591
FXUS65 KBYZ 151619
AFDBYZ

Area Forecast Discussion...Updated
National Weather Service Billings MT
1019 AM MDT Sat Jun 15 2024

.UPDATE...

Showers are lifting north and east through the area this morning.
Thunderstorms are expected to develop over the mountains this
afternoon, moving north and east through the evening hours. MUCAPE
values between 1000-2000 J/kg and deep layer shear values of
30-45kts will allow a few strong to severe thunderstorms, with the
greatest threat over far east MT and northern areas. Strong winds
and large hail are the main threats. A cold front will move
through the area late this afternoon and evening, bringing west to
northwest wind gusts of 20-40 mph through the area. Have updated
PoPs to the latest trends through this evening. STP

&&

.DISCUSSION...

Today through Sunday Night...

Scattered showers are evident on radar early this morning north
and east of Billings. This activity will gradual move east out of
the area through the early morning hours. Upstream, there are
additional scattered showers that are expected to move through our
western areas (west of Billings) through the later morning hours.
This morning`s activity is expected to remain weak.

By this afternoon, another round of showers and thunderstorms is
possible across portions of the area (15-50% chance). This
activity will be aided by a more vigorous shortwave aloft that is
expected to traverse through northern Montana this evening. Even
though the main shortwave will pass to our north, a cold front
will pass through our entire area late this afternoon and evening.
This cold front will bring gusty NW winds to the entire region,
with wind gusts of 20 to 40 mph common. A few isolated to
scattered showers and thunderstorms may accompany the front
(15-50% chance, highest north of Billings), but this activity
should remain relatively weak. The main threat will be localized
areas of enhanced winds where these showers and thunderstorms
develop. Outside of this frontal activity, stronger storms are
also possible (20-30% chance) across far eastern Montana ahead of
the front this afternoon where diurnal instability is expected to
combine with sufficient shear and atmospheric moisture. The main
threat with any storm that develops in this area will be large
hail and strong winds, especially under the longer lasting cells.
This lines up with the day 1 outlook from SPC which has a slight
(2/5) risk for severe thunderstorms in our east today.

Stronger southwesterly winds aloft look to move in ahead of the
front today as well. This will create windy conditions in the
mountains this afternoon, with wind gusts into the 50s (mph)
possible over the highest terrain. If you have outdoor plans in
the mountains today, including the foothills, prepare and be aware
for windy conditions.

Sunday will be mostly dry before chances of precipitation
increase again during the evening/overnight in southeastern MT
with a passage of another (weaker) shortwave (20-45% chance).
Chances of precipitation will also increase in western areas
during this time as our next system begins to move in from the
west (more on this below).

Temperatures today are expected to be in the 70s and 80s over
western and central areas and near 90 in eastern areas. Sunday
will be cooler with temperatures in the 60s and 70s. Arends

Monday through Friday...

The week ahead will be cooler and unsettled with Pacific trofiness
over the area. That said precipitation amounts are significantly
lower in the models over the past 24 hours as the core of the
system is weaker and tracking further north. This puts our neck of
the woods in the drier downsloping wind sector of the system.
There will still be a good amount of instability with colder core
of upper level air over the region, leading to widespread mean
precipitation amounts of .25 to .60 inches across the area Monday
into Wednesday, while probabilities for half an inch or more of
precipitation range from 20 percent along the southern state line,
to 60 percent along the Musselshell river valley. Monday night
into Tuesday morning brings the best chance for snow with snow
levels dropping to under 7000 feet by Tuesday morning. With
precipitation amounts lower, snow accumulations decreased as well.
That said, those traveling over the Beartooth Pass or into
Yellowstone Park should expect wintry conditions and slick roads
from late Monday through at least mid-day Tuesday.

Weak ridging will dampen the chance for precipitation Wednesday
into Thursday, though there will still be a chance of unorganized
afternoon/evening showers and thunderstorms as temperatures warm
up enhancing instability in the heat of the day.

Another Pacific Trof works into the area Thursday night into
Saturday. This system will pull enhance plains moisture into the
region ahead of it setting up a better chance for substantial
precipitation with shower and thunderstorm activity.

Temperatures will be mainly in the 60s Mon/Tue,70s for the rest of
the week. Chambers

&&

.AVIATION...

Light shower activity will continue to push east and northeast
this morning. By mid day expect thunderstorms to develop over
area mountains and move east-northeastward through the afternoon
and evening hours. Latest hi-res models indicate the strongest
storms will be found over far southeast MT and northern areas.
Wind gusts of 50 kts are the greatest threat, but large hail is
possible as well.

Winds outside of thunderstorms will be gusty (35 to 50kts) in the
mountains and foothills by 18-20z, spreading into the lower
elevations as a Pacific cold front moves into the area 21-23z.
These gusty west to northwest winds late afternoon will linger
into the evening hours, especially east of Billings. The
west/northwest winds will bring an end to convection as they move
through.

TS POTENTIAL TIMES TODAY:

BIL: 20-00Z
LVM: 19-23Z
MLS: 20-02Z
SHR: 18-22Z

Chambers/STP

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Sun     Mon     Tue     Wed     Thu     Fri
-------------------------------------------------------
BIL 083 049/072 049/062 044/064 045/073 051/077 056/077
    2/W 20/B    27/W    74/T    12/T    23/T    24/T
LVM 076 038/068 041/056 036/060 037/069 043/074 049/075
    5/T 30/N    38/T    74/T    23/T    33/T    24/T
HDN 087 049/073 050/067 044/065 045/074 051/079 056/079
    2/W 20/B    37/W    84/W    12/T    32/T    34/T
MLS 088 051/072 051/064 047/064 045/072 052/077 056/077
    2/W 30/U    36/W    94/W    22/W    43/T    44/T
4BQ 092 051/073 052/067 047/063 044/072 052/078 056/076
    2/T 20/B    45/W    83/W    23/T    43/T    44/T
BHK 090 049/072 047/065 046/063 042/071 050/075 054/076
    3/T 50/N    44/W    84/W    12/W    43/T    44/T
SHR 089 046/072 045/070 042/063 042/072 048/078 052/077
    1/B 10/B    45/T    63/T    23/T    33/T    35/T

&&

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

&&

$$
weather.gov/billings