27/504 PM.
Temperatures will remain above normal through Monday, especially inland of the beaches, warmest over the weekend. Dense fog will affect coastal areas each day through Saturday or Sunday. Much cooler conditions expected Tuesday through the end of the week, along with gusty winds and a chance of rain at times.
(Fri-Mon), 27/807 PM.
Overall, a rather pleasant day across the district. Away from the coast, and marine layer influence, temperatures topped out in the 80s. In fact, both Palmdale and Lancaster set daily records today for high temperatures.
Forecast-wise for the short term, no significant issues are expected. Models continue to indicate upper level high pressure over northern Mexico will continue to flatten and weakening through Monday. At the surface, onshore flow will persist with only minor day-to-day variations in the surface pressure gradients.
With this pattern, marine layer stratus/fog will continue to impact the coastal plain through Sunday then extend a bit further inland Sunday night and Monday morning. Currently, the marine inversion is near 1000 feet deep, but should gradually deepen through the weekend. So, there may be some dense fog along the coast tonight/Saturday morning, but do not anticipate widespread coverage enough to warrant any advisories. However the night shift need to monitor that potential. Other than the marine layer issues, skies should remain mostly clear through the period with some scattered cirrus clouds from time-to-time.
As for temperatures, warm conditions will persist through Sunday with temperatures away from the coast still remaining around 10-20 degrees above normal while the marine layer influence will keep coastal areas cooler. On Monday, all areas will experience a cooling trend with high temperatures generally dropping 5-10 degrees from Sunday's numbers.
As for winds, the continued onshore flow will generate gusty southwesterly winds across interior sections each afternoon and evening. Based on forecast gradient trends, these winds should gradually strengthen from day-to-day. However at this time, any advisory-level winds are expected to remain localized in the foothills of the Antelope Valley.
(Tue-Fri), 27/807 PM.
For the extended, latest models continue to sing the same song. A powerful upper low will move across the Pacific Northwest Tuesday through Friday. As this occurs, our area will experience a noticeable cool down through Thursday as thickness lower and onshore flow increases. From the Tuesday through Thursday time frame, high temperatures will be hovering around seasonal normals. On Friday, there will some slight warming across the area as the previously mentioned low moves inland.
As for rain chances, models continue to scale back on the chances as well as the amounts. So for the Tuesday through Thursday time frame, chance POPs look like the winner for now. Latest QPF numbers indicate rainfall totals, if any, will be under 0.25 inches. Based on current ensembles, these reduced numbers look good as they indicate little chance of amounts greater than 0.50 inches and 30-50% chance of amounts between 0.10 and 0.50 inches.
As for winds, the increasing onshore flow will continue to generate gusty southwesterly winds across interior sections. There will be a chance of advisory-level gusts across these areas through next week. So, the winds will need to be watched closely.
28/0003z.
At 2230Z at KLAX, there was a 900 ft marine layer. The top of the inversion was at 2200 feet with a temperature of 21 C.
High confidence in TAFs for KPRB, KPMD, KWJF, KBUR, and KVNY.
Low to moderate confidence in remaining TAFs. Low clouds and fog with predominantly LIFR conds expected for the overnight period. However, lower confidence exists in the arrival time of low clouds, which could differ by +/- 2 hours from TAF times. Conditions could be off by one flight category and there is a 20% chance of LIFR conds down to 1/4SM FG at any of the airfields.
KLAX, Low to moderate confidence in the 00Z TAF. Expecting a faster return of cigs this evening, most likely in the 02-03z time range. When cigs do develop, fairly high confidence of LIFR to IFR cigs, with a 10-20% chance of VLIFR conditions down to 1/4SM FG. No significant east wind component expected.
KBUR, High confidence in the 00Z TAF. VFR conditions expected through period, with a small chance (10-20%) of mvfr vsbys in haze early Saturday morning.
27/807 PM.
High confidence in winds and seas staying under Small Craft Advisory (SCA) levels through at least Monday, except for a 30-50% chance of low-end SCA winds beyond 20 miles from the Central Coast Saturday Night through Sunday night.
Moderate risk of dense fog with visibility under one mile will continue through at least Saturday.
There is a growing risk for widespread strong SCA or low-end Gale Force winds over most coastal waters (including nearshore and the Santa Barbara Channel) late Thursday through Friday of next week.
Ca, NONE. PZ, NONE.
