614 
FXUS66 KSGX 080452 AAA
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
945 PM PDT Wed Apr 7 2021

.SYNOPSIS... 
Increasing onshore flow will bring gusty west winds to the mountains 
and deserts tonight where a Wind Advisory will be in effect starting 
at 10 PM. Thursday through Sunday will be dry with seasonal 
temperatures at the coast to around 10 degrees above average in the 
deserts. A trough of low pressure from the north will bring cooling 
next Monday through Wednesday.

&&

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

No changes were needed this evening. Abundant high cloudiness 
continues to flow into SoCal from the subtropical Eastern Pacific, 
and low clouds will be slow to form overnight, but we still expect 
coastal stratus at least patchy well after midnight. A wind advisory 
remains in effect overnight for the mountains and deserts with gusts 
around 55 mph likely at times.

Previous Forecast Discussion (issued at 200 pm PDT): 

 Skies were clear at 1 PM but the visible satellite loop showed a 
swath of high clouds over the ocean streaming eastward that will 
traverse SoCal skies this evening. 

Ridging aloft over the Southwest will bring seasonally warm weather 
west of the mountains Thursday through Sunday. Despite the fact that 
ocean water temperatures have finally crept upward from the upper 
50s to the lower 60s, coastal highs will remain in the mid to upper 
60s from a cool afternoon sea breeze each day. Valley highs of 75-85 
will be a few degrees above average. The hottest area relative to 
average will continue to be in the Lower Deserts. April is off to a 
torrid start in this area. The average high temperature at Palm 
Springs over the first six days of April is 12 degrees above 
average. (The observed average high was 96.7 compared to a normal of 
84.7). The hot weather will continue through the weekend with highs 
in the mid to upper 90s. It will finally turn a little cooler next 
week. 

Mountain and Desert winds tonight and Thursday: A low pressure 
trough passing by to the north tonight will bring strong winds to 
the mountains and deserts through Thursday morning. Mountain waves 
will likely surface in some areas with gusts from 50 to 60 mph at 
the most wind prone sites. A Wind Advisory has been issued 10 PM 
tonight until 6 AM Thursday. Thursday afternoon and evening will 
also be breezy in the mountains and deserts. 

Long Range Outlook for Next Week: Mean 500 mb troughing prevails 
over the West early next week. The GEFS and EC ensembles project a 
strong shortwave digging down the Intermountain West across Nevada 
and Arizona. This pattern will drive cooler northerly flow into the 
West, and also bring greater support for stronger north to northeast 
winds into SoCal next Tuesday and Wednesday. 

&&

.AVIATION... 

080310Z...Coastal low clouds will develop again tonight along the 
coast and could impact KSAN/KCRQ/KSNA 06-15Z. Timing is uncertain 
but cigs are likely to be 600-1000 ft MSL, locally 300-400 ft MSL at 
times. Patchy fog 3-6SM expected as well. Elsewhere, SCT clouds at 
or abv 18000 ft with unrestricted vis through Thursday.

&& 

.MARINE...
Northwest winds occasionally gusting 25-30 knots are expected at 
times during the afternoons and evenings through Sunday, especially 
over the far outer waters near San Clemente Island. The strongest 
winds will likely be Thursday night and then again Friday afternoon 
and evening. Gusty winds will continue over the offshore waters 
Saturday and Sunday, but not as strong. See the Small Craft Advisory 
for details.

&&

.SKYWARN... 
Skywarn activation will not be needed this week. 

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory from 10 PM this evening to 6 AM Thursday for 
     Coachella Valley-Riverside County Mountains-San Bernardino 
     County Mountains-San Diego County Deserts-San Diego County 
     Mountains-San Gorgonio Pass Near Banning.

PZ...Small Craft Advisory from 5 PM this afternoon to 3 AM Friday 
     for Waters from San Mateo point to the Mexican Border 
     Extending 30 to 60 nm out including San Clemente Island.

&&

$$

PUBLIC...Moede/JMB
AVIATION/MARINE...PG