24/303 AM.
A shallower marine layer is expected over the next few days. Warm weather will peak on today and continue into Thursday. A cooling trend with a more pervasive marine layer cloud pattern and below normal temperatures is expected Friday into the weekend.
(tdy-Fri), 24/806 AM.
***UPDATE***
Latest visible satellite imagery shows yet another morning of marine layer stratus across the coasts and some valleys. Low clouds have arrived to the eastern portion of the San Fernando Valley. Aircraft data indicates top of the marine layer is at 1800 ft.
Satellite also shows cloud growth across eastern San Gabriels this morning. Even with lingering moisture, there isn't enough lift to generate and maintain convection. This is visible by both satellite and webcams which show a flat appearance which is more indicative of a stable atmosphere. An isolated shower is still possible (5%) through this morning.
Regarding the heat, expecting the warmest weather Today. Lingering into Thursday. Followed by a cooling trend Friday into the weekend. No wind issues in the immediate near-term. Forecast remains on track.
***From Previous Discussion***
Yesterday's ridge will flatten out today. Hgts will fall to about 590 dam. Onshore flow will increase as well. The eddy, however, is absent and this will limit the amount of low clouds into the valleys. Max temps will be similar to ydy's except for some warming in the vlys due to the lack of marine layer. It will be a little drier as drier air moves in from the west. A low level heat advisory remains in effect for the LA vlys and the LA interior cstl areas.
Weak cyclonic flow moves into the state on Thursday and will be accompanied by an increase in onshore flow both to the north and east. Look for and increase in the morning low clouds and for the vlys. The low clouds will clear slowly and some beaches may remain cloudy for most of the afternoon. The strong onshore push to the east will generate gusty afternoon winds in the Antelope Vly in the afternoon. Max temps will be similar to today's, perhaps a little cooler in the vlys.
Friday will see a substantial increase in cyclonic flow and there will be strong onshore flow. Look for plenty of low clouds across the csts/vlys with slow clearing and no clearing for many beach areas. The onshore push may well bring advisory level winds to the western Antelope Vly and its foothills in the afternoon and early evening.
Sundowner potential increases on Friday, with likely advisory level winds especially on Saturday. Most max temps will cool 2 to 4 degrees and max temps will end up a few degrees blo normal.
Gusty winds will develop across SW SBA county in the evening and advisory level gusts look likely for the western portion of the SBA south coast.
(Sat-Tue), 24/236 AM.
June Gloom will be back with a vengeance during the xtnd period. An unseasonably cold upper low will move into the the PACNW and slowly move through. A trof associated with the upper low will be draped over CA for the 4 day period. Hgts will fall to around 584 dam. Strong onshore flow will continue to the east. While there will be moderate onshore flow to the north in the afternoon it will be much weaker in the mornings. Look for plenty of night through morning low clouds across the csts/vlys every day. Clearing will be on the slow side and a few beaches will remain cloudy in the afternoon. Portions of the SBA south cst may be the exception as local north flow may keep the low clouds away.
Look for a big cool down on Saturday followed by minimal changes Sun thru Tue. Max temps will mostly be in the 70s across the csts/vlys (mid to upper 60s at the beaches) and only lower to mid 80s for the inland areas. These max temps are 3 to 5 degrees cooler than normal at the csts and 5 to 10 locally 12 below normal across the vlys and inland areas.
There will be local north winds in the evening across the portions of the SBA south cst as well gusty afternoon winds in the Antelope Vly.
24/1003z.
At 0829Z at KLAX, the marine layer was 900 feet deep. The top of the inversion was 2800 feet with a temperature of 22 C.
High confidence in TAFs for KPMD & KWJF.
Moderate confidence in TAFs for KPRB, KBUR and KVNY with a 30 percent chc of IFR cigs 11Z-17Z.
Moderate confidence in the remainder of TAFs. VFR conds may arrive +/- 90 min from fcst time. There is a 25 percent chc of LIFR cigs 11Z-16Z at KSBP, KSBA, KOXR and KCMA
KLAX, Moderate confidence in TAF. VFR conds could arrive anytime between 18Z and 2030Z. No significant east wind component is expected.
KBUR, Moderate confidence in TAF. There is a 30% chance of OVC006 conds 11Z-17Z.
24/656 AM.
High confidence in winds and seas remaining below Small Craft Advisory (SCA) levels through today. Local gusts could reach 21 kts near Point Conception and across the western Santa Barbara Channel later this afternoon into the evening. Chances for SCA criteria gusts increase Thursday evening across the northern waters and will expand to the south Friday into the weekend. SCA winds will be strongest on Saturday, and will reach into the nearshore waters along the Central Coast and Santa Barbara Channel at times. Seas will near 10 ft Saturday evening through Monday morning. Thereafter, conditions look to quiet down a bit through mid next week.
Ca, Heat Advisory remains in effect until 9 PM PDT Thursday for zones 88-368-372-373-379-380-548. (See LAXNPWLOX). PZ, NONE.
