03/707 PM.
A major and long lasting heat wave is expected to persist through all of next week with dangerously hot temperatures. Clouds and dense fog are expected over portions of the coastal waters tonight into Sunday morning, most likely over the waters off the Central Coast. There is a small chance the fog will move onshore over the Central Coast beaches tonight as well.
(Sat-Tue), 03/834 PM.
***UPDATE***
Temperatures today were in the 90s to 100s, as is expected for the next few days. These temperatures are up to 10 degrees above normal for this time of year along the Central Coast and the Antelope Valley, but 10 to 20 degrees, locally higher, above normal for the remainder of the area. Only Burbank and NWS Oxnard broke records today, though several stations were within a few degrees of their daily records.
Light offshore flow, with sub-advisory level winds is expected to continue through tomorrow, keeping the marine layer clouds away from the coasts south of Point Conception, and near the immediate coasts of the Central Coast overnight. Additionally, the offshore flow will contribute to warm overnight lows, leading to little relief from the oppressive heat. Conditions will be extremely similar tomorrow as what happened today, and temperatures will continue to be within a few degrees of their daily records for a lot of the area.
Forecast looks to be in shape and no evening updates were needed.
***From Previous Discussion***
The forecast through the coming week has really not changed at all as strong high pressure will maintain its grip over the region. Adding to this is the 2-4mb offshore gradient which is the main driver pushing this heat all the way to the coast. Ensemble gradient forecasts indicate a very slow onshore trend, basically less than a half millibar per day. So at least in the short term, cooling will be negligible. And even in areas that do cool slightly it really won't be perceivable. With this in mind the heat advisory for areas north of Pt Conception has been extended through Wednesday evening. And all other heat hazards remain in place through at least Thursday. There will be a few records this week, mainly near the coast as most inland areas are not quite reaching record territory.
(Wed-Sat), 03/106 PM.
The hot weather will continue all of next week with a very slow cooling trend, (1-2 degrees per day), and mainly just near the coast. Cooling for interior areas will won't begin until Friday so there is a 20-30% chance that at least some heat advisories will be needed on Friday. More significant and widespread cooling is expected next Saturday and continuing into early the next week. Recent model trends are indicating at least a 20-30% chance of some showers next weekend based on the latest ensemble tracks of Hurricane Rachel. Some increasing swells from Rachel are possible as early as mid week.
04/0204z.
At 2355Z at KLAX, there was no marine layer. There was a weak surfaced based inversion with a top at 1500 ft and a temp of 32 C.
High confidence in VFR TAFs for all sites except for KSBP & KSMX. Chances of VLIFR/LIFR conds between 04/09Z-16Z for these sites is 10-20%.
KLAX, High confidence in the VFR 00Z TAF. Less than 10% chance of any low CIGs or VSBY, but if it were to occur, VLIFR/LIFR conds likely. East wind component likely a touch stronger tomorrow morning peaking 04/12Z-18Z nearing 7-8kts.
KBUR, High confidence in the VFR 00Z TAF.
03/744 PM.
Generally quiet conditions expected across the coastal waters through the forecast period. Localized Small Craft Advisory (SCA) gusts may occur each afternoon and evening between Point Conception and San Nicolas Island, off the coast of Point Dume, and across the San Pedro Channel.
03/745 PM.
Quiet conditions are expected through the weekend, aside from the heat. Meanwhile, another hurricane (Rachel) will likely bring a larger- than- Polo southerly swell to southern California for much of the coming work week. The window of most concern is Tuesday through Friday. Elevated surf up to 5-6 ft is likely with a lower chance of high surf 7 ft or higher across exposed south facing beaches. High tides of 6.5-7.0 ft are expected. Unlike previous events, morning and evening tides will be similar in height. Initially, the swell will have a more SE direction (150-160) targeting areas like Long Beach Tuesday and Wednesday. As Rachel moves westward, the swell direction will become more southerly (170-190) Thursday and Friday targeting areas like Zuma. There is a high risk for Beach Hazard Statements and a moderate risk for Coastal Flood Advisories and High Surf Advisories along the LA/VTA coastline. Stay tuned for future updates.
Ca, Extreme Heat Warning in effect until 8 PM PDT Thursday for zones 38-87-88-349>358-362-366>375-548-550. (See LAXNPWLOX). Heat Advisory in effect until 8 PM PDT Wednesday for zones 341>345-347-348. (See LAXNPWLOX). PZ, NONE.
