236
FXUS65 KBYZ 222001
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
201 PM MDT Sat Jun 22 2024

.DISCUSSION...
Today through Sunday night...

Warmer conditions continue today, with highs in the low 80s across
much of the area already. Isolated showers and thunderstorms are
possible east of a Harlowton-Billings-Sheridan line through this
evening. The strongest storms could produce heavy rainfall, small
hail, and some gusty winds.

Sunday will be quite warm with high temperatures in the 90s and
around 100, especially in the Yellowstone River Valley where the
probability of seeing 100F is 40-80%. Models show 850mb
temperature anomalies of 10-13C across the area along with normal
to above normal PWATs between 0.7-1.1". By late afternoon/ early
evening, a cold front associated with a shortwave from Canada will
pass through the region, as a result, adequate mixing and above
normal PWATs will produce isolated to scattered thunderstorms
tomorrow. Stronger storms will be capable of producing heavy
rainfall, hail, and gusty winds. The latest SPC Day 2 Severe
Thunderstorm Outlook has a small area in Northern Musselshell and
Northern Rosebud Counties for strong winds and hail. Instability
from soundings is plentiful given the very warm profiles, with MUCAPE
values approaching 2000 J/kg. DCAPE values are also in the
1000-2000 J/kg range, any stronger storms would be capable of
producing strong wind gusts.

Matos


Monday through Saturday..

Monday through Wednesday will be warm and mostly dry w/ zonal
flow followed by flat ridging (w/ above normal heights). There is
a weak shortwave which along with some low-mid level frontogenesis
should be enough to produce a few showers & thunderstorms Monday
afternoon/night (w/ some convection possibly lingering thru the
night in southeast MT). There is only a low chance (<10%) of weak
diurnal convection on Tuesday over the mountains, as heights will
be rising. The ridge axis shifts east and opens the door to
isolated late day thunderstorms Wednesday over the western
mountains. As already mentioned, temps will remain above normal on
these days, with highs mostly 80s Monday/Tuesday, then upper 80s
to mid 90s Wednesday per surge of pre-frontal warmer air out of
the southwest.

Things get more interesting beginning Thursday as a fairly deep
Pacific trof moves into the PacNW. Pwats will be on the increase
once again, with height falls/ascent, leading to a much greater
probability (30-50%) for afternoon and evening showers &
thunderstorms. This is a day to keep an eye on for potential
severe weather. Temps will be in the 80s to lower 90s, coolest
west, but there is some uncertainty here as a cold front will be
arriving either during the day or by evening. Friday will be
post-frontal and cooler, with a continued good chance of showers
and thunderstorms. All indications are that cooler and more stable
conditions will keep any thunderstorms non-severe, but this is
also something to watch. Also, the cooler ensembles show mid
levels turning cool enough (700mb temps near 0C) to produce some
snow showers over the higher elevations of our western mountains
by late Thursday night and Friday. Otherwise, highs on Friday
should be in the upper 60s and 70s.

However the Thursday/Friday period pans out, Saturday is looking
dry w/ seasonable temps as ridging builds back over the region
behind the departing trof.

JKL


&&

.AVIATION...

VFR conditions are expected through the forecast period. Isolated
showers and thunderstorms are possible from K3HT to KSHR and east
this afternoon. Sunday afternoon/evening, isolated to scattered
thunderstorms are possible, with stronger storms north of KBIL
capable of producing hail and strong wind gusts.

Matos

&&

.PRELIMINARY POINT TEMP/POPS...

    Sun     Mon     Tue     Wed     Thu     Fri     Sat
-----------------------------------------------------------
BIL 059/098 062/089 057/086 058/092 061/089 057/073 050/076
    01/U    21/U    10/U    00/U    12/T    44/T    31/U
LVM 054/095 055/089 049/088 052/090 056/085 050/072 044/075
    01/N    11/N    00/U    01/U    13/T    44/T    21/U
HDN 058/100 060/092 056/088 057/094 060/092 055/075 048/077
    00/U    20/U    20/U    00/U    11/U    33/T    31/U
MLS 059/097 065/088 059/087 058/091 064/090 059/076 051/076
    00/U    20/U    10/U    00/U    11/U    53/T    41/U
4BQ 059/097 067/090 059/087 059/093 064/094 059/079 052/076
    10/U    20/U    20/U    01/U    11/U    32/T    31/U
BHK 057/094 064/088 056/084 055/088 060/089 056/077 049/076
    10/U    20/U    20/U    01/U    11/U    43/T    41/U
SHR 055/097 060/092 055/088 054/092 059/092 053/077 047/077
    00/U    21/U    20/U    00/U    01/U    23/T    31/U

&&

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

&&

$$
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