A trough of low pressure sweeping across the region brought gusty onshore winds to the mountains and deserts on the 26th and 27th. Winds rapidly transitioned to locally strong offshore winds early on the 28th.
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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 SGX wrote it up.
A trough of low pressure sweeping across the region brought gusty onshore winds to the mountains and deserts on the 26th and 27th. Winds rapidly transitioned to locally strong offshore winds early on the 28th. Apart from a few local gusts into the 70s, peak wind gusts were limited to the 35-55 mph range. No significant impacts were 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 Nov 27, 9:00 PM PST, 3 hours 50 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
900 PM PST Mon Nov 27 2017
.SYNOPSIS...
Building high pressure on Tuesday will bring warmer weather and
moderate offshore winds along the coastal foothills and mountain
passes. Otherwise, Fair, dry, and mild through Friday with periods
of thicker high clouds at times. Over the weekend, a trough of low
pressure will bring cooler weather, gusty westerly winds in the
mountains and deserts, and a chance for showers.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Peak westerly wind gusts recorded today reached 70 mph at White
Water West RAWS (In the San Gorgonio Pass), 67 MPH at Volcan
Mountain, 65 MPH on the ridges above Culp Valley in the Borrego
Desert, and 55 mph at Burns Canyon.
The surface pressure gradients have weakened considerably and turned
offshore from the NE. Winds have already responded and turned N-NE
over northern areas and become locally gusty. Expect the winds to
strengthen through early Tue morning with local strong NE wind gusts
below the Cajon and Morongo Pass areas, and through the Santa Ana
Mtn canyons. Currently, the stronger winds are not expected to be
widespread enough to warrant a Wind Advisory.
Where the winds drop off completely or become very light, clear
skies and dry air will radiate heat away rapidly. It looks like it
will be cold enough for frost across the high Desert, so a Frost
Advisory has been issued trough Tuesday morning.
No forecast changes this evening.
From previous discussion...
The rain over and west west of the mountains exited the region
around noon. Rain amounts ranged from Trace amounts to a max of
0.12" both Glen Helen Regional Park and Rimforest in San Bernardino
County. To see the rainfall summary, copy and paste this link into
your browser: goo.gl/2oiYta
The ridging both aloft and at the surface is not very strong Tuesday
and as a result the offshore winds will only be weak to locally
moderate in the mountains and passes. On Wednesday and Thursday the
light offshore flow will continue in the mountains and passes, but
turn weakly onshore in coastal and valleys zones ahead of a weak
upper level trough off the SoCal coast. This trough will bring mid
and high clouds Wednesday, but no precipiation. Overall the next few
days will be dry and warm with above average temperatures.
The outlook for the weekend is not any clearer than it was
yesterday. Both the GFS and ECMWF project an amplifying trough
making landfall along West Coast, but there is still a large model
spread on its track. The ECMWF remains the wettest model, and the
GFS is the drier model with a more inside track. So while
precipitation amounts remain in limbo for early next week,
confidence is high that this pattern will bring cooler, windy
weather next Sunday and Monday.
&&
.AVIATION...
280500Z...Mostly clear skies and unrestricted vis will prevail
through Tuesday evening. Local northeast surface winds 20-30 knots
with gusts to 40 knots will occur through/below Cajon Pass and
Banning Pass, in the Santa Ana Mountains and Foothills, the Little
San Bernardino Mountains and near crests of the San Diego County
Mountains through 20Z Tue, along with strong up/downdrafts and local
LLWS.
&&
.MARINE...
Northwest winds have decreased to below 20 knots over the coastal
waters, though seas of 6 to 9 feet will occur tonight through
Tuesday in the outer coastal waters mainly due to a WNW swell from
290 degrees at 14-15 seconds. Otherwise, no hazardous marine weather
is expected through Saturday.
&&
.Beaches...
A quick push of WNW swell will bring 3-6 ft surf to the beaches
tonight and Tuesday. The highest sets will occur in southern San
Diego County. An increased risk for strong rip currents will
accompany the elevated surf.
&&
.FIRE WEATHER...
Mostly weak offshore flow Tuesday into Thursday with locally
stronger northeast winds in and below the favored passes and
canyons. Even so, the stronger gusts will mostly be less than 40
mph. Lowest daytime humidities for the inland valleys and inland
Orange County will fall to 10 to 15 percent on Wednesday and
Thursday. Any critical fire weather conditions will be limited.
There are somewhat greater chances for wetting precipitation
along and west of the mountains next weekend for Saturday night
and Sunday.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Frost Advisory from midnight tonight to 9 AM PST Tuesday for
Apple and Lucerne Valleys.
PZ...None.
&&
PUBLIC...JAD/Moede
FIRE WEATHER...Moede
AVIATION/MARINE/BEACHES...MaxwellThe national radar mosaic for the moment the first event began.
2 high wind. Local standard time, as filed.
The mesonet station in Whitewater reported a peak westerly wind gust of 70 mph between 0050 PST and 0150 PST.
The mesonet station at Pleasants Peak reported a two and a half hour period with easterly wind gusts over 70 mph. A peak gust of 73 mph occurred between 0200 and 230 PST.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2017Every state in 2017This day in weather historyWarnings in California, November 2017
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: 727723, 727722.