363
FXUS65 KBYZ 020818
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
218 AM MDT Sun Jun 2 2024

.DISCUSSION...

Today through Monday...

Weak shortwave continues to produce showers and some embedded
thunderstorms at 08z, mainly N-NE of Billings, but just recently
there are storms popping up over southern Carter County. Air mass
in far southeast MT has become increasingly unstable thru the
night courtesy of a southeasterly low level jet...and now the
instability is being realized w/ passage of a mid level front.
Overall, this activity will spread W to E between now and sunrise
and should exit southeast MT in the 12-15z time frame. Cannot rule
out small hail in any stronger storms.

Further west, there are isolated light showers over southwest MT
as another weak wave traverses the zonal flow aloft. Generally
speaking, there is broad troffing/cyclonic flow over ID/MT, with
a couple of embedded weak shortwaves...so shower potential will
linger through the remainder of the night and this morning across
our western parts as well. By this afternoon, we will see
synoptic scale subsidence spread in from the west, and mid level
warming that will lessen the instability. NBM pops and prob TS
remain too high, however, mid level lapse rates and moisture
should be sufficient for scattered light showers over the
mountains and along the foothills this afternoon and early
evening...with a low risk of thunder. We will also see mixed
westerly winds today with gusts into the 20s in spots. Temps today
should max out in the 70s.

Next Pacific trof is associated with an extensive moisture plume,
and will move inland tonight. Cloud cover and tighter downslope
gradients will yield a mild night with breezy SW winds along the
foothills. Tonight should remain dry other than some light
showers over the western mountains.

Ascent will increase thru the day Monday as the next wave
approaches. Showers and embedded thunderstorms are expected by
afternoon, with greatest coverage (60-90%) over the west during
the daytime hours. The progressive flow and cloud cover will keep
instability limited to 200-500 j/kg (per HREF), so thunderstorms
will remain weak but could produce elevated wind gusts in our west
by late afternoon. Highs tomorrow will range from the lower 70s
west to mid 80s east. The risk of showers/thunderstorms and gusty
winds will spread east and continue Monday night (see extended
discussion below).

JKL

Monday Night through Saturday...

An approaching trough will sweep a cold front across Montana,
Monday night into Tuesday morning. Highs for Tuesday will be in
the low to mid 70s with the frontal passage. The chance for
showers and general thunderstorms are moderate to high (60-90%)
for most of the forecast area through Tuesday morning.
Precipitation accumulation amounts are not anticipated to be high,
with the chance for 0.1" of QPF at 30-60% for most of the region,
although, locally higher amounts are possible with stronger
thunderstorms producing heavy rainfall.

The bigger story is the gusty winds expected to fill in behind the
departing cold front on Tuesday. With strong subsidence left
behind the front and lapse rates in the 8-9 C/km, turbulent mixing
will result in strong descent. Surface winds in the 10s-20s mph
and gusts up to 40mph are expected across the area. With 700mb
winds approaching 50 knots in the W/NW counties, even higher
gusts are expected, especially in Wheatland County where the NBM
has an 80% chance of wind gusts of 55mph or greater.

Upper ridging will begin building into the mountain west Tuesday
night and continue through the extended forecast period.
Increasing heights will bring warm and dry conditions with
temperatures in the low to mid 80s, Wednesday thru Saturday. The
chance for precipitation is less than 25% across the area into
the weekend.

Matos

&&

.AVIATION...

Scattered showers and isolated thunderstorms will impact the
region today, with early morning TS and erratic wind gusts
potentially impacting KMLS, K97M and KBHK thru 12z. By afternoon,
convection will be weak and focused near the mountains and
foothills. Tonight will be mostly dry with only a slight chance of
showers over the mountains. Overall, VFR will prevail over the
next 24 hours, with local MVFR/IFR in any heavier showers (most
likely in the east early this morning). Mountains may be obscured
at times. JKL

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Mon     Tue     Wed     Thu     Fri     Sat
-------------------------------------------------------
BIL 075 055/078 049/075 054/079 051/081 053/082 055/080
    2/W 13/T    71/N    00/U    00/U    01/U    11/U
LVM 075 054/071 044/071 054/078 048/083 052/083 052/079
    3/T 18/T    70/N    00/N    00/U    11/U    12/W
HDN 077 052/081 049/075 051/079 047/082 051/085 054/080
    2/W 12/T    81/U    00/U    00/U    00/U    11/U
MLS 076 054/081 050/073 054/075 047/079 050/082 054/078
    1/B 02/W    81/N    00/N    00/U    00/U    10/U
4BQ 076 052/083 052/072 054/075 049/079 053/082 054/078
    0/U 02/W    71/U    00/U    00/U    00/U    11/U
BHK 076 051/084 048/071 050/073 045/076 047/079 048/074
    2/T 12/T    61/N    00/N    00/U    00/U    10/U
SHR 074 049/080 047/074 049/079 047/081 050/083 052/078
    2/T 12/T    71/B    00/U    00/U    11/U    21/U

&&

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

&&

$$
weather.gov/billings