FXUS65 KBOI 200912
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
312 AM MDT Tue May 20 2025

.SHORT TERM...Today through Thursday night...At 2 AM MDT there
were still a couple lightning strikes in the Owyhee Mountains, 
suggesting thunderstorms are possible into the morning. Best 
instability this morning (although only marginal) is indicated 
in the west-central Idaho mountains, so we added isolated 
thunderstorms there through 9 AM MDT. After that, models show 
gradual stabilization, with no further chance of thunderstorms 
until Thursday afternoon, again along our northern CWA border 
when the next Pacific trough moves inland. Meanwhile, breezy 
cool weather will continue today under strong WNW flow aloft. 
Strongest winds, 20-30 mph with gusts to 35 mph, will blow this 
afternoon in south-central Idaho including the Camas Prairie. 
Wednesday should be 5 degrees warmer than today, and also less 
windy, as a short wave Pacific upper ridge moves inland, and 
Thursday another 2 degrees warmer before the next upper trough 
moves inland across WA. That trough will produce a 30 to 50 
percent chance of showers across the northern half of our CWA, 
and 10-20 percent chance of thunderstorms in our northern 
mountains, then clearing Thursday night as the trough passes by 
to our north. 

.LONG TERM...Friday through Tuesday...One last Pacific trough 
forecast to move inland Friday, with another 20-30 percent 
chance of showers and thunderstorms across our western and 
northern areas. After that, an upper ridge will build strongly 
northward from the Great Basin bringing sunny, warmer days 
Saturday through Monday. High temps Saturday will be in the 60s 
through 70s, then about 5 degrees warmer Sunday, and another 5 
degrees Monday, then dropping back slightly Tuesday. A weak 
upper trough off California will increase clouds late Monday, 
leading to a 20 percent chance of showers over eastern Oregon 
and west- centtral Idaho Monday night and Tuesday.

&&

.AVIATION...VFR. Lingering showers may continue across SW ID
(KBOI and KEUL) through the early morning. Mountains obscured 
at times in precipitation. Snow levels in the 5500-6500 feet
MSL range overnight. Surface winds: Variable 5-10 kt overnight,
becoming NW 10-15 kt with gusts up to 25 kt late this morning 
and afternoon. Winds aloft at 10kft MSL: W-NW 15-25 kt.

KBOI...VFR. Some more light rain and vicinity showers are 
possible until early morning. Variable winds 5-10 kt, becoming 
NW 10-15 kt with gusts up to 25 kt Tuesday late morning/early 
afternoon.

&&

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

&&

$$

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SHORT TERM...LC
LONG TERM....LC
AVIATION.....JY