San Mateo Point to the Mexican Border from 30 to 60 nm out including San Clemente Island Marine Forecast
|Today...Wind Variable Less Than 10 Kt...Becoming W To 10 Kt With Gusts To 15 Kt In The Afternoon. Wind Waves 2 Ft Or Less. Mixed Swell W 3 To 4 Ft At 14 Seconds And S 2 To 3 Ft At 9 Seconds.|
|Tonight...Wind Nw 10 Kt. Gusts To 15 Kt In The Evening. Wind Waves 2 Ft Or Less. Mixed Swell W 4 To 6 Ft At 14 Seconds And S 2 Ft At 13 Seconds.|
|Sat...Wind Variable Less Than 10 Kt. Wind Waves 2 Ft Or Less. Mixed Swell W 3 To 6 Ft At 13 Seconds And Sw 1 To 2 Ft At 16 Seconds.|
|Sat Night...Wind Variable Less Than 10 Kt. Wind Waves 2 Ft Or Less. Mixed Swell W 3 To 5 Ft At 12 Seconds And Sw 1 To 2 Ft At 16 Seconds.|
|Sun...Wind Variable Less Than 10 Kt. Wind Waves 2 Ft Or Less. Mixed Swell W 3 To 4 Ft At 10 Seconds And Sw 1 To 2 Ft At 16 Seconds.|
|Sun Night...Wind Variable Less Than 10 Kt. Wind Waves 2 Ft Or Less. Mixed Swell W 2 To 4 Ft And Sw 1 To 2 Ft.|
|Mon...Wind Variable Less Than 10 Kt. Wind Waves 2 Ft Or Less. Mixed Swell W 2 To 3 Ft And Sw 2 Ft.|
|Mon Night...Wind Variable Less Than 10 Kt...Becoming Nw 10 Kt After Midnight. Wind Waves 2 Ft Or Less. Mixed Swell W 2 To 3 Ft And Sw 2 Ft.|
|Tue...Wind Nw 10 Kt With Gusts To 15 Kt. Wind Waves 3 Ft. Mixed Swell Nw 2 To 3 Ft And S 2 To 3 Ft.|
|Tue Night...Wind Nw 10 Kt. Gusts To 15 Kt In The Evening. Wind Waves 3 Ft In The Evening...Becoming 2 Ft Or Less. Mixed Swell W 2 To 3 Ft And Sw 3 Ft.|
| 209 AM PDT Fri Sep 25 2020 |
Synopsis for the far southern California coast - PZZ700
At 2 AM, a 1020 mb high was 940 NM southwest of San Francisco and a 1008 mb low was located over Needles. Weak onshore flow will continue through early in the week. A coastal eddy will circulate tonight through Saturday night.
| Area Forecast Discussion|
National Weather Service San Diego CA
958am PDT Fri September 25 2020
Seasonal temperatures will continue into the weekend with night and morning coastal low clouds and fog. The heat will begin to build in on Sunday with much warmer high temperatures for next week with strong high pressure aloft over the West. There will also be periods of at least weak offshore flow with gusty east to northeast winds for the mountains into the valleys. It will also be very dry inland with the combination of gusty winds and low humidity increasing the fire danger for the mountains into the valleys.
FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... At 10 AM, low clouds were quickly clearing out, with only some low clouds sticking around the immediate coast. A coastal eddy developed overnight, deepening and lifting marine layer clouds. A mostly sunny day is in store for the region, with the exception of some low clouds sticking around the beaches through the afternoon. Low clouds will redevelop this evening and overnight, spreading into the western valleys by daybreak as a coastal eddy again develops.
An upper level trough will continue to move by to the north today, strengthening onshore flow and spreading cooling inland with only minor differences for temperatures on Saturday. Temperatures will be right around normal for most areas through Saturday, with the exception of the deserts, which will be 4 to 8 degrees above normal.
The big story for the upcoming week is the heat and dry conditions. High pressure will begin to build over the western states on Sunday, bringing a warming trend to the region through much of next week. The greatest warming will occur in the valleys, where temperatures will be 10 to 15 degrees above normal for much of the week. Temperatures in the Inland Empire and in the San Diego valleys will be in the upper 90s to over 100 in some spots, with the warmest days Tuesday through Thursday. Temperatures in the lower deserts have trended cooler, keeping above normal temperatures for that area, but not reaching excessive heat levels.
There is still uncertainty regarding the offshore wind event possible Sunday through at least Tuesday. Models and their ensembles show quite a bit of spread in the winds, so confidence is low in the timing and strength of the offshore winds. We will at least see weak offshore flow, with the potential for moderate offshore flow during that time frame. Northeast to east wind gusts look to remain below 35 mph in the mountains and through the San Gorgonio Pass, with higher gusts possible in the windier locations. There are a small set of ensemble members supporting periods of moderate to strong offshore flow during a couple of time period, potentially on Sunday night into Monday, and again Tuesday afternoon and evening. However, models have not agreed on a consensus yet in regards to timing and strength. Trends in the models will continue to be evaluated in the coming days.
No hazardous marine conditions are expected through Tuesday.
Onshore flow will prevail through Saturday. Southwest to west wind gusts less than 35 mph will combine with lowest daytime humidity around 10 percent in the deserts to bring a few hours of elevated fire weather conditions for the deserts onto the desert slopes of the mountains during the afternoons and evenings through Saturday.
Temperatures will begin to warm on Sunday, with weak offshore flow. Lowest humidity in the mountains will fall to around 15 percent with gusty east to northeast winds, with gusts mostly 35 mph or less. This will bring near critical fire weather conditions to the mountains on Sunday.
For Monday through Thursday, strong high pressure aloft along the West Coast will bring much warmer high temperatures with low humidity for inland areas. Periods of at least weak offshore flow are expected for much of the week. This would bring periods of gusty east to northeast winds for the mountains into the inland valleys with periods of near critical to critical fire weather conditions.
A small portion of the models support the potential for one or more periods of moderate to potentially stronger offshore flow with stronger and more widespread east to northeast winds for the mountains into the valleys. Timing and strength of the winds are still fairly uncertain, and trends will continue to be monitored in the coming days.
.SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions.
.SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE.