textproduct: San Diego

SYNOPSIS

The flow aloft will become gradually southwesterly with drying of monsoonal moisture the next few days. There remains a slight chance of showers and thunderstorms for the mountains and deserts from late this morning through this afternoon. In addition to drying aloft, there will also be gradual drying of lower level moisture through early next week. High temperatures will cool through Thursday, then slowly warm into the middle of next week.

SHORT TERM (Today through Friday)

A developing weak low pressure system near the West Coast will bring drier southwest flow aloft with drying of monsoonal moisture and gradual cooling through Thursday.

Cooling of high temperatures will spread inland through Thursday with Thursday high temperatures near average at the coast to as much as 8 to 12 degrees below average for the mountains and inland valleys. High temperatures for Thursday will range from the 70s near the coast to the 80s for the Inland Empire with the lower deserts around 100. High temperatures on Friday will warm a few degrees.

Drying of monsoonal moisture will occur over the next few days as the flow aloft becomes southwesterly. There is a slight chance of showers and thunderstorms from late this morning through this afternoon, mainly near the mountains and extending into portions of the high desert. Any remaining chances for showers or thunderstorms for Thursday afternoon should be limited to the San Bernardino Mountains northeastward into the high desert.

LONG TERM (Saturday through Tuesday)

For the weekend, high pressure to the east will strengthen while a trough of low pressure off the California coast maintains drier southwest flow aloft. For early next week, there are some differences in the placement of low pressure near or farther off the California coast with greater spread in the high temperature guidance. Cluster analysis shows the model solutions that are cooler are those with the low pressure along the California coast versus farther off the coast with those solutions with low pressure near the coast representing around 20 percent of ensemble solutions.

High temperatures will slowly warm for Saturday through Tuesday. High temperatures on Saturday will range from around average near the coast to 4 to 8 degrees below average for the mountains and inland valleys. For next Tuesday, high temperatures will range from around average near the coast to around 5 degrees below average for the mountains and inland valleys with the lower deserts a few degrees above average for the lower deserts.

High temperatures on Saturday will range from the 70s near the coast to the mid 80s to mid 90s for the Inland Empire with 100 to 104 for the lower deserts. For next Tuesday, high temperatures will range from the 70s near the coast to the 90s in the Inland Empire with 106 to 110 for the lower deserts.

AVIATION

120930Z....Coast/Valleys...Areas of low clouds with bases 1700-2000 ft MSL continuing to fill in over the San Diego County coasts and valleys and spreading around 15-20 mi inland through 15Z. Coverage for Orange County, including around KSNA, will remain patchy with low confidence in timing and duration of any CIGs. Low clouds clearing to the coast 15-18Z, then spreading back inland beginning around 13/00Z with bases around 1500-2000 ft MSL and tops to 2500 ft MSL. Low clouds moving into the inland valleys overnight with a 40- 50% chance of CIGS at KONT and KSBD. Local vis 2-5 SM in BR where clouds near terrain in the valleys.

Mountains/Deserts...ISO SHRA/TSRA developing after 19Z today, most likely from KL35 north into the high desert. CB bases near 15,000 ft MSL with tops to 30,000 ft MSL. Gusty outflow winds possible VCTY TSRA. Otherwise, increasing high clouds at/above 20,000 ft MSL this afternoon.

MARINE

No hazardous marine conditions are expected through Sunday.

BEACHES

High tides will exceed 7 feet this evening around 930 PM, resulting in minor tidal overflow of low-lying areas along the beach. Surf will be small and is not expected to contribute to the flooding potential. Check the Coastal Flood Advisory for details.

SKYWARN

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

SGX WATCHES/WARNINGS/ADVISORIES

CA...Coastal Flood Advisory until 11 PM PDT this evening for Orange County Coastal Areas-San Diego County Coastal Areas.

PZ...None.