892
FXUS65 KBOI 220204
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
804 PM MDT Fri Jun 21 2024

.DISCUSSION...No changes to current forecast with Saturday a
very hot day and Sunday only a degree or so cooler but also
windier, then 5 to 10 degrees cooler Monday behind a dry cold
front, warming again midweek with Wednesday as hot as this
weekend. A degree or two cooler Thursday, then windy and 15
to 20 degrees cooler Friday behind a significant cold front.
No rain through the period. Increasing fire danger the next
several days due to hot temperatures, low humidity, and
occasional gusty winds.

&&

.AVIATION...VFR. Surface winds: becoming variable 10kt or
less by 22/04Z. Winds aloft at 10kft MSL: W-SW 5-15 kt.

KBOI...VFR. Surface winds N to NW 5-10kt, switching to SE
5-10kt around 22/06Z.

Sunday Outlook...VFR. Hot temperatures will bring high
density altitudes. Surface winds W-SW 10-20kt during the
afternoons, light during the night.

&&

.PREV DISCUSSION...
SHORT TERM...Tonight through Sunday night...Temperatures
will be hot this weekend as a ridge of high pressure builds
overhead. Model blends indicate a 40-80% chance of hitting
100 degrees in the Treasure Valley each day with the best
chance on Saturday. These temperatures are 15-20 degrees
above normal, but a few degrees shy of record highs. Clear
skies and dry air will allow overnight lows to drop into
the low to mid 60s each night, helping to mitigate heat
concerns. Southwest flow aloft will develop as the ridge
axis shifts to our east, with breezy conditions across the
higher elevations starting Saturday and increasing on Sunday.
Wind gusts on Sunday will reach 25-35 mph in the higher
terrain, but will be lighter in the lower elevations. An
upper trough will move by to our north Sunday night and
push a dry cold front through our area. This will bring
locally breezy conditions Sunday night through the Snake
Plain, but no chance of precipitation.

LONG TERM...Monday through Friday...A dry cold front will
exit to our east on Monday, allowing temperatures to cool
by 5-10 degrees from Sunday, but still remaining around 10
degrees above normal. West to northwest winds will be breezy
behind the front, especially in the Magic Valley and in higher
elevations. An upper level ridge will reamplify Tuesday and
Wednesday with its axis just to our east. Temperatures will
be hot once again, and although temperatures are currently
forecast to reach the upper 90s, model blends indicate a
30-50% chance of reaching 100 degrees on Wednesday in the
Treasure Valley. West to southwest flow aloft will bring
breezy conditions especially to the higher terrain.

A pattern change is anticipated late Thursday and Friday
as an upper level trough moves through the Pacific NW.
Temperatures will cool considerably as this system pushes
a cold front through our area, with highs by Friday dropping
to a few degrees below normal. However, the core of the
trough is expected to remain to our north, bringing only
a 10-20% chance of showers and thunderstorms to higher
elevations. Winds will remain breezy as the trough moves
through.

&&

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

&&

$$

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