textproduct: San Diego

SYNOPSIS

A slight chance of afternoon showers and thunderstorms will continue for the mountains through Wednesday as monsoonal moisture slowly decreases. High and low temperatures will continue to warm through Thursday, to as much as 10 to 15 degrees above average, with not much change for Friday. The highest HeatRisk is expected for Thursday and Friday with widespread Extreme HeatRisk for the inland valleys and inland Orange County. This will be followed by a cooling trend for the weekend into early next week with stronger onshore flow and drier southwest flow aloft with high temperatures falling to around average for next Monday.

SHORT TERM (Today through Thursday)

The warming trend will continue through Thursday with warmer days and warmer nights. High temperatures on Thursday will range from the 80s near the coast to 106 to 112 for the Inland Empire with 110 to 116 for the lower deserts. Low temperatures on Thursday will be mostly in the 70s for the coast and valleys and in the mid 80s to mid 90s for the lower deserts.

The highest HeatRisk for the coast and valleys is expected on Thursday and Friday with widespread Extreme HeatRisk for the inland valleys and inland Orange County with Major HeatRisk for most other areas with Moderate HeatRisk limited to the beaches.

Mid level monsoonal moisture will remain in place today with a slight decrease on Wednesday and a greater decrease on Thursday. A slight chance of afternoon showers and thunderstorms, mostly for the mountains, will continue through Wednesday.

LONG TERM (Friday through Monday)

For Saturday through Monday, high pressure will begin to weaken across the area as a low pressure system develops near the California coast, strengthening onshore lower level flow. High temperatures will fall to around 5 degrees above average on Sunday and a few degrees below average for the mountains and inland valleys on Monday. Monday high temperatures will range from the mid 70s to lower 80s near the coast to the 90s for the Inland Empire with 104 to 108 for the lower deserts.

AVIATION

251130Z...Coast...Patchy low clouds 600-1000 feet MSL will be random and intermittent through 16Z. Vis reductions 1-5SM possible where cigs form. Patchy low clouds will form again after 03Z and overnight into Wednesday. Isolated and random cigs would be 600-1000 feet MSL.

Mountains/Deserts...Cumulus based around 9000 feet MSL with CB clouds with tops to 40000 feet and ISO TSRA over mountains and locally into adjacent deserts 19-01Z. Any TS could produce gusty, erratic winds.

Otherwise...SCT clouds AOA 15000 feet MSL.

MARINE

No hazardous marine conditions are expected through Saturday.

BEACHES

A 4-5 foot southerly swell (from 170 degrees) at 13-15 seconds will move into the area Wednesday and Thursday, leading to elevated surf for the south facing beaches of northern San Diego County and Orange County. Surf of 3 to 5 feet, with sets up to 7 feet are expected.

SKYWARN

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

SGX WATCHES/WARNINGS/ADVISORIES

CA...Heat Advisory from 10 AM this morning to 8 PM PDT Friday for Orange County Coastal Areas-San Diego County Coastal Areas.

Extreme Heat Warning until 8 PM PDT Friday for Coachella Valley- Orange County Inland Areas-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Deserts- San Diego County Mountains-San Diego County Valleys-San Gorgonio Pass near Banning-Santa Ana Mountains and Foothills.

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

Extreme Heat Warning from 10 AM this morning to 8 PM PDT Friday for Apple and Lucerne Valleys.

PZ...None.