Area Forecast Discussion
Issued by NWS San Diego, CA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS66 KSGX 092134
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
130 PM PST Sat Dec 9 2017

.SYNOPSIS...
Santa Ana winds will continue through Sunday with areas of strong
gusty easterly winds, strongest Sunday morning. Winds will be weaker
Monday through Thursday, but offshore flow combined with a ridge of
high pressure will continue to keep humidity very low and daytime
temperatures well above seasonal normals. There is a chance that
winds could increase again from the east or northeast by next
weekend. Skies will be mostly clear except for occasional high
clouds, and no precipitation is expected through at least next
weekend.

&&

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

High clouds were moving over the area with locally gusty east winds.
The windiest locations had gusts in the 40s MPH. High-resolution
models, including the local WRF and HRRR, show easterly winds
increasing a little bit more this afternoon before a slight decrease
early this evening. Temperatures were mostly 75-85, with warming
over Friday in coastal Orange County due to more offshore flow
there. A few locations were in the upper 60s along the immediate
coast of San Diego County.

Winds will peak Sunday morning due to a bit more mountain wave
activity and MSLP gradients reaching 6-7 MB offshore from DAG to RIV
and 4-5 MB offshore from IPL to SAN. Due to the more easterly MSLP
gradient, the winds will be strongest in San Diego County versus
other locations, so the high wind warning is in effect for the
mountains/valleys through Sunday afternoon. Wind gusts will locally
exceed 60 MPH in San Diego County and 50 MPH elsewhere, such as near
Banning Pass. Winds decrease late Sunday afternoon/evening with
mostly light winds by Monday, except very locally near and just west
of mountain crests.

Overall, the pattern next week will be high pressure aloft over the
West Coast and the continued deep trough over eastern North America.
A closed low will be somewhere to our south, but the offshore flow
here looks weak to moderate. Thus, warm dry weather will continue
through at least Friday or Saturday, though some model runs have
indicated slight cooling late in the week. Around Saturday, there
could be a trough moving through the interior western US which could
enhance the offshore flow. No precipitation is expected for 10+ days.

&&

.AVIATION...
092100Z...NE to E winds 15-25 kt with gusts to 30-40 kt in the wind
prone passes and canyons and on the coastal mountain slopes and
foothills will create MOD-STG UDDFS/LLWS over and W or SW of the
mountains through 10/0900 UTC. Winds will strengthen 10/0900 UTC
into the rest of Sunday morning with surface gusts 40-50 kt and STG-
SVR UDDFS/LLWS over and W or SW of the mountains. Otherwise, SCT-BKN
clouds AOA 20000 ft MSL and P6SM vis through Sunday morning.

&&

.MARINE...
No hazardous marine weather is expected through Friday.

&&

.FIRE WEATHER...
There will be some variation in winds the rest of this afternoon and
this evening before the next increase late tonight. East winds will
peak early Sunday with windier areas 20-35 MPH from the east with
gusts 45-60 MPH, locally stronger, with poor nighttime humidity
recovery. Winds will diminish steadily from Sunday afternoon through
Sunday night, and the critical fire weather conditions will wane
Sunday night. However, offshore flow will prevail through next week
and continue very low humidity and occasional local gusty winds,
though current indications are that we will have elevated versus
critical fire weather conditions most of the week. Daytime
humidities will mostly be 10 percent or less inland, though sea
breezes could moderate this slightly near the coast.

The Red Flag Warning remains in effect until 8 pm Sunday for most
areas, except coastal Orange County where it expires at 8 pm tonight.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...High Wind Warning until 4 PM PST Sunday for San Diego County
     Mountains-San Diego County Valleys.

     Red Flag Warning until 8 PM PST Sunday for Orange County Inland
     Areas-Riverside County Mountains-Including The San Jacinto
     Ranger District Of The San Bernardino National Forest-San
     Bernardino County Mountains-Including The Mountain Top And
     Front Country Ranger Districts Of The San Bernardino
     National Forest-San Bernardino and Riverside County Valleys
      -The Inland Empire-San Diego County Coastal Areas-San
     Diego County Inland Valleys-San Diego County Mountains-
     Including The Palomar And Descanso Ranger Districts of the
     Cleveland National Forest-San Gorgonio Pass Near Banning-
     Santa Ana Mountains-Including The Trabuco Ranger District
     of the Cleveland National Forest.

     Red Flag Warning until 8 PM PST this evening for Orange County
     Coastal Areas.

PZ...NONE.

&&

$$

PUBLIC/FIRE WEATHER...Maxwell
AVIATION/MARINE...Harrison


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.