02/144 AM.
A major and long lasting heat wave will begin today and last through all of next week with dangerously hot temperatures. Coastal clouds and fog are expected this morning and tonight into Saturday morning, with dense fog possible at times.
(tdy-Sun), 02/126 AM.
Coastal clouds and fog are expected to be limited to the coasts and perhaps some coastal valleys, with little change to the heights. Will have to watch for dense fog formation as the offshore gradients look quite weak (around 1 mb) this morning. Otherwise, expecting a hot day today through most of the area with building high pressure and ongoing offshore winds. Given the limited sea breeze, the most warming should be near the coasts. However, warming may be somewhat limited for northern Santa Barbara County and San Luis Obispo County as mid to high level clouds move in, and should persist through the day. By the weekend, high temperatures in the upper 80s and 90s are expected for the coasts from Santa Barbara southward.
***A VERY DANGEROUS AND LONG LASTING HEAT WAVE TODAY THROUGH AT LEAST NEXT WEEK***
No significant changes to the short or long term forecasts. A dangerous heat wave will begin today and last through at least next week as a strong high pressure system sets up over the eastern Pacific and West coast. Offshore pressure gradients are already weak today (currently near 0.5 mb), and will increase through Sunday, resulting in offshore gradients to the east and north in the 2 to 4 mb range. So while this is an offshore scenario in October, it's not a traditional Santa Ana as the upper support is not sufficient for persistent gusty winds, though there will be brief periods of some sub advisory level north to northeast winds at times. However, in typical Santa Ana fashion, this heat wave will include the beaches, at least south of Pt Conception.
During this heat wave, warmer valley highs are expected to be 102-107, Downtown LA 99-103, and coastal areas from Santa Barbara to LA 90-98. These are 15-20 degrees above normal.
It will be warming in SLO and northern Santa Barbara Counties as well but delayed by a day. By the weekend expecting highs away from the beaches to reach the low to mid 90s and lower 100s in the interior. Heat advisories may need to be extended in certain areas next week but models have been showing just enough cooling early next week to allow the advisories to drop off.
(Mon-Thu), 02/138 AM.
Monday into the rest of the week will feel a lot like this coming weekend, with ongoing offshore winds and persistent high pressure. Will likely see some fluctuations in temperatures as the offshore gradient weakens a bit early in the week, though there are still some model solutions indicating a little more upper level northeast wind support and subsequently even hotter temperatures around Wednesday into Friday, leading to breaking daily high temperature records. Further out, models indicate tropical moisture along with an upper level trough could lead to cooling temperatures by the following weekend.
02/1324z.
At 0355Z at KLAX, the marine layer was 300 feet deep. The top of the inversion was near 2600 ft with a temp of 28 C.
High confidence in VFR TAFs for KPRB, KBUR, KVNY, KWJF and KPMD.
Low to moderate confidence in remaining TAFs. LIFR to VLIFR cigs may come in and out over the next few hours for KOXR, and KSMO. Timing of change groups may be off +/- 2 hours. LIFR to VLIFR will be possible again after 06Z, especially for KSMX and KSBP.
KLAX, Moderate to low confidence in the 12Z TAF. There is a 30% chance for cigs after 08Z. No significant east wind component expected.
KBUR, High confidence in the VFR 00Z TAF. No wind issues expected.
02/146 AM.
Generally quiet conditions expected across the coastal waters through the forecast period. Localized Small Craft Advisory (SCA) gusts may occur each afternoon and evening near Point Conception, off the coast of Point Dume, and across the San Pedro Channel.
02/146 AM.
While we will get a break from the coastal flooding concerns for the rest of the week, another hurricane swell (from Rachel) will likely bring a larger-than-Polo south swell to southern California for much of the coming work week. The highest surf is likely Tuesday through Thursday. The tides at that time will not be extreme, but they should be around 6.5 feet which is high enough to cause some concern, but it all depends on how big the surf ends up. There is a good chance of at least elevated surf (up to 5 or 6 feet) on exposed south facing beaches and a lower chance of high surf (7 feet or higher). Stay tuned for future updates.
Ca, Extreme Heat Warning in effect from 10 AM this morning to 8 PM PDT Thursday for zones 38-87-88-349>358-362-366>375-548-550. (See LAXNPWLOX). Heat Advisory in effect from 10 AM Saturday to 8 PM PDT Sunday for zones 341>345-347-348. (See LAXNPWLOX). PZ, NONE.
