Marine Weather and Tide Forecast for Wrightwood, CA

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

Low clouds have redeveloped along the San Diego County coast this evening, while elsewhere skies remain clear. The 00Z KNKX sounding shows the marine inversion based near 2300 ft MSL, little change from this morning. A weak coastal eddy develops tonight, which may result in a slight increase in the marine layer depth, with low clouds extending into the far southern and western portions of the Inland Empire by Friday morning. Weak troughing remains over the region on Friday with generally little changes in high temperatures from today.

Another upper trough approaches the West Coast by late Friday and digs through interior California and Nevada on Saturday, followed by a second upper low moving from the Pac NW into the Great Basin on Sunday. This will generate gusty west winds across the mountains, deserts, and coastal waters this weekend. Currently peak wind gusts are forecast to be around 40-50 mph, though isolated gusts of 60 mph ore more are likely (70-80% chance)
through the favored passes Saturday afternoon and evening. This trough will also bring considerable cooling with highs falling to 10-15 degrees below normal inland on Saturday. With the trough axis passage late Saturday and a deep marine layer in place, areas of drizzle or light showers are possible along and west of the mountains, with the greatest chances in San Diego County due to the more northwesterly flow. Chances of accumulating precipitation range from around 10% along the LA County border to around 20% along the foothills of the mountains, increasing to around 30-40% across San Diego County from the coastal slopes westward. Chances of 0.10" or more are around 10-25% in San Diego County, highest along the coastal mountain slopes, and less than 10% for areas northward. Based on current timing of the trough, most of this precipitation is expected to fall Saturday evening into Saturday night. There could be some drizzle Saturday morning as well, though the chances of any accumulating precipitation is less than 10%. Height rises on Sunday as the first wave moves out should allow for some warming though highs will still be around 7-12 degrees below normal. Breezy onshore winds will continue into Sunday evening, weakening into Monday as onshore pressure gradients relax and flow aloft weakens.

The trough will be replaced by weak upper ridging early in the week, bringing warmer weather with less marine layer cloud cover.
Around 27% of the ensembles have the final short wave tracking far enough west across the Great Basin to generate weak offshore flow in So Cal Tuesday morning, though the remaining members keep the wave much further inside with a continuation of onshore flow. If the offshore flow were to occur, it would result in warmer and drier conditions west of the mountains on Tuesday. Generally consensus is for weak ridging to continue through at least the middle of next week for continued warming, though a small number of members (around 15-25% of them) try to develop some weak troughing along the Pac NW into Central CA Wed and Thu, which would limit warming. For Wednesday and Thursday, there is a 80-95% chance of highs of 90 degrees or more in the inland valleys and high deserts, and a 90-100% chance of highs of 100 or more in the low deserts. The good news is the chance of highs of 110 or more are less than 10%.

AVIATION
160335Z
Coast/Valleys
Low clouds based 1200-1500 ft MSL have developed along the San Diego County coast and will continue to expand northwards this evening and then 20-25 miles inland overnight, with the potential to reach portions of the Inland Empire by 08Z Fri. There is a 60% chance of low clouds reaching KONT by 12Z Fri. Low clouds expected to clear from the valleys 16-18Z Fri, with most coastal areas scattering out 17-20Z with the potential for patchy clouds to linger along the immediate coast. Low clouds with slightly higher bases 1500-2000 ft MSL will become more widespread again after 00Z Sat.

Mountains/Deserts...Mostly clear skies tonight, with increasing high clouds cover Friday AOA 20000 ft.

MARINE
No hazardous marine conditions are expected through Saturday morning. Stronger winds and higher seas are expected late Saturday into Sunday. Westerly winds 15 to 20 kt gusting 20 to 25 kt with wind-driven waves 6 to 8 feet for outer coastal waters, with wind gusts 20 kt or less and wind-driven waves up to 6 feet expected for inner coastal waters. Hazardous boating conditions for small craft look likely for the outer coastal waters. Winds and waves gradually subside Monday.

BEACHES
Elevated surf will impact beaches late Sunday into Monday. Surf heights of 4-6 feet with local sets to 7 feet are possible along west-facing beaches. Increased surf will result in an increased risk of strong rip currents.

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



SGX WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...None.