Santa Cruz Island to San Clemente Island CA between 60 and 150 NM Offshore Forecast
|Tonight...N To Nw Winds 5 To 15 Kt. Seas 3 To 6 Ft.|
|Tue...N To Nw Winds 5 To 15 Kt. Seas 3 To 6 Ft.|
|Tue Night...N To Nw Winds 5 To 15 Kt. Seas 3 To 6 Ft.|
|Wed...N To Nw Winds 10 To 20 Kt. Seas 4 To 7 Ft.|
|Wed Night...N To Nw Winds 10 To 20 Kt. Seas 4 To 7 Ft.|
|Thu...Nw Winds 15 To 25 Kt. Seas 5 To 9 Ft.|
|Thu Night...Nw Winds 15 To 25 Kt. Seas 7 To 12 Ft.|
|Fri...Nw Winds 15 To 25 Kt. Seas 8 To 13 Ft.|
|Fri Night...Nw Winds 15 To 25 Kt. Seas 8 To 13 Ft.|
|Sat...N To Nw Winds 15 To 25 Kt. Seas 8 To 13 Ft.|
|Sat Night...N Winds 10 To 20 Kt. Seas 6 To 10 Ft.|
| 132 PM PDT Mon Sep 21 2020 |
Synopsis for the far southern California coast - PZZ700
At 1 PM, a 1021 mb high was 500 miles northwest of San Francisco, and a 1008 mb low was near Needles, California. Westerly afternoon sea breezes will prevail through Thursday. A coastal eddy spins up Thursday night which will bring southerly winds Friday and Saturday.
| Area Forecast Discussion|
National Weather Service San Diego CA
852pm PDT Monday September 21 2020
Fair weather will prevail this week. Areas of low clouds and fog will occur at times during the nigheights and mornings near the coast. Some gusty southwest to west winds will occur in the mountains and deserts through Tuesday night. It will be another mild day on Tuesday, but some warming will occur inland on Wednesday and Thursday. Slightly cooler Friday and Saturday, then offshore flow under a building high pressure ridge will bring more hot, dry, and breezy weather early next week. Autumn officially starts at 631am PDT Tuesday.
FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Skies were mostly clear at 8:30pm PDT, but marine clouds were forming along the coast and should thicken and spread inland overnight with patchy fog. The surface pressure gradients had a slight onshore trend with better support of SW-W winds over the mts/ deserts. Peak gusts were 25-35 MPH. The 00Z Miramar sounding was little changed from yesterday afternoon, except for stronger south flow of 15-25 KTS below 13K FT. Some moisture was drawn northward with these winds and resulted in some cumulus over the mts today, but they have disappeared with the sun. No forecast update this evening.
From previous discussion... We will have a couple of troughs moving by to the north this week, though nothing too strong. The first will move by Tuesday with the second around Friday, with a moderate high pressure system over our area Wednesday/Thursday. That will result in the temperature fluctuations--milder with the trough Tue/Fri/Sat and increased west/southwest flow in the mountains/deserts and warmer Wed/Thu, with some highs in the upper 90s in the Inland Empire, even locally 100.
A pattern change will happen around Sunday as an upper high moves over the West Coast, and surface offshore flow develops. This looks like more of an easterly flow versus northerly flow, so most of the gusty east winds will occur on the west slopes in San Diego and Riverside Counties and through Banning/San Gorgonio Pass. Temperatures will be quite warm with near 100 possible west of the mountains again, and humidity will be low, around 10 percent in some valleys possible. That upper high could get strong over the western US early next week based on ensemble projections.
No hazardous marine conditions are expected through Saturday.
Gusty southwest-to-west winds of 15 to 30 MPH are expectd on Tuesday over the mts/deserts. Local gusts 35 MPH are likley near the major passes Tuesday afternoon/evening. Very dry conditions and marginally low RH will elevate the wildfire threat in the afternoon/evening on the desert slopes. The winds may weaken slightly on Wednesday, but it will be warmer with lower RH. Fire weather conditions will remain elevated all week, far inland, especially late afternoons and evenings with the onset of the sea breeze and continued warm and dry conditions.
.SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions.
.SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE.