A weak trough passed through the Pacific Northwest, bringing gusty winds to the desert slopes in Southern California from the 6th through the 7th. There were no significant impacts reported.
Every event with a place to put it; 2 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 SGX wrote it up.
A weak trough passed through the Pacific Northwest, bringing gusty winds to the desert slopes in Southern California from the 6th through the 7th. There were no significant impacts reported.
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 San Diego, CA wrote its last area forecast discussion before the first event at Apr 6, 11:57 AM PST, 2 hours 53 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
1257 PM PDT Fri Apr 6 2018
.SYNOPSIS...
A low pressure system will move through California on Saturday. It
will bring more clouds and periods of stronger and gusty west
winds in the mountains and deserts through Saturday night with
small chances for light rain mainly near the mountains for
Saturday afternoon and evening. Dry with warming for Sunday
through Tuesday with high pressure aloft and weak offshore flow.
Onshore flow will return late Tuesday with much stronger onshore
flow for late Wednesday through Thursday as another low pressure
system moving inland through California brings cooler and windy
weather on Thursday.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
The variable high clouds tracking across our skies is a hint of
the rain system moving through northern and central California. A
strong jet stream across the Pacific will drive a plume of deep
moisture and decent rain across most of the state, except not in
Southern California. The moisture plume will fall apart as it
stumbles into Southern California Saturday. The chances of
measurable rain are quite microscopic, but there is a chance, so
the slight chance in the forecast is mostly to indicate to not be
surprised if a few drops of wet fall from the sky, most likely
from late Saturday morning into Saturday evening. Winds will be of
greater impact, but strong winds will be confined mainly to the
mountain ridgetops and adjacent deserts where top spots will get
top gusts over 45 mph. That could stir up a bit of dust in the
desert. This shortwave trough will quickly exit stage right
Saturday evening. Lingering low clouds in the coastal basin on
Sunday morning will clear out nicely as offshore flow begins to
develop. By Monday the offshore flow peaks, resulting in pockets
of brisk northeast winds in the foothills and portions of adjacent
valleys. High pressure aloft peaks and coincides with the peak of
offshore flow to drive sunny and much warmer weather Monday. Get
ready for a few temps reaching into the 90s in some of the
valleys and inland coastal areas such as northern Orange County.
On Tuesday we turn the flow back onshore, which will bring a
cooling trend west of the mountains along with eventually some
coastal low clouds in a redeveloping marine layer. The overall
longwave pattern over the Pacific continues to be zonal and
progressive, meaning the jet stream and the storm door is still
open for business. Models show a shortwave trough zipping into
California Wednesday and Thursday. If that is realized, look for
decent onshore winds in Southern California's mountains and
deserts. There are hints of rain as well, but we'll need more
convincing from subsequent model runs with a consistent wet
solution to start forecasting the wet stuff. For now, expect
cooler weather, brisk winds in the mountains and deserts, and a
redeveloping marine layer to bring greater low cloud coverage
Wednesday and Thursday.
&&
.AVIATION...
062000Z...Coast/Valleys...SCT-BKN high clouds at/above 20000 ft MSL
will prevail this afternoon with unrestricted vis. BKN stratus will
gradually redevelop in most areas tonight with bases 1800-2500 ft
MSL and tops to 5000 ft MSL. Higher terrain will be obscured with
local surface vis below 1 mile nearby. These conditions will
continue Sat with isolated -SHRA and only partial afternoon
clearing. Timing at any airports is low confidence as the clouds
will be SCT at times versus BKN.
Mountains/Deserts...Areas of west surface winds 20-30 kt with gusts
35-45 kt will continue at times over the mountains/desert mountain
slopes and locally into the deserts through Saturday. Areas of
moderate LLWS and up/downdrafts are expected over and east of the
mountains. Local vis below 3 miles in blowing dust will occur in the
deserts. Otherwise SCT-BKN clouds at/above 20000 ft MSL will
continue through Sat.
&&
.MARINE...
Northwest winds with occasional gusts over 20 kt near San Clemente
Island and outside of 30 nm will continue at times through Sunday,
especially during the afternoons and evenings. Combined seas should
also increase to around 5-8 ft late Sunday into Monday, highest near
and south of San Clemente Island. Winds and seas will lower on
Monday.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory until 5 AM PDT Sunday for Apple and Lucerne
Valleys-Coachella Valley-Riverside County Mountains-San
Bernardino County Mountains-San Diego County Deserts-San
Diego County Mountains-San Gorgonio Pass Near Banning.
PZ...NONE.
&&
PUBLIC...MM
AVIATION/MARINE...MaxwellThe national radar mosaic for the moment the first event began.
2 high wind. Local standard time, as filed.
Gusts of over 60 mph reported at the Whitewater Mesonet station for about 12 hours.
Winds gusted over 60 mph in Burns Canyon over a 3 hour period. Winds were lighter in the rest of the San Bernardino County Mountains.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2018Every state in 2018This day in weather historyWarnings in California, 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: 750757, 750751.