564
FXUS65 KBYZ 012224
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
424 PM MDT Sat Jun 1 2024

.DISCUSSION...
Rest of Today through Sunday Night...

Satellite imagery show a low amplitude ridge shifting across our
region with short wave energy upstream tracking through the
Pacific NW into Idaho. These upstream waves along with a gradual
increase in PWATs (to near 0.75") will bring us a chance of
showers and weak thunderstorms tonight into Sunday (20-40%).

Mesoanalysis indicated increasing shear and CAPE (250-500 J/Kg)
at mid afternoon...especially over the southern portions of our
CWA near the foothills. By late afternoon we still expect to see
weak convection develop in our far west as short wave energy moves
into the area. Any storms will remain weak this evening, but could
produce some erratic wind gusts (maybe up to 35 mph), mainly W-NW
of Billings where CAM`s paint the best probabilities, while a
stronger cell near the foothills could also produce some small
hail due to better shear. Models suggest isold/sct convection
will hold together and continue east overnight with an associated
Pacific front. Models target areas along and north of I-94
activity with the best chance of measurable precipitation in the
overnight hours to early Sunday morning.

Some showers may linger here and there over the eastern border
counties and also the mountains early...but by Sunday afternoon
most of the forcing has moved east and subsidence takes over for
dry conditions. It looks to be a bit cooler (highs low- mid 70s)
w/ mixed west winds gusting perhaps into the 20s.

One other item to note is the southeasterly low level jet expected
to develop this evening in southeast MT. HREF shows dewpts rising
to near 50F with increasing elevated instability. However,
forecast soundings suggest a decent cap in this region, and thus
models do not initiate any convection. This is nonetheless
something to be aware of in case short wave influences manage to
erode that cap. BT

Monday through Saturday...

Monday will see a cold front move through the region bringing
precipitation chances back to the region Monday afternoon into
evening. Looking at convective potential, the ECMWF ensemble
gives the region a near 0% chance for >500J/kg of CAPE. Looking
at GFS soundings, this in mainly due to mid level lapse rates
during the day and low level lapse rates during the evening not
being steep enough. PWAT values will get over 1 in indicating a
moist environment. Models are not showing a low level jet setting
up near the Dakotas. Jet forcing also does not appear to be very
strong. Given these factors, precipitation will likely be
dependent on forcing from the cold front leading to scattered
showers and general thunderstorms. WPC clusters show disagreement
in precipitation amounts but even the highest cluster only showed
about 0.2 inches of precipitation or less. NBM is giving most of
the region a 30-60% chance of getting >0.1 inches of
precipitation. Locations that get under thunderstorms may get more
rain with local 0.25 inch readings possible.

Behind the front, 700mb winds will be strong out of the west in
the 30-40kt range over the plains and near 50kts over the western
mountains. Low level lapse rates will be in the 8-9C/km range
leading to efficient mix down for Tuesday and Wednesday afternoon.
Tuesday, most of the region has a >50% chance of getting a wind
gust over 40mph with locations in Wheatland County having a >90%
chance for getting a gust over 50mph. Winds Wednesday will be
similar to Tuesday with probabilities slightly lower. After the
system moves through Monday into Tuesday, ensembles are in good
agreement that some sort of ridging will return to the region
increasing temperatures and bringing dry conditions. There is
disagreement in exactly how the ridging will look which will
determine how high our temperatures get. Max temperatures Monday
will be in the low 70s in the foothills to low 80s east of
Billings. The cold front will bump down temperatures into the low
to mid 70s for Tuesday. Once the ridging takes over, Wednesday
through Saturday will see above normal temperatures in the mid 70s
to mid 80s across the region. Torgerson
&&

.AVIATION...

VFR will generally prevail the rest of today and through the
night. There will be isold/sct showers and a few weak
thunderstorms starting around 22Z in the west and spreading E/NE
through the evening and overnight. Main threat from thunderstorms
will be gusty wind (10% chance gusts to 35kt).

TS POTENTIAL TIMES TONIGHT:
KBIL: 02-07Z
KLVM: 22-04Z
KMLS: 05-11Z

BT

&&

.PRELIMINARY POINT TEMP/POPS...

    Sun     Mon     Tue     Wed     Thu     Fri     Sat
-----------------------------------------------------------
BIL 052/075 055/078 050/074 054/079 050/081 055/082 058/083
    22/W    02/T    71/N    00/U    00/U    11/U    11/U
LVM 047/073 053/071 044/071 053/079 048/083 053/082 053/081
    33/T    18/T    70/N    00/N    01/U    11/U    22/T
HDN 050/076 053/081 049/076 053/080 048/082 052/084 056/085
    22/W    02/W    81/B    00/U    00/U    10/U    21/U
MLS 053/076 053/081 051/074 054/075 048/080 052/083 054/081
    33/T    01/B    81/N    00/N    00/U    00/U    11/U
4BQ 053/076 053/084 052/072 053/076 048/079 053/083 054/081
    11/U    00/B    71/B    00/U    00/U    00/U    11/U
BHK 052/076 051/082 049/072 050/074 045/077 048/080 049/076
    23/T    02/T    71/N    00/N    00/U    00/U    11/U
SHR 048/073 050/081 047/073 050/079 048/081 051/084 053/082
    12/T    01/B    61/B    00/U    00/U    11/U    21/U

&&

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

&&

$$
weather.gov/billings