Small Craft Advisory 5, NWS San Diego, CA

Area Forecast Discussion...UPDATED
National Weather Service San Diego CA
939 AM PST Wed Feb 12 2025

.SYNOPSIS...
A round of precipitation will spread southeastward across the
area for today and tonight with another round of heavier
precipitation for Thursday into Friday morning. Showers will
continue on Friday and end from the northwest Friday night. There
will also be periods of stronger and gusty southwest to west winds
at times into Friday. Drier with warming for the weekend, then
slightly cooler early next week.

&&

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

Visible satellite at 9 AM was showing widespread cloud coverage
from the coast to the deserts. Periods of light to locally
moderate rain are possible through Thursday morning. More
information can be found on the rain and snowfall forecast in the
Hydrology section below.

Periods of gusty southwest to west winds are expected Thursday and
Thursday night. For the mountains and deserts, gusts 40 to 50 mph
are expected with the potential for gusts of 70 to 80 mph along
the desert slopes of the San Bernardino Mountains and on the
desert slopes of the southern San Diego County mountains. For the
coast and valleys, winds could gust to 25 to 35 mph on Thursday
evening. Temperatures today will be a few degrees cooler than
yesterday for most locations, with high temperatures 15 to 20
degrees below average in the valleys. Widespread below average
temperatures will continue into Saturday.

Showers will taper off by Friday evening with drier and warmer
conditions expected over the weekend. High temperatures on Sunday
will be a few to around 5 degrees above average, in the lower to mid
60s near the coast to the mid 60s to lower 70s in the valleys with
the lower deserts in the mid to upper 70s. Then slight cooling
spreading inland for Monday and Tuesday as a low pressure system
moves inland to the north.

&&

.AVIATION...
121730Z...Coast/Valleys/Foothills...Low clouds and -SHRA continue to
fill in this morning with cigs lowering to MVFR (1500-2500 feet MSL)
area wide through the early afternoon. Cigs and vis will be reduced
further where -SHRA and BR are more persistent, particularly in San
Diego/Orange County. Lowering trend will continue through this
evening as the lower levels continue to moisten further. Prevailing
IFR cigs/vis with increasing coverage of
-SHRA/RA after 06Z tonight into Thursday.

Mountains/Deserts...Surface gusts 25-40 kts slowly diminishing
throughout the day. Coastal slopes of the mtns obscured in FG
through Thursday. Periods of -RA/SN through tonight will transition
to more steady RA around 12z Thursday with pockets of +RA. Cigs in
the High Desert drop to MVFR later this evening with patchy -SHRA
overnight. Cloud bases vcnty PSP will drop below 5000 feet MSL after
00Z. Gusty winds return for the High Desert and desert slopes after
15Z Thursday becoming stronger and more widespread late Thursday.

&&

.MARINE...
Periods of stronger winds and choppy seas are expected later today
through Friday. Brisk southerly winds will increase along the coast
this afternoon into early Thursday. Southwest winds will increase
across the coastal waters Thursday afternoon then diminish Thursday
night. Finally, westerly winds will increase Friday before
diminishing Friday night. Each of these periods of winds could
briefly generate hazardous conditions. No additional hazardous
marine conditions are anticipated Friday night through Sunday.

&&

.BEACHES...
A large westerly swell with a long period will arrive Friday,
generating large surf late Friday through Saturday. Surf of 4 to 6
feet with sets up to 9 feet can be expected, highest on west facing
beaches. There will be a high rip current risk and hazardous
swimming conditions.

&&

.HYDROLOGY...

Periods of light rain expected through the day, with most of the
precipitation focused on Orange and San Diego Counties. Rainfall
rates should be 0.10 inch or less per hour. For Orange and
southwestern San Bernardino Counties through tonight, rainfall and
liquid-equivalent above the snow level is expected to range from
0.30 to 0.60 inch near the coast to 0.75 to 1.25 inches in the
mountains with snowfall of 2 inches above 6000 to 6500 feet and 3
to 6 inches above 8000 feet. For San Diego County, rainfall
through tonight is expected to range from 0.5 to 1 inch near the
coast to 1.5 to 2.5 inches in the mountains. For today and
tonight, the NBM probability for Palomar Mountain to receive 2 or
more inches of rainfall is 70 percent. Snow levels this morning
are around 5500 ft and light snow has been reported at Birch Hill
in Palomar Mountain and in Big Bear. Snow levels are expected to
rise to 6000 to 6500 feet around noon, 7000 to 7500 by late this
afternoon, and to around 8000 feet by Thursday morning. 1 to 3
inches of snow is expected this morning.

Periods of moderate to heavy rainfall is expected Thursday into
early Friday. Isolated heavier rain is possible through the day with
rain rates 0.40 to 0.50 inches per hour, most likely in the
mountains. For lower elevations rain rates during the day Thursday
will be 0.10 to 0.25 inches per hour for the most part. A band of
heavier rain will start in Orange and San Bernardino Counties
Thursday evening, spreading southeast into San Diego County around
midnight. For lower elevations, peak rainfall rates will be near
0.40 inches per hour with peak rainfall rates 0.50 to 0.75 inches
per hour in the mountains. The 99th percentile of the HREF even has
hourly rainfall rates approaching 1 inch per hour on the coastal
slopes of the San Bernardino mountains. There is a 15 to 20 percent
chance of thunderstorms for overnight Thursday. Where thunderstorms
develop will be the most likely places to see rainfall rates near 1
inch per hour.

For Thursday through Friday morning, additional rainfall and liquid-
equivalent above the snow level for Orange and southwest San
Bernardino Counties from around 1.5 inch near the coast to 3 to 5
inches in the mountains with local amounts to around 6 inches. For
northern San Diego County and western Riverside Counties, amounts
are expected to range from 1 to 1.5 inches near the coast to 2 to 4
inches in the mountains with amounts across southern San Diego
County from around 0.75 inch near the coast to around 1.5 inches in
the mountains. For the lower deserts, amounts are expected to range
from around one-quarter inch for locations bordering Imperial County
to around 1 inch for the northern Coachella Valley. For high desert
areas, amounts are expected to range from one-half to one inch
farther inland from the mountains to 1 to 2 inches on the foothills
near the desert slopes of the mountains. For today through Friday,
NBM probabilities for 5 inches or more of rainfall are highest for
the eastern San Gabriel Mountains at 85 to 95 percent.

Both the San Diego River at Fashion Valley and the Santa Margarita
River at Ysidora are forecast to reach Monitor Stage late Thursday
night into Friday morning, with only an 8% chance of the San Diego
River reaching Minor Flood Stage.

A snow level around 8000 feet on Thursday will lower to around 6500
to 7000 feet for early Friday morning. Additional snowfall could be
as much as 1 to 2 feet above 8000 to 8500 feet with 4 to 8 inches
from 6500 to 7500 feet.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Flood Watch from Thursday morning through late Thursday night
     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.

     Wind Advisory until 10 AM PST this morning for San Diego County
     Deserts.

PZ...None.

&&

PUBLIC/HYDROLOGY...CO
AVIATION/MARINE/BEACHES...KW

Preliminary Local Storm Report
National Weather Service San Diego CA
834 AM PST Wed Feb 12 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0834 AM     Snow             1 ESE Palomar Mountain  33.31N 116.86W
02/12/2025  M1.0 Inch        San Diego          CA   Trained Spotter

            Trained spotter measures one inch of snow
            this morning at Birch Hill on Palomar
            Mountain. Snow showers turning to rain this
            morning.

&&

APR