textproduct: Los Angeles

SYNOPSIS

11/209 AM.

A significant and long lasting heat wave is expected to affect the region starting Thursday and extend well into next week with MODERATE to HIGH heat impacts likely.

LONG TERM (SUN-WED)

11/123 PM.

For the extended period, 12Z models continue to exhibit good synoptic agreement. At upper levels, high pressure will build, once again, across the area, peaking in strength by the middle of next week. Near the surface, weak diurnal flow is expected.

Forecast-wise for the extended period, focus will remain on another round of heat. At this time, deterministic models and their respective ensembles, indicate very hot conditions next week (peaking on Tuesday and Wednesday). Once again, high temperatures will be at least 15-25 degrees above normal with warm overnight lows. So, widespread HEAT ADVISORIES are likely along with the potential for record-breaking daily temperatures. Depending on how things develop, monthly temperature records could also be in jeopardy. In addition, the Antelope Valley may break a record next week for the earliest 90 degree day in the calendar year.

Given the unprecedented length and magnitude of this extreme heat wave, heat stress will be increasing each day, especially in areas that aren't used to the heat, like the coastal areas, where people may not have methods to cool off their homes. Try to complete outdoor activities early in the day or in the evening, and don't leave people or pets in cars.

As for chances of any rainfall, both deterministic and ensembles indicate little, if any, precipitation for the area through March 26th.

AVIATION

12/0251Z.

At 2249Z, the marine layer depth at KLAX was around 300 feet deep. The top of the marine inversion was around 1900 feet with a temp of 22 deg C.

Moderate to high confidence in the 00Z TAFs with generally VFR conds expected at all airfields thru the fcst period. There is a 30% chance for brief reduced visibilities for coastal sites from 12 to 15Z.

KLAX...Hi confidence in the 00Z TAF with generally VFR conds expected thru the fcst period. Any easterly winds should remain less than 7 knots. There is a 30% chance for north winds of 3 to 6 kt around 15Z.

KBUR...Hi confidence in the 00Z TAF with VFR conds expected thru the fcst period.

MARINE

11/845 PM.

Moderate to high confidence in the current forecast.

For the outer waters, there is a 60% chance Small Craft Advisory level wind gusts will affect the waters through at least Friday night, although the northern waters (north of Point Sal) may drop below SCA levels during the morning and afternoon hours on Friday. Friday night through Sunday night, there is a 50-60% chance of SCA wind gusts, with the highest chances across the northern waters where local Gale Force gusts will be possible. Seas will be near SCA levels Friday night through Saturday night. Monday and Monday night, there is a good chance conds will drop below SCA levels for all the outer waters.

For the inner water N of Point Sal, conds are expected to be generally below SCA levels through Monday night, except for a 50% chance of SCA wind gusts at times during the afternoon and evening hours Friday and Saturday.

For the inner waters S of Point Conception, conds are expected to remain below SCA levels through Monday night.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Heat Advisory remains in effect from 10 AM Thursday to 8 PM PDT Friday for zones 88-340>342-346>352-354>358-362-366>375-548. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 9 AM PDT Thursday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Thursday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Friday for zone 673. (See LAXMWWLOX).