Wildfire in California, February 18, 2021

Area Forecast Discussion
National Weather Service San Diego CA
934 PM PST Wed Feb 17 2021

.SYNOPSIS...
Warming conditions expected for the end of the week. Temperatures
will cool slightly on Saturday, before a more significant warm up
Sunday through Tuesday. Periods of breezy conditions expected to
fluctuate between offshore and onshore through early next week. The
end of this week will be mostly low cloud free, with a return of low
clouds and areas of fog possible over the weekend.

&&

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

Update:
Winds have subsided this evening but will pick back up overnight
into Thursday as Santa Ana winds blow. The stronger winds will be
confined to immediately below passes and along the coastal
mountain slopes tonight, but will spread out across especially
parts of the Inland Empire Thursday morning after sunrise, far
inland OC and far inland SD where a Wind Advisory is in effect. No
changes were needed to the forecast this evening.

Previous Discussion:
As of 1 PM this afternoon, areas of gusty north winds have mainly
been confined to the Cajon Pass and into the Inland Empire.
Northeast to east winds are beginning to get channeled through the
San Gorgonio Pass and are expected to impact the San Diego and Santa
Ana mountains and foothills later this evening. Over the mountains
wind gusts will mostly be 40 to 45 mph, with wind gusts 25 to 35 mph
in the foothills and valleys. Winds will begin to taper off Thursday
afternoon.

On Saturday, a low pressures system passing inland through
California will bring gusty west winds to the mountains and deserts.
It looks like the strongest wind gusts will be 35 to 40 mph. The
west winds will transition to north to northeast winds as a surface
high sets up over Nevada Sunday. Peak wind gusts will be 35 to 40
mph Sunday and Monday. These gusty north to northeast winds will
diminish into Tuesday.

Warming conditions expected today through Friday, with temperatures
five to locally 10 degrees above average by Friday. Slightly cooler
conditions expected Saturday, with most places cooling to average or
slightly below average west of the mountains. The cooling will be
short lived, as a ridge sets up over the West Coast Sunday
starting a warming trend that will last through at least Tuesday.
Monday and Tuesday will see temperatures in the 80s for the lower
deserts and portions of the Inland Empire, inland Orange County,
and eastern San Diego County.
.AVIATION...
172050Z...FEW-SCT low clouds this afternoon with bases around 2000
feet MSL, becoming clear with unrestricted vis through Thursday.

Local gusty northeast winds will continue through Thursday morning,
with gusts 25-35 mph and LLWS possible vcnty KSBD, KONT, KSNA.
Surface winds will be strongest and most persistent for foothills
and adjacent valleys south and west of the San Bernardino Mountains
where weak to moderate up/down drafts may occur through Thursday
morning.

&&

.AVIATION...
180500Z...VFR conditions w/ unrestricted vis at all terminals thru
Thu night. Periods of light NE SFC winds Wed night into Thu AM
for KSNA, Inland Empire terminals. Sfc gusts 20-25 kts likely at
times for KPSP thru Thu AM. LLWS possible for most areas thru at
least Thu AM, locally longer, and especially likely for Inland
Empire terminals. High likelihood of MOD up/down drafts, and STG
in some areas, particularly in vcnty of KONT, KSBD and KPSP and
strongest over the next 6-12 hrs, diminishing thereafter.

&&

.MARINE...
No marine hazards expected through Friday. Locally strong NW winds
possible Saturday with gusts nearing 25 kts for the Outer Waters,
leading to hazardous boating conditions.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory until 2 PM PST Thursday for Orange County Inland
     Areas-San Bernardino County Mountains-San Bernardino and
     Riverside County Valleys-The Inland Empire-San Diego County
     Valleys.

PZ...NONE.
&&

PUBLIC...Gregoria (Update)/CO (Previous Discussion)
AVIATION/MARINE...Rodriguez