textproduct: Los Angeles

SYNOPSIS

17/256 AM.

A weak to moderate Santa Ana event gusty winds and critical fire weather conditions to portions of Southwest California today. In addition, the very warm temperatures bring a high risk of heat- related illness to all coastal areas. A significant cool down is expected Sunday with a good chance of rain Tuesday or Wednesday.

LONG TERM (TUE-FRI)

17/521 AM.

High confidence in a cool and moist pattern for the middle of next week with at least a brief reprieve from the extreme fire weather conditions as of late. However, we have below normal confidence in forecast details.

Closed and cut-off lows as what is expected next week are notoriously challenging to forecast. Two scenarios seem to be emerging.

Scenario 1 (50-60 percent chance): Cold low pressure that passes through the region in the Tuesday/Wednesday time frame in particular. This scenario is more dynamic with increased potential for bands of moderate to heavy rain with rainfall totals 0.25-1 inch except local 1-2+ inches southwest facing mountain slopes and foothills. Minor flood issues may arise for some areas in this scenario.

Scenario 2 (30-40 percent chance) Cold low pressure passes to our south in the Tuesday-Thursday timeframe. Rain chances more sporadic and less guaranteed with this scenario with generally less than 0.25 inches (about twice this in the mountains) and some areas see little if any rain. The lower totals are related to less near storm dynamics and low pressure to our south inducing weak offshore flow. Historically this type of pattern has cut into rainfall totals, especially near the coast.

Both scenarios would be chilly especially compared to our current weather pattern with highs only in the 60s and 70s.

Weak offshore flow and gradually rebounding temperatures are the most likely scenario heading into next weekend.

AVIATION

17/1221Z.

At 11Z at KLAX, there was no marine layer or inversion.

High confidence in VFR conditions and moderate confidence in winds.

KLAX...High confidence in VFR conditions. There is a 30 percent chance of more than brief 08kt east wind component focused between 15-18Z.

KBUR...High confidence in VFR through the period with moderate confidence in generally light wind. Weak to moderate LLWS of 10-20 kts is possible through 18Z.

MARINE

16/733 PM.

NE to E winds will bring short period and hazardous seas to most of the nearshore waters into Saturday. Winds will be strongest from Ventura to Santa Monica where winds where pockets of 20 to 30 knot winds will form at times. This is a a few knots lower than earlier today, so the previous Gale Warning has been replaced with a Small Craft Advisory. Gusts of 10 to 20 knots will likely also affect the nearshore Central Coast waters as well as the waters from Orange County to Catalina Island. These winds will likely have rapid fluctuations. Benign conditions are expected on Sunday. If you have the option, go out on Sunday and try to stay off the waters Friday and Saturday. Small Craft Advisory NW winds will increase Sunday Night and Monday, especially off the Central Coast. A moderate- strength storm system is becoming more likely in the Tuesday through Thursday timeframe.

FIRE WEATHER

17/305 AM.

Today will likely be the last day of widespread high risk of large fires and rapid fire growth focused across Santa Ana prone areas of Los Angeles and Ventura Counties where a Red Flag Warning continues into this evening. Peak wind gusts of 30 to 50 mph (peaking in many areas mid morning to mid afternoon) will combine with minimum humidities in the 8-20 percent range and high temperatures 85-95, resulting in critical fire weather conditions.

Cooler and more humid conditions are likely next week. Gusty southwest to northwest winds are expected Sunday and Monday, with light to moderate rain likely sometime Tuesday through Thursday.

Residents in high fire risk areas should be prepared in case a fire starts. Review your evacuation plans...what would you bring, where would you go. Stay extra aware of your surroundings. Make sure your vehicle is fueled up. For everyone, avoid using anything that could spark a fire. Be prepared for power outages that are likely over a good portion of our areas.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Wind Advisory in effect until 2 PM PDT this afternoon for zones 88-354-355-358-362-369>380. (See LAXNPWLOX). Heat Advisory in effect until 8 PM PDT this evening for zones 340-341-346-347-349-350-354-355-362-366>368. (See LAXNPWLOX). Red Flag Warning in effect until 8 PM PDT this evening for zones 288-354>358-362-369>382-548. (See LAXRFWLOX). PZ...Small Craft Advisory in effect until 2 PM PDT this afternoon for zones 650-655-676. (See LAXMWWLOX).