21/944 AM.
Hotter than normal conditions will dominate the foreseeable future. The hot daytime and warm night conditions will bring elevated risks for heat illness. Thursday through Sunday will generally be the hottest of the next seven days. Gusty north winds expected Wednesday through Friday.
(tdy-Thu), 21/948 AM.
***UPDATE***
The forecast is generally on track. Increased temperatures on the Central Coast for today, as the lack of a marine layer and tropical airmass is currently trending temperatures 10 to 15 degrees up from 24 hours ago. Elsewhere, temperatures will be around normal for today. Should see some afternoon cloud buildups in the mountains, but the chance for any showers or thunderstorms is under 10 percent. Will make a few changes in the next couple of hours on the current suite of Heat Advisories and Watches. The timing remains on track, and will likely lean more into Heat Advisories than Warnings.
***From Previous Discussion***
Heat is going to be major and only talking point through the short and long term. The primary driver of the heat will be a very warm upper high centered over nrn Texas whose western extent pushes over the state with 594 dam hgts. At the sfc - mdt to stg onshore flow to the east will weaken to lgt to mdt by Thu. There will be weak onshore flow to the north today but it will be turning offshore perhaps by Wednesday, but definitely by Thursday.
Mid level clouds and moisture from Elida have disrupted the marine layer and most areas should be low cloud free this morning. Max temps will rise 1 or 2 degrees today and will end up 2 to 4 degrees above normal except on the Central Coast where max temps in the upper 70s to mid 80s will be about 6 degrees over normals.
The heat kicks into gear on Wednesday as the weakening onshore trends begin. Mdls still show a high probability of a coastal marine layer stratus pattern, but given the lack of low clouds this morning and no real sign of an eddy would not be surprised to see much less in the way of low clouds. Whatever low cloud there will be they will be gone by mid morning. Look for 1 to 2 degrees of warming across the csts with 3 to 6 degrees elsewhere. Heat Advisories start at 1000 am for much of non coastal areas. Extreme Heat Watches them begin in the evening.
Please see the product LAXNPWLOX for all of the heat details and timing information.
Above normal nearshore sea sfc temps and higher than normal PWATs from the two tropical systems passing to the west will keep humidities elevated which will keep overnight lows uncomfortably warm.
Another 2 to 3 degrees of warming on Thursday will bring max temps in the upper 70s to the beaches; 80s and lower 90s to the rest of the csts; 90 to 101 degrees in the vlys except for the western San Fernando Vly where temps will reach up to 106 degrees; the lower mtn elevations and far interior sections will experience highs 100 to 107 degrees.
Gusty Sundowner winds are expected across southern Santa Barbara County each evening. These downsloping winds will bring very warm evening temps and overnights to portions of the SBA south coast extending to the beaches at times.
Due to this stretch of heat and humidity, It's strongly recommended that outdoor activities are confined to the early morning and evening hours.
(Fri-Mon), 21/213 AM.
The upper high migrates westward starting Friday and sets up shop over the 4 corners region. Hgts will increase a few more mb. Offshore flow will continue from the north while onshore flow will persist to the east. Unsure how much stratus there will be each morning if there is any it will be confined to the nearshore area as the higher than normal hgts will keep any marine layer smooshed to under 900 ft. Mdl consensus shows cooling on Friday although there are not many synoptic signals for cooling and would not be too surprised if the cooling is less than fcst.
In general there will be little day to day change. Humidities will continue to be above normal. Max temps will change little day to day. Overnight lows will also continue to be above normal and humid to boot. Heat advisories will likely continue through the period. Citizens need to prepare for a long duration heat wave.
Since the upper high will be in the 4 corners area there will be a non zero chc of monsoon convection. Right now there is mdl indication of convection but that can change and will be watched.
21/1802z.
Around 18Z at KLAX, the marine layer was 1800 ft deep. The top of the inversion was at 3500 ft with a max temperature of 22 C.
High confidence in VFR TAFs for KPMD, KWJF, and KPRB. There is a 10 percent chance of LIFR-IFR conds at KPRB 08Z-17Z Wed.
High confidence in the remaining TAFs through 03Z, then low to moderate confidence. There is a 30 percent chance of IFR/LIFR cig/vis 04Z-18Z Wed for the coastal TAFs, and a 20 percent chance 10Z-15Z Wed for KBUR and KVNY.
KLAX, High confidence through 06Z, then low to moderate confidence in TAF. There is a 30 percent chance of 2SM OVC005 conds 07Z-18Z Wed. No significant east wind component expected.
KBUR, High confidence through 09Z, then moderate confidence in TAF. There is a 20 percent chance of 2SM OVC005 conds 07Z-18Z Wed.
21/834 AM.
Conditions are generally expected to remain below Small Craft Advisory (SCA) levels through this morning. Northwest winds will strengthen, rising to SCA levels by the afternoon, and will likely continue through the rest of the week and into the weekend. Chances also increase for SCA level west to northwest winds across the western half of the Santa Barbara Channel each afternoon and evening during the same time.
A series of moderate period southerly swells will move through the waters through the week and likely beyond, along with a long period southern hemisphere swell arriving late this week. These swells may impact south facing harbors, including the Port San Luis area.
21/852 AM.
Over the eastern Pacific, the remnants of Tropical Storm Elida are forecast to continue moving north-northwest well off the California Coast. In addition, Hurricane Fausto, located 700 NM SW of southern Baja, will move WNW between 15 to 20 N latitude through the next 5 days or longer. This system will produce additional, moderate period southerly swell that will begin to move into the waters late tonight, but not expecting this swell to be too impactful to the beaches. Therefore, High Surf Advisories and Beach Hazards Statements are in effect through Tuesday night.
Finally, an incoming long period, southern hemisphere swell arriving later this week/Thursday night will contribute to continued and potentially more hazardous beach conditions late this week and next weekend. Additional High Surf Advisories and/or Beach Hazards Statements will likely be needed during this time.
Looking beyond the forecast period, a series of tropical systems are forecast to develop off the coast of Mexico and move to the northwest, likely producing multiple rounds of southerly swells over the next couple of weeks.
Ca, Heat Advisory remains in effect from 10 AM Wednesday to 8 PM PDT Monday for zones 38-348-351>353-368. (See LAXNPWLOX). High Surf Advisory in effect until 11 PM PDT this evening for zones 87-354-362-366. (See LAXCFWLOX). Heat Advisory remains in effect from 10 AM to 8 PM PDT Wednesday for zones 88-356>358-369>382-548. (See LAXNPWLOX). Extreme Heat Watch in effect from Wednesday evening through Monday evening for zones 88-356>358-369>382-548. (See LAXNPWLOX). Beach Hazards Statement in effect until 5 PM PDT this afternoon for zones 340-346. (See LAXCFWLOX). Heat Advisory in effect from 10 AM Wednesday to 8 PM PDT Monday for zones 342>345. (See LAXNPWLOX). Heat Advisory remains in effect from 10 AM Wednesday to 8 PM PDT Thursday for zones 349-350. (See LAXNPWLOX). Extreme Heat Warning in effect from 10 AM Thursday to 8 PM PDT Monday for zone 383. (See LAXNPWLOX). PZ, Small Craft Advisory in effect until 3 AM PDT Wednesday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Thursday for zones 673-676. (See LAXMWWLOX).
