Flood in Oregon, March 25 to 31, 2025

Area Forecast Discussion
National Weather Service Boise ID
243 PM MDT Tue Mar 25 2025

.SHORT TERM...Tonight through Thursday night...The warmth will
peak on Wednesday as a negatively tilted upper ridge axis lifts
NEward. Temperature forecasts maintain the near record highs for
on Wednesday with the warmest spots touching 80 degrees.
Afternoon heating/instability paired with plenty of moisture
aloft (precipitable water values around 80th percentile) will
support buildups over SE Oregon and higher terrain of SW Idaho.
Development will be favored over Baker and northern Harney and
Malheur counties in Oregon in the afternoon, transitioning into
the west-central Idaho and Boise mtns in the late
afternoon/evening. Still some uncertainty on coverage,
especially across lower elevations (Snake Plain) on the Idaho
side as dynamics and later timing are less favorable. Have
maintained a 15-30% chance for thunderstorms in these areas
through late evening. For now have left mention out for the
western Magic Valley, but will need to watch for build-ups
across higher terrain to the south which could pose a threat in
the late afternoon. Within this area of thunderstorms the best
dynamics and shear reside over SE Oregon and far western
portions of SW Idaho through Wednesday evening, and this is
where a slight chance for a strong to possible severe
thunderstorms exists as outlined by SPC. Gusty winds looks to be
the more likely threat due to drier near-surface conditions and
strong winds aloft, while hail would be possible from the
stronger storms.

Cooler air works into the region on Thursday as the broad closed
low inches toward the coast. Temperatures will drop to around
normal. Instability will support a 40-60% chance of showers
across higher terrain Thursday afternoon, accompanied by a
15-20% chance of thunderstorms. A minor upper wave embedded in
the southwest flow could help to organize development in the
afternoon/evening which would bump the thunderstorm threat. Snow
levels will gradually drop from around 9kft MSL on Wednesday to
between 6-8kft MSL on Thursday. Any light accumulations will be
limited to the highest peaks.

.LONG TERM...Friday through Tuesday...Weather pattern remains
active through early next week. An upper trough resides off the
northwest coast on Friday. A moist/unstable southwest flow
ahead of it will bring showers to the area, mainly over the
higher terrain. There is also enough instability to support a
slight chance (less than 20 percent) of afternoon and evening
thunderstorms. It will also be breezy and cooler, with highs
near normal. Snow levels are low enough for light snow
accumulations in the mountains above 5500 feet. The trough moves
through our area on Saturday for more showers and light snow
accumulations above 5000 feet. Temperatures cool to slightly
below normal, along with breezy northwest winds. Sunday appears
to be the driest and warmest day through the period as a short-
wave ridge moves across the region. However, it will be short-
lived as the next trough brings showers back into the region by
late Sunday, followed by another trough on Tuesday. Snow levels
of 5000- 6000 feet on Sunday lower to 4500-5500 feet on Tuesday.
There are some model differences, so confidence is low
regarding timing of systems and precipitation amounts.
Temperatures average slightly below normal along with breezy
conditions Monday and Tuesday.

&&

.AVIATION...VFR with mostly clear skies. Patchy fog may form
in the Long Valley (KMYL) late tonight, but confidence is low.
Surface winds: mainly E to SE 5-15 kt. Winds aloft at 10kft: 5-15
kt.

KBOI...VFR and mostly clear. Surface winds: SE 5-15 kt.

&&

.HYDROLOGY...Snowmelt will lead to rises on rivers, creeks and
streams across SE Oregon and SW Idaho over the next several
days. Those with interests near waterways should remain aware of
water levels during this time. A Flood Warning remains in
affect for the Silvies River near Burns, Oregon. A continued
active weather pattern, as highlighted by the CPC 8-14 day
forecast could, result in further rises on area rivers into
early April.

&&

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

&&

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SHORT TERM...DG
LONG TERM....BW
AVIATION.....BW
HYDROLOGY....DG