textproduct: San Diego

SYNOPSIS

Below average temperatures with marine layer low clouds and fog reaching inland to the coastal mountain slopes through Sunday. Gusty westerly winds expected in the mountains and deserts this afternoon and evening. A warming trend is expected Monday through at least the middle of next week. Areas of major HeatRisk possible for the deserts, and moderate HeatRisk for inland Orange County, the inland valleys and mountains through the middle of next week. The marine layer will become shallower next week, staying confined to coastal areas and western portions of the inland valleys.

DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE

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

This morning...The marine layer is about 3,000 ft deep and at this hour low clouds have spread inland to the coastal slopes in some areas. Patches of light drizzle are possible this morning west of the mountains if the saturated layer gets thick enough.

Upper level troughing near the west coast and onshore flow will keep temperatures near or a few degrees below seasonal averages through the weekend. The onshore flow will be strongest this afternoon, producing westerly winds gusting 30-40 mph in the mtns and deserts locally to 55 mph in the northern Coachella Valley below the San Gorgonio Pass. The onshore flow will weaken over the next several days. The marine layer will remain quite deep with low clouds spreading inland to the coastal mtn slopes each night and morning.

For Monday through the middle of next week...A ridge of high pressure building over the west coast will bring a warming trend through at least the middle of next week although after Tuesday, model solutions begin to diverge significantly and introduce more uncertainty into the forecast. At this time, it looks like Wed and Thu will be the warmest days with high temperatures ranging from a few degrees above normal in the coastal areas to 5-12 degrees above normal in the inland valleys, mtns and deserts. This will likely bring areas of moderate HeatRisk to the inland valleys, mtns and high deserts, and areas of high HeatRisk to the lower deserts.

As we approach the end of next week, a percentage of ensemble members show low pressure troughing beginning to weaken and displace the ridge to the south. This could lower temperatures once again, deepen the marine layer and allow low clouds to spread farther inland. If this solution does not verify, the HeatRisk conditions could persist through the end of next week.

AVIATION

190530Z...Coast/Valleys...Low clouds have pushed in from the coast and filled into the adjacent valleys. Low clouds are expected to push into the inland empire and fill the coastal basin over the next few hours. Cloud bases will be 1500-2200ft MSL with local vis reduced 1-5SM where clouds intersect terrain. Low clouds will start clearing inland areas after 16Z, clearing coastal areas by 18Z. Low clouds return after 00Z Saturday for coastal SD, after 04-06Z Saturday for OC, and filling the coastal basin by 09-12Z.

Mountains/Deserts...VFR conditions expected through the TAF period. Breezy westerly winds with gusts 25-35 kts through mountain passes and into deserts through 09Z, returning after 21Z through 09Z Saturday. There could be temporary VIS restrictions in FU (wildfire smoke) in and around the San Gorgonio Pass and the northern Coachella Valley.

MARINE

No hazardous marine conditions are expected through Tuesday.

BEACHES

Elevated surf and strong rip currents continue through Friday. Surf of 3-5 feet with local sets to 6 feet are expected at south-facing beaches. Expect locally hazardous swimming conditions with high rip current and longshore current risk. See the Beach Hazards Statement for more details.

SKYWARN

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

SGX WATCHES/WARNINGS/ADVISORIES

CA...Beach Hazards Statement through this evening for Orange County Coastal Areas-San Diego County Coastal Areas.

PZ...None.