*Annual Rainfall is based on the California Water Year,|
which runs from October 1 through September 30.
FXUS66 KSGX 070412
Area Forecast Discussion
National Weather Service San Diego CA
900 PM PDT Wed Jul 6 2022
Gradual warming will begin on Thursday as high pressure aloft
builds, and our marine layer becomes more shallow and shrinks back
to coastal areas. By this weekend, temperatures will be above
average inland but remain near normal near the coast, with little
change early next week. Areas of morning low clouds and patchy fog
will continue, but mostly be confined to coastal areas after
Thursday. Monsoonal moisture could bring thunderstorms the second
half of next week to the mountains and deserts.
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
Skies were clear except for areas of stratus along the coast, most
common in San Diego County. Aircraft soundings show that the marine
layer has shrunk somewhat, with the inversion base 1200-1400 ft MSL,
so there should be less inland extent. With less deep of a marine
layer and the low pressure trough finally starting to retreat north,
high temperatures Thursday should return to near normal for July.
From Previous Discussion...
The high amplitude trough that has been anchored along the West
Coast for the past week or so will be retreating as the subtropical
high builds north over the Rockies through the coming weekend. This
will bring more typical summer weather to the region as
temperatures rise to normal values, and eventually above, by the
weekend. The building heat inland will maintain a healthy thermal
low over the deserts, which in turn will maintain onshore flow and
afternoon sea breezes. The marine layer will shrink noticeably over
the next couple of days, and only be supportive of coastal low
clouds and patchy fog after Thursday. Some monsoonal moisture may
make an appearance over the weekend on southerly flow aloft. This
may be sufficient for some clouds over the mountains, but it will be
elevated, and instability doesn't look sufficient to produce any
For next week, little change is expected for the first half of the
week, although there will be a chance for our winds aloft to become
more southeasterly. This could transport more monsoonal moisture our
way, but for now, this looks more likely for the latter half of the
week as the subtropical high shifts farther to the north. This is
confirmed by an increasing number of wet ensemble solutions over
070315Z...Coast/Western Valleys...Low clouds with bases 800-1200 ft
MSL are expected to continue to spread north along the San Diego
County coast into Orange County through 07Z. Low cloud coverage is
expected to spread up to 15 miles inland. Scatter out expected 17-
19Z. Intermittent and partial clearing expected at some beaches,
mainly in San Diego County, through Thu afternoon.
Mountains/Deserts...Mostly clear with unrestricted vis through Thu.
Northwest winds with occasional gusts exceeding 20 kt are expected
near San Clemente Island through this evening. Otherwise no
hazardous marine weather is expected through Monday.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
PUBLIC...Maxwell (Update)/10 (Previous Discussion)