Surface high pressure centered over Idaho and Nevada brought strong offshore winds to Southern California from November 8th through 13th. The highest wind gust from the event was 85 mph at Sill Hill on November 12th.
Every event with a place to put it; 18 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.
Surface high pressure centered over Idaho and Nevada brought strong offshore winds to Southern California from November 8th through 13th. The highest wind gust from the event was 85 mph at Sill Hill on November 12th. The air mass on November 8-10th was extremely dry with dewpoints observed at -25 to -40F between 6000 and 9000 feet (matched NKX sounding data). Fuel moisture measured by the USFS was at historical lows (100 and 1000 hour). Power was cut from many wildfire prone communities in anticipation of high winds. Some power lines were knocked over from the winds, but there were no significant fire starts. USFS reported several small wildfires during night hours but they were able to quick control the blazes before spreading.
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 8, 9:28 AM PST, 2 hours 32 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
928 AM PST Thu Nov 8 2018
.SYNOPSIS...
A Santa Ana weather pattern will be in place through most of next
week with periods of gusty offshore winds. The first round of strong
winds will arrive today and continue through Friday, followed by a
second round of gusty winds Sunday and Monday. The humidity will
drop sharply today and will remain very low through next week.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
The Santa Ana has arrived. Northeast winds have surfaced in the San
Bernardino Mountains and through the Cajon Pass with peak gusts at 9
AM of 46 mph at Paivika Ridge in the San Bernardino Mountains, 39
mph at Santiago Peak in Orange County, and 33 mph at Devore in the
Cajon Pass.
Dewpoints fell quickly with the onset of the dry northerly winds. At
5 AM the dewpoint was 47F at Devore Heights (in the Cajon Pass), and
at 6 AM the dewpoint was 25F, a drop of 22F in just one hour.
The strong, dry northeast winds will spread south across the Inland
Empire and into Orange County through the day. Low clouds were
clearing quickly across the Inland Empire and Orange County this
morning, and will clear from San Diego County by late morning.
The pressure gradient from SAN-TPH was a strong -11.3 mb this
morning and will get a little stronger as surface high pressure
builds into northern Nevada. This gradient will generate north to
northeast winds of 20 to 30 mph with gusts to 55 mph below the Cajon
Pass into Orange County. The winds will expand southward into San
Diego County tonight into Friday morning. There will be gusts to 65
mph in a few spots, mainly the Santa Ana Mountains, below the Cajon
Pass, and some of the wind prone ridges in the San Diego County
mountains. Winds will subside late Friday and Friday night with much
weaker and more localized winds on Saturday into early Sunday.
Highs today in the coastal and valley areas will be a little higher
than yesterday from the combination of scouring out the marine layer
plus downslope warming in Orange County. The mountains and deserts
will be cooler. The greatest warming on Friday will be in coastal
areas with lesser cooling for the deserts, mountains, and inland
valleys. The coast will cool a bit on Saturday while inland areas
warm.
On Sunday, another "inside slider" low pressure trough digs
southeast across the Great Basin. This will bring another round of
stronger Santa Ana winds late Sunday into Monday. The pressure
gradient will be oriented more east-west, which would result in
stronger winds in the Riverside and San Diego County mountains and
foothills.
For Tuesday through Thursday, there is more spread in the upper
pattern over the eastern Pacific into the western states. Those
solutions generally favor a continuation of weak to occasionally
moderate strength offshore flow but with low confidence in the
timing of any periods of potentially stronger winds.
&&
.AVIATION...
081700Z...Coast/Valleys...Low clouds sticking around in San Diego
County and in portions of western Riverside County at this hour.
Reduced vis of 2-4 SM at KONT and KSBD through 18Z. Clearing will
continue, with most areas scattered out by 18Z. NE winds have
started to surface with winds 15-30 kts with gusts to 40 kts in mtn
and valley areas, spreading into Orange County and continuing into
tonight. LLWS and moderate up/downdrafts will occur at times in
these areas. Winds will become more widespread this evening and
spread into San Diego County, mainly in foothills and inland valleys.
Mountains/Deserts...Mostly clear with unrestricted visibility today
and tonight. Areas of northeast surface winds 20-30 knots with gusts
to 40 knots in the mountains of San Bernardino County through
tonight.
&&
.MARINE...
No hazardous weather is expected through Monday. Local northeast
wind gusts just off the coast of Camp Pendleton could exceed 20 KT
this afternoon through Friday.
&&
.FIRE WEATHER...
Dry north-northeast winds have surfaced in the San Bernardino and
Santa Ana mountains this morning. Winds will gain strength today and
tonight and spread south into Riverside and San Diego County
mountains with sustained winds of 20 to 30 mph with gusts to 55 mph.
