13/214 PM.
Dense fog to return this evening along the coasts and some valleys lasting through Sunday morning. Temperatures will trend warmer Sunday through Tuesday, then will cool each day thereafter. Low chance for light rain across northern areas next weekend. Followed by a chance for widespread rain during Christmas week.
(tdy-Tue), 13/216 PM.
Satellite imagery shows low clouds situated along virtually the entire coastline early this afternoon. Fog (patchy dense) is expected to move inland by this evening. It is expected to return to the same areas as this morning, maybe slightly less inland. Therefore Dense Fog advisories will likely be issued for similar areas lasting thru Sunday morning. Mist & drizzle may accumulate a few hundredths of an inch where fog occurs.
An east-based Aleutian low will amplify with several vorticity maximums rounding the base. Downstream implications such as PVA and WAA will result in the re- amplification of the ridge over our area on Monday and Tuesday.
Max Temperatures are expected to warm 3 to 6 degrees for coasts and valleys south of Point Conception and 4 to 8 degrees along the Central coast on Monday. Interior areas should remain similar to Sunday. Tuesday's Maximum Ts should be similar to Monday, except across Antelope Valley and adjacent foothills (2 to 4 degrees warmer).
During this period, coasts will average 5 to 10 degrees above normal and inland areas 10-20 degrees above normal. Our current forecast numbers show that Woodlands Hills may near 90 degrees on Monday which would certainly break the daily record set not too long ago (2017). Even on Sunday there is a chance we break the old record of 83 set back in 2004. A handful of sites look to flirt with daily records as well.
Offshore flow looks weaker than this past week, and with a lack of sufficient mid-upper level support, wind advisories appear to be unlikely at this time. At the very least, overnight lows will remain warmer as offshore flow from the north and east continues.
(Wed-Sat), 13/216 PM.
Offshore flow is generally expected through Thursday. LAX-DAG gradient may approach neutral Wednesday morning indicated by ECWMF guidance. By Friday, GEFS/EC are in agreement with onshore trends. However, there is a handful of ensemble members that remain neutral or even slightly negative.
Above normal temperatures are expected to continue through the week despite slight cooling each day through Saturday. Exception will be only the coast where Max Ts may cool to near normal Friday or Saturday depending on how quickly gradients trend onshore. Dense Fog will return whenever this occurs. Max Ts will be in the 60s to low 70s by Saturday.
The latest CPC 8-14 day precipitation outlook is showing “likely above normal” precipitation across the region. There is a small indication that there may be an "appetizer" for northern areas over the weekend, but solutions remain light. The biggest story is Christmas week where Santa may bring presents in the liquid form. The ensemble suites of GFS, EC, and EC-AI are pretty adamant for widespread rain with a "sweet spot": 23rd through the 26th with lingering chances into the following weekend. High uncertainty in timing and amounts at this time.
13/1807z.
At 1815Z at KLAX, the marine layer was 700 feet deep. The top of the inversion was 2800 feet with a temperatures of 21 degrees Celsius.
For 18Z TAF package, high confidence in valley and desert TAFs. Low to moderate confidence for coastal sites due to uncertainties in timing of flight category changes which could be +/- 3 hours of current forecasts.
KLAX, Low to moderate confidence in 18Z TAF. Timing of flight category changes could be +/- 3 hours of current forecasts. There is a 60% chance of VV001 with 1/4sm FG after 08z. 30% chance as early as 04z. No significant easterly wind component is expected.
KBUR, High confidence in 18Z TAF.
13/959 AM.
For the Outer Waters, moderate to high confidence in current forecast. Today through Sunday, high confidence in winds and seas remaining below Small Craft Advisory (SCA) levels. For Monday through Wednesday, there is a 50-70% chance of SCA level winds, especially from Point Conception southward.
For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. Today through Tuesday, high confidence in winds and seas remaining below SCA levels. On Wednesday, there is a 30% 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. Today through Monday, high confidence in winds and seas remaining below SCA levels. For Tuesday and Wednesday, there is a 30-40% chance of SCA level winds across the western half of the Santa Barbara Channel with high confidence in winds and seas remaining below SCA levels elsewhere.
Areas of dense fog with very low visibility will affect much of the coastal waters today through Sunday. The best chances for dense fog will be from the overnight through morning hours with scattered pockets likely through the afternoon and evening.
Ca, NONE. PZ, NONE.
