918
FXUS65 KBYZ 200223
AFDBYZ

Area Forecast Discussion...Updated
National Weather Service Billings MT
823 PM MDT Tue Aug 19 2025

.KEY MESSAGES...

- Hot and dry conditions will continue Wednesday.

- Temperatures Wednesday 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...

A thunderstorm popped up in Custer County and produced half inch
hail. Precipitation and thunder chances were added to the forecast
through 9 PM to account for this storm. It has since moved into
Carter County and weakened significantly, no longer producing
lightning. Additional showers and thunderstorms are not expected.
Torgerson

&&

.DISCUSSION...

This afternoon through Thursday night...

Ridge aloft amplifies tonight over the area, producing the
warmest night of the forecast period, lows in the 60s to lower 70s
central and east. Aiding the warmth will be gusty southerly winds
overnight over the eastern half of the forecast area. These winds
will be stirred up by a southerly low level jet of 30 to 45kts at
850mb (just off the surface) and the warmth of the surface
keeping modest mixing going through the night. Some areas east of
Billings could cool off a bit in the evening only to have
temperatures rise (possibly substantially) overnight as these
winds mix in warmer air from aloft. Continued gusty winds will
keep any current fires in the area active overnight through
tomorrow morning.
Wednesday sees a very warm start and quick warmup as morning
inversion breaks allowing hot air above the surface to rapidly mix
down (in areas that did not see the gustier overnight winds
mentioned above). Additional warming comes from pre- frontal
compressional warming ahead of a late day cold front, or actually
more of a wind shift line during the afternoon with cooler air
arriving overnight Wednesday into Thursday. The takeaway from the
above is Wednesday will be another hot day with highs in the
triple digits across a broad portion of the forecast area. The
going Heat Advisory is in good shape and no plans to adjust it at
this time.

Not a lot of precipitation expected with the cold front Wednesday
night into Thursday. Models keep most of the rain over northern
portions of the state, but some low chances will be present over
our neck of the woods from after midnight Wednesday night,
continuing into Thursday night behind the front. The main impact
with the front will be the much cooler conditions for Thursday
compared to Tuesday and Wednesday. Highs Thursday will be
generally in the low to mid 80s, with the NBM spread for Billings
ranging from 82 to 86 degrees. Thursday night will also be cooler
with lows trending in the 50s most locations. Chambers


Friday through Tuesday...

The theme for the extended is for cooler (highs 75 to 85)
conditions to persist through the forecast period. Upper ridge
re-develops west of the divide into the PacNW with a thermal trof
underneath it. This area of low pressure will keep an easterly
wind over the area. Areas of the northern plains will be under a
northerly flow pattern pulling in cooler Canadian air there. Thus
the easterly winds will be advecting in modified Canadian air
through the forecast. What is missing is any significant
precipitation. NBM 7day precipitation forecast is showing less
than a tenth of an inch across the forecast area through the
middle of next week. That said there will be low chances for a
light shower or thunderstorm somewhere in the forecast area just
about every day. Overall a pleasant forecast for the later half of
August. Make plans to get out and enjoy it. Chambers

&&

.AVIATION...


Slant range visibility may be affected as a result of smoke from
wildfires in Idaho. A low level jet is expected to form over
eastern MT late this evening, bringing some low level wind shear
to KMLS up to 40 kts. VFR conditions will prevail. TS
&&

.PRELIMINARY POINT TEMP/POPS...

    Wed     Thu     Fri     Sat     Sun     Mon     Tue
-----------------------------------------------------------
BIL 067/100 064/084 059/079 055/082 054/083 056/084 057/086
    00/U    11/U    10/U    00/U    00/U    01/U    11/U
LVM 059/096 052/085 049/080 046/082 048/082 049/085 049/085
    01/B    11/U    10/U    00/U    01/U    11/U    11/U
HDN 066/100 062/085 057/080 053/082 052/084 054/086 054/086
    00/H    10/U    21/U    00/U    00/U    00/U    00/U
MLS 072/103 067/086 057/079 053/077 052/079 054/082 055/083
    00/G    21/U    21/U    00/U    00/U    00/U    00/U
4BQ 073/102 068/086 059/078 054/077 053/077 055/080 056/081
    00/G    10/U    42/W    10/U    00/U    01/U    11/U
BHK 072/101 064/084 051/077 047/074 046/075 049/078 051/079
    21/N    20/U    21/U    00/U    00/U    00/U    00/U
SHR 067/100 061/085 053/079 050/080 049/079 051/082 051/082
    00/U    12/T    33/T    11/U    11/U    12/T    11/U

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Heat Advisory in effect until 9 PM MDT Wednesday FOR ZONES
      29>33-36-37-57-58-138-139-169-170-173-235.
     Red Flag Warning in effect from noon to 10 PM MDT Wednesday
      FOR ZONE 123.
WY...Heat Advisory in effect until 9 PM MDT Wednesday FOR ZONE
      199.

&&

$$
weather.gov/billings