512
FXUS65 KBYZ 130846
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
246 AM MDT Mon May 13 2024

.DISCUSSION...

Monday Through Tuesday Night...

Today will see an upper trough from our west move in along with a
surface low pressure system. This low to our north will bring a
cold front through the area with it exiting into the Dakotas by
around 18Z today. In past days it seemed there would be a line of
showers and thunderstorms along this front, this no longer seems
to be the case with models pushing back the onset of precipitation
to around 21Z. Dewpoints will peak in late morning and not change
much or even decrease throughout the day as temperatures
increase. This will bring the best CAPE before any showers start
to develope. With CAPE values <500J/kg, weak jet forcing, and
shear <25kts, today will see popcorn showers and thunderstorms
that could produce small hail and wind gusts near 40kts.
Temperatures will be warm today in the high 70s to low 80s as
ridging moves off to the east. Smoke from Canadian wildfires could
return to the region based on the latest HRRR model runs. From
this morning through early afternoon, areas in our east including
Miles City and Baker could see some patchy smoke.

Tuesday will be cooler in the 60s with the passage of the cold
front and troughing moving in. Southeast Montana will be on the
backside of the low with northwest winds wrapping Pacific moisture
into the area. The overall setup will be similar to Monday
leading to more showers and thunderstorms. Due to the northwest
winds, the locations with the best chance for precipitation will
be locations along the foothills and Bighorn County. Locations in
these areas have a 70-90% chance on getting 0.25 inches of
precipitation while lower elevations have a 40-70% chance. Both
Monday and Tuesday have 50-70% chances of precipitation across
the area. Winds will be breezy Tuesday although models seem to
have backed of on the winds. Gusts into the 20s mph will be
common and areas in Sheridan and Wheatland counties having high
probabilities (>80%) of getting a wind gust over 30 mph. Given the
muted response to the heavy precipitation we have gotten recently
on streams and river, flooding is not expected to be a concern
with this precipitation. Torgerson



Wednesday through Monday...

Cyclonic flow and additional energy dropping into the area from
the northwest will keep shower and thunderstorm chances in the
forecast for Wednesday (15-30% chance over the plains, 40-75%
foothills and mountains). Brief shortwave ridging and drying
Wednesday night is then replaced by a cold front passage on
Thursday, associated with a shortwave crossing along the US/Canada
border. Yet another shortwave and front is progged to cross the
area on Friday. Isolated to scattered showers and thunderstorms
are possible both days (15-40% chance), with breezy northwest
winds (20-30 mph). Cluster analysis shows differing solutions
heading into the upcoming weekend, with varying degrees of ridging
or troughing over the area. That being said, most ensembles point
to at least large scale troughing setting up over the western US,
with unsettled conditions over the region into Monday.

High temperatures look to range from the 60s on Wednesday,
warming up into the 70s for Thursday and Friday. With lower
heights aloft progged for the weekend, temperatures dip back
towards normal, with highs in the 60s Saturday through Monday. STP
&&

.AVIATION...

In general, VFR will prevail for most areas through the period.
Patchy to areas of smoke from Canadian wildfires will lower
visibility to MVFR at times through the morning hours across the
northeast, including KMLS and KBHK. A disturbance moving through
the region will bring increasing shower and thunderstorm chances
this afternoon and evening. Thunderstorms could produce moderate
rainfall, small hail and brief MVFR conditions. STP

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Tue     Wed     Thu     Fri     Sat     Sun
-------------------------------------------------------
BIL 079 051/067 048/068 050/074 049/074 048/065 043/063
    3/T 69/T    53/T    23/T    32/W    23/T    33/W
LVM 078 046/067 044/068 046/074 047/074 044/064 040/063
    3/T 68/T    52/T    13/T    22/W    24/T    33/W
HDN 081 051/069 046/069 047/075 048/074 046/067 042/063
    3/T 78/T    53/T    23/T    32/W    33/T    33/W
MLS 081 053/070 045/068 048/072 048/071 046/066 043/064
    1/K 56/T    22/T    33/W    32/W    32/W    22/W
4BQ 080 052/068 046/067 046/072 048/072 047/066 042/061
    3/T 77/T    32/T    22/T    32/W    22/T    22/W
BHK 081 049/071 041/067 044/070 045/069 043/065 040/061
    2/T 56/T    12/W    23/W    32/W    32/W    22/W
SHR 079 046/067 044/065 042/073 046/074 043/065 040/060
    5/T 89/T    55/T    23/T    42/W    23/T    33/W

&&

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

&&

$$
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