textproduct: San Diego

SYNOPSIS

Strengthening high pressure aloft will continue into Wednesday and Thursday with widespread moderate HeatRisk for inland areas and moderate to major HeatRisk for the lower deserts. There will be a few degrees of cooling for Friday and Saturday as high pressure aloft briefly weakens. For Sunday through Tuesday, there will be increasing humidity and monsoonal moisture as the flow aloft becomes southeasterly. There will be a slight chance of showers and thunderstorms for Sunday through Tuesday with the greater chances over the mountains and during the afternoon and early evening each day. Night and morning coastal low clouds will spread into the far western valleys at times late each night.

SHORT TERM (Today through Thursday)

High pressure aloft will expand across the area and strengthen through Wednesday, then slowly weaken for Thursday and Friday. The warming trend will continue into Wednesday and Thursday with high temperatures around average near the coast to 5 to 10 degrees above average for the deserts, mountains, and inland valleys.

High temperatures on Wednesday and Thursday will range from the lower to mid 70s near the coast to the mid 90s to 105 for the Inland Empire with 113 to 117 for the lower deserts. Low temperatures for the lower deserts will be mostly in the 80s. The Heat Advisory for Wednesday and Thursday has been expanded to include the mountains, mostly below 6000 feet, with high temperatures in the mountains below 6000 feet mostly in the 90s.

The marine layer will become gradually shallower with night and morning coastal low clouds not spreading inland much past the far western valleys.

LONG TERM (Friday through Monday)

For the weekend into early next week, the center of high pressure aloft will reposition over the Great Basin with the flow aloft across the area becoming southeasterly with an increase in monsoonal moisture. With the influx of moisture, high temperatures for inland areas will cool a few degrees and low temperatures will warm a few degrees. High temperatures will cool to within a few degrees of average for Sunday and Monday with high temperatures ranging from the lower to mid 70s near the coast to the 90s for Inland Empire with 104 to 108 for the lower deserts. There will be a slight chance of showers and thunderstorms for Sunday through Tuesday with the greater chances over the mountains and during the afternoon and early evening each day.

Mountains/Deserts

VFR and generally SKC with FEW high clouds AOA 15,000ft.

MARINE

Gusts around 20 to 25 kts are expected at times this afternoon and evening in the outer waters, especially near San Clemente Island. See the Small Craft Advisory for more details. Otherwise, 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...Heat Advisory from 10 AM Wednesday to 8 PM PDT Thursday for Riverside County Mountains-San Bernardino County Mountains- San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Mountains.

Extreme Heat Warning from 10 AM this morning to 8 PM PDT Thursday for Coachella Valley-San Diego County Deserts-San Gorgonio Pass near Banning.

PZ...Small Craft Advisory until midnight PDT tonight for Waters from San Mateo Point to the Mexican Border Extending 10 to 60 nm out including San Clemente Island.