Isolated light showers near the coast this morning, otherwise cool today with highs a few degrees below normal. Warmer and drier weather returns late week, with high temperatures increasing to 5 to 15 degrees above normal and weak to moderate Santa Ana winds, strongest on Saturday.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
, UPDATED AVIATION DISCUSSION,
Isolated light showers have developed over the coastal waters this morning as an upper level trough continues to progress inland across the Western US. Latest hi-res guidance suggests most of these showers will move south and remain off the coast, with only around a 10% chance of these showers moving into the coastal areas. Any accumulation from these showers will be a couple hundredths of an inch or less. Otherwise cool today with highs around 3 to 7 degrees below normal.
Weak Santa Ana winds will develop tonight behind the departing trough. A second short wave trough is forecast to dig south across the Great Basin into Arizona Friday and Saturday, driving relatively stronger Santa Ana winds. Despite only being a few days away, there remains a sizable difference in the forecast pressure gradients between the GEFS and EC Ensemble, with the EC forecasting a stronger event. The CW3E ensemble currently shows a 40% chance of a weak-to-moderate event on Saturday (gusts around 25-40 mph in the wind prone areas), but only a 10% chance of a moderate event (gusts around 35-50 mph). For now winds do not appear to be much of a concern, but this offshore flow combined with an upper level ridge building in from the west will bring considerable warming. By Friday, highs will be anywhere from 5 to 10 degrees above normal west of the mountains with temps in the low to mid 80s for the coastal areas and valleys.
Warming continues into Sunday under upper level ridging and weak offshore flow with highs reaching the upper 80s for the inland coastal areas/western valleys and in general 5-15 degrees above normal for the coasts/valleys, but only a couple degrees above normal for the mountains and deserts. Heatrisk is forecast to reach Moderate for the coastal areas Saturday through Monday. Gradual cooling Tuesday and Wednesday as offshore flow weakens and eventually turns back onshore.
041200, SCT-BKN clouds 3000-4000 feet MSL with isolated cigs to 2500 feet through 17Z, along with -SHRA just offshore or possibly touching the coast in San Diego County. Clearing from north to south by 13-17Z. VFR conditions into Thursday, but with high clouds above 15 kft increasing after 01Z.
No hazardous marine conditions are expected through Sunday.
Tides will increase at the end of the week, reaching 7 ft as early as Thursday in Orange County and Friday in San Diego County. Tides will peak on Sunday/Monday at 7.4-7.6 ft. A northwest swell (from ~300 degrees) of 2-3 ft with a 14-16 second period is predicted to arrive on Friday, likely to persist into next week. If this swell materializes per the current forecast, max surf of 6-7 feet would occur. Between the high tides near 7-7.5 feet and the elevated surf, at least minor coastal flooding is expected during high tides Saturday-Tuesday, especially for more west-facing coastlines.
Reminder, tides mentioned have been corrected to reflect the current trends in actual tide observations.
Ca, None. PZ, None.
