Alpine, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

286
FXUS66 KSGX 190943
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
243 AM PDT Thu Mar 19 2026

.SYNOPSIS...
Record heat for March will continue for inland areas into the
weekend while the marine layer with patchy night and morning low
clouds and locally dense fog keeps the beaches cooler. Cooling
will begin to spread inland over the weekend into early next
week, but with high temperatures for some inland areas remaining
more than 20 degrees above average with daily rather than monthly
records for heat continuing to fall.

&&

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

.SHORT TERM (Today through Saturday)...
High pressure aloft continues to strengthen over southern
California with the heat for inland areas of southwestern
California expected to peak on Friday. Weakening of high pressure
aloft and onshore flow will begin to spread cooling inland over
the weekend into early next week.

There is a weak coastal eddy early this morning with low clouds
and fog over the inner coastal waters extending locally inland
along the coast with fog locally dense. A little less coverage
over land areas is expected for tonight into Friday morning with
increasing coverage of night and morning low clouds and fog for
coastal areas during the weekend.

High temperatures on Friday are expected to be around 30 degrees
above average for the inland valleys and lower elevations of the
mountains with high temperatures ranging from around 80 at the
beaches to the upper 90s to 104 for the Inland Empire with 105 to
110 for the lower deserts. Cooling of high temperatures on
Saturday of around 4 to 8 degrees is expected for all but the
lower deserts.

&&

.LONG TERM (Sunday through Wednesday)...
High temperatures on Sunday will cool a few degrees for most
areas with high temperatures still around 20 degrees above average
for the mountains, deserts, and inland valleys. High temperatures
on Sunday are expected to range from the mid to upper 70s near the
coast to the upper 80s to mid 90s for the Inland Empire with 100
to 105 for the lower deserts. High temperatures for early next
week will fluctuate within a few degrees of Sunday high
temperatures each day.

Except near the coast, widespread daily records for heat will
continue to be tied or broken, but with few or no new monthly
records for March after Friday or Saturday.

&&

.AVIATION...
190900Z...Low clouds and fog VCNTY KSAN with CIGs 200-300 ft MSL and
VIS 0.25-1 mile likely to continue through 15Z. Elsewhere, mostly
clear skies and unrestricted VIS through this evening. Patchy low
clouds and fog returning to the immediate coast after 03Z Friday.

&&

.MARINE...
Patches of fog with visibility 1 nautical mile within 20 miles of
the coast this morning. Otherwise, no hazardous marine conditions
are expected through Monday.

&&

.CLIMATE...
Prior to 2026, the highest 500 mb height for San Diego for March
had been 590 DM. In the prior three soundings for NKX, new records
for the month have been set at 592 DM, 594 DM, and now 595 DM for
late Wednesday afternoon. Prior to this year, the earliest a 500
mb height of 595 DM had occurred at San Diego had been June 4th.
The 500 mb height for the next sounding early this morning will
likely be higher than that. The earliest a height of 596 DM has
occurred is June 5th and the earliest a 500 height of 597 DM has
occurred is June 20th.

The high temperature of 108 on Wednesday at North Shore,
CA, to the east of the Salton Sea, appears to have tied to the
existing highest temperature ever recorded in March in the United
States. There are locations in the Coachella Valley and San Diego
County deserts that could equal or exceed that temperature for
today and especially on Friday.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory until 8 PM PDT Friday for Orange County Coastal
     Areas-Orange County Inland Areas-Riverside County Mountains-
     San Bernardino County Mountains-San Bernardino and
     Riverside County Valleys-The Inland Empire-San Diego County
     Coastal Areas-San Diego County Mountains-San Diego County
     Valleys-Santa Ana Mountains and Foothills.

     Extreme Heat Warning until 8 PM PDT Saturday for Coachella
     Valley-San Diego County Deserts-San Gorgonio Pass near
     Banning.

PZ...None.

&&

$$

PUBLIC/CLIMATE...17
AVIATION/MARINE...PG