650
FXUS65 KBYZ 271838
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
1238 PM MDT Fri Jun 27 2025

.KEY MESSAGES...

- Chance of late day showers or storms over portions of the region
  through Saturday.

- Turning mostly dry Sunday and Monday.

- Turning warmer Monday/Tuesday with highs mid 80s to mid 90s.

- Chance of showers and thunderstorms increases again by the
  middle of next week.

&&

.DISCUSSION...

The rest of today through Saturday Night...

Conditions are similar to yesterday, with MUCAPE values around
400-800 J/kg and shear slightly higher, around 40 kts. Moderate
instability from surface heating combined with modest low level
moisture will result in isolated to scattered convection into the
evening. The Storm Prediction Center has issued a Marginal Risk
(level 1 of 5) across the northern portion of the region. Like
yesterday, model soundings and hodographs favor strong wind gusts
up to 65 mph as the main threat with any strong to severe storms.
With the slightly higher shear, there is a also a small chance
(<5%) for large hail.

Late Friday into Saturday, a low amplitude trough moving across
southern Canada will send a weak front across the CWA. A more
stable air mass will set up behind the front over much of
northern Montana, limiting thunderstorm potential. The mountains
near the Wyoming border and the southeastern corner of Montana
will have the best chance (20-30%) for thunderstorm development
Saturday afternoon and evening, with MUCAPE around 1000 J/kg and
shear around 45 kts. The main threat will again be strong winds.
Archer


Sunday through Friday...

Ridge builds west of the divide into the PacNW Sunday into Monday
tilting the upper flow out of the northwest east of the divide.
Not a lot of moisture in this patter so looking at a mainly dry
forecast both days. The ridge to the west will set up a thermal
low in the lower levels of the atmosphere that will strengthen the
low level jet and bend the low level winds more to the east-
southeast from Tuesday through the rest of next week. This will
begin advecting low level plains moisture into the area Tuesday
boosting PWAT values from around half an inch Sunday to over an
inch on Tuesday and closer to an inch and a quarter Wed/Thu. This
moisture boost will also be enhanced by mid level monsoonal
moisture pushing north along the spine of the rockies underneath
the ridge axis. All of this extra moisture should increase shower
and thunderstorm potential/coverage through the week (especially
in the afternoon and evening hours) and bring a better chance for
significant precipitation amounts where showers and thunderstorms
do develop. A weak northerly cold front should be a good focus for
convective development on Friday.

Temperatures will be warmest Tuesday and Wednesday with many
locations reaching the lower 90s. Combine the additional moisture
and its going to be muggy. Otherwise highs will generally be in
the 80s. Chambers

&&

.AVIATION...

Isolated convection is expected to begin over western terrain
around 20z and spread eastward through the evening hours.
Convection will diminish after 06z, but will not completely
disappear as a weak cold front will sag into the area likely
keeping at least a few light showers if not weak thunderstorms
going through Saturday morning. Main threat from storms today will
be gusts in the 35 to 50kt range with some bowing segments that
could be a bit stronger. Inverted-V soundings should minimize
flight category reduction, keeping precipitation intensity on the
lighter side for this time of year. Still, can`t rule out some
local MVFR visibilities near stronger cells. Outside of convection
expect VFR conditions and light winds through tonight.
Northwesterly winds will be stronger by late morning Saturday with
gusts around 20kts across northern zones and over area foothills.
Chambers
&&

.PRELIMINARY POINT TEMP/POPS...

    Sat     Sun     Mon     Tue     Wed     Thu     Fri
-----------------------------------------------------------
BIL 058/081 058/081 055/087 059/092 062/090 062/088 061/089
    31/U    10/U    00/U    00/U    22/T    32/T    21/U
LVM 050/080 047/080 047/085 054/089 055/086 054/085 053/087
    21/U    00/U    00/U    01/U    23/T    43/T    22/T
HDN 058/083 057/082 052/088 058/094 060/092 059/089 060/089
    31/U    20/U    00/U    00/U    21/B    31/B    21/B
MLS 062/084 058/083 055/086 060/094 064/092 065/090 063/092
    41/U    10/U    00/U    00/U    22/T    32/T    21/U
4BQ 061/083 059/081 055/084 060/091 063/090 063/087 062/089
    10/U    41/U    00/U    00/U    21/B    21/B    21/U
BHK 059/082 054/080 051/083 054/087 059/087 060/086 059/087
    21/U    10/U    00/U    00/U    22/T    32/T    21/U
SHR 054/081 052/079 049/083 054/090 056/087 058/085 056/086
    11/U    32/T    00/U    01/U    12/T    22/T    22/T

&&

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

&&

$$
weather.gov/billings