27/244 AM.
Very hot conditions will dominate the week, with a high risk of heat-related illness. Isolated showers and thunderstorms are possible today and Friday. Significant cooling is likely by Sunday or Monday.
(tdy-Sat), 27/314 AM.
Dangerously hot and muggy conditions will again dominate the weather today and Friday. Mid and high level moisture has moved into the area from decaying tropical systems off Mexico so there will be an increase in clouds with a small chance of an isolated shower pretty much anywhere in the southwest California, though higher elevations will have a slightly higher chance since any drops will be evaporating quickly through their path to the surface. Also can't rule out an isolated clap of thunder, though hi res models are focusing most of the instability farther north in the state.
Temperatures the next couple days will remain hot, but the addition of clouds and possibly some light showers does introduce an element of uncertainty into the forecast, especially today as clouds are likely peaking today. Most of the forecast models are indicating 1-6 degrees of cooling today, with the bigger decreases across the interior, while coastal areas actually rise 1-3 degrees over yesterday. This is a fairly common scenario when tropical moisture moves into the area during a heat wave so confidence is relatively high that the models are on the right track with the temps. With less clouds likely Friday some rebound in temps inland is likely, while coastal areas start to cool as onshore flow returns.
(Sun-Wed), 27/331 AM.
A steady cooling trend will begin no later than Saturday and continue through Monday with high temperatures decreasing by about 5 degrees each day. By early next week highs should be very close to normal and even possibly a few degrees below normal as a trough develops over the Pac NW. By around the middle of next week there will be another tropical system moving west off the coast of Mexico that could introduce some additional moisture and shower chances locally, but temperatures should be close to normal levels for this time of year.
27/1729z.
At 1620Z at KLAX, the marine layer was 1100 feet deep. The top of the inversion was 3000 feet with a temperatures of 31 degrees Celsius.
Overall, moderate confidence in 18Z TAF forecasts. Through the period, a BKN-OVC100-150 deck will continue. There will be the possibilty of light showers and even a 10-15% chance of thunderstorms at all sites through the period.
KLAX, Moderate confidence in 18Z TAF. BKN-OVC100-150 deck will continue through the period with a threat of light showers. There is 10-15% chance of thunderstorms. Easterly winds around 6 knots will be possible (30% chance) through 19Z, then no significant easterly wind component is expected.
KBUR, Moderate confidence in 18Z TAF. BKN-OVC100-150 deck will continue through the period with a threat of light showers. There is 10-15% chance of thunderstorms.
27/705 AM.
For the Outer Waters, moderate to high confidence in current forecast. Through Monday, there is high confidence in Small Craft Advisory (SCA) level winds continuing along with steep, short period seas approaching SCA levels. Additionally, there is a 30% chance of Gale force winds on Sunday around Point Conception.
For the Inner Waters north of Point Sal, moderate confidence in current forecast. Through Sunday, there is a 40-60% chance of SCA level winds each afternoon and evening. On Monday, high confidence in winds and seas remaining below SCA levels. Steep, short-period, seas can be expected through the week.
For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. For a majority of the southern Inner Waters, high confidence in winds and seas remaining below SCA levels through Monday. The only exception will be the western half of the Santa Barbara Channel where there is a 30-40% chance of SCA level winds this afternoon and evening then a 50-70% chance of SCA level winds Friday through Sunday, mainly in the late afternoon and evening hours. Steep, short-period, seas can be expected through the week.
Through this afternoon, there will be the possibility of isolated thunderstorms across all of the coastal waters. Gusty outflow winds and cloud-to-surface lightning will be the main threats.
27/705 AM.
Southerly swell from post-tropical storm Iselle will continue to move through the coastal waters today. Swell heights of 3-5 feet with a period of 11-12 seconds can be expected, producing elevated surf and dangerous rip currents along south-facing beaches of Ventura and LA counties. Therefore, a BEACH HAZARDS STATEMENT is in effect through 11 PM this evening.
Ca, Extreme Heat Warning in effect until 8 PM PDT Friday for zones 38-87-88-349>358-362-366>376-378>383-548. (See LAXNPWLOX). Beach Hazards Statement in effect through this evening for zones 87-354-362-366. (See LAXCFWLOX). Heat Advisory in effect until 8 PM PDT Friday for zones 341>345-347-348. (See LAXNPWLOX). Red Flag Warning in effect until 3 PM PDT Friday for zones 345-353-375>380. (See LAXRFWLOX). PZ, Small Craft Advisory in effect until 3 PM PDT Friday for zones 670-673-676. (See LAXMWWLOX).
