La Habra, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

594
FXUS66 KSGX 220501
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
901 PM PST Thu Nov 21 2024

.SYNOPSIS...
Warm and dry weather will continue through Friday. An atmospheric
river associated with a Pacific storm impacting northern
California will slide south and arrive Saturday but weaken
considerably. A second surge of moisture will develop over the
eastern Pacific associated with the upper trough in place and
bring additional precipitation Sunday night through Tuesday night.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

Clear skies over the region but some marine low clouds are
expected in patches near the San Diego coast late tonight. A warm
day away from the beaches. Air mass 15 to 17C at 850 mb level
after the recent weak Santa Ana winds and result of upper ridging
ahead of the large storm in the east Pacific producing large
rainfall amounts in Norcal, which continues. Similar weather on
Friday, warm and dry, though we start to cool further on the
coast.

The second Norcal atmospheric river is forecast to slide across
Socal on Saturday, but weakening wind speeds and moisture
transport since the energy, and cold air for instability from the
Pacific storm stays to the north and offshore. This will result
in light stratiform precipitation late Saturday into Sunday
morning and tapering off on Sunday, with main orographic enhanced
on the front south facing slopes of the San Bernardino mountains.

A second wave from the main Pacific upper low pulls another
atmospheric river surge into Socal for Sunday and Monday. This has
little better potential especially for San Bernardino mountains.
This west to east surge of moisture is slow to exit on Tuesday and
may linger into Wednesday, though providing light rain south of
San Bernardino mountains. Overall light rain from 3 periods of
precipitation and high snow levels indwell above 8500 feet
finally come down by late Tuesday with the upper trough and colder
air dropping into Socal, but possibly not lower than 7000 feet
MSL by Tuesday night and Wednesday morning with the remnant and
weakening upper low passing over Central California.


&&

.AVIATION...
220430Z...Coasts...Mostly clear skies prevails, but patchy coastal
low clouds (likely based around 700-900ft MSL) are expected to
develop early Friday morning around 10-12z. KSNA has the best
chances for CIGs after 12z (65-70%), with about a 50% chance for
CIGs at KSAN, and only 35-40% chance for KCRQ. The clouds will still
be somewhat patchy, and CIGs could come and go at times. Widespread
VIS restrictions aren`t expected, though intermittent VIS less than
3SM is possible where clouds intersect coastal mesas and higher
terrain. Any clouds look to scatter out offshore around 17-18z,
giving way to mostly clear skies. Low clouds should push back ashore
Friday evening around 00-03z, with likely higher bases and more
inland extent.

Valleys/Mountains/Deserts...Mostly clear skies, relatively light
winds, and unrestricted VIS expected through Friday evening.

&&

.MARINE...
No hazardous marine weather conditions expected through Tuesday.

&&

.HYDROLOGY...
Light rainfall from 3 periods of precipitation Saturday afternoon
through Wednesday. High snow levels do not drop until late
Tuesday. Due to the weakening atmospheric river Saturday and the
second surge of moisture from west to east Sunday night through
Tuesday night, favored from slopes of the San Bernardino mountains
from Crestline to San Gabriel mountains could reach totals of 1
to 2 inches of rain with amounts dropping over to the south
rapidly to under 0.50 inches. Traditional climate gradient or more
rainfall for LA Basin versus San Diego. The intensity of the
rainfall should limit impact to the 3 large burn scars but will
need to be monitored.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.

&&

$$

PUBLIC...Tardy
AVIATION/MARINE...Munyan