Marine Weather and Tide Forecast for Lompoc, CA

.SHORT TERM (TDY-SUN)...06/926 AM.

***UPDATE***

The unsettled weather pattern is underway with patchy clouds widespread across the region. Satellite data shows areas of convective activity over outer waters west of the Channel Islands, with light rain possible. A light showers or thunderstorm and brief gusty winds will remain possible through at least today, particularly across the interior mountains and the coastal waters.

***From Previous Discussion***

The latest surface pressure gradients show a reversal of the flow pattern taking place as the flow regime switches from an offshore flow regime to an onshore flow regime. The reversal is brought to us by an upper-level trough about 300 miles west of Point Conception. Weak onshore pressure gradients have established at this hour, and in the breaks of the middle and high level cloud shield, typical coastal stratus can be seen developing and streaming into the coastal areas this morning.

While a mix of cloud heights can be seen on the latest GOES-W nighttime microphysics RGB imagery, a deep layer of drier air remains in the lowest levels of the atmosphere over most of the area. In fact, radar echoes can be seen the latest radar mosaic, but the bulk of the rain is likely only falling as sprinkles this morning. 850 mb mixing ratios are pretty low this morning, but the air mass should moisten through the day and bring the possibility of shower activity, especially over the mountains. High- resolution multi-model ensemble members favor showers developing over the Ventura and Santa Barbara County mountains this afternoon and evening. Slight chance PoPs have been added to the forecast, but it should be noted that there is a a very slight chance of thunderstorms over the same area. NAM-WRF model soundings over the region advertise a favorable profile for thunderstorms with some CAPE values and some divergence aloft to help showers grow. Lifted index values in the model soundings turn negative during the late afternoon and K-index values approach the mid 30s. The latest SPC Day 1 outlook highlights an area over the northern Ventura County and the backcountry region of Santa Barbara County. Given the dry layer in place and the cutoff nature of the trough, it is not a clear cut situation. If thunderstorms do develop, there is concern placed with gusty outflow winds and dry lightning due to the inverted-v sounding profiles, especially if any storms drift off the mountains into the Santa Ynez Valley or the South Coast of Santa Barbara County.

Cooler temperatures are expected today, but offshore flow pattern will reestablish as the trough digs farther to the south and the region enters the north to northeast sector of the trough. With the counterclockwise circulation around the trough, offshore flow would be prevalent and develop a warmer and drier air mass once again. Advisory level winds cannot be ruled over the weekend, but the latest model solutions are starting to hint at Sundowner winds over Santa Barbara County on Saturday evening and again Sunday evening.

.LONG TERM (MON-THU)...06/342 AM.

The pattern should shift back to onshore on Monday as a storm system approach the region. The latest forecast ensembles indicate a majority of the solutions with rain across the region between Tuesday and Wednesday. Amounts look to be light to moderate at best. Ensemble means range between 0.25 and 0.50 inch, but there is about a 20 percent chance that amounts could be higher or lower than those values. There are still some solutions with no rain at all. If one factors in the deterministic solutions of the GFS and pattern recognition, the forecast ensemble precipitation means seem reasonable. 850 mb mixing ratios are on the drier side between 4 and 6 g/kg and there is a limited warm air advective pattern component inhibiting orographic lift at this point. The forecast goes with WPC values for QPF for now and falls inline goes with NBM values for the current time, but it should be noted that there is likely a locally higher chance of precipitation and higher amounts along the south and southwest facing slopes of the mountains.

A warming trend will likely develop between Thursday and Friday, then a pair of storms looks to move into the region over next weekend and into the third week of February. The second storm system, likely moving over the region between 14th and 15th could end up being the heavier storm system. It does possess some colder air aloft and 850 mb temperatures means drop to near zero, hinting at the possibilities of more instability. There is remains high confidence in much cooler temperatures during this period.

AVIATION
06/1141Z.

At 0800Z at KLAX, the marine layer was 1100 feet deeps with an inversion to 2700 feet with a temperature of 17 degrees Celsius.

High confidence in VFR TAFs for KPMD and KWJF.

For remaining sites, low to moderate confidence in flight cats through 18Z, then high confidence in VFR conds thereafter. High clouds are blocking any view of low clouds, and the high clouds may inhibit the formation of a solid stratus deck, leading to frequent flight cat changes. Min flight cat may be off by one cat.

No significant wind issues anticipated. Less than 10% chance for an isolated shower and lightning strike anywhere, highest over mountains Friday afternoon.

KLAX...Moderate confidence in minimum flight cat through 18Z. 30% chance for no cigs tonight, but moderate confidence in 007-012 being lowest cig height. High confidence in VFR conds after 18Z.
30% chance for east wind component over 6-8 kt through 19Z.

KBUR...Moderate confidence in VFR conds prevailing. 20% chance for IFR-MVFR conds thru 18Z. 5-10% chance for cigs 002-005. High confidence in VFR conds after 18Z.

MARINE
06/917 AM.

A long period west swell will continue to build into the region today. Seas are expected to reach 10-12 feet across the inner waters along the Central Coast and the outer waters from Point Piedras south to San Nicolas Island. Large seas will begin to decrease Saturday, but northwest winds will increase at the same time.
Small Craft Advisory (SCA) winds in the 20-30 knots range will be common across the Outer Waters and along the Central Coast into at least early next week. There is a 40-60% chance for low end Gale Force winds (35-40 knots) during this timeframe, highest chances Sunday.

West to northwest winds will make their way into the waters south of Point Conception Saturday and Sunday afternoon, although likely staying below SCA levels, except for localized gusts to 25 knots. Offshore flow will bring 15-25 knot winds to nearshore areas from Ventura to Santa Monica late Saturday through Monday afternoon, with strongest winds likely along the Malibu Coast late Saturday through Sunday early afternoon.

Choppy waves will be the result of the increase in winds and ocean conditions will remain hazardous into at least Monday.

Patchy dense fog will be tucked underneath the cover of high clouds through late this morning, and there is a moderate chance for dense fog to continue through at least Saturday morning.

BEACHES
06/128 AM.

A long period west swell will continue to build across the coastal waters today, resulting in high surf focused across west facing beaches through Saturday night. Elevated surf will likely continue into next week.

Refer to the SRFLOX and CFWLOX products for more details on the High Surf Advisories along the coast.

LOX WATCHES/WARNINGS/ADVISORIES
CA...High Surf Advisory in effect until 9 PM PST Saturday for zones 340-346-349-350-354-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PST Monday for zones 645-670-673-676. (See LAXMWWLOX).