310
FXUS65 KBYZ 110911
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
311 AM MDT Sat May 11 2024

.DISCUSSION...

Today through Sunday Night...

Warmer and mainly dry conditions can be expected across the area
today with downslope flow in place. A weak shortwave crossing the
region may generate a few light showers or sprinkles (less than
20% chance) during the afternoon and evening over portions of the
area, but for most it should be a dry Saturday. A rumble of
thunder isn`t out of the question over the Bighorns. With
downslope flow in place, temperatures will warm into the 70s and
approach the lower 80s for a few locations today.

Another shortwave dropping into the region from the northwest
will bring isolated to scattered showers and thunderstorms to the
area Sunday afternoon and evening. The wave will also knock
temperatures down a few degrees from Saturday, and allow winds to
shift around out of the east by Sunday night. Highs in the lower
to middle 70s can be expected. STP

Monday through Saturday...

Monday will start out similar to Sunday with shortwave ridging
bringing temperatures 10-25 degrees above average in the mid to
high 70s. Throughout the day Monday however, a shortwave trough
will begin to make its way into our area flattening the ridge.
This will spin up a low pressure system that will track along the
international border. This low pressure system will drag a cold
front across the region bringing precipitation chances. Currently,
the GFS is showing CAPE values of near 1,000 J/kg for some
locations. However, none of the ensembles are showing values this
high, generally keeping them below 500 J/kg. Dew point depressions
will be high with temperatures in the 70s and dewpoints in the
40s, this is leading to GFS soundings having ML CAPE roughly half
of surface CAPE. This could limit convective activity if there is
good mixing which lapse rates suggest there will be. Ensembles
show PWAT values being near 0.7 and GFS soundings show 0-6KM shear
over 30kts for Billings. Taking into account the shortwave trough
and cold frontal forcing lead to the conclusion that there will
be general thunderstorm activity Monday evening into Monday night.

The cold front will bring in stronger winds for Tuesday with most
of the region having a 40-60% chance of getting a wind gust over
30mph. Tuesday will see the return of 50-70% Pops as we get wrap
around from the low. With winds out of the north/northwest, the
best chances for precipitation will be locations in the higher
terrain that get upslope with northerly winds. The combined
rounds of precipitation will bring a 40-70% chance for 0.25 inches
of rain for most. The cold front will bring temperatures down
into the 60s for Tuesday.

Wednesday through the rest of the long term bring significant
uncertainty as ensembles have still have not come into agreement
on the pattern. Some models show the return of troughing and
therefore cooler temperatures and precipitation chances, while
others want to show a ridging pattern returning leading to warmer
temperatures and drier conditions. This uncertainty leads to
20-40% Pops everyday and temperatures in the mid 60s to low 70s.
This is subject to change over the coming days as models hopefully
come into better agreement and details become more clear.
Torgerson

&&

.AVIATION...

Winds will be light over the next 24 hours with minimal cloud
cover. Some passing high clouds may pass over the area around 21Z
today. Torgerson

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Sun     Mon     Tue     Wed     Thu     Fri
-------------------------------------------------------
BIL 078 048/075 048/077 050/066 045/067 046/073 050/072
    1/B 12/T    16/T    58/T    33/R    24/T    33/T
LVM 077 046/078 047/074 045/063 041/066 044/071 045/072
    0/B 12/T    16/T    48/T    33/R    24/T    23/T
HDN 079 046/076 045/078 048/068 044/067 043/074 047/073
    0/U 12/T    15/T    67/T    33/R    33/T    32/T
MLS 079 048/076 047/079 051/066 044/065 044/072 047/071
    0/U 12/T    13/R    55/T    23/R    23/R    32/R
4BQ 076 048/076 044/080 049/068 044/064 044/071 045/070
    0/U 02/T    12/R    65/T    33/R    22/R    32/T
BHK 078 045/074 043/076 048/067 041/063 042/069 042/068
    0/U 12/T    22/R    65/T    22/R    22/R    32/R
SHR 076 044/075 044/077 045/065 041/063 040/071 044/071
    0/U 13/T    15/T    68/T    44/T    23/T    32/T

&&

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

&&

$$
weather.gov/billings