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Forecast Discussion for San Diego, CA

000
FXUS66 KSGX 282041
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
200 PM PDT Tue Mar 28 2017

.SYNOPSIS...
Locally gusty winds will occur below passes and canyons through
Wednesday, mainly below Cajon Pass. Otherwise, skies will be clear
through Wednesday with a warming trend, with highs mostly in the 80s
in the valleys by Wednesday and lower 90s in the lower deserts. Low
pressure aloft will move by to the northeast Thursday and Friday and
bring cooling along with gusty west winds to the mountains and
deserts Thursday with some northerly winds developing Friday. Warmer
weather will return over the weekend under weak high pressure, but
low pressure will bring cooling again early next week.

&&

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

Skies were sunny with temperatures in the 60s along the coast, 70s
in the valleys and Inland Orange County and around 80 in the lower
deserts. Winds were still gusting to 35-45 MPH near and just below
mountain crests in San Bernardino County and the Santa Ana
Mountains, but the trend is downward, and the wind advisory will
expire at 2 PM. Some NE winds were also occurring in the Coachella
Valley from the Joshua Tree area. Winds tonight should mostly stay
below wind advisory criteria but gusts to around 40 MPH will occur
late tonight and early Wednesday in the same windier spots as
mentioned above.

High pressure aloft will build over the east Pacific with a moderate
ridge extending to Nevada and Utah by Wednesday. Strong moist zonal
flow will occur over the Pacific Northwest. Due to clear skies and a
warm profile, with 850 MB temps rising to around 15 C, surface
temperatures will respond and reach levels of 7-15 deg F above
normal Wednesday. Onshore flow will start to develop again Wednesday
afternoon which could bring a few low clouds or fog to the coast
Wednesday night, though this is more likely Thursday night after a
period of stronger onshore flow from the next low pressure system
coming down from the north. This low will track from far northern
California Thursday southeast to Arizona Friday.
Height/temperature/pressure gradients will be tight on the
west/southwest side of the low and result in strong west winds in
the mountains and deserts Thursday afternoon/evening. High-res
models are indicating strong winds could make it into populated
parts of the Coachella Valley, which is more typical with synoptic
scale winds versus mountain wave winds. Northerly winds, similar to
those of this morning, could form Friday as pressure gradients turn
offshore. With the upper low nearby, temperatures will decrease
Thursday and Friday, with temperatures a little below normal Friday.
With the progressive spring pattern, the upper low, despite being
closed, will move east over the weekend, with warming again over So-
Cal. More troughs could move down from the N/NW early next week for
cooling, but models are very inconsistent with details as GFS and
especially GEM are stronger with the troughs, but ECMWF has weak
ridging.

&&

.AVIATION...
282000Z...VFR conditions will prevail through the period under a
clear sky. Locally gusty NNE winds have hit KPSP and expected to
continue over the next couple of hours before diminishing. Winds
elsewhere will gradually lessen as well with light winds tonight
through Wednesday.

&&

.MARINE...
The Small Craft Advisory was cancelled as seas are below 10 feet
along with wind gusts prevailing at less than 20 kt. Winds and seas
will continue to lower through Wednesay. However, strong winds and
large combined seas are expected again late Thursday through Friday.

&&

.BEACHES...
Surf of 3 to 6 feet with occasional higher sets will continue at
times through early next week.

&&

.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...Maxwell
AVIATION/MARINE/BEACHES...Gregoria

NWS San Diego, CA (SGX) Office Area Forecast Discussion

Discussion Script by Ken True at Saratoga Weather - WFO Script by SE Lincoln Weather