Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
725 FXUS66 KSGX 051637 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 937 AM PDT Fri Jul 5 2024 .SYNOPSIS... Hot conditions will continue into next week. The hottest conditions are expected today and Saturday, but above average temperatures will continue for all areas into next week. The marine layer will continue to moderate the daytime warming toward the coast with night and morning coastal low clouds extending into portions of the western valleys at times. Know the signs of heat related illness and if possible, limit your time outdoors during the hottest part of the day. Stay hydrated and if you are spending time outdoors seek shade when possible. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Hot conditions are expected today with highs 7 to 12 degrees warmer than yesterday for the valleys, mountains, and inland Orange County; 3 to 7 degrees warmer than yesterday for the deserts; and 2 to 5 degrees warmer along the coast. Another moisture surge made it into the lower deserts this morning with dew points at 9 AM in the 60s to locally the low 70s. Dew points for Thermal and Palm Springs are running a few degrees lower than this time yesterday, so a few additional degrees of warming in the low deserts compared to yesterday does seem plausible. The heat for areas west of the mountains is expected to peak today, with a few degrees of cooling for most areas west of the mountains. Even with that cooling, highs on Saturday will be 3 to 7 degrees above average for the coast and inland Orange County and 7 to 14 degrees above average for the valleys and mountains. Widespread moderate to major HeatRisk is expected away from the coast west of the mountains through Saturday. HeatRisk and temperatures on Sunday are expected to continue the downward trend. Areas of moderate HeatRisk are expected Sunday through Monday for the valleys. Temperatures for areas west of the mountains are expected to increase again Tuesday into the latter half of next week, with more widespread moderate to locally major HeatRisk. The heat in the deserts will be persistent with highs on Saturday 13 to 17 degrees above average for the High Desert and 6 to 13 degrees above average for the low deserts. HeatRisk in the deserts is expected to stay major to extreme through the weekend and into much of next week. Local high resolution guidance continues to show shallow moisture surges making it into at least the southern portions of the Coachella Valley each morning. How much the moisture retreats for the afternoon heating of the day will greatly impact how high the thermometer goes. Global ensemble guidance is indicating that the atmosphere will dry out early next week, and without the moisture present temperatures could reach near record breaking levels in the lower deserts. For the middle to end of next week, the position of the ridge of high pressure is still uncertain. If the ridge pushes further east, the southerly flow over Southern California will bring more moisture and a better chance for monsoon storms. Current forecast follows NBM with less than 10 percent chance through Friday evening. If monsoon moisture does in fact make it into the area, that keep highs in the desert tapered down but brings the potential for more heating west of the mountains. && .AVIATION... 051530Z...Coast...Low clouds bases 600-1200 ft MSL have retreated west out of most coastal sites and will continue to clear to beaches through 16-17Z. Low clouds with similar bases/vis expected to move inland again 01-05z. Cigs may scatter out briefly overnight 04-09Z but return to BKN-OVC following that. Clearing to the coast again expected 16-19Z. Otherwise, mostly clear skies with unrestricted VIS and seasonable afternoon winds through today. && .MARINE... No hazardous marine conditions are expected through Tuesday. && .BEACHES... A long-period south swell will continue elevated surf. The surf will peak late today through Saturday, before subsiding on Sunday. Sets of 6-7 feet can be expected on south and southwest-facing beaches, especially in Orange County. Check the Beach Hazards Statement for 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 Sunday afternoon for Orange County Coastal Areas-San Diego County Coastal Areas. Excessive Heat Warning until 9 PM PDT Saturday for Riverside County Mountains-San Bernardino County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire- San Diego County Mountains-San Diego County Valleys. Heat Advisory until 9 PM PDT Saturday for Orange County Inland Areas-Santa Ana Mountains and Foothills. Excessive Heat Warning until 9 PM PDT Wednesday for Apple and Lucerne Valleys-Coachella Valley-San Diego County Deserts- San Gorgonio Pass Near Banning. PZ...None. && $$ PUBLIC...CO AVIATION/MARINE/BEACHES...CSP