textproduct: Los Angeles

SYNOPSIS

12/759 PM.

Temperatures will increase each day into mid-week, resulting in widespread Moderate to Major HeatRisk Tuesday through Thursday. Monsoonal moisture moving over the area will add to the discomfort, also bringing the potential for showers and thunderstorms each day, highest in the mountains.

LONG TERM (THU-SUN)

12/158 PM.

High pressure will begin to slowly weaken Thursday as a low pressure system moves into the Pac NW. In addition, onshore flow will return much earlier in the day bringing temperatures back down to within a few degrees of normal in most areas by Friday.

However, one factor to keep a close eye on will be the next tropical system off the coast of Mexico this weekend. While the storm is expected to weaken considerably as it moves northwest, there is a chance of another tropical moisture surge across the area. Models are indicating PW's increasing again to around 1.5" as early as Saturday and remaining high into early next week. At the very least there will be some increasing mid level clouds along with higher humidities. But also can't rule out isolated showers and/or thunderstorms. Temperatures are expected to remain within a few degrees or normal, but the increase in humidity could lead to an increase in heat risk. And there will likely be some increase in south swells as well.

AVIATION

13/0506Z.

At 0426Z at KLAX, there was no marine layer. The top of the inversion was at 2500 ft with a max temperature of 25 C.

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

Moderate confidence in the remaining TAFs. Mid to upper level clouds are likely continue to disrupt the marine layer cloud formation tonight. Any CIGs that do form (30-40% chc) could be patchy, scattering and reforming frequently later tonight into Mon morning.

KLAX...Moderate confidence in the 06Z TAF. There is a 30% chance of BKN012-20 CIGs between 09-16Z Mon, however if they do form they are likely to be patchy and periodic. High confidence that any east wind component will be below 6kt.

KBUR...Moderate to High confidence in the 06Z TAF. There is a 10-15% chance of brief OVC008-015 cigs 12Z-16Z Mon.

MARINE

12/829 PM.

For the outer waters, winds and seas are expected to be below Small Craft Advisory (SCA) levels through Tuesday morning. Then there is a 50%-60% chance of SCA winds and seas developing late Tuesday afternoon and continue through Thursday night or Friday morning, with a 20% chance of Gale Force winds Wednesday. Thereafter, conds will be below SCA levels Friday afternoon through the weekend.

For the nearshore waters along the Central Coast, mainly light winds are expected through Tuesday morning, then increase to SCA levels Tuesday afternoon and persist (60% chance) through Thursday night. Seas will increase to SCA levels Wednesday through thursday. Conds should then drop below SCA levels late Thursday night through the weekend.

For the inner waters south of Point Conception, conds are expected to remain below SCA levels through the forecast period, except for a 60% chance of SCA level wind gusts over the western portions of the Santa Barbara Channel during the afternoon and evening hours Tuesday through Wednesday.

Monsoonal moisture is expected to push over the coastal waters during the next couple of days. As a result, there is a 10% of isolated showers and thunderstorms over the coastal waters through Tuesday. Any thunderstorm that develops could produce dangerous cloud-to- ocean lightning.

BEACHES

12/830 PM.

A longer period, south to southwest swell will continue to affect the coastal waters through this week. With this longer period swell, the potential for larger surf and a greater risk for rip currents will continue.

Evening high tides are expected to increase this week with Monday expected to be the highest tide of 7.1 to 7.7 ft above MLLW. There is the potential for some minor coastal flooding with the evening high tides and south swell. One thing that will need to be watched late this week into the weekend will be the potential of a greater south to southwest swell from potential tropical cyclone over the eastern Pacific.

In addition, a non-zero chance of thunderstorms will be possible along the beaches at times into Tuesday (around a 10% chance overall), and again late week into the following weekend. Any thunderstorms that develop could produce dangerous cloud-to-ground lightning. For more information, please refer to the Beach Hazard Statement.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Heat Advisory remains in effect until 10 AM PDT Tuesday for zones 38-88-343>345-353-368-372-373-375>380-548. (See LAXNPWLOX). Extreme Heat Watch in effect from Tuesday morning through Thursday evening for zones 38-88-341>345-347>358-362-366>376-378>383-548. (See LAXNPWLOX). Beach Hazards Statement in effect through Wednesday evening for zones 340-346-349-350-354-362-366. (See LAXCFWLOX). PZ...NONE.