Area Forecast Discussion
Issued by NWS Los Angeles, CA
FXUS66 KLOX 071716
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
916 AM PST Wed Dec 7 2016
It will be breezy across Ventura and Los Angeles Counties today
with slightly warmer temperatures across the region. There is a
chance of precipitation late tonight through Saturday, mainly
north of Point Conception. Temperatures will be warmer next week.
Not much change with the morning update. Just updated the sky
cover forecast for today based on current satellite imagery.
Mostly cloudy skies for southern SBA County and points south will
give way to partly cloudy skies, at least for a short while today,
before another mass of mid and high level clouds moves in from the
NW later today. North of Point Conception, skies will be mostly
sunny to partly cloudy this morning, then clouds will quickly move
in by late morning or early afternoon.
We are seeing some light NE winds across the region, but the
offshore flow is weaker than models were suggesting the last few
days. NE winds in the mountains will be gusting 20-30 mph, with
even NE lighter winds for the coastal and valley areas of Ventura
and LA counties. High temperatures today will generally be in the
low to mid 60s for coastal/valley areas, with cooler conditions
Main forecast concern for today will be taking a closer look at
the rain potential late tonight into the weekend. A quick look
this morning suggests that rain is still very unlikely south of
Pt. Conception, but may have to increase PoPs north of Pt.
***FROM PREVIOUS DISCUSSION***
Pretty much no change on Thursday south of Point Conception. The
NW flow will continue to bring partly to mostly cloudy skies to
the area. The Max temps will be around 65 degrees. North of Point
Conception there will be more clouds and a chance of rain will
develop as a weak impulse moves through the NW flow. The NW tip of
SLO county will likely see rain but there will be steep pop
gradient from there to Lompoc which will only have a slight chc of
measurable rain. (side note: if it rains but it rains less than a
hundredth of an inch it didn`t rain in so far as POPs go) As is
often the case the extreme NW tip of SLO county will see much more
rainfall than anywhere else. While a third of an inch is possible
for the NW tip all other areas will likely see less than a tenth
of an inch (or nothing at all). All of the clouds and lower hgts
will knock a few degrees off of todays max temps readings and most
areas across the Central Coast will see max temps in the lower
Friday will be very similar to Thursday except that the best chc
of rain will no longer be confined to the SLO county coast. While
rain will remain likely over the SLO county coast a chance of rain
will overspread the rest of SLO county and most of SBA
county...excluding the SBA south coast. The only change south of
Point Conception will be the addition of a chance of rain over the
VTA mtns esp the NW corner.
Not to sound too repetitive but the NW flow will continue
unabated through Saturday night. There will be little to no
change in the conditions that occurred Thu or Fri.
Rainfall totals Thursday through Saturday night could be fairly
significant as the small 6 hourly amounts might add up to a decent
number. The NW tip of SLO county may well see an inch plus of
rain. San Luis Obispo might see a little more than a half inch and
the Santa Maria area about a third.
On Sunday the NW flow turns just a little anti cyclonic and no
more trofs are forecast to move through it. There will still be
plenty of mid and high level clouds around but the rain chc will
end and max temps will nose up a degree or two.
Weak ridging will push in Monday and last into Tuesday. The rain
will end and skies will begin to clear. Max temps will rise to a
few degrees above normal with a return to the 70s for quite a few
coastal and vly locations.
At 1045Z...there was a 4000 foot deep moist layer.
Overall, moderate confidence in 12Z TAFs. Weak offshore flow is
expected this morning which could produce some weak LLWS across
the valleys and mountains. Generally VFR conditions will be
anticipated through the TAF period although some MVFR ceilings
will continue over the LAX coast (especially around KLGB). A weak
frontal system may bring some light showers to San Luis Obispo
county this evening and overnight.
KLAX...moderate confidence in 12Z TAF. There is a 30% chance of
MVFR ceilings 12Z-18Z.
KBUR...high confidence in 12Z TAF as VFR conditions are
anticipated. There is a chance of light LLWS 12Z-18Z.
Significant NE Santa Ana winds are no longer expected today near
the coast. High confidence in winds staying below Small Craft
Advisory (SCA) levels everywhere through Friday morning, except
for SCA South winds likely beyond 10 miles off the Central Coast
tonight into Thursday...and possibly again on Friday. More
widespread SCA level northwest winds are likely Friday night and
Saturday, possibly affecting the western portions of the inner
waters including the Santa Barbara Channel and the Santa Monica
Basin. Expect increasingly choppy/steep seas as well.
PZ...Small Craft Advisory in effect from 9 PM this evening to 3 PM
PST Thursday for zone 670. (See LAXMWWLOX).
.HAZARD POTENTIAL OUTLOOK...(FRI-TUE)
Gusty northwest winds could affect Santa Barbara County and
northern Los Angeles County on Saturday or Sunday.