Wildfire in California, May 11 to 17, 2022

Area Forecast Discussion
National Weather Service San Diego CA
139 PM PDT Wed May 11 2022

.SYNOPSIS...
A upper level trough moving inland from California into the Great
Basin today will bring stronger onshore flow with a few degrees
of cooling and with gusty west winds. Upper level ridging and
surface high pressure from the south will bring strong warming
through the weekend. Temperatures will then gradually fall back
to near seasonal normals early next week.

&&

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

Key Points:
1. Gusty west winds and cooler temperatures through this
   afternoon.
2. Significant warming trend starting on Thursday and lasting
   into early next week.
3. Saturday will be the warmest day for coastal and inland valley
   areas, while Sunday will be the warmest day in the deserts.

A 500mb trough will continue to move inland this afternoon and
evening, spreading cooler air and gusty west winds across Southern
California. Today’s highs will top out just a few degrees
cooler than yesterday as a result of the 500mb trough passing to
our north and onshore flow increasing. Gusty west winds will
continue through this afternoon across the mountains and deserts,
with the strongest gusts of 50 to 55 mph occurring in the desert
foothills and below mountain passes. Wind Advisories remain in
effect until 6 PM for much of these areas.

The warming trend then kicks in starting on Thursday as upper
level ridging builds in from the west and surface high pressure
slowly slides inland from the south. Highs on Thursday top out
roughly 15 degrees higher than Wednesday’s, marking the start of
a significant warming trend. Friday will see highs increase by
another 5 to 10 degrees across many areas. This trend will be
moderated by persistent onshore flow in coastal areas, but some
gradual warming is anticipated nonetheless. Look for highs to be
well above seasonal normals in most areas by Friday, generally 10
to 15 degrees above normal for mid-May. Triple digit temperature
readings likely make their return to the Coachella Valley and the
San Diego County Deserts on Friday as well.

Saturday and Sunday will mark the peak of this weekend’s heat.
Saturday will see many inland valley locations range from the
middle and upper 80s to middle 90s, while the deserts top out
between 102 and 106 degrees. Onshore flow picks up on Sunday which
will spread some cooler air inland, knocking Sunday’s highs
down a few degrees in most coastal and inland valley locations.
The deserts, however, will see their warmest day on Sunday with
highs between 104 and 109 expected. Relief from the heat will be
hard to come by as well for desert areas, as low temperatures on
both Sunday and Monday morning will likely only fall into the
middle 70s.

Nearly-zonal flow aloft then sets in for early next week, which
will moderate the warming trend but not truly usher in a
significant cool-down. As onshore flow increases on Sunday, so too
will the odds of marine layer low clouds and fog returning to
coastal areas. Expect May Grey to return to form by Monday and
Tuesday of next week with abundant night and morning low clouds
and fog. High temperatures across inland areas will generally
remain near to slightly above normal.

&&

.AVIATION...
112010Z...Coast/Valleys...FEW-SCT low clouds with bases around 2500
feet this afternoon. Otherwise, mostly clear with unrestricted VIS
through tonight.

Mountains/Deserts...Areas of gusty west winds will continue at times
through this evening from the mountain crests east through the
desert slopes and into deserts, resulting in MOD-STG up/downdrafts
and local LLWS. Surface gusts in the windy locations will be 30-45
knots. Local surface vis below 3 miles is likely in BLDU this
afternoon.

&&

.MARINE...
Strong northwest winds and high seas will continue through this
evening. Northwest wind gusts to 30 knots and combined seas of 8 to
10 feet will be possible across the outer waters, with gusts to 25
knots in the inner coastal waters, strongest this afternoon/evening.
Otherwise, no additional marine weather hazards are expected
Thursday through Sunday.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory until 6 PM PDT this evening for Apple and Lucerne
     Valleys-San Bernardino County Mountains-San Gorgonio Pass
     Near Banning.

PZ...Small Craft Advisory until 10 PM PDT this evening for Coastal
     Waters from San Mateo Point to the Mexican Border and out
     to 30 nm-Waters from San Mateo point to the Mexican Border
     Extending 30 to 60 nm out including San Clemente Island.

&&

PUBLIC...Adams/Gregoria
AVIATION/MARINE...PG