Prefrontal winds ahead of a cold front brought widespread high gusts and impacts to higher elevation summits and the Baker Valley.
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The episode as NWS BOI wrote it up.
Prefrontal winds ahead of a cold front brought widespread high gusts and impacts to higher elevation summits and the Baker Valley.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Boise, ID wrote its last area forecast discussion before the first event at Feb 29, 9:45 AM MST, 4 hours 15 minutes earlier.
Area Forecast Discussion
National Weather Service Boise ID
945 AM MST Thu Feb 29 2024
.DISCUSSION...The first parts of the winter storm already
affecting the region this morning. Radar showing the well
defined cold front extending from south- central Oregon through
northeast Oregon. Strong winds have been observed across the
higher terrain of southeast Oregon with winds gusts of 60-70 MPH
this morning. Winds will increase for lower elevations over the
next couple of hours with better mixing of the boundary layer.
Upslope snow is ongoing in the West Central and Boise Mountains
above 5500 feet with a mix of rain and snow in the lower
valleys. Overall, the event is unfolding as expected thus far.
The cold front will reach Burns around 21Z, Baker around 22z,
Ontario around 23Z and Boise around 00z today. Instability along
the front will support convective line segments that could
produce brief heavy rain/snow/graupel and lightning. Rain will
switch to snow post frontal though accumulations will be limited
in the valley as ground temperatures will remain above
freezing.
Latest high-res models showing the front slowing as it
continues east through Mountain Home and the Western Magic
Valley this evening becoming more parallel to the upper level
flow. This in turn lingers snow bands across Upper Treasure
Valley and Western Magic Valley through Friday morning. Surface
temperatures still look to remain above freezing through Friday
morning thus limiting snow accumulations to cold surfaces. Heavy
showers could produce up to an inch of snowfall. We will
reevaluate this possibility for the afternoon package. No
updates needed at this time.
&&
.AVIATION...Mainly VFR through morning with localized MVFR-IFR in
snow showers over west-central Idaho mountains (KMYL). A strong cold
front will bring a N-S line of moderate to heavy rain/snow eastward
through SE Oregon (after Thu/20z) and SW Idaho (after Thu/23z).
Precip will begin as rain for low elevation TAF sites with isolated
lightning strikes possible. Showers may transition to a mix of
rain/snow for KONO-KEUL-KBOI this evening, but confidence is low.
IFR to LIFR in heavy precipitation. Mountains obscured.
Surface winds today: SE-SW 10-20 kt with gusts 20-30 kt this
morning. Then, SW 20-35 kt with gusts to 35-50 kt after Thu/17z
ahead of the cold front. Then W-NW 10-25 kt behind the cold front
this evening. Winds aloft at 10kft MSL: SW 40-60 kt over SW Idaho.
SW 50-70 kt over SE Oregon. Areas of low-level wind shear this
morning.
Weekend Outlook...Numerous showers Friday through Sunday bringing
periods of MVFR to LIFR and mountain obscuration. Snow levels 2500-
4000 ft MSL Friday, dropping to valley floors Sat/Sun. South to
southwest surface winds 15-30 kt with gusts to 25-40 kt Friday,
along with areas of low level wind shear. Then, southwest to west
winds 10-30 kt Saturday and Sunday.
&&
.PREV DISCUSSION...
SHORT TERM...Today through Saturday night...Next winter storm
system is approaching the Pacific Northwest and is expected to
impact the forecast area today. Snow has already begun over the
west central ID mountains and Baker County mountains in eastern
OR. Southwest flow continues to increase this morning,
advecting warmer air into the region this morning, with rain
shadowing across SE Oregon and the Snake Basin in ID. Snow
levels will rise to 6000-7000 feet ahead of the cold front
today, with the bulk of the precipitation remaining over the
central ID mountains through this morning. Surface winds
increase to 30-40 mph ahead of the cold front, with gusts to 70
mph across Harney and Malheur Counties in southeast Oregon and
Owyhee County in southwest Idaho (70-95 percent chance of wind
gusts exceeding 55 mph). ECMWF Extreme Forecast Index (EFI)
values of 0.95-0.99 further support current forecast wind values
and the magnitude of the unusual event, which is based on
reforecasts from 2003-2024. Given the magnitude of the wind
across a large area (most of southeast Oregon as well as Owyhee
County, Treasure Valley and the West Central Mountains of
Idaho), that power outages and downed trees likely in forested
areas. High resolution ensembles continue to show the
development of a squall line this afternoon along the cold
front, with a slight chance of thunderstorms, with brief heavy
rain/snow/graupel along the front. Snow showers will continue
over the mountains behind the front on Friday with breezy winds
continuing. Another potent shortwave moves through the area on
Saturday, bringing scattered showers and bands of heavy snow to
the area on Saturday. The snow will come at a
intermittent/showery pace with 6 to 11 inches of snow in the
mountain valleys, and 9 to 18 inches over the mountains from 8pm
MST Thursday through 5PM MST Saturday. Temperatures will be
around 10-15 degrees above normal today in the Snake Basin, with
low 60s possible ahead of the cold front, then falling to
normal on Friday, and around 5 degrees below normal on Saturday.
LONG TERM...Sunday through Thursday...West to northwest flow aloft
and daytime instability will keep snow showers, breezy winds, and
below normal temperatures over the area through Monday. Models begin
to diverge Tuesday and onward, with the mean ensemble guidance
keeping a dominant trough pattern over the Pacific Northwest.
Ensembles and current forecast keep the chance of precipitation
around 20-40% each day through the extended, but deterministic
models are leaning toward the drier solutions. If precipitation
occurs, snow levels will be low enough to support snow showers or a
mix of rain and snow for lower elevations. Temperatures will remain
at least 5 degrees below normal for this time of year.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...High Wind Warning until 8 PM MST this evening IDZ011.
Winter Weather Advisory from 8 PM this evening to 5 PM MST
Saturday IDZ011-013.
Wind Advisory until 8 PM MST this evening IDZ012>014-030-033.
High Wind Warning until 11 PM MST this evening IDZ015-029.
OR...High Wind Warning until 8 PM MST this evening ORZ064.
Wind Advisory until 7 PM PST this evening ORZ062.
High Wind Warning until 11 PM MST /10 PM PST/ this evening
ORZ061-063.
&&
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DISCUSSION...JDS
AVIATION.....TL
SHORT TERM...KA
LONG TERM....SHThe national radar mosaic for the moment the first event began.
1 strong wind. Local standard time, as filed.
The ASOS at Baker City airport measured a wind gust of 49 knots.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2024Every state in 2024This day in weather historyWarnings in Oregon, February 2024
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1163219.