044
FXUS65 KBYZ 280752
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
152 AM MDT Tue May 28 2024

.DISCUSSION...

Through Wednesday night...

A 580dm ridge builds into the region this morning and will bring
sunny skies and warm temperatures. Winds turn southerly unde the
ridge helping to boost temperatures 10 degrees or so above
seasonal levels. The southerly turn of the winds will also begin
to bring better moisture levels into the area ahead of an upper
level trof that arrives Wednesday morning over western zones.
Ahead of the trof tonight expect increased mid and high level
cloud cover and maybe a few light showers over the western
mountains and foothills. Southerly low level jet will increase
over the eastern half of the forecast area overnight with 850mb
winds reaching 40kts. Low level moisture will be shoved into our
area through the night and into Wednesday morning, boosting PWATs
to close to an inch by mid morning.

Scattered showers will get going over areas west of Billings
during the morning hours as the upper trof moves into the area. By
mid day expect convection to increase off area mountains and move
east northeast through the afternoon and evening hours. The
combination of plains moisture advection down low and Pacific
moisture associated with the upper trof will bring PWAT values
well over an inch from Billings to the east, providing the fuel to
support a few strong storms and locally heavy downpours. A couple
of lines of convection are expected Wednesday, the first starts
over SE MT mid day and moves into the Dakotas late afternoon. This
line is forming with the strongest low level convergence and
should have chance chance to develop a few strong to severe
storms. The second develops over the western foothills and gets
into the Billings area around 3pm, moving into the Dakotas by 8pm
or so. Interestingly, this area is showing the propensity for long
lived helicity tracks due the the stronger upper level forcing
behind the front/low level wind shift. While CAPE/Convergence are
strongest Custer/Powder River county and east, the modest CAPE and
stronger Shear profiles further west may drive a more organized
severe threat. The main threat with most storms Wednesday will be
wind. That said this time of year any storm can produce hail with
cold temps aloft (wet bulb zero levels drop to around 10000 feet
msl by 3pm C/W, 12kft E), so can`t rule out large hail especially
with the long track helicity cells.

As mentioned above the high PWAT values will also support locally
heavy rainfall with any stronger storms. NBM statistics show most
areas with a mean in the .25 to .6 inch range Wed/Wed night. The
hi/low range for Billings is .07 to 1.1 inches with a max
potential of 1.6 inches. Convective systems usually show this type
of spread with some areas seeing very little and others a lot of
precipitation, leading to a broad brushed mean that really
doesn`t convey the whole message. The high end potential is the
value that needs to be honored though it will likely only impact
small areas under the stronger cells. As a result of these higher
high end values, WPC has a marginal excessive rainfall outlook
for central and western zones Wednesday.

Conditions quiet down by mid evening, with scattered showers
lingering into the overnight hours. Snow levels drop to around
5500-6500 feet (lowest NW/highest Beartooth and Absarokas)
Wednesday night. With the lingering showers expect 3 to 6 inches
of snow above 7000 feet, and can`t rule out a dusting down to 5000
feet over the western foothills of Park, Sweet Grass, and
Wheatland counties. Bozeman and the Beartooth Pass could both see
some slick conditions into Thursday morning from this snowfall so
plan travel accordingly. Chambers

Thursday through Monday...

Following the front overnight, conditions should be mostly dry
with breezy west winds for Thursday. Mid level disturbances from
slow moving cyclonic flow to our north will continue to provide
an unsettled pattern through the weekend. Best chances for precip
Friday look to be out east with up to a 30% chance possible.
Models then show a potential weak front moving through Saturday
into Sunday bringing a small chance for wet weather. Precipitable
water values also increase during this timeframe, but given the
uncertainty this far out, probabilities remain low for any
noteworthy amounts. Ensembles then generally trend towards ridging
and dryer conditions for Monday. High temperatures will be in the
60s/low 70s Thurs-Fri, increasing into the 70s and low 80s through
Monday. TS

&&

.AVIATION...

VFR conditions will prevail through the forecast period. Showers
and thunderstorms will begin to move through KLVM & KHWQ late
Tuesday evening. TS

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Wed     Thu     Fri     Sat     Sun     Mon
-------------------------------------------------------
BIL 079 054/076 045/064 045/070 046/075 051/076 052/080
    0/U 09/T    81/B    11/B    01/B    12/T    11/B
LVM 078 050/069 038/061 040/069 043/074 046/072 047/076
    1/U 19/T    61/N    01/B    01/B    13/T    12/T
HDN 081 052/078 045/066 043/072 044/078 050/078 050/080
    0/U 07/T    81/B    11/B    10/B    12/T    11/B
MLS 078 055/082 048/065 044/071 046/078 052/079 052/080
    0/U 04/T    71/B    11/B    00/U    11/B    11/B
4BQ 078 055/084 048/065 045/072 045/079 053/079 052/080
    0/U 04/T    70/B    21/B    10/U    11/B    11/B
BHK 074 050/082 045/064 041/070 043/077 050/078 049/077
    0/U 05/T    81/N    12/T    10/U    12/T    11/B
SHR 078 051/080 043/062 040/071 042/078 048/077 048/080
    0/U 06/T    81/B    11/U    00/U    12/T    11/B

&&

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

&&

$$
weather.gov/billings