A trough of low pressure moved through the Inter-mountain West kicking off strong to severe thunderstorms and causing damage around Baker County.
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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.
A trough of low pressure moved through the Inter-mountain West kicking off strong to severe thunderstorms and causing damage around Baker County.
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 7, 6:49 AM PST, 3 hours 41 minutes earlier.
Area Forecast Discussion
National Weather Service Boise ID
849 AM MDT Sat Apr 7 2018
.DISCUSSION...Early update to increase the coverage area of
isolated thunderstorms today, extending it to the remainder of
southwest Idaho and also into our eastern Oregon zones. Overnight,
SPC placed our southwest Idaho zones in a marginal risk for severe
thunderstorms, meaning that severe storms are possible, but
widespread severe weather is not likely. Thunderstorms are
forecast to develop ahead of a short-wave trough and associated
cold front that will move through the area today. This development
will occur after the large area of rain occurring this morning
moves off to the east.
Otherwise, the flood watch continues through this evening. Any
thunderstorms that form and move into the mountains will be
capable of producing heavy rain over ground that has already
received plenty of rain overnight. Streams and creeks may be
unable to handle the runoff. In addition, storms that move over
burn scars may create mudslides. The watch will be maintained
through this evening, and warnings will be issued on a storm-by-
storm basis if necessary. Finally, a wind advisory continues for
the southern portion of the area. Gusts 40 to 45 mph are possible
simply due to gradient winds. Higher gusts will be possible in
thunderstorms.
&&
.AVIATION...This morning widespread mountain obscuration with rain
and high elevation snow and areas of MVFR/local IFR conditions.
Improving to mainly VFR in southeast Oregon after 18z and southwest
Idaho after 00z, except widespread MVFR/IFR snow showers continuing
over the central Idaho mountains through Sunday. Snow levels 8k-10k
ft MSL lowering to 5500-7500 ft MSL after 00z and around 4500 ft MSL
by 12z Sunday. Surface winds southeast to southwest 10-20 kts,
shifting to west and increasing to 20-30 kts with gusts to around 40
kts after 18z. Winds aloft near 10k ft MSL southwest to west 30-50
kts.
&&
.PREV DISCUSSION...
SHORT TERM...Incoming Pacific storm slowed its approach Friday
evening but the initial rain band did materialize in southeast
Oregon around midnight and produced a few hundredths inch of rain
there and as far east as the Owyhee Mountains. Models remain
consistent that significant rain will overspread our CWA today,
with a cold front expected to pass through eastern Oregon midday
and western Idaho this afternoon and early evening. Isolated
thunderstorms are also expected along the front in northern areas.
Southwest or west winds will increase to advisory speeds later
today through this evening. Strongest winds are expected in
southern Harney and Malheur Counties this afternoon. Showers will
decrease from west to east behind the front except in the Idaho
mountains north of the Snake Basin where they will continue tonight
and into Sunday. Colder air behind the front will lower the snow
level from 9000 feet MSL ahead of the cold front to 4500-5000
feet by Sunday morning. Several inches of new snow are expected in
the Boise Mountains and West Central Idaho Mountains. A chance of
rain showers will continue in the Snake Basin and eastern Oregon
tonight and Sunday as the upper trough passes through. Southern
Harney and Malheur Counties in Oregon and most of Owyhee County in
Idaho should stay dry Sunday, though. Strong westerly winds aloft
will also transfer momentum to the surface Sunday afternoon with
speeds again approaching advisory levels in southeast Oregon, the
Snake Basin, and southern Idaho highlands. Temperatures will cool
5 to 10 degrees Sunday from today.
LONG TERM...Sunday night through Saturday...
Progressive pattern continues over the region throughout the
extended period...beginning with an upper ridge over the West Coast
Monday before the next system pushes into the region Tuesday
afternoon. A series of systems then move into the region about every
other day through the end of next week spreading precipitation
through most locations. Snow levels hover around the 6-8000 ft
elevation prior to the frontal bands moving in, then lower to the 5-
6000 ft level behind the fronts. Temperatures should remain around
normal through the extended period. Gusty southeast to southwest
winds should be expected ahead of each system.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Flood Watch through late tonight IDZ011-013-028-033.
Wind Advisory from noon today to 9 PM MDT this evening
IDZ014>016-029-030.
OR...Wind Advisory from noon MDT /11 AM PDT/ today to 9 PM MDT /8 PM
PDT/ this evening ORZ061-063.
&&
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DISCUSSION...SP
AVIATION.....JT
PREV SHORT TERM...LC
PREV LONG TERM....CRThe Pendleton radar (KPDT), 124 km away, was scanning. The volume nearest the first event began at 18:30 UTC.
1 thunderstorm wind. Local standard time, as filed.
Severe thunderstorms raced through the Baker City area downing large trees and power lines.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2018Every state in 2018This day in weather historyWarnings in Oregon, April 2018
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: 745365.