Monsoonal moisture will decrease this weekend, with a slight chance of showers and thunderstorms for the mountains and lower deserts returning for Monday afternoon. Above average high and low temperatures will continue through next week. Widespread moderate to locally major HeatRisk for the coast, valleys, and mountains except near the beaches and for the higher elevations in the mountains, with major to extreme HeatRisk for the lower deserts.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
, UPDATED AVIATION, MARINE, BEACHES DISCUSSION,
Today through tomorrow night,
A strong ridge remains in place through this weekend, with temperatures remaining around 5 to 10 degrees above the seasonal average for this time of year. There will be some monsoonal moisture passing through the mid levels over the region by later on which may allow for a rogue shower or two to develop over the mountains, although it will likely struggle to develop into a thunderstorm, given the lack of instability and overall flow. The marine layer as of this morning has struggled to form with only patchy ceilings along some of the coastal sites, and this will be the case again for tonight. Be advised of all heat products issued, and be sure to stay hydrated!
Monday through Friday,
There will be a slightly better influx of monsoonal moisture for Monday through the rest of the week, although the mid-level flow will still not be favorable for afternoon shower and thunderstorm development to be significant. However, there will still be the chance of isolated showers and thunderstorms each afternoon over the mountains and adjacent deserts, especially by later in the week. It will also remain very hot, with only a slight cooldown on Monday and then gradually increasing towards the middle of the week as the ridge remains stationary and locked in over the desert southwest, translating to the persistence of high temperatures remaining on an average of 5 to 10 degrees above average throughout the rest of the work week. The marine layer will likely have similar results, with struggles to form overnight and likely impacting only the coastal areas for the most part.
231700z, Coast, Low clouds and locally dense fog linger along the immediate coast in San Diego County. Moderate confidence in cigs and vis at the immediate coast clearing 20Z Sun-00Z Mon. Moderate confidence in cigs impacting coastal SD between 10-15Z Mon with bases 200-800ft MSL. Lowered vis 1-3 SM expected with vis less than 1 SM near higher coastal terrain. Low clouds and vis restrictions may linger along the immediate coast after 15Z Mon.
Otherwise, VFR conditions through the TAF period with FEW-SCT clouds AOA 20,000ft MSL after 20Z.
No hazardous marine conditions are expected through Friday.
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. Breaking waves of 4 to 6 feet expected, sets up to 8 feet possible at beaches that face due south. Surf gradually subsides on Friday.
Ca, Extreme Heat Watch from Tuesday morning through Friday evening for Apple and Lucerne Valleys-Orange County Coastal Areas- Orange County Inland Areas-Riverside County Mountains-San Bernardino County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Coastal Areas-San Diego County Mountains-San Diego County Valleys- Santa Ana Mountains and Foothills.
Heat Advisory until 10 AM PDT Tuesday for Orange County Inland Areas-Riverside County Mountains-San Bernardino County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Mountains-San Diego County Valleys-Santa Ana Mountains and Foothills.
Extreme Heat Warning until 8 PM PDT Friday for Coachella Valley- San Diego County Deserts-San Gorgonio Pass near Banning.
PZ, None.
