550
FXUS65 KBYZ 120913
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
313 AM MDT Sun May 12 2024

.DISCUSSION...

Today through Monday Night...

A shortwave dropping into north central Montana was producing
isolated to scattered showers across the Hi-Line with a few
isolated showers for areas northwest of Billings early this
morning. As the shortwave continues to drop south and east
through the morning hours, expect isolated shower chances to
spread east over northern areas. An associated cold front will
drop into the area this morning/afternoon causing winds to shift
around the east and northeast. Isolated to scattered showers and
thunderstorms (15-30% chance) will develop over the area for the
afternoon and evening hours. Thunderstorms should be garden
variety with weak instability in place. Convection is expected to
diminish through the evening hours with ridging building into the
region. Highs will be a few degrees cooler today than Saturday
across central and eastern areas, but still in the 70s for most
locations. Smoke from wildfires in British Columbia and Alberta
is currently dropping into the northern US and will advect into
northeastern areas, including Miles City and Baker this morning.
Smoke should dissipate later today.

Heading into Monday, ridging begins to break down as a Pacific
wave moves into the Northern Rockies. A cold front is progged to
move through the area from west to east during the late morning
and afternoon hours, with an associated trough moving through the
region Monday night. Instability is expected to be modest, with
CAPE values of 500-1000 J/kg and deep layer shear of 20-35kts
greatest over the east. As moisture and energy advect into the
region, showers and thunderstorms are progged to develop first
over the mountains, spreading east through the afternoon and
evening hours. Current precipitation chances range from 30-60%,
greatest during the evening. Temperatures are forecast to warm
into the upper 70s to lower 80s on Monday with compressional
heating ahead of the cold front. STP

Tuesday through Sunday...

Tuesday will see rain showers across much of the area as we get
wrap around from the low pressure system. Winds will be out of the
north/northwest putting upslope areas in the foothills in the
best position for precipitation. For the event as a whole,
including Mondays precipitation (covered in short term), lower
elevations have a 20-40% chance for 0.25 inches of precipitation
while upslope areas in the mountains and foothills have a 70-90%
chance. Tuesday will be breezy behind the cold front bringing
widespread gusts into the 20s and 30s mph. Most of the area has a
50-70% chance of getting a wind gust over 30mph. Temperatures
Tuesday will be in the 60sF.

Models have come into better agreement in a ridging pattern for
Wednesday. About 80% of models now depict a ridging pattern while
the ECMWF deterministic is in the minority 20% of models showing a
troughing pattern. Wednesday could see some lingering showers
though amounts should stay under 0.1 inches. Temperatures
Wednesday will be similar to Tuesday with 60sF across the area.

Thursday through the rest of the long term still has persistent
model disagreement leading to little certainty in the long term
pattern. Thursday, about 80% of models are showing temperatures
in the high 60s to low 70s though the pattern that brings those
temperatures varies. The other 20% of models showing strong
troughing have temperatures in the 50s and expanded precipitation
chances across the area. This is a common theme across the long
term with most models keeping things pretty dry and one WPC
cluster comprising about 20% of models bringing troughing and
precipitation chances. Due to this uncertainty, every day in the
long term has a 20-40% chance for precipitation. Currently,
temperatures Thursday through the weekend look to be in the mid
60s to low 70s with inherent uncertainty due to the unclear
pattern. Torgerson

&&

.AVIATION...

Today will see light winds with some passing mid to high level
cloud. This afternoon will have scattered showers with possibly
some thunderstorms mixed in. Generally VFR conditions are
expected. Torgerson

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Mon     Tue     Wed     Thu     Fri     Sat
-------------------------------------------------------
BIL 076 049/078 050/066 047/068 048/073 049/070 044/064
    2/T 24/T    58/T    44/T    23/T    33/T    23/R
LVM 077 048/077 045/064 043/067 046/072 046/069 041/065
    1/B 15/T    48/T    43/T    23/T    33/R    24/T
HDN 077 046/080 049/067 045/068 045/074 047/071 042/066
    2/T 24/T    68/T    44/T    33/R    43/T    33/R
MLS 074 047/080 050/067 044/067 046/072 047/068 042/065
    2/W 12/T    66/T    23/R    23/R    33/R    22/R
4BQ 077 046/080 050/067 044/065 045/072 047/068 042/067
    2/T 22/T    66/T    33/T    22/R    32/T    22/R
BHK 073 042/080 048/065 041/065 043/070 044/066 039/064
    2/W 02/T    56/T    22/R    23/R    33/R    22/R
SHR 074 044/078 045/065 043/064 041/072 044/069 040/067
    3/T 25/T    68/T    55/T    23/T    33/T    32/T

&&

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

&&

$$
weather.gov/billings