Marsing, Idaho Weather Forecast Discussion

587
FXUS65 KBOI 080230
AFDBOI
Area Forecast Discussion
National Weather Service Boise ID
830 PM MDT Sun Sep 7 2025
.DISCUSSION...Relatively quiet in our CWA today as showers and
thunderstorms shifted to eastern ID. Monday looks breezy, warm,
and dry in our CWA as a Pacific upper low nears the coast. The
low will reach the OR coast late Monday, move inland Tuesday,
then stall in eastern OR Wednesday and Thursday, and finally
move across ID (and weaken) on Friday. The low will bring
significant cooling Tuesday through Friday, with main rainfall
Wednesday and Thursday. Current forecast aligns well with
latest models. No updates.
&&
.AVIATION...Mostly VFR. Isolated showers and thunderstorms
lingering over eastern Oregon will end by 04Z leaving scattered
mid-level clouds over the area. SFC winds variable 5-15 kt.
Winds aloft at 10kft MSL: SW 5-15 kt.
KBOI...VFR. Winds will be light and variable at less than 10 kt
overnight, generally favoring a SE direction after 04Z. VFR to
continue Monday.
&&
.PREV DISCUSSION...
SHORT TERM...Tonight through Tuesday night...A shortwave in
central Idaho will provide just enough moisture and forcing for
storms to develop along our northern and eastern areas this
afternoon and evening. Storms will develop in Baker county, the
West-Central and Boise Mountains, and s-central Idaho in the
Magic Valley, lasting until about sunset when they either
weaken or move northeast out of the area. Storms may produce
outflows up to 50 mph, small hail, and locally heavy rainfall.
As the shortwave moves out of the area tonight, dry southwest
flow aloft will continue as a low-pressure system begins to
move in Monday night. The continuous southwest flow will bring
patchy smoke aloft, but less intense than late last week.
Clearer skies tonight with the dry flow and still moist surfaces
will lead to patchy fog formation in the mountain valleys.
Afternoon gusts along the NV border will also reach about 25
mph, with very low RH at the same time and elevating fire risk.
Increasing clouds Tuesday as the low center moves closer and
dry southwest flow becomes moist. Temps drop to 5-10 degrees
below normal Tuesday as the colder airmass moves in.
Precipitation chances increase as early as Monday night, with
the first real chance of precipitation 30-40% Tuesday afternoon.
While storms Tuesday afternoon will be moving quickly, enough
instability and moisture will support heavy rain rates, and a
marginal risk of flash flooding due to excessive rainfall over
burn scars in Central ID.
LONG TERM...Wednesday through Sunday...Unsettled weather with
below normal temperatures expected through the period. An upper
level low is forecast to move east across the area Wednesday
through Friday followed by a shortwave ridge on Saturday. This
will bring a 40-70 percent chance of precipitation Wed/Thu with
slightly lower probabilities on Fri. There will be enough
instability for at least a slight chance of thunderstorms each
day. Models diverge over the weekend on the progression of the
shortwave ridge and the next Pacific low/trough. With more
uncertainty over the weekend the precipitation probabilities
trend down to 20-40 percent with the best chance for rain across
the north.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.
&&
$$
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DISCUSSION...LC
AVIATION.....MC
SHORT TERM...JM
LONG TERM....TL

NWS BOI Office Area Forecast Discussion