Rowland Heights, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

109
FXUS66 KLOX 180505
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1005 PM PDT Tue Jun 17 2025

.SYNOPSIS...17/924 PM.

A very warm air mass will remain in place through late week,
especially away from the coast and across the interior portions of
the area. Gusty northerly winds will develop once again tonight
across southern Santa Barbara County and through the Interstate 5
Corridor. A gradual cooling trend will begin Thursday as southwest
flow aloft strengthens and pipes a more maritime air mass into the
region.

&&

.SHORT TERM (TUE-FRI)...17/1004 PM.

The latest water vapor imagery shows an upper-level ridge of high
pressure remaining anchored off the Baja California coast this
evening. An upper-level trough in the Gulf of Alaska can be seen
starting to dig south and starting to phase with another trough
near 30N and 140W. A very warm to hot air mass is likely to linger
into late week away from the coast, but southwest flow aloft will
start to strengthen ahead of the trough and bring stronger
onshore flow to the region through late week. KLAX-KDAG and KSMX-
KBFL surface pressure gradients trend strongly onshore over the
next couple days.

A batch of low clouds can be seen off the Central Coast this
evening, but skies remain clear otherwise. The latest model
solutions continue advertise low clouds and fog making a better
push into the Central Coast and the South Bay and Harbor portions
of Los Angeles County, but the low clouds field south of the area
look pretty absent. A look at the forecast guidance reveals south
to southeasterly winds developing after midnight along the South
Coast of California. The forecast keeps the possibility of an eddy
circulation in play, but there is a moderate chance that low
clouds and fog could be overdone across the Los Angeles coastal
areas. It is possible that the eddy could form too far to the west
to have much of an impact.

Gusty Sundowner winds developed again this evening and a wind
advisory was issued earlier across southern Santa Barbara County.
KSBA-KSMX surface pressure gradients peaked at -5.7 mb an hour ago
and local wind gusts to 60 mph were observed earlier in the
evening. The tight pressure gradient helped to make for a strong
Sundowner winds across southwestern Santa Barbara County and two
wildfires developed between Refugio Beach and Gaviota as brief
critical fire weather conditions developed. There appears to be a
break in the northerly surface pressure gradient for Wednesday
night, but the gradient will start to tighten again for Thursday
night and again Friday night and Saturday night.

The latest NAM-WRF pressure gradients are highlighting Friday
evening with KSBA-KSMX surface pressure gradients honing in on -5
mb. NAM BUFR time height sections introduce stronger winds aloft
at KSBA versus tonight and a broader swath of 40+ knot winds at
Gaviota, all indicative of a strong Sundowner wind event setting
up for Friday night. This will need to watched closely over the
coming days, but a high wind watch may be needed as we get closer.

***From Previous Discussion***

.LONG TERM (SAT-TUE)...17/211 PM.

The trough pattern will continue through the weekend and
potentially through most of next week keeping temperatures on the
cooler side of normal with a healthy dose of a deep marine layer
for coast and valleys. Would not be surprised if some of those
mornings are damp with drizzle. Highs mostly in the 60s and 70s
for beaches and coastal valleys and 80s for the interior valleys.

&&

.AVIATION...18/0122Z.

At 0013Z at KLAX, the marine layer was 960 feet deep. The top of
the inversion was around 2700 feet with a temperature of 27 C.

Low confidence in TAFs for KSMX, KSBP, KLGB. For KSMX, there is a
40% chance for VFR conds to prevail through the period. For KSBP
(30%) and KLGB (40%), there is a chance for IFR/LIFR and IFR/MVFR
conds respectively. Moderate confidence in TAF for KSBA due to a
30% chance north sundowner wind do not surface at KSBA. Moderate
to high confidence in remaining TAFs.

KLAX...Moderate confidence in TAF through 06Z, then moderate
confidence in TAF thereafter. There is a 20% chance for cigs
005-012 and/or vsbys 3SM to 5SM between 10Z and 16Z. Any east
wind component is likely to be less than 6 knots.

KBUR...High confidence in TAF.

&&

.MARINE...17/831 PM.

High confidence in gusty, Small Craft Advisory to Gale force
northwest winds across the Outer Waters and Inner Waters along the
Central coast through the weekend. A Gale Warning is in effect
for the Outer Waters and the Inner Waters along the Central Coast
through tonight. Seas will hover around 10 feet for the outers
waters, increasing to up to 14 feet late this week. Moderate to
high confidence in a return of Gale force winds across the waters
through the weekend, starting as early as Wednesday night for the
northern Outer Waters.

Across the Santa Barbara Channel, widespread Small Craft
conditions are expected with local Gale force winds possible
across the western portion of the zone (away from Santa Barbara,
Ventura, and Channel Islands Harbors) through tonight. After a
lull Wednesday, a return of SCA level winds is likely Thursday
through the weekend, potentially impacting immediate coastlines
this weekend. Gale force gusts are possible in the western portion
of the zone Friday and Saturday.

High confidence in conditions remaining below advisory levels in
the Inner Waters off the Los Angeles and Orange County coasts
through Wednesday. Low confidence in forecast for Thursday into
the weekend as winds could increase to SCA levels but may be
confined to the western portion of the zone away from the
immediate coasts.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory remains in effect until 3 AM PDT Wednesday for
      zones 349-351. (See LAXNPWLOX).
     Wind Advisory in effect until 3 AM PDT Wednesday for zones
      350-352. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zones 645-650. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Wednesday for zones
      670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Hall/MW
AVIATION...Phillips/Lewis
MARINE...Phillips/Lewis
SYNOPSIS...Hall

weather.gov/losangeles

Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox