847
FXUS65 KBYZ 030234
AFDBYZ

Area Forecast Discussion...Updated
National Weather Service Billings MT
834 PM MDT Tue Jul 2 2024

.UPDATE...

Quick update to the forecast for latest model trends of overnight
convection potential. Most convection will diminish as the sun
sets this evening, and have already seen a marked downtrend in
convective strength over the past few hours. That said there is
enough energy floating around that an isolated shower or
thunderstorm threat could continue into the early morning hours,
mainly over northeast zones or along the southern state line
areas. Winds will also weaken as the surface inversion sets in
with sunset. Rest of the forecast is in pretty good shape with
lows tonight mainly in the 50s for the lower elevations. 30s and
even some lower 20s forecast fo area mountains tonight. Those
planning travel over the Beartooth Pass tonight through tomorrow
morning should be alert for a dusting of snow and potential slick
spots until the sun melts things off around 9-10am. Chambers

&&

.DISCUSSION...

Through Wednesday Night...

Isolated to scattered showers and thunderstorms were moving
northwest to southeast over the area this afternoon with the
region situated under unstable northwest flow aloft. The strongest
thunderstorms are capable of producing wind gusts up to 40 mph and
small hail. Expect the shower/thunderstorm activity to gradually
decrease during the evening hours.

Shower and thunderstorm chances increase (40-75%) again on
Wednesday as a trough and associated cold front drop south and
east through the area. Highs on Wednesday are forecast to range
from the upper 60s over the west to the 70s elsewhere. A few
stronger thunderstorms are possible over the far southeast and
down into northern Wyoming with strong winds and large hail the
main threats. As the trough shifts east into the Dakotas and
begins to wrap up, moisture and energy over the area will keep
shower and thunderstorm chances continuing into Wednesday night.
Latest probabilities of receiving 0.25 inches or more of rainfall
Wed-Wed night range from 10-50%, highest over the southeast. Snow
levels drop towards 10,000 feet as well, with some light snow
accumulations possible in the southern mountains. STP

Thursday through Tuesday...

SREF and Clusters agreed on wave moving out of the forecast area
on Thursday with NW flow moving in behind the wave through Friday.
MLCAPEs were running around 500 J/kg over the E half of the area
with no significant shear. Moisture will wrap around over the area
behind the departing system on Thu. with 30-50% PoPs E of KBIL in
the morning and more widespread PoPs during the afternoon, ranging
from 20-30% in KLVM to KBIL to 40-70% E and S of KBIL. Highest
PoPs will be over Fallon and Carter Counties. Thunderstorms are
not expected to be strong based on the above. Probability of 0.25
inches or greater of precipitation was 10-15% E of KBIL on
Thursday. Dry conditions are still expected for Thursday night for
Fourth of July celebrations. Highs on Thu. will be in the 70s
which is below normal for this time of year. A drier airmass will
preclude precipitation for Friday and it will be warmer with highs
in the low to mid 80s.

NW flow continues for the weekend. Backdoor cold front drops into
the area on Saturday with a slight chance of precipitation over
the far E and mountains in the afternoon. Highs will be in the
upper 70s to lower 80s. Other than a slight chance of
precipitation over the SW mountains Sunday afternoon, remainder of
forecast period will be dry. A strong upper ridge moves into the
region, but Clusters disagreed on placement of the upper ridge
axis. For example, on Monday, Cluster 1 had the axis well off the
to the W, while Cluster 4 had it moving into the Dakotas. This
uncertainty could have forecast implications, so will need to
watch for better model agreement. For now, had highs in the mid
80s to lower 90s on Monday and Tuesday. Arthur

&&

.AVIATION...

In general, expect VFR conditions to prevail through the period
with W-NW winds gusting 15-25 knots decreasing this evening.
Isolated to scattered showers and thunderstorms over the area will
decrease this evening, with most activity ending by 03z.
Additional showers and thunderstorms develop over the area
tomorrow as another disturbance works through the region. Mountain
obscurations will be possible with any associated showers and
thunderstorms. STP

&&

.PRELIMINARY POINT TEMP/POPS...

    Wed     Thu     Fri     Sat     Sun     Mon     Tue
-----------------------------------------------------------
BIL 054/077 054/076 053/085 057/083 055/083 057/090 059/090
    14/T    53/T    11/U    11/U    11/U    00/U    00/U
LVM 047/073 044/074 046/082 051/083 050/083 052/088 054/090
    14/T    52/T    11/U    01/U    01/U    00/U    00/U
HDN 051/078 051/076 049/084 054/083 051/083 052/090 055/091
    35/T    54/T    11/U    11/U    11/U    00/U    00/U
MLS 053/077 055/075 054/082 057/081 055/083 056/087 059/088
    44/T    55/T    11/U    11/B    10/U    00/U    00/U
4BQ 053/077 053/074 053/082 057/082 055/081 055/088 058/088
    26/T    55/T    11/U    11/B    10/U    00/U    00/U
BHK 051/078 051/073 052/080 054/078 052/080 052/083 055/085
    44/T    46/T    11/U    12/T    11/U    00/U    00/U
SHR 049/075 046/073 046/080 051/081 050/081 050/088 054/088
    26/T    54/T    11/U    11/U    11/U    00/U    00/U

&&

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

&&

$$
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