textproduct: Los Angeles

SYNOPSIS

15/617 PM.

A significant heat wave will affect the region through the coming week, peaking on Tuesday and Wednesday, and then continuing through Friday. MODERATE to HIGH heat impacts will occur each day this week.

LONG TERM (THU-SUN)

15/201 PM.

For the extended, 12Z models continue to exhibit good synoptic agreement through the period. Main feature of note will continue to be the very strong upper level high pressure will continue to slowly drift southeastward Thursday/Friday, before being flattened on Saturday/Sunday as a weak system moves across the West Coast.

Forecast-wise, main issue will continue to be the historic heat event. Based on all available data, the oppressive heat will continue through Friday, before relenting on Saturday/Sunday. So for Thursday and Friday, will continue with the same configuration of EXTREME HEAT WARNINGS and HEAT ADVISORIES from the mountains westward. Again as mentioned in the short term discussion, depending on the strength of the surface pressure gradients, some coastal zones could bump up to warning levels on Thursday and Friday. So, will continue to monitor that potential very closely.

For Saturday, there is a 50% chance that some heat products will need to extended through the evening hours, mainly inland from the beaches. However by Sunday, things should cool down rather noticeably. Therefore, no heat products are anticipated.

As for rain chances, deterministic models (and their respective ensembles) indicate some possibility of light showers after the 25th. However, no significant storms are indicated for Southern California through the end of the month.

AVIATION

16/0115Z.

At 0040Z at KLAX, there was no marine layer. There was an inversion with a top near 1600 ft and a temperature of 26 C.

High confidence in TAFs for KPRB, KSBP, KSMX, KBUR, KVNY, KPMD and KWJF.

Low confidence between 06Z-18Z for coastal sites KSBA to KLGB including KLAX with a 40-50 percent chance that VFR conds prevail.

KLAX...High confidence in the 00Z through 06Z then low confidence through 18Z due to uncertainty in the arrival time and height of CIGs. There is a 20 percent chance of IFR conds between 06-08Z, and also a 20% chance of LIFR conds between 08Z-15Z. Otherwise, 40% chance that VFR conds prevail. High confidence that any east wind component will be below 7 kts.

KBUR...High confidence in VFR 00Z TAF.

MARINE

15/816 PM.

Small Craft Advisory (SCA) conditions will linger into late tonight across the Outer Waters near and north of Point Conception. Thereafter, conditions will likely remain benign through at least mid-week. Moderate chances for SCA winds starting Thursday or Friday across the northernmost outer waters.

For the Inner waters along the Central Coast, conditions are expected to remain below SCA levels through late this coming week. Inside the Southern California Bight, conditions are expected to remain below SCA levels for the foreseeable future.

Dense fog is possible at times this week.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Heat Advisory remains in effect from 10 AM Monday to 10 AM PDT Tuesday for zones 87-88-340>342-345>358-362-366>376-378>380-548. (See LAXNPWLOX). Heat Advisory now in effect from 10 AM Tuesday to 8 PM PDT Friday for zones 87-340-341-346>350-354-355-362-366-367-549-550. (See LAXNPWLOX). Extreme Heat Warning in effect from 10 AM Tuesday to 8 PM PDT Friday for zones 88-342-345-351>353-356>358-368>376-378>380-548. (See LAXNPWLOX). Beach Hazards Statement in effect through Wednesday evening for zones 354-362-366. (See LAXCFWLOX). PZ...Small Craft Advisory in effect until 3 AM PDT Monday for zones 670-673. (See LAXMWWLOX).