25/222 AM.
Very hot conditions will dominate the week, with a high risk for heat illness. Patchy night through morning low clouds and locally dense fog will be confined to some coastal areas. Significant cooling is likely over the weekend but it will remain warm.
(tdy-Thu), 25/912 AM.
***UPDATE***
The heat is on, especially south of Pt Conception today and migrating north Wednesday and Thursday. Heat advisories transition to Warnings south of Pt Conception today at 10am and advisories going into effect for the Central Coast Wednesday and Thursday as onshore flow weakens there.
One potential wrinkle for Thursday is the possibility for increasing mid and high clouds from decaying tropical storms off Mexico. Can't rule out an isolated shower or two, and depending on the extent of the cloud coverage it could cut into some some of the high temperatures.
Here is a list of the current high temperature records today:
Downtown LA. ..102 in 1926 LAX. . . ..84 in 1981 Long Beach. , 103 in 1981 Hawthorne. . 87 in 1015 Santa Monica. .83 in 2005 Burbank. . ..107 in 1981 Van Nuys. . .107 in 2010 Woodland Hills, 115 in 1985 Palmdale. . .108 in 1931 Lancaster. . 107 in 2010 Camarillo. . 85 in 1931 Oxnard. . , 85 in 1931 Santa Barbara. 85 in 1985
***From Previous Discussion***
The next three days will be the peak of the heat event. A large and very warm upper high will sit atop of NM/AZ and will bring 593-594 dam hgts to the area. Onshore gradients will be weak and even offshore from the north in the mornings. The marine layer will be shallow and will not xtnd very far inland. Marine layer stratus will most likely to affect the Central Coast where some dense fog is possible due to the shallowness of the marine layer. There are, however, some signals that an eddy will develop in which case there will be more low clouds south of Pt Conception.
Max temps will range from 100 to 106 degrees all three days across the vlys, lower mtns elevations and far interior. The western San Fernando Vly will be warmer still with max temps from 106 to 112 degrees. The lack of a strong onshore gradient in the afternoon will allow the inland areas of the cstl regions to warm into the 90s with even some 100 to 101 degree readings possible. In addition the the day time highs running 10 to 15 degrees above normal the overnight low will also be 6 to 12 degrees above normal as subsidence from the upper high sets up a strong and hot inversion right at vly/foothill elevations. On Wednesday a the usual onshore push across the Central Coast will disappear and max temps there will rise 8 to 12 degrees with many locations reaching into the 90s.
Almost all of the area is blanketed by Extreme Heat Warnings and Advisories. Please see the product LAXNPWLOX for all details. Residents need to take precautions to avoid heat related dangers when outside.
Sundowner winds will affect southern Santa Barbara County through the week, and should increase some each night. Wind Advisories might be needed tonight and/or Wednesday Night.
(Fri-Mon), 25/223 AM.
A substantial trof will move into the west coast and push the upper high to the south. The flow will slowly switch to the SW during the period and hgts will fall to 588 dam. Some offshore flow may persist in the morning esp from the north, but the afternoon onshore push to the east will increase.
Most max temps will fall 1 to 2 degrees on Friday (except for the Central Coast where better onshore flow will bring 3 to 6 degrees of cooling). This small amount of cooling will not be enough to eliminate the heat risk and all warnings and advisories will continue. Look for 5 to 10 degrees of cooling across the csts/vly on Saturday as the trof and onshore flow really begin to affect the weather (the mtns and far interior will see 2 to 4 degrees of cooling). On Sunday all areas will cool 3 to 6 degrees and this will bring many areas to or even below normal max temps. 2 to 4 additional degrees of cooling is likely next Monday and this will reduce coastal max temps to the 70s (upper 60s/lower 70s Central Coast) and in the mid 80s to mid 90s for the vlys.
25/1637z.
At 1615Z at KLAX, the marine layer was 1100 feet deep. The top of the inversion was 3100 feet with a temperature of 29 degrees Celsius.
For 18Z TAF package, high confidence in KPRB, KSBA, KBUR, KVNY, KPMD and KWJF.
For KSMX and KSBP, there is 20-30% chance of LIFR/VLIFR conditions 08Z-17Z.
For KOXR, KCMA, KSMO, KLAX and KLGB, there is a 20% chance of IFR/LIFR conditions 08Z-17Z.
KLAX, High confidence in 18Z TAF. There is a 20% chance of IFR/LIFR conditions 08Z-17Z. No significant easterly wind component is expected.
KBUR, High confidence in 18Z TAF as CAVU conditions are expected through the period.
25/659 AM.
For the Outer Waters, high confidence in current forecast. Today through Saturday, Small Craft Advisory (SCA) level winds are expected across all of the Outer Waters. Additionally, seas will hover near SCA levels through the week.
For the Inner Waters north of Point Sal, high confidence in current forecast. Today through Saturday, SCA level winds are expected each afternoon and evening. Additionally, seas will approach SCA levels by late this 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 Saturday. The only exception will be the western half of the Santa Barbara Channel where there is a 60-80% chance of SCA level winds through Saturday in the late afternoon and evening hours.
Ca, Heat Advisory in effect until 10 AM PDT this morning for zones 38-87-88-349>358-362-366>376-378>380-548. (See LAXNPWLOX). 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). Heat Advisory in effect from 10 AM Wednesday to 8 PM PDT Thursday for zones 341-347-348. (See LAXNPWLOX). Heat Advisory in effect until 8 PM PDT Friday for zones 342>345. (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 from 3 PM this afternoon to 3 AM PDT Wednesday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Thursday for zones 670-673-676. (See LAXMWWLOX).
