Mesoscale low pressure systems brought several impulses of heavy snow to southeast Oregon, mainly over Jordan Valley, OR. This delayed traffic and caused delays on US Highway 95.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS BOI wrote it up.
Mesoscale low pressure systems brought several impulses of heavy snow to southeast Oregon, mainly over Jordan Valley, OR. This delayed traffic and caused delays on US Highway 95.
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 Apr 5, 2:38 AM MST, 5 hours 22 minutes earlier.
Area Forecast Discussion
National Weather Service Boise ID
338 AM MDT Fri Apr 5 2024
.SHORT TERM...Today through Sunday night...A pair of shortwaves,
one over western OR and one over central CA, embedded in the
main upper level trough over the west will consolidate into one
later this afternoon. The trough will track over northern NV and
SE OR and SW ID late this afternoon. Snow levels fall to
2500-3500 ft MSL this morning before rising to around 3500-4000
ft this afternoon. The winds aloft will shift to the SE and
then E later this afternoon and the upper level dynamics causing
the moderate to heavy precipitation weaken considerably by this
afternoon. Precipitation will become lighter this afternoon,
with snow showers continuing in the mountains, especially in
Idaho. The center of the trough now tracks along the NV border
into SE Idaho by Saturday morning. With this track a little
farther south and east than previously forecast, precipitation
amounts have trended down, especially across eastern OR, with
the exception of southern Malheur County. Snow levels fall to
valley floors on Saturday morning, with snow showers generally
over the Idaho side through Saturday afternoon. There is a
slight chance of snow in the lowest valleys, but minimal
accumulation expected. A weak shortwave moves into the region
on Sunday afternoon, bringing a reinforcement of cooler air
aloft. The cold air aloft will cause enough instability on
Sunday afternoon for snow and graupel showers, especially over
the mountains. Temperatures will be around 10-15 degrees below
normal today, warming 3-5 degrees on Saturday and Sunday.
.LONG TERM...Monday through Friday...A ridge of high pressure
will build beginning on Monday, bringing a warming trend
through the rest of the long term period. Temperatures will be
10 degrees above normal through Thursday with mostly dry
conditions, with the warmest temperatures anticipated on
Thursday. While models mostly agree in the evolution of the
synoptic pattern, variations in the depth of the ridge late next
week lead to some uncertainty in the temperature forecast.
Additionally, a more shallow ridge may bring some moisture
across the Wallowas and West Central Mtns, leading to an
increase in precipitation chances on Friday. Models seem to
favor drier forecasts, with very light and isolated
precipitation if anything on Friday.
&&
.AVIATION...MVFR/IFR and local LIFR conditions in numerous
showers, continuing through Friday. Low stratus over KJER/KTWF
overnight. Moderate/heavy precipitation rates at times,
especially in the afternoon. Mountains obscured. Snow levels:
down to valley floors overnight, rising to 4000 ft MSL during
the day. Surface winds: W-NW 5-15 kt. Gusts to NW 20-30 kt for
KBKE-KONO corridor. Winds aloft at 10k feet MSL: in southeast
Oregon N-NW 10-20 kt, in southwest Idaho S 20-40 kt becoming S
15-20 kt after Fri/12z, light and variable along the ID/OR
border.
KBOI...Mix of snow and rain through Friday morning. While snow
is favored, surface temps above freezing will limit
accumulation. MVFR/IFR in morning showers. Shower coverage
decreasing around Fri/17Z with improving flight category.
Transitioning to isolated rain showers through Friday afternoon.
Snow and rain mix returning Friday night. Surface winds: W-NW
5-15 kt.
Weekend Outlook...Numerous snow showers bringing MVFR/IFR and local
LIFR conditions through Saturday morning, mainly in SW Idaho.
Mountains obscured. Showers decreasing from W to E Saturday, along
with improving conditions. Isolated shower activity continuing
through Sunday. Snow levels generally 3000-4000 ft MSL. Winds W-NW 5-
15 kt with gusts to 25 kt for Sat and Sun, except W-NW 20-30 kt with
gusts to 40 kt for KMUO/KJER/KTWF Saturday.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 9 AM to 9 PM MDT Saturday IDZ016-028-030.
Winter Weather Advisory until noon MDT Saturday IDZ029.
OR...None.
&&
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SHORT TERM...KA
LONG TERM....JM
AVIATION.....JMThe national radar mosaic for the moment the first event began.
1 heavy snow. Local standard time, as filed.
A trained spotter measured 7.0 inches of snow in Jordan Valley, OR.
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, April 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: 1173813.