29/704 PM.
Rain chances continue through much of the weekend, with the peak of the rain likely occuring Saturday night evening into Sunday morning. Warmer and drier conditions expected early next week, with the potetnial for more light rain by the middle of next week.
(Thu-Sun), 29/704 PM.
***UPDATE***
A cool and cloudy day across the forecast area saw high temperatures generally around a few degrees cooler compared to yesterday. Some very light sprinkles fell across the area with a few areas recording one hundredth of an inch, including here at the office in Oxnard. All eyes turn to what should be a relatively beneficial rainfall through Halloween weekend, however, even light rain may disrupt outdoor Halloween plans. The forecast remains on track with light showers possible through Saturday morning and the potential for more steady rain with higher rain totals Saturday afternoon/evening into Sunday morning.
***From Previous Discussion***
For the short term, main focus remains on rain chances across the district. Models continue to be on the same broad synoptic page, but differ in the details. An upper low will continue to spin off the Pacific Northwest coast through Saturday, before moving inland on Sunday. This will result in a very sharp trough, or a weak upper low, impacting the area this weekend.
Overall, the last couple of model runs have trended a bit "drier" and further south with this storm, but ensembles, especially the ECMWF suite, still indicate a decent number of moderate to heavy rainfall members. So, at this time, there is high confidence in widespread rainfall across the area, but only moderate confidence in amounts through the Halloween weekend.
Today through Saturday morning, there will be some scattered light showers just about anywhere with a deep moist layer in place across the area. Rainfall totals, if any, through Saturday morning will be on the order of a few hundredths of an inch. By Saturday afternoon/evening, the main storm will move eastward towards Southern California, moving inland during the day on Sunday. As alluded to above, the heaviest rainfall Saturday night and Sunday looks to remain south of LA county. Current rainfall totals look to generally be in the 0.25 to 1.00 inch range across the area with locally higher amounts (up to 2.00 inches) possible across favored mountain slopes. Given the continued uncertainty between models, there still is a 20% chance of amounts about double the expected totals and a 20% chance of amounts about one half of the expected totals.
As for rain rates, the best instability looks to remain south of LA county. So, rainfall rates are expected to be in the 0.10 to 0.33 inch/hour range. Additionally, any thunderstorm threat looks to be minimal (under a 10% chance).
(Mon-Thu), 29/1255 PM.
For the extended, latest models are exhibiting good synoptic agreement through the period. At upper levels, ridge will develop over the area Monday/Tuesday then will shift eastward as a upper low sweeps northeastward across northern California on Wednesday and Thursday. At the surface, weak offshore flow will prevail on Monday/Tuesday with a return of weak onshore flow by Wednesday and Thursday.
Forecast-wise, the above synoptic pattern will result in benign weather for the area. With the ridge overhead and weak offshore pressure gradients, Monday and Tuesday will be dry and warmer with high temperatures topping out in the upper 60s and 70s. There will be some northeasterly winds, due to the offshore pressure gradients, but any winds are expected to remain below advisory levels.
For Wednesday and Thursday, a slight cooling trend can be expected with some increase in high clouds. With the upper low moving northeast into northern California, there will be a low chance (less than 20%) of some light showers across the Central Coast.
29/2313z.
At 2212Z at KLAX, there was a deep moist layer to 5500 feet. marine layer was 5000 ft deep. The top of the inversion was at 8000 ft with a temperature of 10 C.
High confidence in VFR TAFs for KPMD & KWJF.
Moderate to high confidence in TAFs with VFR cigs for remaining sites, with infrequent periods of 020-030 MVFR cigs. Additionally, there is 10-25% chance of -DZ or -SHRA from late tonight through the TAF period.
KLAX, Moderate to high confidence in TAF. VFR cigs likely with infrequent periods of BKN020-030 cigs. 15-25% chance of -DZ or -SHRA from around 30/06Z through the period. Any east wind component is expected to remain under 8 kt.
KBUR, Moderate to high confidence in TAF. VFR cigs likely with infrequent periods of BKN020-030 cigs. 10-20% chance of -DZ or -SHRA from around 30/06Z through the period. No wind issues expected.
29/921 PM.
Conditions are expected to remain below Small Craft Advisory (SCA) levels through Saturday. Light rain is expected now through Friday. A low pressure system will bring more moderate to potentially locally heavy showers Saturday into Sunday morning. Sunday, there is a 60% chance for widespread northwest SCA winds for the outer waters, and a 50% chance for SCA winds through the inner waters, including the Santa Barbara Channel and inner waters south of Point Mugu.
29/915 PM.
Very high tides between 7.2 and 7.5 feet (roughly 1.0-1.4 feet above astronomical predictions) are expected during the morning hours through Friday over all coastal areas, with the highest towards Los Angeles County.
Minor coastal flooding is likely purely based on the high tides. Similar extreme tides in the past tell us that coastal communities should expect shallow flooding of harbor walkways, beach parking lots and bike paths. With swells and surf on the lower-end during these extreme tides (2-4 feet), the threat of more moderate impacts should be limited to the most vulnerable areas. With all of these considerations, Coastal Flood Advisories are in effect through Friday.
Ca, Coastal Flood Advisory in effect until 2 PM PDT Friday for zones 87-340-346-349-350-354-362-366. (See LAXCFWLOX). PZ, NONE.
