Marine Weather and Tide Forecast for Ramona, CA

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

Marine clouds cleared to beaches by 10 am but then sea breeze pushed back more to the beaches and near I-5. Marine layer is slightly lower today but widespread with tops 1200-1400 feet MSL.
A new clearing area is forming over northern Orange County from Long Beach land area and a new Catalina Eddy is also evident. The upper ridge of 592 DM 500 mb heights is now centered directly over Socal, so air mass is a little warmer with 26 to 29C at 850 mb level. Clearing will likely hold at the beaches again on Sunday due to strong inversion but breaks into Orange County and parts of San Diego coastline.

Upper heights start to lower on Sunday but similar air mass in place. On Monday with the approach of a weak upper trough from the Pacific, there is cooling of 1C aloft along the coast and marine layer should also start to deepen. Inland for the deserts there is little change with 29C at 850 mb in place. By Tuesday air mass lowers to 22-23C at 850 mb on the coast and 26-27C for desert with notably increase to southwest flow aloft.

Despite synoptic cooling on Tuesday and Wednesday, inland valleys to deserts still are 5 to 10F above averages.

There is a more significant upper trough from the Pacific for late next week, that would return temperatures to near averages by Friday and into Saturday. However, this system is forecast to close off over the Great Basin or Desert Southwest and could bring some offshore flow in its wake and return to above normal temperatures by next Sunday and Monday.

AVIATION
052030Z
Coasts/Far Western Valleys
Stratus with bases 400-800 ft MSL and tops to 900-1200 ft MSL cleared out to the beaches earlier this morning, but have since nudged back onshore a few miles with the sea breeze. The edge of the clouds could dance a mile east/west through the afternoon before solidly pushing 5-10mi inland after 00z. Cloud bases should lower to 200-500ft MSL by 12z. Areas of VIS 1-3SM this afternoon and evening become 0-2SM for 09-16z. Clouds and fog look to clear back to the beaches once again around 18z Sunday morning, likely nudging a few miles back onshore again for the late morning/early afternoon with the sea breeze.

Valleys/Mountains/Deserts...SCT and locally BKN cumulus with bases 12000-15000 feet MSL over the mountain crests until 01Z this afternoon. Otherwise, mostly clear skies with unrestricted VIS expected through Sunday afternoon.

MARINE
Visibility locally reduced to around 1-3 nm in fog/haze likely through the afternoon and evening hours, especially for the nearshore waters. Higher confidence fog with visibility down to 1 nm or less along the nearshore waters for late tonight, persisting through Sunday afternoon and into late Monday morning. Otherwise, no hazardous marine conditions are expected through Thursday.

FIRE WEATHER
Elevated fire weather conditions due to the lower daytime humidity, poor recovery at night above the marine layer and conditions hot daytime temperatures which are 10 to 20 degrees above averages. Southwest flow increases on Tuesday, up to 20 knots at 850 mb level. Fuels are very dry and stressed from the heat wave and summer with limited monsoon.

CLIMATE
Inland valleys, foothills, mountains and deserts will be 10 to 20 degrees above 30 year averages for Saturday to Monday. This brings the potential for additional records. Ramona normal high is 82F and the record on Sunday is 98F for example. Palm Springs average high is 92F and a forecast of 111F is 19F above average and at the record level. The mountains are the same with Palomar mountain normal of 72F and a forecast of 89F. For the Inland Empire, Lake Elsinore average high is 86-87F and forecast and record is 103-105F.

Palm Springs on pace to be warmest first week to October with average temperature of 96F.

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



SGX WATCHES/WARNINGS/ADVISORIES
CA...Excessive Heat Warning until 8 PM PDT Monday for Coachella Valley-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Deserts-San Diego County Valleys-San Gorgonio Pass Near Banning-Santa Ana Mountains and Foothills.

Heat Advisory until 8 PM PDT Monday for Riverside County Mountains-San Bernardino County Mountains-San Diego County Mountains.

PZ...None.