376
FXUS65 KBOI 191000
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
347 AM MDT Sat Apr 19 2025

.SHORT TERM...Today through Monday night...At 3 AM MDT a
cold front associated with a weak upper trough extended from
Saskatchewan, through Alberta, southern BC, to the WA coast.
The front and trough are forecast to pass through our CWA this
afternoon and evening with clouds and breezy northwest winds,
but light rain showers only in northern-most mountains. Due to
the late arrival of the front, high temps today will be 4 to 8
degrees warmer than yesterday. Only slight cooling will be felt
behind the front, and Sunday will end up as warm as today, but
northwest winds will be stronger with afternoon gusts to 30 mph
in south-central Idaho and in the southwest Idaho Highlands
(i.e., south of the Snake Basin). Cooling aloft will create a
slight chance of thunderstorms Sunday afternoon and evening in
south-central Idaho. A more significant upper trough in southwest
Canada will deepen over our CWA Monday, with high temps 5 to 10
degrees cooler than Sunday, but with no clearly-defined surface
cold front. All rivers are forecast to stay below flood stage
the next several days.

.LONG TERM...Tuesday through Saturday...Fair weather is expected
across the region as a dry, broad troughing pattern initially
dominates, allowing for a gradual warming trend. With unfettered
insolation high temperatures will climb to 5-10 degrees above
normal by Thursday, while lows hover around 2-4 degrees above
normal through the period. However, a change in the pattern
will take place starting Thursday afternoon as increasing
moisture and instability begin to move in from the west in
advance of a fairly well organized North Pacific low pressure
system. Models differ on whether it becomes a closed low or
stays an open trough, and also differ on its positioning.
Regardless, this new, changing pattern will facilitate
increasing cloudiness along with chances (up to 40%) for
showers across the forecast area.  Showers may become more
convective in the afternoons due to daytime heating and
orographic lift. Wind speeds will also reach breezy levels
from the west during this pattern transition.

&&

.AVIATION...VFR. Middle and high clouds increasing from the
northwest after 18Z as a cold front approaches. Isolated
rain showers north of KBKE-KMYL from 21Z through 03Z Sunday.
Clearing from the northwest after 06Z Sunday. Surface winds:
variable less than 10 kt through 18Z, then northwest 10-20 kt
21z through 03Z Sunday. Winds aloft at 10kft: NW 15-25 kt.

KBOI...VFR. After 18Z clouds at or above 150 MSL increasing
from the northwest. Surface winds: Variable less than 8 kt
through 18Z, becoming northwest 8-14 kt through 03Z Sunday,
then decreasing.

Sunday Outlook...VFR. Broken-overcast clouds at or above 150
MSL. Scattered rain showers north of KMYL. Scattered rain
showers and isolated afternoon thunderstorms south of the
Snake River in Idaho. Surface winds: W-NW 15 to 25 kt, with
afternoon gusts to 30 kt. Winds aloft at 10kft: W 15-25 kt.

&&

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

&&

$$

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SHORT TERM...LC
LONG TERM....WH/LC
AVIATION.....LC