29/1226 PM.
Dry and warmer weather is expected into next week, but a return of low clouds and fog will moderate coastal temperatures. Sunday and Monday will likely be the warmest with highs 5 to 10 degrees above normal. Locally gusty north winds over the weekend.
(Fri-Mon), 29/753 PM.
Latest satellite and surface observations indicate clear skies across the region this evening. West to northwest winds, gusting 25-40 MPH, are continuing across the Antelope Valley, Central Coast and the Santa Ynez Range.
Forecast-wise for the immediate short term, no significant issues are expected. Overnight, the northwesterly winds will continue to decrease. Overnight, marine layer stratus/fog is expected to develop across most of the coastal plain as well as the Salinas River Valley. However, confidence in the areal extent of the stratus development is moderate at best. Other than any stratus, skies will be mostly clear overnight.
For Saturday through Monday, latest models do not indicate anything to deviate from current forecast. At upper levels, a rather non-descript ridge will "build" over the area. Through Monday, H5 heights will gradually increase from day-to-day. At the surface, moderate onshore gradients will continue to the east with an increase in northwesterly offshore gradients. With this pattern, skies will remain mostly clear except for some night and morning stratus/fog across the coastal plain. Temperatures will be on the increase through Sunday with near persistence temperatures on Monday. By Sunday and Monday, coastal areas will have highs generally in the 70s while 80s to mid 90s temperatures can be expected from the valleys eastward. Based on current Heat Risk numbers, do not anticipate any significant heat issues through the period.
One thing to watch through the weekend will be northerly winds. As the northwesterly offshore pressure gradients increase, northerly winds will increase across the usual areas (Central Coast, Santa Ynez Range and the I-5 Corridor). At this time, there looks to be a chance of advisory-level northerly winds this weekend, mainly across the western half of the Santa Ynez Range. This will need to be monitored closely.
(Tue-Fri), 29/132 PM.
While heights will continue to rise through Tuesday, most of the models solutions show a baggy trough continuing along the West coast, maintaining light to moderate onshore flow and keeping highs withing a few degrees of normal. There is a very small percentage solutions that swing gradients back to lightly offshore by Wednesday which would result in additional warming. And some warming is still the likely outcome for far interior areas which tend to mirror the height trends more than the gradients. But for coast and valleys the most likely outcome is slight cooling, but highs still within a few degrees of normal. There also will likely still be a marine layer for most coast and valley areas, which is typical for this time of year.
For the rest of the week just minimal day to day changes with dry weather and temperatures near normal. However, ensemble gradients are favoring an increase in onshore flow Thursday and Friday which would favor at least a minor cooling at least for coast and valleys, though 500 and 850mb heights are trending up slightly which would suggest either little change or slight warming for interior areas.
29/2241z.
At 2230Z at KLAX, there was no marine layer or inversion, but there was a moist layer up to 5500 feet.
Overall for the 00Z TAF package, high confidence in KWJF and KPMD. For all other sites, moderate confidence in TAF forecasts due to uncertainties with behavior of marine layer. Timing of flight category changes could be +/- 4 hours of current forecast. For KSBA, KCMA, KBUR and KVNY, there is a 30-40% chance of CIG/VSBY restrictions in the 10Z-17Z time frame.
KLAX, Moderate confidence in 00Z TAF. Timing of flight category changes could be +/- 3 hours of current forecasts. There is a 20% chance that CIG/VSBY restrictions do not develop overnight. Any easterly wind component overnight is expected to remain at 5 knots or less.
KBUR, Moderate confidence in 00Z TAF. There is a 30-40% chance of CIG/VSBY restrictions in the 10Z-16Z time frame.
29/753 PM.
For the Outer Waters, moderate to high confidence in current forecast. Tonight through Monday morning, high confidence in a combination of Small Craft Advisory (SCA) level winds and seas. From Monday afternoon through Wednesday, the combination of SCA level winds and seas is expected to continue. On Saturday night, there is a 30-4% chance of Gale force winds and again on Wednesday night.
For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. Tonight through Sunday night, high confidence in SCA level winds during the afternoon and evening hours. For Monday through Wednesday, there is a 40-50% chance of SCA level winds in the afternoon and evening hours.
For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. Tonight through Sunday night, there is a 60-80%chance of SCA level winds across the western half of the Santa Barbara Channel during the late afternoon through evening hours with winds and seas remaining below SCA levels elsewhere. For Monday through Wednesday, high confidence in winds and seas remaining below SCA levels.
Ca, NONE. PZ, Small Craft Advisory in effect until 3 AM PDT Saturday for zones 645-650. (See LAXMWWLOX). Small Craft Advisory in effect until 9 AM PDT Monday for zones 670-673-676. (See LAXMWWLOX).
