Apple Valley, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

406
FXUS66 KSGX 201049
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
349 AM PDT Fri Mar 20 2026

.SYNOPSIS...
Widespread moderate Heat Risk with areas of major Heat Risk will
continue through today. Heat Risk will decrease for the weekend,
with minor cooling. Even with the cooling, temperatures will
remain above average into next week. Patchy marine layer low
clouds and fog will be present at times, most likely to impact the
coastal waters and immediate coast. Stronger onshore flow will
likely spread marine layer low clouds and fog farther inland for
the weekend.

&&

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

...NEW AVIATION AND MARINE DISCUSSION BELOW...

Low clouds and fog are developing over the coastal waters this
morning but are being kept offshore by drainage winds enhanced by
weak offshore pressure gradients. The low clouds and fog could
move onto the beaches late this morning as a weak sea breeze
develops. Otherwise, skies are clear under the extensive dome of
high pressure now centered over southwestern AZ.

Today will be another day of record-setting temperatures with
daytime highs in the 90s to low triple digits in the inland
valleys, the 70s to low 90s in the coastal areas, the mid 90s in
the upper deserts and near 110 in the low deserts. The mountains
below 6000 ft will see temperatures in the 80s.

Temperatures begin to trend downward on Saturday as the upper
level high weakens and gets displaced southeast while onshore flow
strengthens. The temperature change will be most noticeable in the
coastal areas a the onshore flow spreads cooler marine air, with
low clouds and fog, a little farther inland. However, daytime
temperatures will still be 10-25 degrees above seasonal averages.

Sunday will likely be cooler still as the ridge is replaced by
weak troughing over SoCal and the onshore flow continues.
Temperatures in the coastal areas will likely be in the 70s while
the inland valleys will be in the 80s to low 90s. The lower
deserts will be in the low triple digits and the high deserts will
be in the low 90s. These temperatures are still 9-20 degrees
above seasonal averages. Marine layer influence will likely spread
even farther inland.

The ridge rebuilds over the western states for next Monday
through Thursday, with a corresponding upward trend in
temperatures. Current solutions indicate the ridge won`t be as
strong as it`s been the last few days but we can expect several
more days of unseasonably high temperatures.

A percentage of model solutions show the ridge weakening again
next Friday, with stronger onshore flow combining to bring us some
relief from the heat.


&&

.AVIATION...
201100Z...SKC across the area currently except for patchy FG
lingering just offshore. FG may intermittently creep into coastal
areas this morning. 30% chance for vis less than 1SM at KSAN and
less than 20% at KCRQ, KSNA. Clearing 15Z-17Z. Similar story for
Friday evening and overnight with patchy FG expected to
intermittently reduce vis for coastal areas starting 03-06Z.
Everywhere else, VFR conditions expected through the TAF period.

&&

.MARINE...Very patchy fog over nearshore waters will continue to
locally reduce vis to near 1 nautical mile through mid morning.
There is greater confidence for areas of fog Friday evening and
overnight with highest chances hear the coastline once again.
Otherwise, no hazardous marine conditions are expected through
Tuesday.

&&

.CLIMATE...
Here are a list of locations currently forecast to break/tie
monthly high temperature records today March 20th:

Today:

             FORECAST HIGH  RECORD YEAR     AVG    +/-

    RIVERSIDE         100    98 IN 1997      73    27   Monthly Record: 102
    RAMONA             94    92 IN 1997      68    27   Monthly Record: 95
    ALPINE             94    86 IN 2001      68    25   Monthly Record: 96
    BIG BEAR LAKE      79    70 IN 1997      52    27   Monthly Record: 80
    IDYLLWILD          86    77 IN 1997      60    25   Monthly Record: 90
    PALOMAR MOUNTAIN   84    76 IN 1972      57    28   Monthly Record: 83
    LAKE CUYAMACA      86    79 IN 1956      56    31   Monthly Record: 84
    CAMPO              96    87 IN 1997      69    26   Monthly Record: 96
    PALM SPRINGS      107    97 IN 1997      80    27   Monthly Record: 107
    INDIO             108    98 IN 1997      81    27   Monthly Record: 108
    THERMAL           108   101 IN 1997      82    26   Monthly Record: 108
    BORREGO           108    95 IN 2017      80    26   Monthly Record: 105

Here are a list of locations currently forecast to break/tie
monthly highest low temperature records on Friday:

Today:


             FORECAST LOW   RECORD  YEAR

    ANAHEIM            63     59 IN 2015 Monthly Record: 69
    VISTA              62     59 IN 2015 Monthly Record: 67
    RIVERSIDE          66     58 IN 2015 Monthly Record: 66
    LAKE ELSINORE      61     57 IN 1986 Monthly Record: 61
    ESCONDIDO          61     59 IN 2015 Monthly Record: 63
    RAMONA             56     50 IN 2023 Monthly Record: 63
    ALPINE             71     55 IN 1990 Monthly Record: 63
    BIG BEAR LAKE      42     38 IN 2017 Monthly Record: 48
    IDYLLWILD          63     43 IN 2017 Monthly Record: 53
    PALOMAR MOUNTAIN   64     56 IN 1997 Monthly Record: 64
    LAKE CUYAMACA      65     53 IN 2017 Monthly Record: 55
    CAMPO              57     51 IN 1951 Monthly Record: 58
    PALM SPRINGS       75     64 IN 2017 Monthly Record: 78
    INDIO              72     69 IN 2010 Monthly Record: 76
    THERMAL            69     64 IN 2013 Monthly Record: 69
    BORREGO            69     64 IN 2013 Monthly Record: 73

&&

.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 this evening 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...PG
AVIATION/MARINE...KW