279
FXUS65 KBOI 170242
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
842 PM MDT Thu May 16 2024

.DISCUSSION...A dry cold front continues moving towards the area
this evening, and will pass through late tonight and Friday
morning. Winds behind the front will be strong, especially from
Elmore County and points south and east. A wind advisory has
been issued for this area and no changes will be made to the
advisory at this time. Otherwise, the front will bring much
cooler temperatures to the region, and it looks like we are
headed into an extended period of temperatures near or below
normal.

&&

.AVIATION...VFR and mostly clear. Local visibility reduction
from smoke near prescribed fires, especially in the southwest
Idaho mountains. Surface winds: W to NW 5-15 kt with local gusts
to 25 kt. Winds aloft at 10kft MSL: W 15-25 kt, increasing to
25-40 kt after 06Z/Fri.

KBOI...VFR. A few high clouds and some hazy skies near the
foothills due to smoke from prescribed burns in the Boise
Mountains. Surface winds: Briefly N from 02-04Z, then NW 5-10
kt overnight, becoming NW 15-20 kt with gusts 25-30 kt around
15Z Friday.

Weekend Outlook...Isolated showers along a cold front in the
central ID mtns Friday morning. Otherwise, VFR and mostly clear
through Saturday, becoming partly cloudy Sunday. Chance (20-50%)
of showers in the central ID mtns on Sunday. Snow levels
4500-5500 ft MSL. Surface winds very breezy on Friday W-NW 15-25
kt with gusts 25-40 kt, and again on Sunday W-NW 10-20 kt with
gusts to 30 kt.

&&

.PREV DISCUSSION...
SHORT TERM...Tonight through Saturday night...A dry cold front
associated with an upper trough in western WA/OR this afternoon
will move across SE Oregon this evening and SW Idaho late
tonight. The winds are not expected to be very strong along its
passage with gusts only to around 30 mph. However, the post-
frontal winds ramp up during the later morning that persist
through the afternoon and early evening, especially east of
Boise where a Wind Advisory has been issued. Sustained winds of
25-35 mph with gusts to around 50 mph develop by late morning
from near Mountain Home east to Fairfield, Jerome, and Twin
Falls areas. The pressure gradient relaxes later in the evening
which will allow the winds to diminish by late evening. Models
are in agreement that the moisture associated with the trough
remains to our north, but there is a 15 to 30 percent chance of
showers north of McCall. Temperatures will be 10 to 20 degrees
cooler with highs generally in the 50s higher elevations and 60s
lower elevations. Dry and warmer conditions are expected on
Saturday ahead of the next `dry` cold front that is due to
arrive Saturday night. Breezy conditions will continue on
Saturday and with the passage of the cold front Saturday night.

LONG TERM...Sunday through Thursday...An upper level trough
will move through the area on Sunday. The core of the trough
will remain to our north, but a cold front will cool
temperatures around 10 degrees from Saturday. A 20-50% chance of
showers will develop across the central Idaho mountains, but
dry conditions are expected elsewhere. Snow levels 4500-5500
feet may allow for a dusting of snow on mountain peaks. The
trough will also bring breezy conditions, with gusts 25-40 mph.
Gradual warming is expected Monday and Tuesday as the trough
gradually exits the area. An upper level low will move into the
Pacific Northwest Wednesday and Thursday, bringing our next
chance of precipitation to the entire area. There is still
uncertainty in the track of the low, which will determine which
areas see significant precipitation. Precipitation chances
increase Tuesday night through Wednesday as the low approaches
and peak on Thursday, with a 20-60% chance in all areas. Snow
levels are expected to drop to 4000-6000 feet as the low center
moves overhead, with potential for late-season light mountain
snow. Cooler temperatures and breezy winds are also expected as
the low moves inland.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 9 AM to 9 PM MDT Friday IDZ014-016-028-030.
OR...None.

&&

$$

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DISCUSSION...SP
AVIATION.....SP
SHORT TERM...BW
LONG TERM....ST