834
FXUS65 KBOI 072050 CCA
AFDBOI

Area Forecast Discussion...CORRECTED
National Weather Service Boise ID
250 PM MDT Sat Jun 7 2025

.SHORT TERM...Tonight through Monday night...Heat will build
through the short term period, and extend into the long term. An
Extreme Heat Watch has been issued for the Lower Treasure Valley
of Oregon from Monday afternoon through Tuesday evening as
record or near-record temperatures are forecast. This will be
that area`s second significant heat event of the year, and we`re
not even technically in summer yet. Surrounding areas,
especially along the Snake River in Canyon and Ada counties,
will also be especially hot Monday and Tuesday. This heat is due
to an upper level ridge that was centered just off the coast
this afternoon. It will shift east tomorrow, and pass over our
area as it flattens out Monday into Monday night. The ridge will
also bring mostly clear skies and (relatively) light winds
through the short term.

.LONG TERM...Tuesday through Saturday...The upper-level ridge
that had brought warmer than normal temps over the weekend will
persist through Tuesday, keeping temperatures high (possibly
record breaking in lower valleys). The extreme heat watch for the
Lower Treasure Valley in Oregon is valid until 04z Wednesday as a
result of this. Beginning Tuesday afternoon through Wednesday
evening, an upper- level shortwave trough brings southwesterly
flow aloft and lower geopotential heights. Precipitation chances
increase to 15-30% Tuesday afternoon into early morning Wednesday,
then increase further to 30-60% in SW ID Wednesday afternoon into
evening. Thunderstorm chances are maximized as peak diurnal
heating and height falls occur, with the greatest chance as of now
being afternoon Wednesday at 15-30% chance. MUCAPE values greater
than 300 J/kg along with bulk shear values of over 30 kts appear
possible near the shortwave trough axis, with the joint
probability of both co-located maximizing Wednesday afternoon
along the ID/NV border at 20-50%.


Thursday dries out a bit with the upper-level shortwave trough
moving to the east, however, a longwave upper-level trough begins to
overspread the region from the British Colombia coast, keeping SW
flow aloft. There is bad agreement between the GFS and ECMWF on
timing and intensity of the longwave trough pushing an embedded
shortwave through the area. PoPs will be raised to levels
indicative of this uncertainty from late Thursday afternoon
through Saturday, with thunderstorms also being a distinct
possibility in higher elevations with the height falls and peak
diurnal heating. Temperatures trend downward closer to normal
Wednesday through Saturday, although max temps will still be
5-10 degrees above normal.

&&

.AVIATION...VFR. High density altitude tomorrow afternoon. Surface
winds: W-NW 5-12 kt through 08/03Z. Light and variable winds
overnight. Winds aloft at 10kft MSL: W-NW 5-15 kt.

KBOI...VFR. NW 5-10 kt this afternoon. Light and variable winds
overnight.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...Extreme Heat Watch from Monday afternoon through Tuesday
     evening ORZ064.

&&

$$

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SHORT TERM...SP
LONG TERM....CH
AVIATION.....CH