828
FXUS65 KBOI 162036
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
236 PM MDT Sat May 16 2026

.KEY MESSAGES...
- Cool with temperatures 10 to 15 degrees below normal and gusty
  winds on Sunday.

- Rain and snow tonight across SE Oregon with accumulations
  above 5000 feet.

- Patchy frost possible Monday morning in the Snake Plain mainly
  east of Mountain Home.

&&

.SHORT TERM /Through Monday Night/...
Showers and isolated thunderstorms this evening over e-central
Oregon and w-central ID mtns will scale back this evening with
sunset. A minor trough off the BC coast this afternoon will
deepen as it drops through the Pac NW overnight. It`s a more
impressive wave as it pushes through SE Oregon Sunday morning
and will bring an area of light to moderate precipitation to
southern Harney and Malheur counties in Oregon and far southern
Owyhee County in Idaho. Precipitation type will be mostly snow
as snow levels drop to 4500 feet. This will result in
accumulations of up to 2 inches above 5000 feet with 2-4
inches above 6000 feet (mainly Steens Mtn). Not sure this will
impact roads given warm surface temperatures, but Hwy 95 from
Blue Mtn Pass to the OR/NV border could see brief slushy
accumulation. Instability showers/thunderstorms will fire off
over higher terrain on Sunday on the backside of the upper low.
Northerly winds of 20 to 30 mph with gusts of 30 to 45 mph will
setup across SE Oregon and SW Idaho. In this instance the more
northerly component will focus the strongest winds across SE
Oregon and from Murphy to Bruneau in the Snake Plain.

A broad trough remains over the western US on Monday, putting
our area under northwest flow aloft. Daytime heating will bring
cumulus buildups over the mountains, which could put down a
sprinkle on higher peaks. With the core of the cold air to the
east temperatures Monday will run 6-10 degrees warmer than
Sunday. Winds remain breezy across SE Oregon and the lower Snake
Plain in Idaho with gusts of 25 to 40 mph in the afternoon.

For frost and freeze concerns, the wind tonight should be
enough to keep frost/freeze at bay across most of the lower
Snake Plain. The coldest spots will be Gooding/Jerome/Hazelton
area with lows of 35-40 expected. Sunday night will see
temperatures a couple of degrees cooler, and forecast remains
consistent with forecast lows of 33-37 from Mountain Home to
Twin/Jerome. Have added patchy frost wording to areas from
Glenns Ferry to Hazelton where the winds are lightest.

&&

.LONG TERM /Tuesday through Saturday/...
Showers will linger across the higher terrain of southwest
Idaho Tuesday/Wednesday as the upper level trough makes it`s way
east. Northwest flow aloft will prevail behind this trough the
work-week, with increasing heights supporting a warming trend
throughout the period. Come Friday, a shortwave embedded in the
northwesterly flow will graze our area; this will give way to a
slight chance of showers, primarily over the West Central
Mountains. This shortwave will also slow the warming trend come
Friday. Following that shortwave, ridging will likely build in
through the coming weekend with a deepening Gulf of Alaska low.
Temperatures are forecast to be 5-10 degrees above normal after
Wednesday. Winds will be on the breezier side throughout the
period, with afternoon gusts to 20-25 mph across the typical
windy areas.

&&

.AVIATION /18Z Saturday through Sunday/...
Issued 1144 AM MDT SAT MAY 16 2026

Generally VFR. Brief MVFR-IFR conditions in scattered
showers/isolated thunderstorms this afternoon near KBKE-KMYL.
Showers becoming more widespread overnight outside of the Snake
plain. Mtns obscured in precip. Snow levels: 4.5-6.5 kft MSL
this afternoon, lowering to 3-4kft MSL overnight. Surface winds:
W-NW 10-20 kt with gusts to 20-30 kt this afternoon. Then N-W
5-15 kt overnight. Winds aloft at 10kft MSL: W-NW 15-25 kt.

KBOI...VFR with increasing mid-clouds. Surface winds: NW 10-20
kt with gusts up to 30 kt this afternoon. Gusts decreasing
after sunset.

Sunday Outlook...increasing showers outside of the Snake Plain
early Sun/AM, then isolated to scattered showers Sun/PM mainly
over the w-cntrl mtns. Brief periods of IFR-LIFR in mtn snow/low
ceilings. mtns obscured. Snow Levels: 3-4 kft MSL Sun/AM,
rising to 4-5kft MSL Sun/PM. Surface winds: N-NW 10-25 kt with
gusts 25-40 kt.

&&

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

OR...None.

&&

$$

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SHORT TERM...DG
LONG TERM....NF
AVIATION.....NF