204
FXUS65 KBYZ 250057
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
657 PM MDT Mon Jun 24 2024

.UPDATE...
Local radar shows isolated/scattered weak convection spreading
eastward off the Beartooth-Absarokas, making it as far as central
Rosebud County as of 650pm. Mesoanalysis shows MLCapes on the
order of 500 j/kg across our south, with CIN, and less cape the
further north you go, so fully expect tonight`s convection to stay
weak and over the southern half of our cwa. To this point none of
the activity has produced more than 20-30 mph gusts. Later
tonight there are hints of a weak southeasterly low level jet
nosing from SD into far southeast MT...in a region of deeper
moisture, so feel that the greatest potential for a t-storm of
substance (but not severe) is overnight in Carter County. Have
made a few pop/wx adjustments based on the convection`s coverage.
Remainder of forecast is in good shape.

JKL

&&

.DISCUSSION...
Tonight through Tuesday night...

Zonal, westerly flow is settled in across the area today with high
temperatures in the 80s and low 90s. There is some lingering
moisture around with some modest instability, mainly in the
southwestern mountains. As a result, the chance (<25%) for
isolated showers and thunderstorms exists this afternoon and
evening. The chance for precipitation moves into the far east late
tonight bringing the chance (<25%) for an isolated shower or
thunderstorm. Winds gusting in the 20s-30s mph are expected this
afternoon and evening in the western mountains and foothills as a
result of diurnal mixing.

Ridging will begin to build back into the Northern Rockies on
Tuesday, resulting in warm and dry conditions. High temperatures
will be in the 80s to 90F. Overnight lows will be in the 50s
tonight and Tuesday night.

Matos

Wednesday through Sunday...

Ridging will continue to build over the area on Wednesday as
temperatures climb into the mid 80s to low 90s. There will be
decent Gulf Moisture streaming into the central and eastern areas
on Wednesday with southeasterly flow. The probability for
precipitation for much of the forecast area is in the range of
20-50%. While instability values are not very high, there could
be enough in place for a few stronger showers and thunderstorms.

An upper trough and associated low will move into the Northern
Rockies on Thursday, bringing a cold front across the state in the
afternoon to evening hours. A very warm day is in store prior to
the frontal passage, with high temperatures in the mid 90s. The
latest NBM probability for a temperature of 95F or greater on
Thursday is 25-65%, highest for locations in the Yellowstone River
Valley and the SE counties. With the arrival of the cold front,
increased chances for showers and thunderstorms are forecast. A
better setup for widespread precip and potentially stronger
thunderstorms is in place Thursday, with monsoonal moisture
raising PWATs to 1-1.4" in the central and eastern areas. Models
disagree on the extent of instability on Thursday, but high PWATs
and 30-60 knots of deep layer shear should be more than adequate
for some strong thunderstorms to form.

The chance for precipitation will linger into Friday as the low
continues to move east in NE MT/ Southern Canada. The current
probability of precipitation across the area Thursday through
Friday morning is 30-80% with the highest probabilities north of
Sheridan County. Cooler temperatures are forecasted for Friday
with highs in the upper 60s to mid 70s. With the troughing,
heights may fall enough for near freezing temperatures to be felt
in the higher mountain elevations (>10kt). A few snow showers
can`t be ruled out for the high peaks in the Absaroka/Beartooths
and Crazy Mountains, overnight Thursday and Friday. The latest NBM
72-hour probability of at least 0.25" of total QPF from Wednesday
morning to Saturday morning is 20-60%, with the highest chances in
the mountains and along and north of US Hwy 212.

Ridging will slowly begin to build back into the region again
Saturday into Sunday, with warming temperatures and mostly dry
conditions in store. Highs in the 70s on Saturday, climbing into
the 80s and low 90s on Sunday.

Matos

&&

.AVIATION...

Isolated showers and thunderstorms will track west to east this
evening, mainly from the Beartooths eastward, and staying mostly
south of KBIL. Localized gusts to 30 knots and brief MVFR
possible. KSHR could see a TS up thru 04Z but the chance of this
is low (10%). An isolated storm could impact far southeast MT
overnight. Otherwise, VFR will prevail over the next 24 hours. JKL

&&

.PRELIMINARY POINT TEMP/POPS...

    Tue     Wed     Thu     Fri     Sat     Sun     Mon
-----------------------------------------------------------
BIL 058/087 058/089 063/091 054/073 048/076 052/086 058/079
    20/U    00/B    24/T    52/W    10/B    02/T    45/T
LVM 049/088 053/087 057/084 046/070 042/077 048/085 052/074
    10/U    03/T    36/T    42/T    10/U    13/T    56/T
HDN 057/088 055/091 060/094 053/075 046/079 052/091 057/082
    20/U    00/B    24/T    51/U    10/U    01/U    45/T
MLS 057/086 056/089 064/093 058/073 046/073 054/090 060/080
    00/U    00/U    33/T    51/N    10/U    11/U    54/T
4BQ 059/088 057/090 066/096 057/076 048/076 055/091 059/082
    20/U    01/U    22/T    41/U    10/U    11/U    34/T
BHK 055/086 052/085 061/087 055/073 045/071 050/083 057/079
    00/U    00/U    33/T    61/N    11/B    11/N    54/T
SHR 053/088 054/089 059/093 051/074 043/080 052/092 056/082
    20/U    01/B    12/T    31/U    10/U    01/U    34/T

&&

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

&&

$$
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