Strong northerly winds developed across the mountains of Los Angeles county. Wind gusts up to 60 MPH were reported.
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 LOX wrote it up.
Strong northerly winds developed across the mountains of Los Angeles county. Wind gusts up to 60 MPH 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 Los Angeles, CA wrote its last area forecast discussion before the first event at Apr 27, 12:58 PM PST, 1 hour 57 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
158 PM PDT Thu Apr 27 2017
.SYNOPSIS...
A high system with offshore flow will bring fair skies...gusty winds
at times...and above normal temperatures into next week. The weekend
will have the warmest temperatures.
&&
.SHORT TERM...(TDY-SUN)
Gusty north to northwest flow pattern continues and we'll be
getting another surge tonight into Friday morning as a reinforcing
shot of upper level energy drops into the Great Basin. This could
be the strongest of the bunch this week (at least for LA County) as
models show solid 40-50 kt around 850mb and strong subsidence to
drive the stronger winds aloft down to the surface. So warnings
look good for the Grapevine area tonight and some of that will
filter down into the valleys and possibly even down into the LA
Coast as well.
Not too much change in temps Friday, but Saturday as we transition
to a solid advisory level Santa Ana event temps will definitely
jump several degrees, especially coast/valleys.
The Santa Ana is a one off event this time as Sunday we turn back
onshore and highs drop 4-8 degrees for coast/valleys (though
similar or slightly warmer farther inland).
.LONG TERM...(MON-THU)
Fairly quiet week next week as the ridge eventually moves squarely
over the west coast and dominates the pattern. Pretty standard
onshore flow each day so while above normal temps will continue
highs should mostly top out in the 70s for the coast and 80s for
the valleys. 90s likely reserved for the extreme inland areas like
the Antelope Valley and interior SLO County. This pattern is
definitely favorable for a marine lyr return at some point next
week, but exactly when is hard to say. When it does it will be
confined to the coast and likely include areas of dense fog as the
inversion will be very strong but also very shallow.
&&
.AVIATION...27/1800Z.
At 1600Z, the marine layer depth at KLAX was around 1000 feet.
The top of the inversion was 2100 feet with a temperature of 16
degrees Celsius.
Good confidence in the 18z TAF package. VFR conditions are
expected at all TAF sites through the period.
Gusty northwest to north winds will continue through the TAF
period with the potential for LLWS/turbulence at coastal and
valley TAF sites through this evening.
KLAX...Good confidence in 18Z TAF. There is a 30% chance of north
cross wind gusts near 30 knots from 00-10z.
KBUR...Good confidence in 18Z TAF. VFR conditions are anticipated
through the period. There is a 40% chance of LLWS/turbulence
issues through the TAF period.
&&
.MARINE...27/200 PM.
For the Outer Waters, high confidence in current forecast. Gale
force winds will continue through Friday night then subside to
Small Craft Advisory (SCA) levels Saturday through Monday.
For the Inner Waters, moderate to high confidence in current
forecast. For the waters north of Point Sal, SCA level winds will
continue through Friday night before subsiding on Saturday.
However for Sunday and Monday, there is a 60% chance of winds
increasing to SCA levels again. For the waters south of Point
Conception, SCA level west to northwest winds will continue
through Friday night. From Saturday through Monday, winds are
generally expected to remain below SCA levels. However, there is a
50% chance of SCA level northeast winds Saturday from Ventura
south to Santa Monica.
Due to strong winds throughout the waters, seas will be very
choppy in all areas this week, making for hazardous boating
conditions through the week.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 9 PM PDT this evening for zones
34-35. (See LAXNPWLOX).
Wind Advisory in effect until 9 AM PDT Friday for zones
39-44>46-52-59-547. (See LAXNPWLOX).
Beach Hazards Statement in effect through Friday evening for
zones 40-41. (See LAXCFWLOX).
High Wind Warning in effect until 9 AM PDT Friday for zones
53-54. (See LAXNPWLOX).
Wind Advisory in effect until 3 PM PDT Friday for zone 88. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Saturday for
zones 645-650-655. (See LAXMWWLOX).
Gale Warning in effect until 3 AM PDT Saturday for zones
670-673-676. (See LAXMWWLOX).
&&
.HAZARD POTENTIAL OUTLOOK...(SUN-THU)
No significant hazards expected.
&&
PUBLIC...MW
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...STu
weather.gov/losangelesPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1009 AM PDT THU APR 27 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0857 AM NON-TSTM WND GST 6 SSW CASTAIC LAKE 34.57N 118.74W
04/27/2017 M66 MPH LOS ANGELES CA MESONET
MESONET STATION WTPC1, WHITAKER PEAK.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
110 PM PDT THU APR 27 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1157 AM NON-TSTM WND GST 2 N SANTA CLARITA 34.44N 118.51W
04/27/2017 M51 MPH LOS ANGELES CA MESONET
MESONET STATION SAUC1, SAUGUS.
&&1 high wind. Local standard time, as filed.
The RAWS sensor at Camp Nine reported north winds gusting to 60 MPH.
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, April 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: 683850.