textproduct: Los Angeles

SYNOPSIS

05/256 AM.

Cloudy and cool conditions will continue through this afternoon. Warming and drying to follow Wednesday through the next weekend, with high temperatures approaching 90 degrees in some areas by Friday and even a few degrees higher over the weekend.

LONG TERM (FRI-MON)

05/256 AM.

The 4 day xtnd fcst is going to be a warm one, although just how warm remains a bit of question. The ridge with 582 hgts will remain over the state through Saturday. On Sunday and Monday the main upper high will move atop of Srn CA and hgts will around 585 dam. The big question mark is the sfc flow in the E/W direction. Good confidence that the N/S grad will vary from weak offshore flow in the morning to weak onshore in the afternoon. Looking at the EC ensembles for the E/W flow (The GFS ensembles have proven to have a drastic onshore bias and were not considered) there is an annoying near 50/50 split between the number with onshore flow and the number with offshore flow. The current forecast follows the average of them all which results in a fairly weak onshore push. This does not seem too unreasonable given that it is May. If the E/W grad turns out more onshore then the cst/vlys temp fcst will be too warm. Conversely if the flow is more offshore than fcst then there will be even more warming. That all said look for 1 to 2 locally up to 4 degrees of warming each day Friday through Monday with mid 70s to mid 80s across the csts and mid 80s to lower 90s across the vlys. These max temps would be 5 to 10 degrees over normal. The lower elevations of the mtns and the far interior will end up in the mid 90s or about 15 degrees over normal.

AVIATION

05/1705Z.

At 15Z at KLAX, there was a deep moist layer up to 8000 ft.

High confidence in VFR TAFs for desert airfields (KPMD & KWJF).

Moderate confidence in remaining TAFs. Patchy MVFR CIGs possible across the LA Basin (06/10Z-18Z) that may affect airfields KSMO, KLAX, & KLGB. 20% chance low clouds do not develop at KPRB. 30% chance CIGs do not develop at KSBP.

For all sites with forecasted CIGs, arrival and clearing times should be accurate within +/- 2 hours.

KLAX...Moderate confidence in TAF. 30% chance MVFR CIGs enter airfield 06/10Z-18Z. Otherwise, VFR conditions are expected. Good confidence that any east wind component will remain less than 5 kts.

KBUR...Moderate confidence in TAF. 30% chance of IFR-MVFR CIGs to develop 10Z-15Z Wed. Otherwise, VFR conditions with no wind issues are expected.

MARINE

05/738 AM.

Small Craft Advisory (SCA) winds will be common across the Santa Barbara Channel and near the Channel islands this afternoon and evening. These winds will likely reach the nearshore waters especially along the Ventura coastline. Low-end SCA level NW winds are also likely across along the Central coast.

From Wednesday through Saturday, SCA level NW winds are expected to strengthen each day and will peak Friday afternoon and evening. These winds are likely to reach 20 to 30 kts across the outer waters. There is about a 15% chance of GALE Force winds during this timeframe. SCA level winds are also likely at times across the nearshore waters along the Central coast and into at least western portions of the SB channel.

Short period seas will build during this timeframe especially across the outer waters - reaching 10 feet by Friday peaking at 11 to 13 feet Friday night through Saturday night.

LOX WATCHES/WARNINGS/ADVISORIES

CA...NONE. PZ...Small Craft Advisory in effect until 9 PM PDT this evening for zones 645-650. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM this afternoon to 9 PM PDT this evening for zone 655. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Wednesday for zones 670-673-676. (See LAXMWWLOX).