13/108 PM.
A warming trend early this week will give way to dangerous heat by mid week. A few showers and thunderstorms could impact interior areas during the afternoon hours through Tuesday. Gusty northwest to north winds will impact southern Santa Barbara County to the Interstate 5 Corridor during the afternoon through overnight hours Tuesday and especially Wednesday. Cooler weather is expected Friday and through the weekend.
(tdy-Thu), 13/159 PM.
Another warm and muggy day across the area with monsoon moisture continuing to move into the area from the southeast. So far as of 1pm thunderstorms have not developed as cloud cover has likely interfered with the convective processes and kept temperatures down by at least 20% of their full potential. Satellite imagery is showing some clearing to the south so there is still at least a slight chance of late afternoon showers and thunderstorms, the best chances still being in the mountains.
The rest of the forecast remains in tact. Monsoon moisture is expected to decrease Tuesday leading to much more sunshine which will allow temperatures to reach to near full potential, meaning temps in the mid 90s to 105 in the valleys and mid to upper 80s in the intermediate areas between the coast and valleys (eg. Downtown LA), and mid to upper 70s at the coast. An Extreme Heat Warning will begin Tuesday morning and continue through Thursday evening for most areas away from the immediate coast.
Temperatures with this heat wave will peak on Wednesday as gradients to the east turn lightly offshore, delaying the arrival of sea breeze. Highs on Wednesday are expected to be 3-6 degrees warmer than Tuesday. Can't stress enough the importance of minimizing outdoor activities, particularly between 10am and 7pm when temperatures will be at their highest.
One additional significant weather factor will be the expected development of strong and hot Sundowners across the Santa Ynez Range and down into the foothills and coastal areas of the Santa Barbara County south coast. Winds will start up Tuesday evening but peak Wednesday evening gusting to 35-50 mph with local gusts up to 60 mph possible in the foothills and mountains. Add to that the very hot airmass in place and downsloping effects, temperatures could easily reach the 90s all the way to the coast and possibly around 100-102 in the foothills. A Fire Weather Watch is in effect for all of the Santa Barbara South Coast and Mountains Wednesday into Thursday morning.
2-4 degrees of cooling is expected Thursday but highs will still be 6-12 degrees below normal.
(Fri-Mon), 13/154 PM.
Very gradual lowering of midlevel heights later this week into the weekend, combined with the eventual influx of deep moisture from distant, low-latitude East Pacific storms bringing increasing cloudiness, along with reinforcing onshore flow, will all contribute to temperatures slowly cooling to near-normal readings by next weekend. Hot conditions will still be present on Thursday when heat headlines remain in effect. While a few diurnally enhanced showers cannot be ruled out over the high terrain late this week and into the weekend owing to the increasing moisture, confidence in the development of this activity is too minimal for mention in the forecast at this time. Otherwise, the onshore flow will bring an increase in night through morning patchy low clouds and fog across coastal areas by next weekend.
13/1717z.
At 1630Z at KLAX, the marine layer depth was 700 ft. The top of the inversion was at 2100 ft with a max temperature of 25 C.
Low to Moderate confidence in the TAFs. Patchy low clouds during the night through morning resulting in uncertainty in CIGs for coastal and coastal valley sites. There is a 20-30% chance for thunderstorms at KPMD/KWJF from 13/18Z through 14/00Z. These storms would be capable of producing erratic winds / turbulence and heavy rainfall.
KLAX, Moderate confidence in TAF. Timing of flight cat changes may be off +/- 2 hours. Timing of IFR CIGs near 006 could be off +/- 2 hours, and CIGs may be intermittent when forecasted. No significant east wind component expected.
KBUR, Moderate confidence in TAF. No wind issues expected
13/731 AM.
NW winds are expected to strengthen to Small Craft Advisory (SCA) levels Tuesday afternoon and will continue through Thursday night across the Outer Waters. There is also 20% chance of Gales later Wednesday into Thursday. Seas are forecast to build over 10 feet in conjunction with these winds. The elevated winds and seas will extend into the western Santa Barbara Channel and nearshore waters along the Central coast at times through this period. While a few showers may drift across the local waters through early parts of this week, thunderstorms are unlikely.
13/1017 AM.
Dangerous rip currents and breaking waves with elevated surf are expected for coastal areas and the beaches of Los Angeles, Ventura, Santa Barbara, and San Luis Obispo Counties, as enhanced southerly swell continues. A Beach Hazards Statement remains in effect through Wednesday evening for these areas. Minor coastal flooding will be possible during the evenings, given abnormally high tides of 7.0 to 7.6 feet. Later this week and into the weekend, distant storms over the East Pacific waters well south of the area could produce increasing southerly swell resulting in even more significant beach hazards by the weekend.
Ca, Heat Advisory remains in effect until 10 AM PDT Tuesday for zones 38-88-343>345-353-368-372-373-375>380-548. (See LAXNPWLOX). Extreme Heat Warning in effect from 10 AM Tuesday to 8 PM PDT Thursday for zones 38-88-349>353-356>358-368>375-378>383-548. (See LAXNPWLOX). Heat Advisory in effect from 10 AM Tuesday to 8 PM PDT Thursday for zones 87-341>345-347-348-354-355-362-366-367-376-377-549-550. (See LAXNPWLOX). Beach Hazards Statement in effect through Wednesday evening for zones 340-346-349-350-354-362-366. (See LAXCFWLOX). Fire Weather Watch in effect from Wednesday afternoon through Thursday morning for zones 349>353-376>378. (See LAXRFWLOX). PZ, Small Craft Advisory in effect from noon Tuesday to 3 AM PDT Friday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM Tuesday to 3 AM PDT Friday for zone 673. (See LAXMWWLOX). Small Craft Advisory in effect from 6 PM Tuesday to 3 AM PDT Friday for zone 676. (See LAXMWWLOX).
