323
FXUS65 KBOI 090228
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
828 PM MDT Sat Jun 8 2024

.DISCUSSION...Storms are moving through SE Oregon this evening,
with a couple severe warnings issued for estimated hail sizes of
1" and greater. Gusty outflow winds may accompany any storm,
with a general range of 40-50 mph, but gusts up to 60 mph remain
a possibility. The remoteness of these storms is making it
difficult to produce estimates using the radar, especially when
it comes to surface wind speed estimates. Storms are forecast to
continue until around midnight, although significant weakening
may take place after sunset as solar heating cuts off. Models
vary in overnight impacts, with a few still showing a brief
outflow and high-based showers/storms moving through the
Treasure Valley. Confidence for outflow gusts is highest in the
Lower Treasure Valley. Forecast remains unchanged, Sunday will
still see widespread convection with a 5% chance for severe
storms mainly near the Magic Valley. Storms on Sunday may
produce locally heavy rainfall, but flash flood potential will
be limited by the fast moving nature of precipitation.

&&

.AVIATION...Mainly VFR. Isolated showers/thunderstorms in SE
Oregon, then into w-central Idaho after Sun/06Z. Localized
storm outflow winds up to 30-40 kt, as well as MVFR conditions
due to brief mod/heavy rain. Showers continue overnight in
e-central OR, but expand in coverage to most of the area after
sunrise on Sunday. Storms expected to redevelop Sunday
afternoon/evening, with the strongest storms along the ID-NV
border and the Magic Valley Surface winds outside of storm
activity: N to NW 5-15 kt, then variable less than 10 kt
overnight. Winds at 10k ft MSL: variable 5-15 kt.

KBOI...VFR. Surface winds W to NW 5-15 kt, then variable
overnight. A 10 percent chance of showers/thunderstorms capable
of outflow winds reaching terminal between Sun/07Z-09Z. Light
rain showers possible all day Sunday. Confidence in the
formation of afternoon thunderstorms is low, with a less than
15% chance of a storm within the vicinity of the airport.

&&

.PREV DISCUSSION...
SHORT TERM...Tonight through Monday night...The atmosphere is
becoming unstable late this afternoon and isolated thunderstorms
are expected to develop over portions of southeastern Oregon
early this evening. These thunderstorms will produce gusty
outflow winds in their vicinity. Moisture will increase over the
entire area on Sunday ahead of weak upper level shortwave
trough which will move across the area on Sunday afternoon
bringing scattered thunderstorms to the area. Some of these
thunderstorms may produce brief heavy rainfall rates, especially
in portions of the west central mountains of Idaho. Meanwhile,
thunderstorms on Sunday afternoon in portions of south-central
Idaho, including the Magic Valley, are likely to produce very
gusty winds with a marginal risk (around 5 percent chance) of
becoming severe. The shortwave trough will exit towards the east
on Monday with dry conditions and slightly cooler temperatures
expected.


LONG TERM...Tuesday through Saturday...A dry west to east zonal
flow pattern on Tuesday will continue through Thursday with no
precipitation expected. Temperatures will be about 10 to 12 degrees
above normal during this time. By Friday, the flow aloft shifts
to SW as a large upper level trough moves toward the coast of
SW Canada. This trough is forecast to move inland on Saturday
allowing temperatures to cool back down to near normal. There
does not appear to be much of a moisture tap with the incoming upper
level trough, at least initially, so dry weather is expected to
continue through Saturday.

&&

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

&&

$$

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DISCUSSION...JM
AVIATION.....JM
SHORT TERM...JB
LONG TERM....JB