Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 211939
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
139 PM MDT Sat May 21 2022

.DISCUSSION...
Tonight through Sunday Night...

Satellite imagery shows cool northwest flow over our region,
resulting in a large field of cellular clouds especially east of
Billings where scattered showers have developed. Over the the west
half of our cwa (including around Billings), cumulus has become
flatter as a result of slowly building heights from the west. Air
mass is also quite dry in our west...note the dew point of only
18F at Livingston. For this reason have scaled back pops a bit in
our west, while keeping scattered showers going til early evening
in the east. Cannot rule out a lightning strike or two in our east
per shallow instability extending into the -10C to -20C layer.
Otherwise, expect at least partial clearing and light easterly
winds tonight...and a good shot of a frost or freeze most
locations. Places like Livingston and Harlowton should reach the
20s again. Eastern sites will be colder tonight than this morning,
with lows generally 28-33F everywhere Billings eastward. Here is
a summary of forecast and record lows for tonight:
 Fcst Record
Billings 33 31 (2021)
Livingston2927 (2002)
Miles City3033 (2002)
Sheridan2628 (1915)

On Sunday, weak circulation currently over WA will move to eastern
ID and south central MT, providing ascent for another round of
scattered showers...with a bit greater potential for a few
t-storms given warmer temps and a bit more diurnal instability.
Expect some light shower activity to linger thru Sunday night in
our east as PV max moves slowly across the area. Most locations
will see less than a tenth of an inch of precip, while mountains
should pick up a couple more inches of wet snow above 7000 feet.
Temps on Sunday will reach the mid 50s to lower 60s. Sunday night
will be not as cold with mid to upper 30s most places...though a
frost is still possible for one more night especially close to the
foothills.

JKL

Monday through Saturday...

A shortwave trough will be moving through the eastern part of the
area on Monday accompany by a slight chance of afternoon showers
and thunderstorms over far eastern and southern areas including
KSHR. A deeper trough follows for Tuesday with a more widespread
chance of showers and isolated thunderstorms. Highest chances will
be W of KBIL and over the NE Bighorns. SREF showed 700-500 mb lapse
rates of 7 degs C/km both days. A ridge builds into the area on
Wednesday, and remains over the area on Thursday with drier
weather. The next trough approaches the area Friday with more
showers and isolated thunderstorms. Model clusters had the trough
moving through the region at different speeds for more showers and
thunderstorms on Saturday. Temps will be a little below normal to
start the extended period, then there will be a warming trend with
temps around 80 in KBIL Thu. and Friday. Saturday will be cooler
with the trough in the area. Arthur

&&

.AVIATION...

Scattered showers will linger into the early evening, mainly east
of KBIL. Look for brief MVFR conditions in the heavier showers,
while mountains are frequently obscured in snow showers. Late
tonight will be dry, but another round of rain showers and
mountain snow showers is expected Sunday. Once again, expect local
MVFR at lower elevations and frequent mountain obscurations
tomorrow.

There is a small risk of localized fog in far southeast MT late
tonight, but this will not impact any TAF sites.

JKL

&&

.PRELIMINARY POINT TEMP/POPS...

    Sun     Mon     Tue     Wed     Thu     Fri     Sat
-----------------------------------------------------------
BIL 033/061 038/066 043/066 044/072 048/080 053/080 052/070
    12/W    20/U    14/W    21/B    00/B    12/T    33/T
LVM 029/056 032/063 039/061 038/069 045/077 049/075 044/064
    25/T    11/U    26/T    21/B    00/B    13/T    45/T
HDN 029/063 035/067 040/068 043/073 046/081 052/083 051/071
    01/B    21/U    03/W    21/B    00/U    01/B    33/T
MLS 030/060 038/066 042/068 044/071 050/080 054/083 054/074
    00/U    21/U    01/B    21/B    00/U    01/B    32/W
4BQ 029/060 037/062 039/065 043/069 048/078 052/084 053/072
    22/W    21/U    01/B    21/U    00/U    00/B    22/W
BHK 027/058 036/062 038/064 041/069 047/076 050/080 050/072
    20/U    22/T    01/U    11/U    00/U    01/B    32/W
SHR 026/059 034/062 037/062 039/068 045/078 050/081 049/069
    12/T    32/T    05/T    31/U    00/U    01/B    23/T

&&

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

&&

$$
weather.gov/billings


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