Area Forecast Discussion
Issued by NWS Los Angeles, CA
Issued by NWS Los Angeles, CA
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409 FXUS66 KLOX 020455 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 955 PM PDT Mon Jul 1 2024 .SYNOPSIS...01/759 PM. A significant heatwave will impact the region this week through early next week, with dangerously hot temperatures across much of the area. High temperatures by mid to late week are expected to reach 95 to 105 degrees in many areas away from the coast, with highs upwards of 105 to 115 over interior valleys and foothills, including the Antelope Valley. Very warm to hot conditions could extend closer to the coast by late this week. Patchy night to morning dense fog will be possible near the coast tonight into early Tuesday. && .SHORT TERM (MON-THU)...01/759 PM. ***UPDATE*** Highs today peaked in the 90s across many interior areas, including some readings in the upper 90s in the Antelope Valley, the San Fernando Valley, and in the Salinas Valley. Highs are forecast to increase by anywhere from 3 to 12 degrees across the area on Tuesday, aided by weak offshore gradients forecast for LAX to Daggett and between Santa Maria to Bakersfield. Excessive Heat Warnings will begin Tuesday morning across the mountains, Antelope Valley and the far interior of San Luis and Santa Barbara Counties, and by Wednesday morning for the remainder of the valleys and Santa Monicas, excepting the coast and coastal basins. The warnings have been extended through next Monday. The peak in heating will occur Friday and Saturday, with Friday being the warmest. For the overnight period into early Tuesday, the marine layer is expected to bring patchy dense fog to coastal areas, also extending a short distance into some of the coastal valleys. As the ridge aloft expanding over the area, the marine layer will shrink, with any low clouds becoming confined closer to the coast. Winds through the short term should be typical onshore winds each afternoon to evening period, affecting the interior passes and canyons, and the Antelope Valley. Smith .LONG TERM (FRI-MON)...01/215 PM. The heat will really kick in later in the week into Saturday as the high pressure center over northern California reaches 600dam. Models still indicating some northerly flow developing across the Central Coast and southern Santa Barbara County as well as the northern mountains, creating a favorable pattern for hot Sundowners Friday and Saturday evenings. While the hottest temperatures will still be across inland area, strong downsloping slow off the Santa Ynez Mountains will provide a temperature boost across the coastal areas of southern Santa Barbara County with highs well into the 90s possible and very warm overnight temperatures as well. Elsewhere, temperatures will continue to warm through Saturday. Highs inland will be 10-15 degrees above normal and at the coast 5-10 degrees above normal with minimal and early clearing of marine layer. Models are suggesting a few degrees of cooling Sunday but then very little change Monday. While it`s possible that temperatures may technically drop into more of heat advisory category in some previously warned areas Sunday/Monday, opted to just extend the Excessive Heat Warning through Monday. The combination of these very hot temperatures, areas of low humidities and possible sundowner winds will lead to fire weather risks. Please see the fire weather discussion below for all the details. && .AVIATION...02/0255Z. At 00Z at KLAX, the marine layer was 600 feet deep. The top of the inversion was at 2600 feet with a temperature of 28 Celsius. For 00Z TAF package, high confidence in KPRB, KPMD and KWJF TAFs as CAVU conditions are expected thru the period. Moderate to high confidence in KBUR and KVNY where cigs will most likely stay out of the area, however some brief reduced vis around 12-14Z cannot be ruled out. For 00Z Coastal TAFs, low to moderate confidence in current forecast. Timing of return of CIG/VSBY restrictions could be +/- 4 hours of current forecasts. KLAX...Moderate confidence in 00Z TAF. Timing of return of CIG/VSBY restrictions could be as early as 04Z and as late as 07Z. Also, there is a 30% chance of LIFR conditions 12Z-15Z. No significant easterly wind component is expected. KBUR...High to moderate confidence in 00Z TAF. Cigs will most likely stay out of the area, however some brief reduced vis and clouds around 12-14Z cannot be ruled out. && .MARINE...01/950 PM. For the Outer Waters, moderate to high confidence in current forecast. Through tonight, high confidence in Small Craft Advisory (SCA) level winds. Local winds near gale force are possible early on. For Tuesday through Thursday, high confidence in winds and seas remaining below SCA levels. For Friday and Saturday, there is a 20-30% chance of SCA level winds. For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. Winds have fallen below SCA levels, but a SCA was issued due to steep, choppy short period seas in effect until 3AM Tuesday. For the rest of Tuesday through Saturday, high confidence in winds and seas remaining below SCA levels. For the Inner Waters south of Point Conception, high confidence in current forecast. Today through Saturday, winds and seas will remain below SCA levels. Patchy dense fog (with visibilities one nautical mile or less) will continue to impact the coastal waters through the week. The areal coverage of the dense fog will likely decrease each day. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...Excessive Heat Warning now in effect from 11 AM Tuesday to 6 PM PDT Monday for zones 38-343>345-353-376>379-381>383. (See LAXNPWLOX). Excessive Heat Warning in effect from 11 AM Wednesday to 6 PM PDT Monday for zones 88-342-348-351-352-356>358-369>375-380. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday for zones 645-670-673-676. (See LAXMWWLOX). && $$ PUBLIC...MW/Smith AVIATION...Phillips MARINE...Phillips/RAT SYNOPSIS...Cohen/Smith weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox