590
FXUS65 KBOI 251531
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
931 AM MDT Sat May 25 2024

.DISCUSSION...Isolated light showers were occurring this morning
across the area, mainly in the mountains and in southern Twin
Falls County. These will continue to move east as an upper level
trough moves east out of the area. There should be enough
moisture and cold air aloft behind the trough for additional
showers, and perhaps a weak thunderstorm, this afternoon over
our Idaho side. This is already in the forecast and no changes
will be made at this time. The next chance for thunderstorms
will arrive Tue aft/eve.

&&

.AVIATION...Mostly VFR in valleys. Local MVFR in KGNG/KJER/KTWF area
will improve to VFR by 18Z. Widespread MVFR ceilings in mountains
will obscure terrain through this afternoon. Scattered mtn showers
and isolated afternoon thunderstorms with snow levels 6500-7500
feet. Surface winds: NW 10-20 kt with gusts to 30 kt through this
evening. Winds aloft at 10kft MSL: W 15-25 kt.

KBOI...VFR through Sunday. NW winds gusty at times through this
evening.

Sunday Outlook...VFR. Isolated IFR in mtn valley fog through 16Z.
Surface winds W-NW 5-15 kt, locally up to 20 kt east of KMUO.

&&

.PREV DISCUSSION...
SHORT TERM...Today through Monday night...An upper level trough
will move across our area today and bring showers and isolated
thunderstorms. The highest chance of precipitation (40-70%)
will be across the central Idaho mountains and near the
Idaho/Nevada border. Elsewhere, precipitation chances will be
10-30% with the highest chance this morning. Showers will
diminish late this afternoon and end this evening as the trough
exits our area. Temperatures today will be 5-10 degrees below
normal. Expect another day of breezy winds with afternoon gusts
of 20-30 mph, except up 40 mph in the Magic Valley. An upper
level ridge will move overhead tonight and Sunday, and then
amplify on Monday. This will bring mostly sunny skies and a
warming trend. Highs will increase about 5 degrees on Sunday,
then another 10 degrees on Monday with lower valleys reaching
the lower 80s. Winds will decrease on Sunday but remain breezy
across south-central Idaho, with generally light winds in all
areas Monday. A weak system may bring a shower/thunderstorm to
southeast Oregon (5-10% chance) Monday night, but confidence is
too low to include in the forecast at this time.

LONG TERM...Tuesday through Saturday...Good agreement amongst
the deterministic and ensemble data indicating a strong ridge in
place to start the long term period, with a trough poised to
impact the region off the coast Tuesday. This pattern is
expected to spread southwest winds aloft over Oregon and Idaho,
leading to some of the warmest temperatures of the year thus
far. Model blend probabilities of reaching 90 degrees are now
between 40-60% for the lower valleys, with 80-90% chance of 85
degrees or higher. Guidance is suggesting that the heat will be
short-lived, with another series of upper level troughs
impacting the region mid/late week. While significant
uncertainty exists, ensemble data is suggesting a return to
temperatures in the mid/lower 70s for the remainder of the week
after Tuesday. The troughs are expected to raise the chance of
showers as well with POP values approaching 15-45% each day,
with the highest chances over the central mountains of Idaho.

&&

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

&&

$$

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DISCUSSION...SP
AVIATION.....DG
SHORT TERM...ST
LONG TERM....MC