Ion and Marine Discussion for 00z TAF Package,
At 11:30 AM, temperatures were running 3 to 7 degrees warmer than yesterday in the Inland Empire, San Bernardino mountains, and inland Orange County with temperatures similar to a few degrees cooler than 11:30 AM yesterday elsewhere. Visible satellite is showing partial clearing along the immediate coast, with the potential for widespread clearing this afternoon. Low clouds are expected to reach into portions of the valleys again overnight into Sunday morning. Highs Sunday are expected to remain below average but will trend a few degrees warmer than today.
Additional warming is expected into the middle of the week as a ridge of high pressure builds aloft from the south. Current forecast has high temperatures for inland locations 5 to 10 degrees above average with localized areas of moderate HeatRisk away from the coast and areas of major HeatRisk in the low desert by Wednesday. The forecast has trended cooler by a few degrees for Tuesday through Thursday, which has limited the geographic extent of moderate HeatRisk in the valleys and major HeatRisk in the low desert. Based on the current forecast, hottest day is expected to be Wednesday with Tuesday and Thursday a few degrees cooler than Wednesday.
Guidance continues to indicate an increase in precipitable water for the middle to end of next week. This will most likely result in limited daytime heating, warmer than normal overnight low temperatures, and more humid feeling conditions. As far as the marine layer goes, the building high pressure and influx of moisture will result in a shallower marine layer and limited low cloud development. While the most likely scenario is for dry conditions to prevail, there is a 10-15 percent chance showers or thunderstorms may develop over area mountains Wednesday afternoon.
Most ensemble solutions are now on board with a shortwave trough moving into the Pacific Northwest by Thursday. This will displace the ridge aloft and result in a gradual cooling. By next Saturday, conditions are expected to be within a few degrees of normal.
Below average temperatures with marine layer low clouds and fog reaching into portions of the valleys this weekend. For the first half of the week, widespread moderate to areas of major HeatRisk possible for the deserts and widespread minor to locally moderate HeatRisk for inland Orange County, valleys, and mountains. The marine layer will become shallower next week, staying confined to coastal locations. Gradual cooling expected for the second half of the week.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
.Updated Aviation and Marine Discussion for 00z TAF Package,
At 11:30 AM, temperatures were running 3 to 7 degrees warmer than yesterday in the Inland Empire, San Bernardino mountains, and inland Orange County with temperatures similar to a few degrees cooler than 11:30 AM yesterday elsewhere. Visible satellite is showing partial clearing along the immediate coast, with the potential for widespread clearing this afternoon. Low clouds are expected to reach into portions of the valleys again overnight into Sunday morning. Highs Sunday are expected to remain below average but will trend a few degrees warmer than today.
Additional warming is expected into the middle of the week as a ridge of high pressure builds aloft from the south. Current forecast has high temperatures for inland locations 5 to 10 degrees above average with localized areas of moderate HeatRisk away from the coast and areas of major HeatRisk in the low desert by Wednesday. The forecast has trended cooler by a few degrees for Tuesday through Thursday, which has limited the geographic extent of moderate HeatRisk in the valleys and major HeatRisk in the low desert. Based on the current forecast, hottest day is expected to be Wednesday with Tuesday and Thursday a few degrees cooler than Wednesday.
Guidance continues to indicate an increase in precipitable water for the middle to end of next week. This will most likely result in limited daytime heating, warmer than normal overnight low temperatures, and more humid feeling conditions. As far as the marine layer goes, the building high pressure and influx of moisture will result in a shallower marine layer and limited low cloud development. While the most likely scenario is for dry conditions to prevail, there is a 10-15 percent chance showers or thunderstorms may develop over area mountains Wednesday afternoon.
Most ensemble solutions are now on board with a shortwave trough moving into the Pacific Northwest by Thursday. This will displace the ridge aloft and result in a gradual cooling. By next Saturday, conditions are expected to be within a few degrees of normal.
210000z, Coast/Valleys, Patchy low clouds are just starting to redevelop over coastal San Diego County, though coverage should remain patchy for the next few hours. Thereafter, low clouds spread northward and inland overnight, reaching into portions of the Inland Empire by 10-12z. 60% chance for cigs to reach KONT and 30% chance at KSBD. Bases may hover near or just below 2000 ft MSL this evening, but should rise to 2000-2500 ft MSL sometime early Sunday morning. Clouds scatter toward the coastline 16-19z. Low clouds with lower bases return to San Diego County coastal areas 01-03z Mon.
Mountains/Deserts, VFR conditions expected through the TAF period. Westerly wind gusts of 25-40 kts will continue this evening along desert slopes and locally into deserts. Local VIS reductions 4-6 SM in BLDU during periods of strong gusts and moderate up/downdrafts in lee of mtns. Winds slowly diminish from 06-12z Sun. Westerly winds of similar strength return for the same areas Sunday afternoon and evening.
No hazardous marine conditions are expected through Thursday.
Ca, Beach Hazards Statement through Sunday evening for Orange County Coastal Areas-San Diego County Coastal Areas.
PZ, None.
