617
FXUS65 KBOI 281758
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
1158 AM MDT Mon Sep 28 2026

.UPDATE...Updated aviation discussion.

&&

.KEY MESSAGES...
- Cloudy skies and isolated rain showers continue in SW Idaho
  this morning, clearing from west to east throughout the day.

- Fair skies and warmer temperatures Tuesday through the
  weekend, ranging 5-10 degrees above normal.

- Breezy northwest winds expected the next several afternoons,
  mainly in the Upper Treasure/Magic Valleys and the surrounding
  terrain.

&&

.SHORT TERM /Through Wednesday Night/...
Issued 246 AM MDT MON SEP 28 2026
An elongated trough over the western U.S. continues to bring
cloud cover, virga, and isolated rain showers across far
southeast Oregon and southwest Idaho this morning. Skies will
clear from from west to east throughout the day as the low and
subsequent moisture head eastward. This will allow temperatures
to warm for eastern Oregon and portions of southwestern Idaho
today, while south-central Idaho is likely to remain cooler with
the extended influence of the low. 500mb heights will begin to
rise in west-northwest flow tonight through Wednesday, yielding
warmer, drier conditions area-wide. The W-NW flow will also
contribute to breezy surface winds for the western Snake Plain
and surrounding terrain in the afternoons today through
Wednesday.

&&

.LONG TERM /Thursday through Monday/...
Issued 246 AM MDT MON SEP 28 2026
A flattened ridge, centered over the southwest U.S., will
dominate the region Thursday through the weekend, with
temperatures climbing to 5-10 degrees above normal. A couple of
weak disturbances may infiltrate the ridge Friday through
Sunday, which would increase cloud cover and bring more
uncertainty for temperatures. However, precipitation chances
remain below 10 percent during this time-frame. Early next week,
models favor a strengthening ridge along the West Coast that
would support dry, warm, and fair conditions across southeast
Oregon and southwest Idaho.

&&

.AVIATION /18Z Monday through Tuesday/...
Issued 1153 AM MDT MON SEP 28 2026
VFR with clearing skies this afternoon through tonight. Patchy
morning fog/low stratus in sheltered mountain valleys Tuesday
morning. Surface winds: W-NW 5-15 kt, afternoon gusts to 25 kt
from KBOI to the south/east. Winds aloft at 10kft MSL: W-NW 5-15
kt.

KBOI...VFR with clear skies. Surface winds: W-NW 4-10 kt,
increasing to 10-15 kt with gusts to 20-25 kt this afternoon
after 20Z, lowering to 6-11 kt in the evening after Tue/02Z.

&&

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

OR...None.

&&

$$

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AVIATION.....JY
SHORT TERM...SH
LONG TERM....SH