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030
FXUS65 KBOI 280224
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
824 PM MDT Mon May 27 2024

.DISCUSSION...
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Isolated thunderstorms are popping up over Harney
County as of 8:00pm MDT. These will likely weaken as the evening
progresses, with continued dry conditions with warm overnight
easterly winds expected over the rest of the region into the
night. Several areas reached the mid-80s this afternoon for
their daily highs, with still higher temperatures expected
tomorrow. This will allow for widespread instability to form
ahead of the shortwave trough and cold frontal passage tomorrow.
Strong thunderstorms look to begin by late afternoon (~3-5pm
MDT) over the Magic Valley and early evening (~5-7pm MDT) over
southeast Oregon-Treasure Valley. The strongest storms with
gusty winds and hail looks to be over Baker County, OR and
northern portions of Malheur County, OR, especially as the cold
front moves in by early tomorrow night. Forecast looks to be on
track for the next few days, so no updates are necessary.
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&&

.AVIATION...
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VFR through late Tuesday morning with intermittent
cloudiness over eastern Oregon. Thunderstorm chances increasing
Thursday afternoon at KBKE/KBNO and KTWF/KJER, with low confidence
(30% chance) of directly affecting terminals. Scattered storms may
develop near KEUL/KONO close to 29/00Z. Surface winds: E-SE 5-15 kt
overnight, becoming W 10-15 kt in W of KBOI after 18/17Z. Gusty
outflow winds possible. 10kft MSL: SW 15-30 kt.

KBOI...VFR with mostly clear skies. Winds becoming SE around 12 kt
after 28/05Z. W winds around 10 kt likely by 28/19Z. Low chance
(20%) of thunderstorms in the vicinity between 28/22Z and 29/00Z.
Higher chances (40%) after 29/00Z with gusty outflow winds possible.
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&&

.PREV DISCUSSION...
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.SHORT TERM...Tonight through Wednesday night...Any lingering
showers over Harney county this evening will dissipate shortly
after sunset taking with them the chance for locally gusty
outflow winds. Tuesday will be an active day as a shortwave
trough will swing into Pac NW. Morning virga showers, indicative
of increasing moisture and instability aloft, are possible over
far SE Oregon and SW Idaho. By early afternoon, dynamic forcing
ahead of the trough, coupled with increasing instability and
surface energy will spur thunderstorm initiation over SE Oregon
and higher terrain of southwest Idaho. The shear environment
would favor development of stronger, longer-lived storms
capable of producing gusty outflow winds and hail. Gust
potential is in the 50-60 mph range. Given the pattern have
gone with scattered coverage (25-35%) for thunderstorms Tuesday
afternoon/evening.

Areas that don`t pick up thunderstorm outflow winds will see
gusty winds accompanying the cold front passage Tuesday
evening. Gust potential with the front is up to 45 mph, but
could be stronger through SE Oregon and portions of the Snake
Plain if enhanced by thunderstorm outflow. Winds of this scale
and speed could produce blowing dust which would reduce
visibility. The chance for showers and thunderstorms contracts
into the w-central Idaho mountains Tuesday night as the upper
wave lifts into MT. Winds remain breezy behind the front Tuesday
night, and will maintain speed on Wednesday as flow aloft mixes
to the surface. The chance for mountain showers will decrease
on Wednesday as the air mass stabilizes in the wake of the
departing low. A late spring roller coaster of temperatures
will play out as highs from Tuesday to Wednesday will drop
nearly 20 degrees. For lower elevations temperatures of near 90
on Tuesday will fall off to around 70 on Wednesday.

.LONG TERM...Thursday through Monday...Deterministic and
ensemble model solutions are favoring the development of a less
amplified W-NW flow pattern through the weekend. However there
is still uncertainty in details regarding minor waves embedded
in the flow. For now carrying dry conditions through Sunday with
a low chance of showers returning on Monday. After Thursday
temperatures are on the upswing warming back above normal for
Sat/Sun/Mon which will place lower valleys into the 80s and mtns
near 70.
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&&

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

&&

$$

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DISCUSSION...SA
AVIATION.....JR
SHORT TERM...DG
LONG TERM....DG