National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS65 KBOI 230932
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
332 AM MDT Tue Apr 23 2024

.SHORT TERM...Today through Thursday night...A weak upper ridge
supporting the dry conditions shifts east this morning.
Southwest flow aloft develops this afternoon as an upper trough
approaches the west coast. Some moisture available for
convection residing in central Nevada will move northward and
cross the Nevada border for isolated showers in our southern
areas this afternoon. There may be enough instability to support
up to a 20 percent chance of thunderstorms in southern Harney
County this evening, accompanied by wind gusts of 30-40 mph.
The moisture will continue to advect further northward as the
trough moves closer to our area on Wednesday for a better chance
of showers, mainly across southern areas near the Nevada border
(30-60 percent chance). This is also the area that could have
enough instability to support up to a 20 percent chance of
afternoon and evening thunderstorms. Once again, the
thunderstorms will be capable of producing gusty winds up to 40
mph. The trough exits to the east on Thursday as another Pacific
trough takes aim on the Northwest. This system is more organized
and shows better potential for showers to spread into the area
by Thursday night, especially in the higher elevations. The
system will also be accompanied by a cold front, resulting in
breezy to locally windy conditions on Thursday. Warmer
temperatures are expected today and Wednesday, averaging 5 to 10
degrees above normal, then cooling several degrees on Thursday
with the arrival of the cold front.

.LONG TERM...Friday through Tuesday...An upper level trough
will move across our area on Friday, bringing showers and cooler
temperatures. Precipitation chances will rise to 40-90%, and
cold temperatures aloft combined with strong surface heating
will result in a 10-20% chance of afternoon thunderstorms. Highs
will drop to a couple degrees below normal. The trough will
move east over the weekend as a deep upper level low moves
across the Gulf of Alaska. A 20-60% chance of showers will
continue on Saturday and Sunday as moisture lingers behind the
departing trough, with the highest chances each afternoon over
the mountains. Southwest flow aloft will develop late Sunday
into Tuesday as the low approaches the Pacific Northwest. This
should allow temperatures to rebound a few degrees to near
normal. Moisture and a couple weak impulses moving through the
flow will bring a continued threat of showers to our area. Winds
will be breezy through the period, especially in the Magic
Valley. Snow levels will fluctuate through the period, but
should generally remain above 5500 feet MSL. However, cooler
temperatures and lower snow levels are possible next week as the
center of the trough eventually moves inland.

&&

.AVIATION...VFR under thin high clouds. Increasing mid-level
clouds with isolated showers and thunderstorms developing over
SE OR and far SW ID after 21Z Tuesday. Surface winds: variable
10 kt or less, except gusts up to 35 kt near showers and
thunderstorms. Winds aloft at 10kft MSL: NW 5-15 kt, becoming SW
after 18Z.

KBOI...VFR. Surface winds generally SE less than 10 kt, but
variable direction at times.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.

&&

$$

www.weather.gov/Boise

Interact with us via social media:
www.facebook.com/NWSBoise
www.twitter.com/NWSBoise

SHORT TERM...BW
LONG TERM....ST
AVIATION.....ST