Area Forecast Discussion
Issued by NWS Billings, MT

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500
FXUS65 KBYZ 210821
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
221 AM MDT Sat Sep 21 2024

.DISCUSSION...
Through Sunday night...

Weak cyclonic flow aloft will prevail today, but without much
forcing or deeper moisture, no precipitation is expected. Look
for some low clouds in the east early, otherwise skies will be
mostly sunny by afternoon. With a cooler air mass in place highs
today will be in the lower 60s with 40s in the high country. Weak
ridging Saturday night will give way to more modest height falls
Sunday as another weather system tracks across Canada with
prefrontal warming boosting highs Sunday back into the lower/mid
70s. The Canadian system will drag another front across the high
plains and our area Sunday night. This feature looks mainly dry,
but the EC is indicating a chance of light showers in our western
zones late Sunday night into Monday, so we will carry some low
Pops in the Park County, Crazies region. BT

Monday through Friday...

An upper trough and cold front will move across the Northern
Rockies on Monday. Ahead of this system, high temperatures will be
around normal, in the upper 60s and low 70s. The chance for
precipitation increase with frontal passage (around midday),
though models still disagree on the extent of this increase. The
deterministic ECMWF continues to lead the way with moisture and
the chance for precip, while the GFS, Canadian, and NAM are much
more bullish. Nevertheless, the current NBM forecast is leaning on
the EC run, resulting in a low to moderate (15-50%, best chance
in the western areas) chance for showers. Light, high elevation
snowfall will also be possible with this system, with snow levels
around 10kft. Expect winds to increase from the WNW, with gusts in
the 10s-20s mph into Tuesday morning.

There is high confidence among ensemble members that upper
ridging will begin to rebuild across the Mountain West, Tuesday.
Normal to slightly above normal temperatures (70s to low 80s) and
dry conditions will be felt through Friday.

Confidence in the next weather pattern is low, next Friday and
Saturday. Current cluster analysis generally depicts zonal flow
from the WSW, while several ensembles and deterministic`s are
showing an upper trough developing in the PNW. The current
forecast has temperatures dropping down into the upper 60s to low
70s next weekend. Keep an eye out for changes in the forecast if
you have plans later in the week.

Matos
&&

.AVIATION...

VFR conditions will generally prevail through the period. Patchy
areas of MVFR due to low cloud bases are possible this morning,
in the east.

Matos
&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Sun     Mon     Tue     Wed     Thu     Fri
-------------------------------------------------------
BIL 061 040/073 051/072 047/075 050/083 054/082 051/080
    0/U 00/U    12/W    00/U    00/U    00/U    00/U
LVM 063 034/075 043/070 042/077 047/083 049/081 046/079
    0/U 00/U    12/W    00/U    00/U    01/U    00/U
HDN 062 035/074 045/072 042/076 046/085 050/083 049/082
    0/U 00/U    02/W    00/U    00/U    00/U    00/U
MLS 062 039/072 047/072 044/075 048/083 052/081 050/082
    0/U 00/U    01/B    00/U    00/U    00/U    00/U
4BQ 061 037/074 045/071 044/074 047/083 052/083 051/084
    0/B 00/U    01/B    00/U    00/U    00/U    00/U
BHK 063 036/071 043/071 042/074 045/082 050/081 048/082
    0/B 00/U    00/B    00/U    00/U    00/U    00/U
SHR 063 033/075 043/070 040/075 044/085 049/085 048/084
    0/B 00/U    03/W    00/U    00/U    00/U    00/U

&&

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

&&

$$
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