textproduct: San Diego

SYNOPSIS

Strengthening high pressure aloft and weak offshore flow will bring near-record high temperatures to much of southwestern California today and inland from the coast on Friday. Onshore flow for the weekend will bring some cooling for the coast into the valleys but with high temperatures remaining well above average. For next week, stronger high pressure aloft will bring additional warming for inland areas with record or near-record heat for March for much of next week. Widespread moderate or greater Heat Risk is expected for much of next week beginning on Monday for the valleys, inland Orange County, and the lower deserts with heat-related illnesses likely for sensitive populations.

SHORT TERM (Today through Saturday)

There will be weak offshore lower-level today with high pressure aloft continuing to strengthen. Northeast winds will gust to 25 to 35 mph along and below the coastal slopes of the mountains. High pressure aloft will begin to weaken on Friday and continue to weaken on Saturday as a low pressure system moves inland through the Pacific Northwest. Weak onshore flow will return Friday and Saturday with the local WRF showing a coastal eddy developing on Friday night and continuing for Saturday night along with some deepening of the marine layer.

Mid and high clouds are still expected to spread across the area for late Friday through late Saturday. This could provide some disruption to the low clouds and fog that might otherwise return to the coast for Friday night into Saturday morning. As that mid and high level moisture moves east of the area for Saturday night, a return of low clouds and fog along the coast is more likely for Saturday night into Sunday morning.

The Heat Advisory continues for the coast and valleys for today and Friday. High temperatures for the coast and western valleys will warm 12 to 18 degrees today with high temperatures for inland coastal areas into the western valleys as much as 20 to 25 degrees above average. For the coast and valleys, high temperatures will range from the lower to mid 80s near the coast to the lower to mid 90s for inland coastal areas into the western valleys with the lower deserts in the mid to upper 90s. Widespread moderate Heat Risk is expected today for inland coastal areas into the valleys. Much of southwestern California will have high temperatures near or exceeding record high temperatures for the date.

For Friday, high temperatures will cool slightly for coastal areas with the mountains and deserts warming a few degrees. For Saturday, greater cooling of high temperatures of 4 to 8 degrees is expected for the coast and valleys onto the coastal slopes of the mountains. Saturday high temperatures will be around 10 degrees above average near the coast and 15 to 20 degrees above average for the valleys, mountains, and deserts with high temperatures ranging from the 70s near the coast to the 80s for the valleys and inland Orange County with the lower deserts in the mid to upper 90s.

LONG TERM (Sunday through Wednesday)

For the weekend, high pressure will strengthen off the West Coast with strong high pressure aloft moving to near the West Coast on Monday, then only very slowly inland for Tuesday and Wednesday. The strongest high pressure aloft will be centered over southern California on Tuesday and Wednesday with slight strengthening of that high pressure for Thursday and Friday. ECMWF ensemble guidance for inland areas is warmer and trending warmer for the latter half of next week.

On Sunday, the greatest warming is expected for the inland valleys onto the lower coastal slopes of the mountains as high pressure aloft begins to strengthen. Warming of a few to around 5 degrees will occur for most areas on Monday and again on Tuesday with high temperatures on Tuesday around 30 degrees above average for the inland valleys onto the lower coastal slopes of the mountains.

On Tuesday, high temperatures near the coast will be mostly in the lower to mid 80s with inland Orange County and the San Diego County valleys mostly in the 90s with the Inland Empire in the upper 90s to 102. The lower deserts will reach 103 to 107. Several record high temperatures for the month of March could be tied or broken, especially for the deserts, inland valleys, and portions of inland Orange County.

The mountains and deserts will continue to slowly warm for Wednesday and Thursday while there could be some day-to-day fluctuations for coastal areas. NBM probabilities for the Thermal high temperature to equal or exceed 110 increases to 50 percent on Wednesday and 65 percent on Thursday.

MARINE

No hazardous marine conditions are expected through Tuesday.

BEACHES

Long period southerly 2-3 ft swell at 19-21 seconds will create elevated surf and a high rip current risk along south and southwest-facing beaches through tonight. Surf heights peaking at 3- 6 feet with sets to 7 feet.

SKYWARN

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

SGX WATCHES/WARNINGS/ADVISORIES

CA...Heat Advisory until 8 PM PDT Friday for Orange County Coastal Areas-Orange County Inland Areas-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Coastal Areas-San Diego County Valleys.

PZ...None.