167
FXUS65 KBYZ 201426
AFDBYZ

Area Forecast Discussion...Updated
National Weather Service Billings MT
826 AM MDT Wed Aug 20 2025

.KEY MESSAGES...
- Hot and dry conditions continue today.

- Temperatures today will push over 100 degrees in many
  locations, with record highs possible.

- This stretch of warm and dry weather will bring an increased
  risk for wildfires. Take care to avoid causing a spark!

- Cold front Wednesday night will bring cooler temperatures (75-85
  degrees) through the weekend, but precipitation chances remain
  low.


&&

.UPDATE...

Updated several weather elements this morning. First, northerly
winds have worked south into the area quicker than forecast this
morning due to outflows from overnight storms over far northern
Montana. Models have latched onto this and are keeping light
northerly flow over central areas through the day which holds
temperatures a few degrees below previous forecasts, and just
below Heat Advisory thresholds. As a result have cancelled the
advisory for Musselshell, Yellowstone, Treasure and northern Big
Horn counties. That said, it will still be hot with mid to upper
90s forecast, so continue to use heat precautions and take it easy
out there today. Adjusted forecast winds to reflect the northerly
flow.

With the northerly winds sagging further south today the models
have also stepped up convective chances over the western mountains
and foothills by mid-day. This activity then shifts northeast this
afternoon and evening as the main frontal push arrives. Bumped up
thundestorms chances in these areas. Not a lot of precipitation
forecas with this activity, but there could be some stronger wind
gusts (40-50mph) with any storms that do form. Rest of the
forecast on track for today.

Red Flag Warning continues for the southern portion of fire zone
123, for areas mainly south of Big Sky. Chambers

&&

.DISCUSSION...

Today through Thursday night...

Today will again be hot and dry, with highs in the mid 90s to low
100s. A Heat Advisory remains in effect for the eastern half of
the region through 9 PM tonight.

This morning, a low level jet is bringing wind gusts around 20-30
mph near the Dakota border. These winds are expected to decrease
in the afternoon. However, coupled with hot and dry conditions,
fire weather concerns are increased, and this will keep any
current fires in the area active through the morning hours.

Late today, a cold front moving across the region will end the
heat and bring a low chance (10-30%) of precipitation through
Thursday morning, with the highest chance north of Billings.
Ahead of the front, winds over the west will increase in the
afternoon and evening. Given the already high fire weather
concerns, a Red Flag Warning is in effect over the far west from
noon today through 10 PM, with locations south of Big Sky as the
area of most concern.

Upper level flow will turn northwesterly Thursday, allowing more
seasonal conditions to end the work week as cooler Canadian air is
pulled into the region. High temperatures on Thursday will be in
the 80s, around 10-15 degrees cooler than today. Archer

Friday through Tuesday...

Large scale troughing over the eastern US and upper ridging to the
west will keep the area under northwest flow aloft. Thermal
troughing to the west of the divide will keep easterly winds
in place, allowing for modified Canadian air to continue to move
into the area from the northeast. As a result, temperatures are
expected to remain near to below normal through the extended
period, with highs of 75 to 85 degrees most days. Low chances for
showers and thunderstorms look to occur over the southern
mountains and adjacent areas most days (30% or less) as weak
energy floats through the northwest flow. No widespread, nor
significant precipitation is expected through the long term. STP

&&

.AVIATION...

A low level jet over eastern MT will bring low level wind shear
into the morning hours, with up to 40 kts at KMLS. VFR conditions
are expected to prevail through the period. Isolated showers and
thunderstorms are possible later this afternoon and evening as a
cold front passes through the region. Slant range visibility
reductions are possible due to smoke from nearby and regional
wildfires. STP

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Thu     Fri     Sat     Sun     Mon     Tue
-------------------------------------------------------
BIL 097 064/083 059/077 054/080 053/081 054/082 054/083
    0/U 10/U    10/B    00/U    00/U    01/B    11/U
LVM 096 053/085 049/078 045/082 046/081 048/082 048/083
    1/B 20/K    00/U    00/U    01/B    12/T    12/W
HDN 099 061/085 058/079 053/081 050/081 051/082 052/085
    0/U 10/U    21/B    00/U    00/U    01/B    10/U
MLS 101 067/084 058/078 052/076 050/076 051/079 053/082
    0/G 11/U    20/B    00/U    00/U    00/U    00/U
4BQ 102 068/085 060/077 053/075 051/075 053/078 053/080
    0/G 10/U    51/B    10/U    00/U    01/B    10/U
BHK 101 064/084 053/077 046/074 046/073 046/076 050/079
    0/N 10/U    20/U    00/U    00/U    00/U    00/U
SHR 099 060/084 053/077 049/078 048/077 050/079 050/081
    0/B 11/U    43/T    21/U    01/U    12/T    11/U

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Heat Advisory in effect until 9 PM MDT this evening FOR ZONES
      31>33-36-37-58-138-169.
     Red Flag Warning in effect from noon today to 10 PM MDT this
      evening FOR ZONE 123.
WY...Heat Advisory in effect until 9 PM MDT this evening FOR ZONE
      199.

&&

$$
weather.gov/billings