textproduct: San Diego

SYNOPSIS

High temperatures will gradually rise through Friday and Saturday to as much as 10 to 15 degrees above average for the inland valleys. Weak onshore flow will spread low clouds and cooling into the coast and valleys for Sunday and Monday with not much change for the deserts.

DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE

SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES...

Update: The forecast remains unchanged, with a gradual warming trend through Friday, and then temperatures flattening out through Saturday, before a cooling trend begins Sunday into Monday. There will still be some gusty easterly winds across the higher terrain, and offshore at the coast. Because of the offshore flow and low RH values in the lower levels, the marine layer has been non-existent in recent days, and looks to remain that way through at least Sunday morning, until there is a better push of onshore flow. Some of the deterministic models are reflecting a possible inside slider dropping down going into the early part of next week, which looks to remain dry, although there could be some increased winds, and notably cooler temperatures.

Previous discussion submitted at 145 PM:

This afternoon...Temperatures are generally warmer than at this time yesterday especially in the mountains and deserts, although the coastal areas are near or a little cooler. Surface pressure gradients are offshore but only enough to support east winds gusting to around 25 mph in the wind-prone locations of the mtns. A weak upper level disturbance embedded in the flow to our southwest will bring increasing mid and high clouds over SoCal tonight through Wednesday. This could prevent low temps from dropping as low as this morning.

From previous discussion... An amplified ridge of high pressure over the west coast will weaken a little and shift eastward briefly on Wednesday as a shortwave trough moves inland to our north. This may slow the general upward trend in temperatures but that trend will continue into Saturday under mostly clear skies as the ridge rebuilds. Friday and Saturday will likely be the warmest days with high temperatures reaching the low 80s in portions of the inland valleys. These temps are 10-15 degrees above average. Temps elsewhere will mostly be in the lower to mid 70s near the coast, with the lower deserts in the low 80s. Nights will continue to be cool through the end of the week but the lack of moisture will likely limit

For Sunday and Monday... The dominant ridge is weakened significantly and displaced eastward on Sunday and Monday as a more vigorous shortwave trough moves in from the Pacific. This will bring a return of onshore flow, with marine layer low clouds/fog and lower temperatures spreading inland. Forecast details are uncertain but Monday looks like it will be the coolest day with daytime high temps near to about 7 degrees above seasonal averages.

Temperatures begin to rebound next Tuesday as the upper level ridge begins to rebuild and the marine layer is once again restricted to the immediate coast.

AVIATION

280500Z...VFR conditions with SCT-BKN high clouds AOA 20000 feet MSL through Wednesday.

MARINE

No hazardous marine conditions are expected through Sunday.

SKYWARN

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

SGX WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...None.