There will be a few gusts to 65 mph in mountains and foothills of
the Santa Ana Mountains, and near the ridge tops of the San Diego
County mountains. Lowest humidity this afternoon will fall to 5 to
10 percent, and then from 3 to 8 percent on Friday.
Another round of strong Santa Ana winds will arrive Sunday and
Monday. The strength of this system is being evaluated. The pressure
pattern will be a little different than today, with surface high
pressure over Colorado instead of Nevada/Utah. This east-west
oriented pressure gradient will bring stronger winds to the
Riverside and San Diego County mountains and passes. Humidities will
remain very low, likely in the single digits.
Weak to occasionally moderate strength Santa Ana winds will continue
Tuesday through Friday of next week.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...High Wind Warning from midnight tonight to 6 PM PST Friday for
Riverside County Mountains-San Diego County Mountains-San
Diego County Valleys-San Gorgonio Pass Near Banning.
Red Flag Warning from 10 AM this morning to 10 PM PST Friday for
Orange County Coastal Areas-Orange County Inland Areas-
Riverside County Mountains-Including The San Jacinto Ranger
District Of The San Bernardino National Forest-San
Bernardino County Mountains-Including The Mountain Top And
Front Country Ranger Districts Of The San Bernardino
National Forest-San Bernardino and Riverside County Valleys
-The Inland Empire-San Diego County Inland Valleys-San
Diego County Mountains-Including The Palomar And Descanso
Ranger Districts of the Cleveland National Forest-Santa Ana
Mountains-Including The Trabuco Ranger District of the
Cleveland National Forest.
High Wind Warning from 10 AM this morning to 6 PM PST Friday for
Orange County Inland Areas-San Bernardino County Mountains-
San Bernardino and Riverside County Valleys-The Inland
Empire-Santa Ana Mountains and Foothills.
PZ...NONE.
&&
PUBLIC/FIRE WEATHER...Moede
AVIATION/MARINE...Connolly/PGThe national radar mosaic for the moment the first event began.
16 high wind, 2 strong wind. Local standard time, as filed.
CalState San Bernardino Mesonet reported a wind gust of 56 knots between 1200 and 1300 PST on November 8th.
Fremont Canyon Mesonet reported a wind gust of 64 knots between 1800 and 1900 PST on November 8th.
CalState San Bernardino Mesonet reported a wind gust of 51 knots between 1200 and 1300 PST on November 11th.
Fremont Canyon Mesonet reported a 50 knot wind gust between 0600 and 0700 PST on November 12th.
Sill Hill Mesonet reported a wind gust of 74 knots between 0800 and 0900 PST on November 12th.
Alpine Mesonet reported a wind gust of 60 knots between 0800 and 0900 PST on November 12th.
Mesonet hp016 near Santa Ysabel reported a 58 knot wind gust between 0800 and 0900 PST on November 12th.
Witch Creek Mesonet reported a wind gust of 50 knots between 0900 and 1000 PST on November 12th.
Boulder Creek Mesonet reported a 54 knot wind gust between 0900 and 1000 PST on November 12th.
Sherilton Valley Mesonet reported a 51 knot wind gust between 0900 and 1000 PST on November 12th.
Hellhole Canyon Mesonet reported a wind gust of 54 knots between 0900 and 1000 PST on November 12th.
Crestwood Mesonet reported a wind gust of 59 knots between 1000 and 1100 PST on November 12th.
Highland Springs Mesonet reported a 54 knot wind gust between 1200 and 1300 PST on November 12th.
Otay Mountain Mesonet reported a wind gust of 52 knots between 0500 and 0600 PST on November 13th.
Alpine Mesonet reported a wind gust of 60 knots between 0700 and 0800 PST on November 13th.
Mesonet station povsd (Pamo Valley) reported a wind gust of 55 knots between 1000 to 1100 PST on November 13th.
West Rancho Bernardo Mesonet reported a 35 knot wind gust between 1200 and 1300 PST on November 13th. Utility company preemptively shut off power in this area in anticipation of strong winds. Downed power lines were reported in the area on the morning of November 13th.
Rancho Santa Fe Mesonet reported a 22 knot wind gust between 1200 and 1300 PST on November 13th. The utility company reported downed power lines in the area where they preemptively shut off power due to forecast strong winds.
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, November 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: 792618, 792614, 792619, 792629, 792612, 792624, 792626, 792621, 792623, 792625, 792627, 792620, 792628, 792633, 792632, 792634, 792630, 792631.