textproduct: Los Angeles

SYNOPSIS

30/113 PM.

Little change in weather conditions is expected through Thursday with temperatures 4-8 degrees above normal. Areas of morning low clouds and fog are possible near the coast as well. A major and long lasting heat wave will begin Friday and last through all of next week at least with with dangerously hot temperatures.

LONG TERM (SUN-WED)

01/249 AM.

The xtnd forecast shows little change in the heat. There may be a couple degrees of cooling from Saturday's very hot numbers but no where near enough to reduce the heat danger. The combination of light offshore flow and high pressure aloft will allow for little day to day change in max temps Mon Tue and Wed. Max temps during this period will mostly be 10 to 15 degrees above normal. Weak offshore flow overnight and a strong inversion likely around 900 ft will keep overnight lows above normal as well limiting the body's ability to recover overnight.

Another heat related problem will be an increase in humidity courtesy of Hurricane Rachel. The increased in humidities will arrive Monday and will likely continue through Wednesday. Rachel is forecast to track to the west it will send ocean swells along with the aforementioned moisture . There's even a small (5-15) percent chance of a mtn shower or thunderstorm in the afternoons.

Even through this heat wave will not likely produce record heat it will still be very dangerous due to the prolonged duration of the event. The relentless heat will have a hazardous wearing down effect on people esp the very young and old.

One bit of good news the long range mdls are now showing cooler temps arriving a few days earlier than with the fcst ydy. Today's mdls show improving conditions starting around the 10th rather than the 13th.

AVIATION

01/0948Z.

At 0505Z at KLAX, the marine layer was 1100 ft deep. The top of the inversion was near 3000 ft with a maximum temp of 25 C.

High confidence in VFR TAFs for KWJF and KPMD.

Low confidence in KBUR & KVNY TAFs with a 40 percent chc of no low clouds (or only for a very brief time)

Moderate confidence in remaining TAFs. Timing of change groups may be off +/- 2 hours. CIG height accuracy +/- 300 ft of fcst. There is a 30 percent chc that KSBA will not see vis AOB 3/4SM.

KLAX...Moderate confidence in TAF. VFR conds may arrive as late as 2000Z. There is a 30 percent chc of OVC012 conds aft 15Z. No significant east wind component expected.

KBUR...Low confidence in TAF. There is a 40% chance of no low clouds or only a brief 30 to 40 minute period of low clouds.

MARINE

01/712 AM.

Generally quiet conditions expected across the coastal waters for the forseeable future. Localized Small Craft Advisory (SCA) gusts near 21 kts may occur each afternoon and evening near Point Conception, off the coast of Point Dume, and across the San Pedro Channel.

BEACHES

01/712 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 the early to middle part of next week. Thankfully 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. Stay tuned for future updates.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Extreme Heat Watch in effect from Friday morning through Thursday evening for zones 38-87-88-349>358-362-366>375-548-550. (See LAXNPWLOX). PZ...NONE.