17/1149 PM.
Steady cooling through Friday with below normal temperatures continuing through the weekend. There will ample low clouds each morning through the weekend. Gusty onshore winds will affect interior areas through the week. A significant warming trend remains on track for next week with heat impacts expected.
(tdy-Sat), 18/830 AM.
***UPDATE***
A deep marine layer is in place this morning as strong onshore flow continues. The 12Z Vandenberg sounding showed the top of the marine layer clouds was around 2300-2500 ft and several pilot reported cloud tops were around 3200-3600 ft across LA County to as high as 4000 ft in the Ontario area. Visible satellite this morning showed an expansive marine cloud layer that was even still expanding in some of the inland valleys of Ventura and LA counties at 8 AM PDT.
The forecast for today remains on track with the low stratus likely taking until midday/early afternoon to clear out to the coast and temperatures will be ~3-6 degrees cooler across most areas away from the coast.
***From Previous Discussion***
June Gloom will continue through the short term.
At the upper levels there will be weak flow today. The flow will turn weakly cyclonic on Friday and will then become zonal on Saturday. Hgts will remain near 588 dam through the period. Much more importantly will be the strong onshore flow both to the N and E. The push to the east will be near 10 mb each afternoon.
The marine layer is near 2500 ft deep. This marine layer along with the strong onshore flow has produced enough marine layer stratus to cover all of the csts, vlys and even the coastal slopes. There may be enough lift esp near the foothills to produce some morning drizzle. Clearing will be slow today and many beaches will not clear at all esp across VTA county.
Max temps will cool again today by 3 to 6 degrees (a little less at the already cool beaches) bringing vly temps down into the mid 70s to lower 80s or 4 to 8 degrees blo normal. Another 1 to 2 degrees of cooling is on tap for Friday and only a few of the warmest vly locations will see highs of 80 or 81 while the rest of the area sits in the 70s (the nearshore area will actually not escape the 60s). Max temp will change little on Saturday as the area remains swaddled by the cool marine air.
The strong onshore push will bring near advisory level gusts to the western Antelope Vly and its foothills. There will also be stronger than normal sea breezes that will last longer into the evening.
(Sun-Wed), 18/232 AM.
Not too much excitement on Sunday and Monday. Zonal flow will continue over the state. The onshore flow will weaken just a little bit. This should decrease the morning cloud coverage a little bit and allow for somewhat better and faster clearing. Look for 1 or 2 degrees of warming on Sunday. 3 to 6 degrees of warming is possible Monday as hgts rise a little and compresses the marine layer.
The mdls have backed off a little on the warm up slated for next Tue-Thu. At one time an upper high was fcst to move over Srn CA now it appears that it will stay to the SE. Hgts should still warm to an above normal 594 dam. At the sfc mdt-stg onshore flow will persist in the W to E direction but the onshore push to the north will weaken through the period. The higher hgts will likely smoosh the marine layer to 1000 ft or less which will greatly reduce the amount of clouds making it into the vlys in the mornings. This compression will strengthen the marine inversion which will hinder the clearing near the shore. The current forecast calls for 2 to 4 degrees of warming each day Tue and Wed with little change on Thursday. This warming would bring vly temps into the mid 80s and lower 90s. Since this is the day 6 and 7 forecast there is still lower confidence and it is not out of the question the the fcst could snap back to a warmer one.
18/1656z.
At 1636Z at KLAX, the marine layer was 1700 ft deep. The top of the inversion was near 4000 ft with a temperature of 19 Celsius.
High confidence in KPMD & KWJF.
Fair confidence in TAFs - VFR transition could be up to 2 hours later than fcst.
KLAX, Moderate confidence in TAF. VFR conds may arrive any time 19Z-22Z. No significant east wind component expected.
KBUR, Moderate confidence in TAF. VFR conds may arrive any time 18-19Z.
18/205 AM.
Fairly high confidence in winds and seas staying below Small Craft Advisory (SCA) criteria through Saturday, but typically gusty winds of 15 to 20 knots will form each afternoon and evening over several nearshore spots.
17/715 PM.
A long period south to southwest swell (14 seconds and 17 seconds) will continue to affect the coastal waters through at least Friday. A Beach Hazard Statement is in effect through Thursday evening due to elevated surf of 3 to 6 feet on south- facing beaches of Ventura County Beaches, Malibu Coast, and Los Angeles County Beaches. Portions of the Southern Santa Barbara County Beaches could see surf to 2 to 4 feet.
High tides will continue to lower and should stay below 7.0 feet MLLW. The coastal flooding risk has lowered significantly as a result.
Ca, Beach Hazards Statement in effect through late tonight for zones 349-350-354-362-366. (See LAXCFWLOX). PZ, NONE.
