Marine Weather and Tide Forecast for Huntington Beach, CA

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

A weak ridge off the Pacific continues to snag to the NE over CA this afternoon as an upper level low moves into New Mexico. This has prompted weak offshore winds for interior areas with light onshore flow toward the coast. We've also seen warm temperatures out there for the date with some valleys in the lower 80s as of the noon hour. As the ridge of high pressure over the State weakens throughout the day, pressure heights will begin to fall, deepening the marine layer. Per latest HRRR guidance, clouds and fog will form tonight into Sunday morning with moderate confidence.
Some areas may see dense fog under 1/4 of a mile, so travel with care. The marine layer will deepen further into Sunday night and Monday, providing greater cooling for inland areas and clouds progressing further into the valleys by Monday morning, which will give a lesser chance of dense fog at lower elevations.

A trough of low pressure currently in Southeast Alaska will move southward into the Northern Rockies and the Desert Southwest by early next week. Upper level winds substantially increase as the trough digs through Nevada and Arizona. As the pressure gradient tightens and a surface high moves into the Great Basin, gusty Santa Ana winds and very dry air will result across Southern California.
Model projections depict near a 10mb gradient expected between San Diego and Las Vegas, indicating strong wind potential.

Latest hi-res model forecast guidance is getting a better grip on the start time of the these NE and E winds. Confidence is increasing that winds begin during mid Monday morning across mountain passes, pushing into western valleys by Monday afternoon and evening. Winds will be strongest and push farthest west toward portions of the coast on Tuesday morning and afternoon, decreasing throughout the day Wednesday. Valleys will see wind gusts primarily between 30 and 45 MPH, foothills 40-55 MPH, and locally over 60 MPH for mountain passes and canyons. Since this weather pattern favors a more easterly wind component, east-west oriented passes will see the highest winds, including the San Gorgonio Pass and across the San Diego County mountains/foothills. This will lead to critical fire weather conditions as dry fuels and low relative humidity values set in. Please take this time to secure any valuable property and practice wildfire safety measures by creating defensible space around residences and avoiding outdoor burning.

As the trough pushes eastward into the Plains, brief high pressure will move into the area, relaxing the pressure gradient. As it does so, we can expect calmer winds with fair weather. By around Friday, the weak ridge hangs on while a trough moves closer to the West Coast. Model guidance has shown a trend of this trough staying further north with the ridge staying over the West, so this would maintain a dry regime with temperatures slightly above average.
Chances are small, but light precipitation still not out of the question by next weekend if the trough dips south enough, though hopes are dwindling.

AVIATION
072100Z
Coasts
Clear skies and VFR conditions prevailing through this evening. Low clouds are expected to develop around 06z this evening, and push 5-10 miles inland around 06-08z. Cloud bases will be 200-400 ft MSL and vis to be 0-2 SM, with areas of dense FG with vis to 1/8-1/2 SM at times, especially for the higher coastal mesas. Highest confidence for CIGs /FG at KSAN (60-70%), followed by 50-60% for KSNA, and lower confidence for impacts at KCRQ (30-40%).
Clouds/fog should begin to lift/clear around 16-17z, with full clearing to the beaches by 18z. Low clouds/fog could linger at the beaches into the afternoon hours.

Valleys/Mountains/Deserts...Mostly clear skies and VFR prevail through Sunday afternoon.

MARINE
More widespread fog with visibilities around 1SM or less is expected to develop around 03-06z this evening, continuing into Sunday morning. Another round of fog is possible Sunday night into Monday, but should be less dense over the waters. With increasing offshore wind on Tuesday, winds may gust up to 20-25kts, primarily off the northern San Diego County coasts.

BEACHES
Dense fog is expected to roll in sometime this evening, likely bringing visibility below 1 mile, with 0 to 1/4 mile visibility at times. Clouds/fog should lift/thin some by late Sunday morning, but some spots could see foggy conditions linger into the afternoon.
Another round of fog is possible Sunday night into Monday, but should be less dense on the beaches.

FIRE WEATHER
A moderate to locally strong Santa Ana wind event will unfold with gusty northeast and east winds expected Monday through Wednesday.
Winds will begin late Monday morning and afternoon, peak in strength Tuesday morning and afternoon, and gradually fade through Wednesday. Riverside and San Diego County mountain foothills and adjacent inland valleys are expected to have the strongest winds.
Local gusts over 60 mph through favored passes and on mountain foothills. Gusts of 35-45 mph are expected in parts of the inland valleys. By Tuesday afternoon, relative humidity values should drop near 5-10% for inland areas and 15-25% at the coast.
Overnight recoveries will be poor increasing to only 15-30%. Low humidity, strong winds, and dry fuels will lead to critical fire weather conditions from Monday through Wednesday morning, highest risk on Tuesday. Wednesday and Thursday will see lighter winds, but humidity will still lower near 5-20% each afternoon.

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

SGX WATCHES/WARNINGS/ADVISORIES
CA...Red Flag Warning from 10 AM Monday to 4 AM PST Wednesday for Riverside County Mountains-Including The San Jacinto Ranger District Of The San Bernardino National Forest-San Bernardino County Mountains-Including The Mountain Top And Front Country Ranger Districts Of The San Bernardino National Forest-San Bernardino and Riverside County Valleys -The Inland Empire-San Diego County Inland Valleys-San Diego County Mountains-Including The Palomar And Descanso Ranger Districts of the Cleveland National Forest-San Gorgonio Pass Near Banning-Santa Ana Mountains-Including The Trabuco Ranger District of the Cleveland National Forest.

PZ...None.