21/227 AM.
Widespread rain will develop later today and continue into Thursday with a chance of thunderstorms. A weak Santa Ana will develop in the storm's wake by the weekend for dry and warmer conditions.
(tdy-Sat), 21/150 PM.
This has been a tricky storm to figure out although comparing the rainfall totals so far (ending at 1pm) with the model projections everything is pretty much on track. Santa Barbara got hammered with a couple hours of heavy rain and thunderstorms before 9am that dropped around an inch of rain, then very little since then. Most of the rain this afternoon has been in Ventura and LA Counties but most of it under a tenth of an inch per hour.
Going forward, the models continue to aim the most rain towards SLO and Santa Barbara Counties, and particularly the Santa Ynez range and the south coast. That matches up with the current position of the two primary rain bands across the area, one being just west of the Central Coast and the other over Ventura and LA Counties. The western band appears to the the stronger of the two and the most likely to create the strongest rain tonight. And models are in agreement with that, indicating a 60 to 90% chance of rain rates of 0.75"/hour later this afternoon through tonight. Some of that may come in the form of thunderstorms. The Flood Watch remains in effect for most of SB County through Thursday afternoon. No watches currently in effect in SLO County but any thunderstorms that develop could result in heavy rain and flooding.
Across Ventura and LA Counties the rest of today and tonight, the chance of rain rates of 0.75/hour have lowered to 30-40%, however, as the main upper low approaches later tonight into Thursday, increasing rain rates are likely with isolated thunderstorms. Due to the south facing aspect of the Santa Monica mountains, that area and the adjacent coastline remains in a Flood Watch through Thursday. In addition, the forecast sounding for LA showed over 2000 cape which indicates there's a potential for rapidly developing thunderstorms and there is still a small risk (around 5%) of a weak tornado.
Dry and warmer weather will return Fri and Sat with light offshore in place. At this time any offshore winds are expected to mostly below advisory levels.
(Sun-Wed), 21/205 PM.
A low grade Santa Ana event will continue into next week continuing the dry and warmer pattern. Onshore flow is expected to return around mid week with temperatures returning to normal levels. There are some model solutions indicating a return of wet weather around Halloween.
22/0001z.
At 23Z at KLAX, there was no marine layer nor an inversion.
Low to moderate confidence in 00Z TAF package. Rain will turn to showers across the region this evening and continue through Thursday. There is a 30%-50% chance of MVFR CIGs at times with the rain.
There is a 10-20% chance of TSRA through the period with the chances spreading south and east this evening.
KLAX, Moderate confidence in 00Z TAF. There is a 50% chance that CIGs remain at VFR levels through the period with a 30%-50% chance of MVFR cigs at times. There is a 10%-20% chance of TSRA for much of the fcst period. There is 30% chance of an easterly wind component of 7-10 knots tonight.
KBUR, Low to moderate confidence in 00Z TAF. IFR cigs at fcst time should improve quickly. Then there is a 50% chance that CIGs remain at VFR levels through much the period with a 30%-50% chance of MVFR cigs at times. There is a 10%-20% chance of TSRA for much of the fcst period.
21/123 PM.
For the Outer Waters, high confidence in current forecast. Tonight through Thursday night, winds and seas are expected to remain below Small Craft Advisory (SCA) levels. On Friday, northwest winds will increase to SCA levels. For Saturday through Monday, winds and seas are expected to remain below SCA levels.
For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. There is a 30-40% chance of SCA level winds Friday afternoon and evening. Otherwise, high confidence in winds and seas remaining below SCA levels through Monday.
For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. Through this evening, there is a 60-80% chance of SCA level southeasterly winds across all the southern Inner Waters. For Thursday through Monday, high confidence in winds and seas remaining below SCA levels for most areas. The only exception will be the western half of the Santa Barbara Channel with a 50-70% chance of SCA level winds late Friday afternoon and evening.
Through Thursday, showers and isolated thunderstorms will impact all of the coastal waters. Any thunderstorms that develop will be capable of producing gusty/erratic winds, locally rough seas and even waterspouts.
Ca, Flood Watch in effect through Thursday afternoon for zones 348>353-362-369-370. (See LAXFFALOX). Beach Hazards Statement in effect through late Thursday night for zones 354-362-366. (See LAXCFWLOX). PZ, Small Craft Advisory in effect until 8 PM PDT this evening for zones 650-655. (See LAXMWWLOX).
