerly flow before ridging begins to build in Monday.

Enough moisture will remain for isolated showers and thunderstorms
(10-30% chance) through Monday afternoon, with the best chance
over the mountains and over the southeastern corner of the region.
As ridging builds in, precipitation becomes less likely, with
generally a 15% or less chance Tuesday and Wednesday afternoon.

Under the ridge, temperatures will warm, with highs increasing
from upper 70s to mid 80s Sunday to mid 90s to triple digits
Wednesday. The best chance (30-50%) for temperatures above 100
will be along river valleys from Billings east. Lower relative
humidities will accompany these temperatures, with many locations
falling into the teens Tuesday and Wednesday. No breezy
conditions are expected at this time, but still take care not to
cause a spark!

For the end of the week, models have come into better agreement
for a weak disturbance to move through the region, bringing
scattered showers and thunderstorms (20-40% chance), although the
exact timing is still uncertain. Archer

&&

.AVIATION...

Scattered showers and thunderstorms will spread over the area from
the southwest to northeast this afternoon and evening. Isolated
showers and thunderstorms will linger over northern areas into the
overnight hours. Period of greatest thunderstorm coverage is
between 21-03z. Strong wind gusts to 45kts will be the main
threat with this afternoon and evening convective period. Outside
of local MVFR conditions near stronger thunderstorms, VFR
conditions will prevail. STP

&&

.PRELIMINARY POINT TEMP/POPS...

    Sat     Sun     Mon     Tue     Wed     Thu     Fri
-----------------------------------------------------------
BIL 058/083 055/082 058/088 061/096 063/098 062/089 060/085
    36/T    40/U    10/U    00/U    00/U    11/B    21/U
LVM 048/076 045/081 049/087 052/093 055/093 055/085 051/083
    57/T    20/U    01/U    10/U    11/U    11/B    21/U
HDN 058/085 054/084 055/090 058/097 060/099 060/090 058/086
    55/T    60/U    10/U    00/U    00/U    11/B    21/U
MLS 062/086 057/082 058/089 061/097 065/099 065/091 060/086
    45/T    81/U    11/U    00/U    00/U    10/B    11/U
4BQ 061/086 057/079 059/086 062/094 064/097 065/090 060/083
    45/T    81/U    21/U    10/U    10/U    10/B    21/U
BHK 057/083 055/078 055/085 057/091 060/095 060/090 057/085
    43/T    82/T    11/U    11/U    10/U    11/B    21/U
SHR 053/085 049/081 051/086 055/093 057/096 057/087 055/081
    35/T    41/U    11/U    01/U    01/U    11/B    22/T

&&

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

&&

$$
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