11/243 AM.
A cooling trend will affect the region through the weekend with max temps dropping to below normal by Sunday. The sticky tropical air will finally exit the region by this weekend. Marine layer clouds will likely return to many coastal areas.
(tdy-Sun), 11/243 AM.
Heat advisories are in effect today for the coastal areas south of Pt Conception as very warm overnight lows will combine with todays highs which are 5 to 10 degrees over normal.
The ridge that brought the very high hgts will flatten out and hgts will fall to a about 588 dam. At the sfc there will be weak to moderate onshore flow in the E/W direction. The N/S gradients will feature weak offshore flow in the mornings and weak onshore flow in the afternoons.
This will kick off a three day cooling trend with most max temps falling 4 to 8 degrees today, 3 to 6 degrees Saturday and 2 to 4 degrees Sunday. By Sunday Max temps will mostly be in the upper 70s to 80s across all of the csts/vlys or 3 to 6 degrees blo normal.
The marine cloud layer is advancing down the coast and there are signs of an eddy. Marine layer stratus will slowly increase in coverage through the period, although the very warm sea sfc temps will have an inhibiting effect.
The real good news is the the humidities will fall back to normal. PWs over srn LA county ydy were near 1.70" and will fall to 1.3" today and then to .85" Saturday.
The decrease in available mositure will eliminate the threat of afternoon convection.
Not much in the way of winds through the short term. Just the typical gusty west afternoon winds in the Antelope Vly and the evening Sundowners west of Isla Vista on the SBA south coast.
(Mon-Thu), 11/242 AM.
Not much change through Wednesday, with zonal flow continuing at the upper levels. Temperatures will remain below seasonal normals. Weak to moderate onshore flow will continue with light northerly offshore flow each night through morning. There will likely be some morning low clouds each day with the greatest coverage across the Central Coast. Skies, otherwise, will be mostly clear.
A good degree of mdl confusion creeps into the forecast later Wednesday into Thursday as the mdls struggle with the handling of some energy coming out of British Columbia. The sfc pattern is also in question as there is wide assortment of possible values ranging from 1mb onshore to 6.5 mb onshore. A broad sampling of all of the mdls results in a forecast of 2 to 3 degrees of warming, but this is a low confidence fcst.
No significant wind issues are expected, although there will be the usual gusty southwesterly winds each afternoon across the mountains and deserts and the typical near advisory level evening gusts across the SW corner of SBA county.
11/0945z.
At 0841Z at KLAX, the marine layer was 700 ft deep. The top of the inversion was at 3100 ft with a temperature of 28 C.
High confidence in VFR conditions for all inland sites.
Low confidence in TAFs for KSMX and KSBP where there is a 30-40 percent chc of LIFR conds 11Z-16Z. Moderate confidence in TAFS for KLAX, KSMO and KLGB where there is 30 percent chc of IFR cigs 12Z-16Z. Fair confidence in TAFs for KSBA and KCMA with a 15 percent chc of IFR cigs 12Z-16Z.
KLAX, Moderate confidence in TAF. There is a 30% chance of BKN008 conds 12Z-16Z. There is a 30% chance of an 8kt east wind component thru 16Z.
KBUR, High confidence in TAF.
11/243 AM.
Conditions are expected to become increasingly hazardous across the outer waters into the weekend. A Gale Watch (50-60% chc) has been issued for PZZ676/673 Saturday evening into Monday morning. The coastal Jet may develop across PZZ670 Saturday evening causing winds to increase there as well, but confidence in winds reaching Gale force is low at this time. Otherwise, SCA winds are expected across the outer waters through Saturday afternoon or longer. Small Craft Advisory (SCA) conditions are expected to reach into the nearshore waters along the Central Coast and the Santa Barbara Channel at times (especially during afternoon/eve hours) through early next week.
Ca, Heat Advisory in effect until 6 PM PDT this evening for zones 349-350-354-355-362-366>368. (See LAXNPWLOX). Wind Advisory in effect until 6 AM PDT early this morning for zones 349-351. (See LAXNPWLOX). PZ, Small Craft Advisory in effect from 3 PM this afternoon to 9 PM PDT this evening for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT early this morning for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM this afternoon to 3 AM PDT Saturday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 9 AM PDT Monday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect until 6 PM PDT Saturday for zones 673-676. (See LAXMWWLOX). Gale Watch in effect from Saturday evening through Monday morning for zones 673-676. (See LAXMWWLOX).
