Flash Flood Warning 14, NWS San Diego, CA

511 
WGUS76 KSGX 071812
FFSSGX

Flash Flood Statement
National Weather Service San Diego CA
1012 AM PST Sat Nov 7 2020

CAC065-071-071822-
/O.EXP.KSGX.FF.W.0014.000000T0000Z-201107T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-San Bernardino CA-
1012 AM PST Sat Nov 7 2020

...FLASH FLOOD WARNING FOR THE APPLE AND EL DORADO BURN SCAR WILL 
EXPIRE AT 1015 AM PST THIS MORNING FOR RIVERSIDE AND SAN BERNARDINO 
COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed any remaining road closures.

A Flash Flood Watch remains in effect until 800 PM PST Saturday for 
a portion of southwest California.

LAT...LON 3407 11712 3407 11713 3420 11693 3399 11668
      3390 11689 3397 11706

$$

Small

Area Forecast Discussion
National Weather Service San Diego CA
923 AM PST Sat Nov 7 2020

.SYNOPSIS...
Two fast-moving storm systems from the north will impact Southern
California this weekend. The first today, will bring widespread
showers and isolated thunderstorms, with heavy snow in the northern
mountains, the second on Sunday, will focus more over San Diego
County. Both will keep temperatures well below average, and bring
strong, gusty winds to the mountains and deserts. Fair, dry, and
cool weather is expected for much of next week.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

Satellite imagery this morning showed an impressive open-cellular
cumulus (indicative of strong cold air advection) charging south
along the CA Coast. Farther to the east, lightning strikes were
occurring over central AZ. A few lightning strikes have occurred in
the SGX area as well (north of San Diego County) and radar shows
pockets of strong reflectivity form scattered cells moving rapidly
east across the forecast area. Rainfall amounts overall have been
light (one-quarter inch or less) except on the coastal slopes where
one-half to as much as an inch has fallen. the 12Z Miramar sounding
showed strong cooling below 12K FT with steep lapse rates below 6K
FT. SW winds have reached 60KT at 12K FT. Snow has been report
around 4500 FT this morning so the snow level may be near that, but
is expected to rise closer to 5K this afternoon. Some light snow
accumulations have been reported above 5000 FT. No forecast updates
planned this morning.

From previous discussion...

The first storm of the season will impact Southern California
this weekend. The center of the cold core upper low is over NorCal
this morning and will be moving southward. Scattered showers and
gusty winds in the mountains and deserts have already been
impacting SoCal since last evening. See rainfall and wind gust
summaries headlined on our webpage weather.gov/sandiego

There has been a recent increase in shower activity along the
coast and even more defined shower activity is located near Point
Conception and points north and moving southeast. This area will
move into our area this morning and afternoon with an uptick in
shower coverage and intensity. There is even a slight chance of
thunderstorms as instability increases this morning through the
afternoon. A Flash Flood Watch continues in effect for the Apple
and El Dorado burn scars for the potential of debris flows
occurring.

There will likely be somewhat of a break in the shower action
tonight, though some showers will continue, especially in the
mountains. Another shortwave will rotate southward on Sunday,
leading to another round of more widespread showers Sunday morning
into the afternoon.

The rain will add up with storm totals of 1-3 inches forecast
along the coastal mountain slopes, even up to 4 inches in the San
Diego County mountains. The San Diego valleys 1.00-1.75 inches,
SD coast 0.50-1.00 inches, Orange County coast into the Inland
Empire 0.30-0.80 inches and the deserts less than 0.25 inches.

Cold air is moving in from the north and this will cause snow
levels to lower to about 4500 feet, so snow will add up with
up to 6 inches to 6000 ft...6-12 inches 6000 to 7000 feet...and
12 to 18 inches 7000 to 8000 feet. The heaviest snow will fall
this afternoon and evening, lighter snow tonight, before another
bout of heavier snow developing Sunday morning through afternoon.

West winds will continue strong along the desert mountain slopes
and across parts of the deserts where a Wind Advisory is in
effect for wind gusts to 50 mph. Localized gusts to 70 mph will
occur along rural desert slopes.

The storm will move away Sunday night with clearing skies, leading
to a sunny early-mid next week under seasonably cool conditions,
though temps will gradually warm, but chilly nights ahead.

Late next week there is a high degree of forecast uncertainty as
some models keep storm systems far enough north to leave SoCal
dry, while others show additional  as early as
Thursday night-Friday. The forecast is dry for now and we will
watch model trends.

&&

.AVIATION...
071700Z...BKN-OVC clouds mainly higher mountains westward obscuring
higher terrain. Cloud sct-bkn 1500-2500 FT MSL merging with higher
layers, with tops to near 12000 feet MSL. Scattered showers, along
with Isolated thunderstorms. Thunderstorm tops to near 20000 feet
MSL with small hail in heavier showers.

West to southwest winds with gusts up to 25 kts west of the
mountains and up to 50 kts across the mountains. This will lead to
strong up/downdrafts and LLWS over and east of the mtns.

Otherwise, east of the mountains mainly sct-bkn clouds AOA 10,000 ft
with unrestricted vis through Sat.

&&

.MARINE...
Northwest winds of 15-25 kts with gusts to 30 kts will continue
through the weekend, along with combined seas of 8-12 ft and steep
waves. The winds and swells will peak today and Sun before subsiding
Mon. A Small Craft Advisory is in effect through early Mon morning
for gusty winds and high combined seas. Periods of showers are
likely tonight through Sun night. No hazardous marine conditions are
expected after Mon morning.

&&

.BEACHES...
High surf is expected through the weekend, with the highest surf on
this afternoon through Sunday, or 4 to 9 feet for the beaches of OC
and SD County. Highest surf likely to occur in southern San Diego
County, especially Imperial Beach and near the border, also
producing high rip current risk and dangerous swimming conditions. A
small craft advisory is now in effect and replaces the beach hazards
s statement through late Sun night for high surf and strong rip
currents.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Winter Storm Warning until 6 PM PST Sunday for Riverside County
     Mountains-San Bernardino County Mountains.

     Wind Advisory until 10 PM PST Sunday for Apple and Lucerne
     Valleys-Coachella Valley-San Diego County Deserts-San Diego
     County Mountains-San Gorgonio Pass Near Banning.

     Flash Flood Watch from 8 AM PST this morning through this
     evening for San Bernardino County Mountains-San Bernardino
     and Riverside County Valleys-The Inland Empire-San Gorgonio
     Pass Near Banning.

     High Surf Advisory through late Sunday night for Orange
     County Coastal Areas-San Diego County Coastal Areas.

PZ...Small Craft Advisory until 4 AM PST Monday for Coastal Waters
     from San Mateo Point to the Mexican Border and out to 30 nm-
     Waters from San Mateo point to the Mexican Border Extending
     30 to 60 nm out including San Clemente Island.

&&

PUBLIC...10/Gregoria
AVIATION/MARINE...Small