15/834 AM.
High pressure and offshore flow will bring very warm and dry conditions across the region through the weekend. Gusty Santa Ana winds will continue through the end of the week, mainly across portions of Los Angeles and Ventura Counties. A slow cooling trend will begin Friday.
(tdy-Sat), 15/850 AM.
***UPDATE***
A warm and dry air mass remains over southern California as offshore flow enters its eighth day with several more still to come. It will be another day of 80s across most coast/valley areas but like yesterday not quite high enough for records. The 24 hour temperature change map shows a large area of cooling this morning through the hwy 14/118 corridor but this is mostly due the drop off in wind speeds. By the end of the day not expecting temperatures to deviate too much from yesterdays levels, but overall likely down 1-3 degrees. Low end wind advisories continue across inland portions of the LA/Ventura Valleys but that's limping along due to the absence of winds aloft. Will be canceling those for today, though high res models do show a slight increase in winds Fri/Sat as offshore gradients trend stronger in response to pressure rises across the Great Basin. As a result there may be a need to re-issue some advisories tomorrow.
***From Previous Discussion***
A 589 dam upper high is parked over Redding CA. 585 dam hgts cross over SBA/VTA/LA counties. The high will weaken over the next few days and hgts will decrease to 579 dam by Saturday. At the sfc there will be between 3 and 5 mb of offshore flow through the period.
Skies today will be clear, but satellite shows low clouds gathering the west across the outer waters. The decreasing hgts and not too strong offshore push will likely allow some low clouds to develop and move into western SBA county and the Long Beach Torrance area on Friday morning. There is substantial disagreement with the low cloud forecast on Saturday. The slim majority of the ensembles bring low clouds to most of the coasts, but a substantial amount keep enough offshore winds in the area to limit the low clouds to Friday morning's locations and nothing more.
Low end wind advisories are in place for the Santa Ana Wind Corridor through Friday afternoon, but currently the winds are under performing. The winds will increase during the usual 700am to 1000am peak, but there is a chc that they will still not reach advisory levels. Mdls show an uptick in winds compared to today for Friday morning. Still this portion of the advisory will need to be evaluated after today's peak ends. There is not that much difference in the synoptic parameters from today to tomorrow.
The falling hgts and somewhat weaker offshore flow will bring a very slight cooling trend of 1-2 degree/day (some sites will see no change on any of the 3 days) to the area starting today. Max temps will fall from the upper 70s to mid 80s today to the mid 70s to lower 80s by Saturday. Max temps will mostly be 8 to 12 degrees above normal through the period.
(Sun-Wed), 15/1225 AM.
Offshore flow and weak ridging will continue over the state through the xtnd period, although by Wednesday some changes begin to occur. The offshore push should not be powerful enough to keep marine layer stratus away from the coasts where it might generate some dense fog later at night through the early morning. The weakening offshore flow and lowering of hgts will contribute to a continuous cool trend with Sunday's max temps across the csts/vlys falling from the 70s to lower 80s to the Mid 60s to lower 70s by Wednesday. Max temps will be near normal by Wednesday.
The GFS deterministic run brings a fully formed 552 dam upper low to the area Friday, while the EC only has dry fast moving NW flow. The AI mdls and ensembles are much less impressive and while there is a high chc of a pattern change - the chc of an actual rain event remains under 40 percent.
15/1155z.
At 10Z over KLAX, there was no marine layer. There was a surface based inversion with a top at 1200 ft and a temperature of 25 C.
High confidence in VFR conditions everywhere through at least this evening. Small chances of IFR or lower conditions at immediate coast Friday morning.
At KVNY KCMA KOXR, there is a moderate risk of gusts 20-30 knots and/or LLWS 10-20 knots. Lower than normal confidence however. High confidence in relatively light winds (under 15 knots) at all other airports.
KLAX, High confidence in VFR through at least Friday, and any east wind component will be 6 knots or less.
KBUR, High confidence in VFR through at least Friday. Less than 20% chance of NE winds 15+ knots surfacing, but LLWS 10-15 knots likely at times.
15/153 AM.
Low confidence on winds from Ventura through Santa Monica from now through Friday. Computer projections continue to show much stronger NE winds compared to what is being observed. As such, winds could be 10 to 15 knots at their peak or 15 to 25 knots. Kept the Small Craft Advisory (SCA) going but delayed it for a few hours, but the likelihood of it needed to be all together cancelled is growing. Otherwise and elsewhere, high confidence in relatively light winds through the weekend.
A long period west to northwest swell is filling in the region, but wave heights will stay under 8 feet through the weekend and into next week.
Ca, None. PZ, Small Craft Advisory in effect until 3 PM PST this afternoon for zone 650. (See LAXMWWLOX).
