17/256 AM.
A weak to moderate Santa Ana event gusty winds and critical fire weather conditions to portions of Southwest California today. In addition, the very warm temperatures bring a high risk of heat- related illness to all coastal areas. A significant cool down is expected Sunday with a good chance of rain Tuesday or Wednesday.
(tdy-Mon), 17/830 AM.
***UPDATE***
Latest satellite and surface observations indicate mostly clear skies across the area. Santa Ana winds, generally gusting in the 30-50 MPH range, are observed.
Forecast-wise, everything still on track for the immediate short term. Gusty Santa Ana winds will max out late this morning then gradually diminish through the afternoon. So, current expiration time of 200 PM looks good for the WIND ADVISORIES. As for the HEAT ADVISORIES, they still look good for the coastal plain today as heat risk will be at MODERATE to HIGH levels, but today should be the last day of advisory-level heat.
One thing to watch will be the batch of high clouds to the south of the area. As these clouds stream northward, skies may take on a more partly cloudy tilt, especially across Ventura and LA counties. There have been some reports of sprinkles over far Southern California this morning along with LightningCast data indicate some potential lightning over the far southern waters. Overall, given the dryness of the lower atmosphere, do not anticipate any precipitation issues for the CWA, but it is something to monitor through the day.
***From Previous Discussion***
Weak to moderate Santa Ana winds will peak again this morning into the early afternoon with low end advisory level gusts of 30 to 50 mph or roughly 10 to 20 mph weaker than yesterday's peak for most areas. Low pressure to our south will support winds focused from the east, not the more typical northeast direction as seen yesterday. Red Flag Warnings continue within much of Los Angeles and Ventura Counties
Moderate to high heat impacts continue today, although temperatures will be a touch cooler as gradients should weaken enough to allow a brief seabreeze near the coasts. Mid-to-high clouds streaming in from the south may accelerate cooling a bit more towards LA County.
The cooling trend will be more pronounced Sunday into Monday, with temperatures falling to near normal by Monday in advance of our next system. Good confidence that the Heat Advisories at the coast will be allowed to expire Saturday evening.
(Tue-Fri), 17/521 AM.
High confidence in a cool and moist pattern for the middle of next week with at least a brief reprieve from the extreme fire weather conditions as of late. However, we have below normal confidence in forecast details.
Closed and cut-off lows as what is expected next week are notoriously challenging to forecast. Two scenarios seem to be emerging.
Scenario 1 (50-60 percent chance): Cold low pressure that passes through the region in the Tuesday/Wednesday time frame in particular. This scenario is more dynamic with increased potential for bands of moderate to heavy rain with rainfall totals 0.25-1 inch except local 1-2+ inches southwest facing mountain slopes and foothills. Minor flood issues may arise for some areas in this scenario.
Scenario 2 (30-40 percent chance) Cold low pressure passes to our south in the Tuesday-Thursday timeframe. Rain chances more sporadic and less guaranteed with this scenario with generally less than 0.25 inches (about twice this in the mountains) and some areas see little if any rain. The lower totals are related to less near storm dynamics and low pressure to our south inducing weak offshore flow. Historically this type of pattern has cut into rainfall totals, especially near the coast.
Both scenarios would be chilly especially compared to our current weather pattern with highs only in the 60s and 70s.
Weak offshore flow and gradually rebounding temperatures are the most likely scenario heading into next weekend.
17/1800z.
At 18Z at KLAX, there was no marine layer nor an inversion.
High confidence in VFR conditions and moderate confidence in winds.
KLAX, High confidence in VFR conditions. E wind near 7 kts should switch W between 17/19-21Z. Then, light E wind 18/10-17Z should remain below 8 kts.
KBUR, High confidence in VFR TAF. Weak to moderate LLWS and Turbulence is possible through 17/21Z.
17/815 AM.
Small Craft Advisory (SCA) conditions will linger through this morning nearshore from Point Dume to Ventura and out past the Channel Islands. SCA winds may linger into the early afternoon across eastern portion of the Santa Barbara Channel including nearshore (Ventura/Channel Islands Harbors) as winds shift onshore.
Benign conditions are expected on Sunday. Small Craft Advisory NW winds will increase Sunday Night and Monday, especially off the Central Coast. A moderate- strength storm system is becoming more likely in the Tuesday through Thursday timeframe.
Ca, Wind Advisory in effect until 2 PM PDT this afternoon for zones 88-354-355-358-362-369>380. (See LAXNPWLOX). Heat Advisory in effect until 8 PM PDT this evening for zones 340-341-346-347-349-350-354-355-362-366>368. (See LAXNPWLOX). Red Flag Warning in effect until 8 PM PDT this evening for zones 288-354>358-362-369>382-548. (See LAXRFWLOX). PZ, Small Craft Advisory in effect until 2 PM PDT this afternoon for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until noon PDT today for zones 655-676. (See LAXMWWLOX).
