03/1241 PM.
Temperatures will be slightly above normal inland and near normal along the coast through Friday, then dropping below normal over the weekend and into next week as a large low pressure system develops over the West coast. Skies will be mostly clear except for night and morning low clouds and fog across the coast and valley areas.
(Wed-Sat), 03/941 PM.
***UPDATE***
High temperatures trended warmer today as high pressure strengthened over the region. Coastal areas remained fairly cool (60s to near 70) with plenty of marine layer clouds and onshore flow. Tomorrow could see a bit more warming near the coasts due to less marine layer clouds. However, still expecting strong onshore flow especially on the Central Coast which will limit warming. Interior areas should trend 2-5 degrees warmer with high pressure lingering. Temperatures were adjusted a bit to account for cooler values near the coasts and warmer values over the interior. Saturday, a strong low pressure system will bring 5-10 degrees of cooling and lead to an expansion of marine layer clouds as it deepens.
Wind advisories were issued for gusty north winds (peaking at 45-50 mph) over the Santa Ynez Range, near the I-5 Corridor and portions of the western Antelope Valley foothills tonight. Otherwise, the current forecast looks on track.
***From Previous Discussion***
Increasing dry northerly flow has managed to clear the stratus from most of the Central Coast this afternoon and it looks like this will remain the case at least for the next day or two. This pattern is also creating some gusty winds across the coastal areas and through the Gaviota pass where gradients are expected to increase to 3-4mb from the north. Latest hi res models keep winds mostly below advisory levels so for now no wind hazards are in effect but this could change. The shift in wind direction has created significant warming for inland portions of the Central Coast with temps up 5-10 degrees. Likely a similar pattern Thursday, then turning cooler with a return of the marine layer Friday and through the weekend.
Elsewhere, a similar story with regard to temperatures where many inland areas today are up 5-10 degrees, but along the coast very little change. The marine layer was around 2200 feet this morning and forecast sounding show slight lowering tonight, so likely a little less and/or earlier clearing across some of the valleys but still starting off the day with low clouds and fog for most coastal areas. Temps expected to be close to today's levels in most areas, meaning near normal at the coast and 4-8 degrees above normal inland.
Going forward, a cooling trend is expected to start Friday as a large upper low moves over the West coast. 2-4 degrees of cooling is expected each day through Sat. A deepening marine layer is expected as well, leading to much later clearing times, possibly not clearing some coastal areas through the afternoon.
(Sun-Wed), 03/121 PM.
Lower confidence in the 4-7 day forecast as some of the ensemble models are suggesting the upper low arriving later this week may linger longer into next week. This would not an unusual pattern for this time of year and would not be surprised to see June gloom conditions continuing longer. The model percentages seem to be favoring that situation at least for now but possibly only by about a 60/40 chance. If the warmer situation prevails the difference would likely only be on the order of around 5 degrees with highs 3-6 degrees above normal so the impacts would be relatively minor.
04/0232z.
At 0122Z at KLAX, the marine layer was 800 feet deep. The top of the inversion was near 3800 feet with a temperature of 25 degrees Celsius.
For 00Z TAF package, moderate to high confidence in forecasts for KWJF and KPMD with VFR conditions expected. Gusty winds may end 2 hours earlier or later than forecast.
For all other TAFs, moderate confidence in current forecasts. Timing of flight category changes could be +/- 3 hours of current forecasts. LIFR conditions are possible for most TAF sites.
KLAX, Moderate confidence in 00Z TAF. Timing of return of CIG/VSBY restrictions could be +/- 3 hours of current forecast. There is a 30% chance that CIGs could return at MVFR levels tonight, and a 20% chance for brief LIFR cigs. No significant easterly wind component is expected.
KBUR, Moderate confidence in 00Z TAF. There is a 30% chance cigs fail to reach the TAF site.
03/758 PM.
For the Outer Waters, moderate confidence in current forecast. Into early Thursday morning, GALE force winds are expected, especially for the northern waters. Thursday afternoon through Monday, high confidence in combination of Small Craft Advisory (SCA) level winds and seas with a 20-30% chance of Gale force winds (especially across PZZ670).
For the Inner Waters north of Point Sal, moderate confidence in current forecast. This evening through Monday, there is a 60-80% chance of SCA level winds during the afternoon and evening hours, with seas approaching SCA levels at times.
For the Inner Waters south of Point Conception, moderate confidence in current forecast. For a majority of the southern Inner Waters, winds and seas will remain below SCA levels through Monday. The only exception will be the western half of the Santa Barbara Channel where there is a 20% chance of SCA level winds late tonight and a 30-40% chance on Saturday and Sunday.
Ca, Wind Advisory in effect until 5 AM PDT Thursday for zones 349-351-352-378-381. (See LAXNPWLOX). PZ, Small Craft Advisory in effect until 9 PM PDT Thursday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Thursday for zone 650. (See LAXMWWLOX). Gale Warning in effect until 3 AM PDT Thursday for zones 670-673-676. (See LAXMWWLOX). Small Craft Advisory in effect from 3 AM to 9 PM PDT Thursday for zones 670-673-676. (See LAXMWWLOX).
