Another weak atmospheric river moved over SoCal between March 6-11, bringing light to moderate rain, significant lightning and snow between 5000 and 7000 ft. Urban rainfall impacts from heavier rain showers occurred in the Inland Empire.
Every event with a place to put it; 7 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.
Another weak atmospheric river moved over SoCal between March 6-11, bringing light to moderate rain, significant lightning and snow between 5000 and 7000 ft. Urban rainfall impacts from heavier rain showers occurred in the Inland Empire. Significant lightning from warm frontal lift and instability occurred throughout most of the region, with 500 cloud flashes and 330 cloud-to-ground strikes. Gusty winds occurred with this system, with the top wind gust of 98 mph at Burns Canyon in the San Bernardino Mountains.
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 Mar 6, 2:45 AM PST, 3 hours 15 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
245 AM PST Wed Mar 6 2019
.SYNOPSIS...
There will be scattered showers and isolated thunderstorms early
this morning with more widespread rainfall as a cold front moves
across southwest California for this morning into this afternoon.
Periods of showers will then follow into Friday evening with the
greatest coverage from late Thursday night into early Friday. Snow
levels above 8000 feet, will gradually lower to around 4000 feet
on Friday. There will be periods of stronger and gusty southwest
to west winds in the mountains and high deserts into this evening,
and again Friday into Friday evening. Saturday will be mostly dry
and a little warmer with more showers for Sunday through early
next week.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (Today through Friday)...
Upper level low pressure is centered off the northern California
coast early this morning. There have been scattered showers along
with some thunderstorms overnight in portions of southwest
California as isentropic lift of a weakly unstable atmosphere has
been sufficient to generate the thunderstorms. The combination of
fast cell movement exceeding 40 mph and a dry subcloud layer has
kept rainfall from the thunderstorms quite light so far, mostly
one tenth inch or less. The biggest cluster of lightning strikes
has been from eastern portions of the Inland Empire into the San
Bernardino Mountains between 12:30 and 1:30 AM. Across San Diego
County from the coast to the mountains, temperatures were lowest
during late Tuesday evening, then have been rising slowly
overnight.
Scattered showers with a slight chance of thunderstorms will
continue into this morning in advance of a cold front that will
move across southwest California later this morning through this
afternoon with more widespread rainfall. Periods of showers will
then follow into Friday afternoon with the more widespread showers
for late Thursday night and early Friday as another low pressure
system moves inland through California. Snow levels above 8000
feet will gradually lower from this afternoon into Friday to
around 4000 to 4500 feet Friday.
Through Friday afternoon, additional rainfall for Orange,
southwestern San Bernardino, and western Riverside Counties will
range from one half to three quarters of an inch near the coast to
1 to 2 inches in the mountains with locally greater amounts. For
San Diego County, rainfall will range from one third to one half
inch near the coast to one half to one inch in the mountains with
locally greater amounts. There will be around one quarter inch in
the high deserts and one tenth inch or less in the lower deserts.
Snow levels above 8000 feet will lower to around 7000 feet early
this evening, to 6000 to 6500 feet late tonight, 5000 to 5500 feet
Thursday, and 4000 to 4500 feet for Thursday night and Friday.
Several inches of snowfall is possible on the highest peaks in the
mountains of San Bernardino and Riverside Counties today with a
few inches of snowfall down to around 7000 feet through late
tonight.
There will be periods of strong gusty southwest to west winds in
the mountains and high deserts through tonight with the winds
peaking this morning. There will be another round of stronger and
gusty southwest to west winds for the mountains and deserts for
Friday into Friday evening.
&&
.LONG TERM (Saturday through Monday)...
Saturday will be mostly dry and a little warmer under weak high
pressure. A low pressure system off the northern California coast
on Saturday afternoon will move southward off the California coast
into Sunday night, then move inland through southern California
and northern Baja for late Monday and Monday night. This will
bring more showers for Sunday and Monday. Another low pressure
system moving southeastward through the Great Basin could bring
some additional showers around Tuesday.
&&
.AVIATION...
061001Z...Coasts/Valleys/Mountains...SCT-BKN clouds mainly AOA 8000
ft MSL overnight with SCT -SHRA and isolated -TSRA. Occasional CIGS
near 2500 ft MSL possible in showers this morning. More widespread
showers likely after 16Z, with areas of CIGS 2500 ft MSL and
local 3-5 SM vis. Coastal mountain slopes becoming obscured in
clouds/fog through this morning. Showers and mountain obscurations
will continue into tonight.
Deserts...Occasional -SHRA and ISO -TSRA possible in the deserts
through the early morning. S to SW winds with sfc gusts 35-45 kt
developing along the desert mountain slopes and locally into the
deserts through the morning and continuing through evening as
winds gradually shift to the SW to W. MOD-STG UDDFS and LLWS
possible over the mountains and adjacent desert areas.
&&
.MARINE...
Isolated thunderstorms over the coastal waters will continue this
morning. Otherwise, scattered showers will continue at times
through Friday. West winds will strengthen early Friday morning,
with gusts up to 30 kt possible into early Saturday morning.
&&
.BEACHES...
A Beach Hazards Statement is in effect early this morning for
lightning. The threat of lightning will diminish later this morning.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory until 7 AM PST Thursday for Apple and Lucerne
Valleys-Riverside County Mountains-San Bernardino County
Mountains-San Diego County Mountains.
Winter Weather Advisory until 1 AM PST Thursday for San
Bernardino County Mountains.
PZ...NONE.
&&
PUBLIC...17
AVIATION/MARINE/BEACHES...APR/MMThe national radar mosaic for the moment the first event began.
3 high wind, 3 flood, 2 heavy snow, 1 dense fog, 1 debris flow, 1 winter weather. Local standard time, as filed.
Burns Canyon mesonet recorded a peak wind gust of 98 mph between 0600 and 0700 PST on March 6th.
Wrightwood mesonet recorded a peak wind gust of 76 mph between 0600 and 0700 PST on March 6th.
CalTrans reported street flooding on Highway 60 and Rubidoux Blvd in Riverside due to heavy rain and clogged drains.
Toro Peak mesonet recorded a peak wind gust of 63 mph between 0900 and 1000 PST on March 6th.
CalTrans reported HOV lane flooded on northbound 5 freeway due to heavy rain.
CalTrans reported dense fog with visibility less than a mile in the Cajon Pass around 1100 PST on March 6th.
CalTrans reported flooding in the right hand lane of Highway 60 due to heavy rain.
CalTrans reported mud/rock slide on Highway 18 east of Lakeview Point.
CoCoRaHs observer reported 11 inches of storm total snow in Fawnskin.
Public reported 12.5 inches of storm total snow in Big Bear City.
Emergency Manager reported 3 inches storm total snow at Palomar Mountain.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2019Every state in 2019This day in weather historyWarnings in California, March 2019
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: 814752, 814753, 814893, 814754, 814894, 814897, 814895, 814898, 814886, 814887, 814896.