Flash Flood Warning 41, NWS Billings, MT

Area Forecast Discussion
National Weather Service Billings MT
127 PM MDT Sat Jul 1 2023

.DISCUSSION...

Through Monday Night...

Showers and thunderstorms were developing over the southern
mountains, with increasing showers and thunderstorms over western
and south central Montana, as a shortwave moved into the region
this afternoon. Expect isolated to scattered showers and
thunderstorms to develop over western areas through the afternoon,
spreading east into the evening as the wave slides through the
area. Temperatures will top out in the 85 to 95 degree range
today, highest over the northeast. With the warm temperatures, and
overall drier conditions, the strongest storms will be capable of
wind gusts of 50 to 60 mph into the evening.

Westerly downslope flow in place on Sunday will keep similar
temperatures in place with highs in the 80s and 90s. A backdoor
front, associated with an upper low crossing central Canada will
begin to drop into the area Sunday evening. As the front drops
south, there is a chance for showers and thunderstorms overnight,
mainly over central and eastern zones. A reinforcing shot of
cooler air dropping in from the north will bring highs in the 70s
to lower 80s on Monday, along with increasing shower and
thunderstorm chances. Greatest precipitation chances look to be
across the southern mountains and foothills (50-70% chance), with
decreasing chances to the north. A few storms could be strong,
with modest instability in place. STP

Tuesday through Saturday...

The Fourth of July is shaping up to be one of the coolest on
record for many areas across southern Montana and northern
Wyoming. Here is a look at some forecast high temperatures vs the
record minimum max temps ever recorded on July 4th:

Location   Fcst High    Record Min High (year)

Sheridan:    62             65 (1915, 1958)
Billings:    63             63 (1999)
Livingston:  62             60 (1993)
Miles City:  67             63 (1993)

A trailing shortwave trough will cut through Montana Tuesday with
widespread rain developing across southern Montana and northern
Wyoming Tuesday afternoon into Tuesday night. No severe weather is
expected with the cool temperatures, but there is generally a 50
percent chance of at least a half inch of rain to the southeast
of Billings and a 25 to 40 percent chance elsewhere. Chances are
much lower for an inch or more of precipitation with the Bighorns
and the foothills seeing the best chances at around 30 percent.

In addition to the precipitation and cool temperatures, northwest
flow behind the front has a chance to bring some smoke into the
area from the wildfires in Canada. Last but not least, these
below-normal temperatures will allow precip in the higher
elevations (above 10,000 ft) to occur as snow, hence the Beartooth
Pass at the top does have a medium chance to observe snow once
again this summer on the 4th. Overall, expect a cool, wet, and
possibly hazy Independence Day.

Broad cyclonic flow persists over the area for the rest of the
work week after Tuesday, bringing at least a small chance for
storms each day, and keeping temperatures mild. Highest
confidence for the next widespread shot of storms and rain looks
to occur on Friday or Saturday as ensembles have a another defined
trough cutting across the area. Details are highly uncertain, and
will continue to keep an eye on this system throughout the week.

Mottice/Vertz

&&

.AVIATION...

Primarily VFR conditions will prevail through tonight. Scattered
showers and thunderstorms are developing over the higher terrain
and will spread east through the evening hours. These storms will
be higher based with less rain making it to the ground, so not
anticipating more than localized and brief MVFR visibility near
precipitation areas. Wind gusts to 40kts are likely near and ahead
of any thunderstorms, with an isolated 50kt gust at around a 15
percent probability.

-Mottice

&&

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

&&

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