Area Forecast Discussion
Issued by NWS San Diego, CA

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000
FXUS66 KSGX 281641
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
941 AM PDT Sat Mar 28 2020

.SYNOPSIS...
Fair and dry weather today will give way to increasing clouds and a
chance for showers as a weak trough drops south over the West.
Precipitation will be light, with the best chance over the mountains
where snow is expected above 5500 feet. Some gusty westerly winds
will develop over the mountains and deserts as well Sunday night.
Fair, dry, and warmer weather develops on Monday and persists
through much of the new week under northwest flow aloft.

&&

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

...Update...

Tranquil weather will prevail today as temps start to warm under
partial sun (under some high level cloudiness). It was a cold
morning with 30s over the inland valleys and the high desert.
Teens and 20s in the mountains. 40s near the coast and the lower
deserts. No changes were needed to the forecast this morning. See
previous discussion below for further forecast details.

...Previous Discussion (Issued at 215 AM PDT Sat Mar 28 2020)...

Other than some patchy low clouds along the coast, skies were clear
over SoCal at 2 AM PDT. A veil of higher clouds in advance of a weak
trough off the PacNW was visible approaching the Central Coast. Weak
to moderate onshore sfc pressure gradients were in place over the
region, keeping onshore flow and a moderately deep marine layer west
of the mts.

Weak ridging aloft will quickly fade today, as yet another trough
slides SE along the Coast, and across SoCal Sunday night. There
appears to be sufficient moisture and lift for scattered showers to
break out, with some enhancement over our mountains, where upslope
flow will contribute. The westerly winds will become gusty over the
ridges, desert slopes and deserts from Sunday evening through early
Monday morning but likely remain just below Advisory criteria.

The trough will slide well east of the area on Monday, allowing a
substantial increase in atmospheric heights/thickness and lighter
winds. Some warming will be felt on Monday afternoon, but will it
will be more noticeable on Tuesday, when afternoon temperatures will
climb above average for the first time in a couple of weeks for many
areas.

Weak ridging over the EastPac, and troughing over the lower 48,
maintains a dry northwest flow aloft over CA most of next week. It
should be a quiet period in an otherwise traditionally stormy part
of the year. The marine layer will be challenged next week, until
perhaps late in the week, when some weak troughing aloft redevelops
over the West. This would support slightly better onshore flow. The
model solutions seem more unstable beyond next week, with a number
of cutoff systems and higher amplitude waves emerging over the
EastPac.

&&

.AVIATION...
281530Z...Coast/Valleys...FEW-SCT clouds at/above 20,000 ft MSL with
unrestricted vis through today. SCT-BKN clouds expected after 07Z
Sunday, with bases 2500-3000 ft MSL.

Mountains/Deserts...High clouds at/above 20,000 ft MSL with
unrestricted vis through tonight.

&&

.MARINE...
No hazardous marine weather is expected through Sunday morning.
Northwest winds will increase Sunday afternoon and evening, with
gusts up to 25 kts possible, producing hazardous conditions for
small craft at times.  Winds will weaken by Monday morning.

&&

.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...Gregoria (Update)/10 (Prev Discussion)
AVIATION/MARINE...PG


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