605
FXUS65 KBOI 181541
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
941 AM MDT Tue Jun 18 2024

.DISCUSSION...Moisture and instability associated with a weak
upper trough will be marginally supportive of convection this
afternoon. The highest chances (30-50 percent) are in central
Idaho. There is also a slight chance (less than 20 percent) of
afternoon thunderstorms in central Idaho. Temperatures recover
about 10 degrees from yesterday, but still around 10 degrees
below normal today. No updates.

&&

.AVIATION...Isolated showers/thunderstorms will begin this
afternoon over higher terrain in SW ID/NE OR, mainly in the
Wallowa and West Central Mountains. Generally VFR, except
MVFR/IFR conditions in rain and snow showers. Snow levels
6000-7000 ft MSL. Surface winds: variable less than 10 kt,
except erratic winds with gusts to 30 kt near showers and
thunderstorms. Winds aloft at 10kft MSL: W-SW 10-15 kt.

KBOI...VFR with a few high clouds. Surface winds: variable less
than 6 kt becoming E-SE 4-8 mph after Wed./06Z.

&&

.PREV DISCUSSION...
SHORT TERM...Today through Thursday night...A weak upper-level
trough will linger over the region today, maintaining the chance
for precipitation, especially across the higher terrain of
southwest Idaho. This afternoon, there appears to be sufficient
instability for thunderstorms to develop alongside the showers,
with the best chance for thunderstorms across the West Central
and Boise Mountains. Temperatures will rise about 10 degrees
from yesterday`s highs, reaching the low 70s in the lower
valleys.

The weak through will persist over the Intermountain West
through Thursday. Temperatures will continue to warm, increasing
by another 10 degrees on Wednesday. However, a weak low
pressure system passing to the north will limit the warming to
around 5 degrees on Thursday. By Thursday, temperatures will
reach about 5-8 degrees above normal.

LONG TERM...Friday through Tuesday...Persistent southwest flow
aloft and steadily increasing heights among all guidance
supports dry conditions and a warming trend through the weekend.
Confidence is high that valley max temperatures will reach the
upper 90s by the weekend. Thickness values support highs greater
than or equal to 100 degrees for portions of the lower Snake
Plain including Boise, but models are struggling to get quite
that high. Currently, there`s a 30% chance for 100 or higher in
that area on both Saturday and Sunday. Temps should drop to
about normal Monday/Tuesday as an upper trough moving through
the PacNW, though guidance disagrees on the track of the trough
slightly so confidence is low in the amount of cooling.

&&

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

&&

$$

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DISCUSSION...BW
AVIATION.....SA
SHORT TERM...JDS
LONG TERM....JM