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Area Forecast Discussion (AFD)

Issued by San Diego, CA (SGX)

                            
000
FXUS66 KSGX 251541
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
841 AM PDT Mon Mar 25 2019

.SYNOPSIS...
Fair and warmer today. On Tuesday, high clouds will increase and 
cooling will begin to spread inland, continuing through midweek as a 
low pressure trough moves inland to the north. The trough will bring 
a slight chance of showers Wednesday night and early Thursday, along 
with gusty winds over the mountains and deserts.  It will be dry, 
with a warming trend through the upcoming weekend.

&&

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

It was mostly clear across SoCal this morning. The 12Z Miramar 
sounding indicated the marine layer was only about 2K FT deep with 
warming of 5 C or more below 6500 FT. Surface pressure gradients 
were weak and winds light. The warming indicated on the sounding, 
coupled with abundant sunshine should translate to a warmer 
afternoon. No forecast updates.

From previous discussion...

.SHORT TERM (Today through Wednesday)...
Early this morning, high pressure aloft is centered over the Great
Basin with a large closed low pressure system off the West Coast. 
Satellite imagery shows very patchy stratus over the coastal
waters and adjacent portions of the San Diego County coast. The
warming on Sunday will continue today and continue into Tuesday
for the deserts. Strengthening onshore flow will begin to spread
cooling inland on Tuesday and Wednesday as the low pressure system
off the West Coast moves very slowly eastward. It will also bring
increasing high clouds across southern California on Tuesday and
Wednesday.

&&

.LONG TERM (Wednesday night through Sunday)...
As that low pressure system moves inland to the north, it will
bring a slight chance of light precipitation along and west of the
mountains for late Wednesday night into early Thursday. It will
also bring stronger onshore flow for late Wednesday into early
Thursday with periods of stronger and gusty southwest to west
winds for the mountains and deserts with the stronger gusts to
around 50 mph.

As that low pressure system weakens and moves inland, high 
pressure aloft will develop off the West Coast on Friday, 
strengthen and move to near the West Coast on Saturday, then begin
to move inland on Sunday. For southern California, this will 
bring dry weather with a warming trend. This warming would push 
high temperatures to 10 to 15 degrees above average on Sunday for 
inland areas and 5 to 10 degrees above average near the coast. The
warming with the GFS is a little greater than with the ECMWF.

&&

.AVIATION... 
251530Z...Coast/Valleys...Patchy low clouds have mostly dissipated, 
leaving clear skies for today and tonight. Low confidence that 
patchy and intermittent low clouds could redevelop after 05Z tonight 
1500 ft MSL and below at KSAN, KCRQ, and KSNA.  

Mountains/Deserts... Clear skies expected through tomorrow. 

&&

.MARINE...
No hazardous marine weather is expected today and Tuesday. There is 
a slight chance of isolated showers late Wednesday into Thursday, 
rain is not expected to be significant. A passing storm system will 
bring northwest winds of 12-15 KTS with gusts to 20 KTS Thursday 
evening. These conditions may be hazardous for small craft.

&&

.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...10/Martin
AVIATION/MARINE...CO/PG