Area Forecast Discussion
Issued by NWS Los Angeles, CA
FXUS66 KLOX 251153
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
453 AM PDT SAT JUN 25 2016
High pressure aloft will continue to build back into the region
this weekend, bringing another round of widespread triple digit
heat to many areas away from the coast Sunday through Tuesday.
Some relief from the heat is expected by the middle of next week
as the high pressure gradually weakens and shifts east into the
four corners region.
The winds are coming in a little weaker than anticipated and the
advisories for the Antelope Vly and the SBA south coast have been
cancelled. The winds are still blowing through the I-5 corridorand
that advisory will continue until 10 am. The weaker winds have
allowed for better marine layer penetration and the vly will wake
up to pretty solid stratus overcast this morning. The vlys will
clear out by mid morning but it may take until early afternoon for
the coasts to clear completely. Temps are the big deal for today
591 DM hgts will combine with offshore flow from the north and
weakening onshore flow to the east today to send max temps away
from the beaches to numbers well above normal. Of special note is
the Santa Clarita Vly where the offshore flow will be
strongest...this should be warmest area away from the deserts
today. The marine layer will keep the coastal temps only a degree
or two above normal.
The marine layer will smoosh tonight as hgts build. The eddy
should be very weak or non existent and these factors will only
allow stratus to develop over the la coast with a little slop over
into the San Gabriel Vly.
Good `n` warm for Sunday and Monday for the Vlys and the interior
sections. Hgts will be 594 DM Sunday and 596 DM Monday. Look for
plenty of triple digit heat in the Vlys and the interior each day.
Monday may be a little more humid which could lead to heat warning Heat
Index values. That will have to be watched. Nearer to the beaches
it will still be warm but much more tolerable...only about 4
degrees above normal.
Overnight lows in areas the 600 to 900 foot elevation levels will
remain very warm since they will be sitting in the teeth of the
Both the GFS and the EC agree that the heat will continue through
Wednesday. The upper high will be centered over eastern NC and 594
DM hgts will continue over the area. The seabreeze will pick up a
little and there will be some slight coastal cooling.
The upper high is now forecast to weaken into a ridge late
Wednesday. This ridge is then forecast to then slide slowly to the
east. No great shakes for the forecast just a cooling trend.
Of note...however...neither mdl now shows the previously four
corners high. So the chc of monsoon flow no looks much less
likely. in fact...the partly cloudy sky wording in the later part
of the fcst now looks overdone.
At 08Z, the marine layer was around 1200 feet deep at KLAX. The
top of the inversion was around 3700 feet with a temperature
around 25 degrees Celsius.
South of Point Conception...IFR to MVFR conditions should spread
into coastal and Los Angeles County Valley terminals through 14Z.
VFR conditions should redevelop between 15Z and 18Z. A later
return of IFR to MVFR conditions is expected tonight.
North of Point Conception...VFR conditions are expected throughout
the period, except for a chance of VLIFR to LIFR conditions at
Central Coast terminals through 14Z at the latest. There is a
chance of LIFR to IFR conditions at Central Coast terminals after
KLAX...MVFR conditions should persist through at least 16Z or as
late as 18Z. There is a 40 percent chance of IFR to MVFR
conditions after 04Z increasing to 80 percent around 09Z.
KBUR...MVFR conditions should persist through 16Z, then VFR
conditions should develop for the remainder of the period.
A Gale Warning will continue for far northern outer waters
through early Sunday. Small craft advisories will also continue
through early Sunday for the remaining portions of the outer
waters as well as the nearshore waters north of Point Conception.
It is likely the Gale Warning will be allowed to expire tonight;
however, periodic small craft conditions are expected throughout
the weekend across the outer waters. Small Craft Advisories will
likely be extended beyond late tonight and into at least Monday
morning. There is a chance that small craft conditions will linger
through much of next week, especially for the Northern Coastal
Waters. Steep short-period seas will likely be prevalent
throughout the period across the outer Coastal Waters.
Patchy dense fog will occur across the Coastal Waters west of Los
Angeles County through this morning...and may linger over the San
Pedro Channel and Santa Monica Bay through the afternoon.
.FIRE WEATHER...24/800 PM.
Red flag warning remains in effect through 10 AM Saturday due to
combination of gusty northwest to north winds and low humidities.
Norhwest to north winds gusting between 40 and 55 mph will impact
portions of the Red Flag Warning area tonight, with the strongest
winds focused across the mountains (especially the I-5 corridor
and Santa Ynez Range), and western portions of the Antelope
Valley. Very dry air is expected to overspread the much of the
mountain areas tonight, with single digits and teens being common
near wind prone areas. The Red Flag Warning conditions for the
Santa Barbara South Coast will be more localized tonight, mainly
focused across the foothills and western portions of the South
The very dry air is expected to linger through Sunday. The winds
will likely diminish Saturday but gusty north winds may redevelop
Saturday evening over the Santa Ynez range.
CA...Beach Hazards Statement in effect through this afternoon For
zones 34-35. (See LAXCFWLOX).
High Surf Advisory in effect until 5 PM PDT this afternoon
For zones 40-41-87. (See LAXCFWLOX).
Wind Advisory in effect until 10 AM PDT this morning For
zones 53-54. (See LAXNPWLOX).
Red Flag Warning in effect until 10 AM PDT this morning For
zones 239-252>254-259. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Sunday For
zones 645-673-676. (See LAXMWWLOX).
Gale Warning in effect until 3 AM PDT Sunday For zone 670. (See LAXMWWLOX).