FXUS65 KBOI 191824
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
1224 PM MDT Tue May 19 2026

.UPDATE...Updated aviation discussion.

&&

.KEY MESSAGES...
- Frost Advisory for the western Magic Valley until 8 AM MDT
  this morning.

- Warming trend and continued generally dry the rest of the
  week.  Monday should be the warmest day. 

- Cold front early Tuesday, then windy and turning cooler with
  a chance of showers and thunderstorms.

&&

.SHORT TERM /Through Thursday Night/...
Issued 248 AM MDT TUE MAY 19 2026
Patchy frost this morning in the western Magic Valley but Wednesday 
morning will be milder with no frost. Gradual warming trend today
through Thursday as the main upper trough shifts east of the 
Continental Divide. However, another weaker upper trough, in BC 
early this morning, will dig southward into eastern ID Wednesday
and limit the warming in our area. This second trough will be 
close enough to our CWA for a slight chance of showers in 
eastern Valley County Wednesday evening, and also slightly 
stronger wind in the Magic Valley Wednesday afternoon. Otherwise,
no eventful weather through Thursday night.

&&

.LONG TERM /Friday through Tuesday/...
Issued 248 AM MDT TUE MAY 19 2026
A ridge of high pressure will build over the Western US by the end 
of this week, bringing generally warm and dry conditions to the 
region through Monday. Temperatures will be about 10-15 degrees 
above normal. On Saturday, a quick moving shortwave trough will move 
through the region bringing low chances of showers and thunderstorms 
(<10% chance) over high terrain in southwest Idaho and the OR-NV 
border. The ridge will reach peak strength on Sunday, with high 
temperatures near 90F in the Treasure Valley. By Monday, there is 
widespread model agreement in a deep upper level low moving into
the Pacific Northwest. The low will then move into the region 
on Tuesday, cooling temperatures off by 10-20 degrees and 
bringing breezy winds with a chance of showers and thunderstorms
(20-30% chance).

&&

.AVIATION /18Z Tuesday through Wednesday/...
Issued 1214 PM MDT TUE MAY 19 2026
VFR. Scattered high based cumulus clouds will continue over the
area with some producing virga and gusty winds. Surface winds
generally W to NW at 5-15 kts, except in the vicinity of virga
where gusts to 35 kts are possible this afternoon. Winds light
and variable less than 10 kts tonight across the area. Winds
W-NW 10 to 15 kts on Wednesday.

KBOI...VFR. Surface winds NW 10 to 15 kts this afternoon. Winds
light and variable less than 5 kts tonight. Winds W-NW 10 to 15
kts on Wednesday.

&&

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

OR...None.

&&

$$

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AVIATION...JB
SHORT TERM...LC
LONG TERM....SA