691
FXUS65 KBOI 201003
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
403 AM MDT Sat Jul 20 2024

.SHORT TERM...Today through Monday night...Upper level ridge
will continue to expand over the area today, with a few degrees
of warming compared to Friday. Record high temperatures
possible over the short term in some locations, depending on how
thick the smoke is. Wildfire smoke continues to impact the
area, limiting temperatures a few degrees below previous
forecasts. We used bias corrected temperatures over the past 10
days to account for wildfire smoke the temperature forecasts in
the short term. The hot conditions will support unstable
conditions, with isolated thunderstorms over central ID
mountains and along ID/NV border this afternoon. A shortwave off
the CA coast will support increased chances of thunderstorms on
Sunday afternoon, especially across eastern OR as the system
moves north along the WA/OR coast. A slight chance of
thunderstorms continues into Monday afternoon as this system
slowly tracks northeastward. Thunderstorm threats will mainly be
erratic outflow wind gusts up to 50 mph and lightning.
Excessive heat warnings, and heat advisories remain in effect.

.LONG TERM...Tuesday through Saturday...The upper level ridge
will continue through at least Thursday with continued hot
conditions. The ridge will also have substantial moisture in it
with precipitable water values in the 70-80th percentile for
this time of year. This will keep a threat of thunderstorms each
afternoon through Thursday, mainly over the higher terrain. A
trough over southwest Canada will bring cooler temperatures by
next Friday and Saturday, with temperatures cooling to near
normal or a few degrees below.

&&

.AVIATION...Low VFR/MVFR and local IFR from smoke. High density
altitude from heat. Isolated thunderstorms Saturday afternoon
near NV border and central ID mountains, with 30-40 kt outflow
winds possible. Surface winds: NW-NE 5-15 kt. Gusts up to 15-25
kt near KBKE KONO this evening. Winds aloft at 10kft MSL:
variable 5-15 kt.

KBOI...Low VFR/MVFR due to smoke. High density altitude from
heat. Surface winds: S-SE 5-10 kt overnight, then NW-NE 5-15 kt
with occasional gusts up to 15-20 kt Sat afternoon.

Sunday Outlook...Low VFR/MVFR to local IFR from smoke. High
density altitude from heat. Scattered thunderstorms Sun
afternoon mainly over E Oregon and the SW Idaho mountains, with
35-45 kt erratic outflow winds. Surface winds: E-SE 5-15 kt.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Excessive Heat Warning until 9 PM MDT Wednesday IDZ012-014-033.
     Heat Advisory until 9 PM MDT Wednesday IDZ015-016-029-030.
OR...Excessive Heat Warning until 9 PM MDT /8 PM PDT/ Wednesday
     ORZ063-064.
     Heat Advisory until 8 PM PDT Wednesday ORZ061-062.
     Fire Weather Watch from Sunday morning through late Sunday
     night ORZ636-637.

&&

$$

www.weather.gov/Boise

Interact with us via social media:
www.facebook.com/NWSBoise
www.twitter.com/NWSBoise

SHORT TERM...KA
LONG TERM....KA
AVIATION.....KA