590
FXUS65 KBOI 060611
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
1211 AM MDT Mon Apr 6 2026

.UPDATE...Updated aviation discussion.

&&

.KEY MESSAGES...
- High pressure will bring well above normal temperatures and
  dry conditions through Monday, with some valley highs
  reaching the mid 70s.

- A slight chance of showers and thunderstorms will develop
  late Monday afternoon across the higher terrain of southeast
  Oregon and the west central Idaho mountains.

- A dry cold front passing through Tuesday will bring breezy
  winds and a 5 to 10 degree cooling trend, primarily for
  northern areas.

&&

.SHORT TERM /Through Wednesday Night/...
Issued 211 PM MDT SUN APR 5 2026
The upper level ridge axis will move directly overhead tonight
and Monday, maintaining the dry and unseasonably warm weather
across the region. Low temperatures tonight will remain mild,
generally in the upper 30s to mid 40s in the lower valleys. For
Monday, high temperatures will continue their upward climb,
reaching 10 to 15 degrees above seasonal normals. Many lower
valley locations, including the Treasure Valley, will see highs
in the mid 70s.

As the ridge begins to shift eastward Monday afternoon, a weak
system approaching from the west will introduce just enough
instability and moisture for a slight chance (15 to 25 percent)
of showers and thunderstorms. This activity is expected to be
confined to the higher terrain of southeast Oregon and the west
central Idaho mountains during the late afternoon and evening
hours.

By Tuesday, a more potent upper level trough will move into the
Pacific Northwest from the north, pushing a dry cold front
through the area. While this front lacks significant moisture,
it will tighten the pressure gradient, resulting in breezy
northwesterly winds. The strongest winds are expected across the
western Magic Valley and Camas Prairie with gusts up to 45 mph.
High temperatures on Tuesday will be trickier to pinpoint due
to the timing of the front; northern zones will see a noticeable
cooling of 5 to 10 degrees compared to Monday, while southern
areas may remain warm until the front passes later in the
evening. Tuesday night will be notably cooler and breezy as the
front clears the region.

&&

.LONG TERM /Thursday through Monday/...
Issued 211 PM MDT SUN APR 5 2026
A slight cool down is in store Wednesday as the grazing
shortwave exits our area to the east and switches flow to be out
of the northwest. Guidance is coming into alignment on the
slower progression of a low that will develop off of the coast
of California. As alluded to in previous discussions, this will
favor a generally drier and warmer solution for our area. The
exception to this will be in SE Oregon and near the Idaho Nevada
border. As the California low slowly moves east, moisture
advection around the low will lead to a 10-25% chance of
precipitation in southern Harney County Wednesday afternoon. As
well as a 15-40% chance of precipitation Thursday afternoon,
mainly in SE Oregon and near the ID/NV border. It is worth
mentioning that there is still some uncertainty regarding the
speed of this low, which translates into the precipitation
chances. Southerly flow will allow for a warming trend through
the end of the workweek. Late Friday into the weekend,
precipitation chances will increase area-wide as the low moves
inland.

&&

.AVIATION /06Z Monday through Tuesday/...
Issued 1210 AM MDT MON APR 6 2026

VFR and high clouds. Isolated showers/thunderstorms in
northeast OR and W-central ID developing late afternoon, with
20-30 kt outflow wind gusts. Surface winds: variable 10 kt or
less, then SW-NW 5-15 kt in the afternoon. Winds aloft at 10kft
MSL: SW to W 5-15 kt.

KBOI...VFR and high clouds. Surface winds: SE 4-10 kt, shifting to
NW 4-10 kt around Mon/18Z.

&&

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

OR...None.

&&

$$

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AVIATION.....SH
SHORT TERM...JDS
LONG TERM....NF