857
FXUS65 KBYZ 080759
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
159 AM MDT Tue Jul 8 2025

.KEY MESSAGES...

- Hot temperatures Today and Wednesday (upper 80s to 102). Heat
  Advisory some areas Wednesday.

- Isolated Dry thunderstorms with strong wind gust potential
  Wednesday afternoon/evening.

- Cold front brings precipitation chances Thursday and Friday;
  Highs in the 70s Friday.

- Accumulating snow possible above 10kft Thursday night
  (Beartooth Highway).

- Warmer next weekend, but low confidence forecast Sunday-Tuesday.


&&

.DISCUSSION...

Through Wednesday night...

Heat is the word for the short term. Ridging aloft with plenty of
sun, and stronger mid level zonal downslope flow will help boost
temperatures well into the 90s today. Can`t rule out a few triple
digits over central areas. Pre-frontal warming Wednesday will add
a few degrees to todays readings, with triple digits in the
forecast for most locations from Yellowstone county east to Custer
and Powder River counties. NBM probabilities for 100+ degrees
Wednesday are 60-90 percent in these areas. The HeatRisk forecast
which takes into account length of time the heat persists, along
with humidity and other human factors, is at a 3/5 in the hottest
areas, high enough to go with a Heat Advisory for these triple
digit areas. Will issue the Heat Advisory with this forecast
package from 9am-9pm Wednesday.

Forecast for the short term look dry. Models have at times tried
to develop a few mountain initiated showers/thunderstorms,
especially late Wednesday, but any convection will be fighting
very warm 700mb temperatures. In general 700mb temperatures of
+12c or warmer will cap convection, even in the mountains. Current
forecast for Wednesday afternoon is for 700mb temperatures +13 to
+16c, so well above that threshold. So, any low pops through
early Wednesday evening are probably wishful thinking. That said
it is hard to ignore the latest HREF showing widely scattered
mainly dry convection developing late Wednesday afternoon
producing pockets of strong (50+mph) wind gusts. SREF is also
showing strong dry thunderstorm potential in the afternoon/early
evening. Will have to keep an eye on this dry thunderstorm
potential for wind impacts to outdoor activities, and fire impacts
with strong winds and dry lightning.

Mid level temperatures do begin to cool mid to late evening
Wednesday as a Pacific trof and associated cold front arrive. This
combination of cooling aloft and surface convergence may be
enough for low precipitation chances to be a more reasonable
thought later Wednesday night into the early morning hours as the
atmosphere especially down low begins to moisten up. Chambers

Thursday through Tuesday...

Upper trof pushes a Pacific cold front through the forecast area
Thursday morning. This will drop temperatures from the triple
digits Wednesday to the mid/upper 80s Thursday, then into the 70s
Friday with 60s likely in the higher foothills (Red Lodge).
Precipitation really holds off until late in the day Thursday as
the main upper trof transits from Alberta southeast across the
area Thursday night into Friday morning. Models have been steadily
bumping up precipitation chances and accumulations with this
system over the past few days, along with cooling temperatures
Friday as the core of the upper system drops right over eastern
Montana. Probabilities for a quarter inch or more of
precipitation Thursday night into Friday morning have increased
into the 35 to 55 percent range for most of the area, with the
highest probabilities west of Rosebud county and south into the
Sheridan foothills.

Interestingly, and coming on the heels of the Hot temperatures
Tuesday and Wednesday, snow levels drop to around 10kft Thursday
night through Friday morning. The latest NBM shows several inches
of snow accumulation at and above that elevation in the
Beartooth/Absaroka, including over portions of the Beartooth
highway. Will keep an eye on this for a possible Winter Weather
advisory for the pass Thursday night. Anyone planning high
elevation outdoor activities Thursday/Friday should be prepared
for wet conditions low to mid elevations, and winter like
conditions above 10kft.

Flat west to northwest flow aloft fills in over the area behind
exiting trof on Saturday. This downslope gradient plus good
sunshine will boost temperatures from the 70s Friday into the mid
to upper 80s for Saturday. Sunday into Tuesday looks more
uncertain regarding temperatures and precipitation as the NBM is
warming temperatures into the 90s with mid to upper 80s Monday and
Tuesday, but many ensemble members push a cold front and
northerly surface winds into the area Sunday. Another shot of
northerly winds arrives Monday in some ensembles and the
deterministic ECMFW is showing a cool and rainy day on Tuesday.
So, there is low confidence in the late weekend early next week
forecast at this time. Chambers

&&

.AVIATION...

VFR conditions will prevail through the TAF period. Over the
foothills, including near KLVM, winds will increase out of the
west this afternoon, with gusts to around 20-25 kts. Otherwise,
winds will remain mostly light. Archer

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Wed     Thu     Fri     Sat     Sun     Mon
-------------------------------------------------------
BIL 097 064/100 064/086 054/076 053/089 060/090 062/087
    0/U 02/T    22/T    72/W    00/U    00/U    11/U
LVM 093 056/095 054/083 047/075 046/086 052/089 054/088
    0/U 02/T    23/T    61/U    00/U    00/B    11/U
HDN 097 062/101 062/087 053/075 050/088 056/091 059/088
    0/U 02/T    21/U    83/W    00/U    00/U    11/U
MLS 097 066/102 065/089 056/075 053/087 059/091 061/086
    0/U 01/G    21/U    73/W    10/B    00/U    11/U
4BQ 094 067/097 065/087 055/072 052/084 059/088 062/086
    0/U 01/U    20/B    63/T    10/U    00/U    10/U
BHK 090 062/098 060/086 053/070 048/082 055/087 056/085
    0/U 01/U    21/B    53/T    10/U    00/U    11/B
SHR 094 059/097 058/086 049/070 044/084 053/088 055/085
    0/U 02/T    21/B    65/T    10/U    00/U    11/U

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Heat Advisory in effect from 9 AM to 9 PM MDT Wednesday FOR
      ZONES 29>33-57-173-235.
WY...None.

&&

$$
weather.gov/billings