August 22, 2017
66.7 °F
Dew Pt.
58.9 °F
1014.5 hPa 
0.0 mph 
0.00 in 
  0.00 in/hr
UV index
Solar rad.
100 W/m²

Tonight: Mostly clear, with a low around 65. Calm wind.
Mostly Clear

Tuesday: Sunny, with a high near 93. Light and variable wind becoming southwest 5 to 10 mph in the afternoon.
Lo 65 °F Hi 93 °F
FXUS66 KLOX 220627

1127 PM PDT Mon Aug 21 2017


A weak upper low just west of Point Conception will maintain
overnight low clouds and fog, along with cooler than normal
temperatures through late in the week. As the upper low moves
inland...a warming trend is expected starting Friday, with
significant warming possible over the weekend.



The marine layer has shrunk to about 1100 feet and the capping
inversion is quite weak. There are 2 MB offshore trends both from
the north and the east. There are no low clouds anywhere near
coasts. All of the latest mdl guidance shows very little in the
way of low clouds for Tuesday morning. Will not buy fully into
this idea but did take low clouds out of all areas this evening
and totally removed them from the vlys and the SBA south coast.

Coastal max temps were a little warmer than fcst today and with
a weaker marine layer expect a little more warming tomorrow. The
forecast has been updated to reflect these warmer temps and
clearer skies.



Between the reduced marine lyr and another 1-2mb of offshore
trends most areas should see a few degrees of warming Tuesday,
especially the coasts and valleys.

A slight onshore trend Wednesday and Thursday may bring a degree
or two of cooling to coast and coastal valleys Wednesday but
otherwise very little change. Low clouds will continue to push
into the valleys overnight and clear to around the coast or just
offshore during the afternoon. Monsoon moisture will remain well
to the east so no convection expected.


Friday will be the beginning of what appears to be a significant
warming trend that will last at least through the middle of next
week. Friday and Saturday will just be a couple degrees warmer
with still some decent onshore flow in place and low clouds
likely still reaching the coastal valleys overnight. By Sunday,
however, high pressure is expected to strengthen from the
southeast and onshore flow will be weakening quite a bit. Highs
expected to reach the triple digits in the warmer valleys Sunday
and even warmer Monday. And by next Tue or Wed we could be looking
at some weak offshore flow in the morning and highs into the 90s
for some coastal areas and well over 100 for the valleys. The door
is open for monsoon moisture but models still not showing
anything moving into our area at least through early next week.



At 05Z, the marine layer depth was around 1000 feet deep at KLAX.
The top of the marine inversion was around 2150 feet with a
temperature near 22 degrees Celsius.

Moderate confidence in the current forecast. IFR to MVFR
conditions will likely develop at coastal and valleys, with the
highest confidence for coastal terminals. There is a chance of
LIFR conditions at terminals north of Point Conception between 10Z
and 16Z. VFR conditions are expected to redevelop between 16Z and

KLAX...There is a 80 percent chance of IFR to MVFR conditions
between 08Z and 18Z.

KBUR...There is a 60 percent chance of IFR to MVFR conditions
between 11Z and 16Z.


.MARINE...21/815 PM

Outer Waters, Good confidence through Wednesday afternoon then moderate
confidence. Through Wednesday, winds and seas will remain below
Small Craft Advisory (SCA) levels. For Wednesday night, there is a
60 percent chance of SCA level winds developing. For Thursday and
Friday, the winds will likely remain at SCA level and northwest
to west swell will build to 6-7 ft.

Inner Waters, high confidence in current forecast. For the waters
north of Point Sal, winds and seas will remain below SCA levels
through Wednesday. From Wednesday night through Friday, SCA level
winds will be possible mainly in the afternoon and evening. For
the waters south of Point Conception, winds and seas will remain
below SCA levels.




A significant heatwave could develop this upcoming weekend and
continue into early next week.




NWS LOX Office Area Forecast Discussion