Marine Weather and Tide Forecast for South Pasadena, CA

.SHORT TERM (SUN-WED)...27/821 PM.

At upper levels, cyclonic flow will persist over the area through Monday then a weak ridge will move overhead on Tuesday before another weak trough develops on Wednesday. Near the surface, moderate onshore flow to the east and weak northerly offshore flow will persist through Tuesday with an increase in the onshore gradients on Wednesday.

Forecast-wise, no significant issues are expected through the short term period. With cyclonic flow and deep moist layer in place, partly to mostly cloudy skies with a slight chance of light showers will continue through this evening, mainly over the mountains and foothills. Overnight, the skies will clear and are expected to remain mostly clear through Tuesday. However by Tuesday night, the increase in onshore flow and decreasing H5 heights will allow for the marine layer stratus and fog to return to the coastal plain (and possibly some of the lower coastal valleys) with some increase in high level clouds as the weak upper trough develops.

As for winds, the developing northerly offshore gradients will generate some gusty northerly winds across the Santa Ynez range through the period. Based on forecast gradients and high resolution models, best chances for widespread advisory-level winds looks to be Monday evening across the western Santa Ynez Range. As for the onshore flow to the east, any advisory-level southwesterly winds across the mountains/deserts should remain very localized through Tuesday. However with the increase in onshore gradients on Wednesday, there may be some more widespread advisory-level southwesterly winds across the mountains and deserts.

Finally for temperatures, a warming trend can be expected through Tuesday for all areas with rising thicknesses/H5 heights and mostly clear skies. However on Wednesday, the combination of the upper level trough and increase marine influence will bring several degrees of cooling to all areas.

.LONG TERM (THU-SUN)...27/156 PM.

For the extended, a somewhat unsettled pattern can be expected for the area. On Thursday, a weak upper low will develop over the area with a much stronger/colder low impacting the area on Saturday and Sunday. As expected, models have some differences in the details, but either model indicates rather unsettled weather for early May.

For Thursday, the weak upper low should not be too much of an issue. Afternoon temperatures will hover around seasonal normals.
Onshore gradients will continue to produce night and morning low clouds and fog across the coastal plain and lower coastal valleys.

On Friday, will anticipate conditions fairly similar to Thursday.
However for Saturday and Sunday, as the upper low drops southward across the area, cooler and cloudier conditions are anticipated.
Based on both deterministic and ensemble data, there will be the chance for some showers just about anywhere Saturday/Sunday and there could even be the possibility of some thunderstorms. One caveat to this pattern is the fact that models do not handle upper lows over Southern CA very well in the early Spring. So, the forecast could take a drier or wetter turn over the coming days.

AVIATION
27/1844Z.

At 1804Z at KLAX, there was no marine layer nor inversion.

High confidence in TAFs for KPMD and KWJF.

Moderate confidence in the remainder of TAFs. Scattered light showers at KPRB, KSBP, and KSMX thru around 20Z Sun. MVFR to VFR conds and several clouds decks at times expected thru fcst pd.

KLAX...Moderate confidence in TAF. BKN030-050 likely through much of the period. There is a 15% chance of east wind component reaching 8 kts from 10Z to 18Z Mon.

KBUR...Moderate confidence in TAF. There is a 20% chance of -SHRA through Sun afternoon. BKN030-050 likely through much of the fcst pd.

MARINE
27/759 PM.

Moderate confidence in forecast.

For the Outer Waters, widespread Small Craft Advisory (SCA) level winds are likely tonight through at least Tuesday night. However, there may be a brief lull in SCA level winds Monday morning in PZZ670. There is a 30-40% chance of SCA level winds Wednesday, highest over the northern waters.

For the Inner Waters north of Point Sal, SCA winds are possible during the afternoon/evening hours Monday and Tuesday (50-70% chance), with lowest chances on Tuesday.

For the Inner Waters south of Point Conception, SCA level winds across the SBA Channel will continue through late tonight. There is a 50-60% chance of SCA level winds for western portions of SBA Channel Monday afternoon/evening, with much lower chances Tuesday through Wednesday.

Seas are generally expected to remain below SCA levels through the work week. However, seas could approach SCA Criteria at times across far western portions of the Outer Waters through Wednesday.

LOX WATCHES/WARNINGS/ADVISORIES
CA...Beach Hazards Statement in effect through Wednesday evening for zones 362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Monday for zones 645-650. (See LAXMWWLOX).
Small Craft Advisory in effect until 9 PM PDT Tuesday for zones 670-673-676. (See LAXMWWLOX).