National Weather Service Forecast Discussion

Dicussion provided by the National Weather Service Forecast Office located in San Diego, California

000
FXUS66 KSGX 162045
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
145 PM PDT Thu Sep 16 2021

.SYNOPSIS...
Seasonally cool conditions are expected through this weekend.
Winds will turn offshore Monday into Tuesday and high temperatures
will slowly rise through next week. Night and morning low clouds
will cover the coast and valleys through the weekend.

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

At 1 PM, skies were clear across Southern California. Temperatures
were running 2 to 6 degrees below at this time yesterday, and
highs are expected to range 2 to 10 degrees below normal this
afternoon west of the mountains. Highs will be near seasonal
averages for the deserts. High temperatures are expected to remain
pretty steady through Sunday, only varying a degree or two each
day. Night and morning low clouds will cover the coast and much of
the valleys each night and morning through this weekend.

A weak, longwave trough is situated off the coast today.
Increasing upper-level moisture will move into the region on
Friday, producing some high clouds across our area, but very dry
conditions near the surface will prevent any precipitation. An
amplified longwave trough will progress eastward through the
Pacific Northwest and Great Basin on Saturday and Sunday. The main
impacts for Southern California will be some breezy winds across
the mountains and the deserts slopes this weekend. Peak wind gusts
are expected to reach 25-40 mph.

As the upper low moves eastward early next week, a ridge will
begin to develop across the eastern Pacific. This will set the
stage for winds to turn offshore late Monday into Tuesday. At
this time, Santa Ana winds look to remain on the weaker side.
Highs will slowly warm through the week, with temperatures
expected to return to near normal or slightly above normal by
Wednesday.

&&

.AVIATION...
161930Z...Coast/Valleys...Mostly clear skies expected through 03Z
Friday. After 03Z cigs likely to return to coastal TAF sites,
spreading into the valleys including KONT/KSBD after 08Z Friday. Vis
of 3-5SM BR/HZ possible near higher coastal terrain and along the
inland extent of the stratus in the valleys. Low clouds and vis
restrictions expected to clear 16-18Z Fri.

Mountains/Deserts...Clear skies with unrestricted vis into Friday.

&&

.MARINE...
No hazardous marine weather is expected through Wednesday.

&&

.BEACHES...
Elevated surf of 3 to 5 feet, with sets to 6 feet is possible at
Orange County and northern San Diego County beaches today. Surf will
continue to decrease through the weekend. Strong rip and longshore
currents are likely at all beaches today.

&&

.FIRE WEATHER...
Fire weather conditions will continue elevated to locally critical
for a few hours along the desert slopes and near passes today, where
very low RH (5-10%) and gusty southwest to west winds will prevail,
especially in the afternoon and evening. Slightly higher RH is on
the way for Fri-Sat with a slight increase in winds by Saturday.
Temperatures will remain near or below average through the weekend,
followed by warming to around average early next week under high
pressure aloft and weak offshore flow.

&&

.SKYWARN...
Skywarn activation will not be needed today.


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&

$$

PUBLIC...Schenk
AVIATION/MARINE...CO

NWS SGX Office Area Forecast Discussion