Nampa, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

842
FXUS65 KBOI 022117
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
317 PM MDT Wed Jul 2 2025

.SHORT TERM...Tonight through Friday night...An upper-level
shortwave trough has made its way into SE Oregon this afternoon. Thunderstorms
are ongoing and forming across much of SE Oregon and parts of
SW Idaho. Satellite reveals widespread cumulus development over
the past two hours leading up to this as well as continued
robust development. A Red Flag Warning remains in effect today
for the likelihood of scattered lightning over much of eastern
Oregon. In addition, an Heat Advisory is in effect for the Lower
Treasure Valley of Oregon through tonight. Although
temperatures will be a few degrees less hot compared to
yesterday, the relative humidity will be higher, resulting in
similar heat risk. Mesoscale models have decreased coverage over
the past few runs, however, forecaster confidence has remained.
The primary threats are damaging wind gusts, with gusts up to
40-50 kts possible, and small hail. DCAPE values of near 1300
J/kg are becoming widespread as 20Z, with local maxima of 1600
J/kg or greater being forecast. With these values, strong wind
gusts are certainly possible if storms can capitalize on the
CAPE values near 500 J/kg.

Thursday morning into afternoon will be quiet before a strong
upper-level shortwave trough moves into the area
evening/overnight Thursday into Friday. Precipitation chances
will increase as this moves in, with moisture values and
temperatures sufficient to threaten thunderstorms again for both
days. DCAPE values and temperatures will be lower on both days.
The threats are mainly focused close to the NV border Thursday
evening, increasing to become widespread Friday.Our current
thinking is that we may see significant storms late Thursday
night extending right on into Friday morning and through the day
Friday. The trough is notably stronger than the one we will see
today, but thermodynamic parameters will be weaker.

.LONG TERM...Saturday through Wednesday...As the upper-level
trough that impacted the region Friday moves east, another
upper-level trough will stall out over the coast of California
over the long term period. As this happens, a strong upper-level
ridge will build in over the Desert Southwest and Great Basin.
Dry southwesterly flow will envelop SE Oregon and SW Idaho. This
will lead to a steady increase in temperatures Saturday through
Wednesday. Disagreement among long range models is high on how
the upper-level low off the coast of California will progress,
whether it rides the ridge or otherwise, however, the ridging
is well agreed upon. Temperatures will begin around 5 degrees
below normal Saturday, near normal Sunday, 5 degrees above
normal Monday, and around 10 degrees above normal Tuesday and
Wednesday. Lower elevation locations may experience 100 degrees
starting Monday (10-20% chance), with higher chances of reaching
100 degrees Tuesday and Wednesday (30-60% chance).


&&

.AVIATION...Mainly VFR. Isolated showers and thunderstorms to
continue through 06Z this evening across SE Oregon and the higher
terrain of SW Idaho with gusts to 50 kt. Scattered showers and
thunderstorms across SE Oregon and the central ID mountains on
Wednesday, and isolated elsewhere across southern ID. High density
altitude due to heat. Surface winds: WNW 10-20 kt, becoming variable
less than 10 kt overnight. Winds aloft at 10kft MSL: variable 5-15
kt.

KBOI...VFR. High density altitude due to heat. Isolated showers and
thunderstorms possible this evening and again tomorrow afternoon.
Surface winds: WNW 8-12 kt.


&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...Red Flag Warning until midnight MDT /11 PM PDT/ tonight
     ORZ670-672>675.
     Red Flag Warning from 2 PM to 8 PM PDT Thursday ORZ670-672.
     Heat Advisory until 9 PM MDT /8 PM PDT/ this evening ORZ064.

&&

$$

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SHORT TERM...CH
LONG TERM....CH
AVIATION.....SA