A 5- to 7-foot northwesterly (295-degree, deep-water)
swell (with an 8- to 15-second period) is forecast along
our coastline this afternoon into tonight. Combined
with today's and Thursday morning's swell will be
5- to 7-foot southerly (190-degree, shallow-water) seas.
A series of intense low-pressure systems with near
hurricane force winds will travel across the northern
Pacific into Sunday. These storms will produce large
swell events along the Northern and Central California
A 9- to 11-foot west-northwesterly (280-degree, deep-
water) swell (with a 12- to 14-second period) will
arrive along our coastline Thursday, increasing to 13
to 15 feet (with a 14- to 16-second period) by Friday.
This west-northwesterly (290-degree, deep-water) swell
is expected to peak at 18 to 20 feet (with a 16- to
18-second period) Saturday morning, decreasing to 16
to 18 feet by Saturday afternoon and night with the
Note: As this swell travels southeastward at 25 knots
toward the Central Coast, it should peak at 41
feet with a 17-second period at the SE Papa
NOAA marine buoy (600 nautical miles west of
Eureka) Friday morning at 8 a.m.
The West California NOAA marine buoy (357
nautical miles west of San Francisco) is
expected to see the swell peak Friday evening
at 7 p.m. at 36 feet with an 18-second period.
The offshore NOAA marine and CDIP buoys along
the Central Coast will see swell heights near
27 feet on Saturday.
A 10- to 12-foot west-northwesterly (290-degree, deep-
water) swell (with a 14- to 16-second period) is
expected along our coastline on Sunday, increasing to
11 to 13 feet (with a 13- to 15-second period) by
Note: Combined with Sunday's swell will be 10- to 12-
foot southerly (190-degree, shallow-water) seas.
A 9- to 11-foot west-northwesterly (290-degree, deep-
water) swell (with an 11- to 14-second period) is
forecast on Tuesday, decreasing to 6 to 8 feet with
the same period next Wednesday.
The high-pressure ridge responsible for the dry weather
has shifted southward in response to a deep trough of low
pressure over the eastern Pacific. This condition has
opened the storm door for California as vigorous upper-
level winds draw in a series of low-pressure systems.
The first system in this series will be a cold front
that will produce increasing clouds with sprinkles/light
rain showers this morning into this afternoon. As the
front approaches San Luis Obispo and northern Santa Barbara
counties tonight, the southerly winds will build
to moderate gale-force to fresh gale-force (32 to 46 mph)
levels along the coastline and showers will turn to study
rain tonight into early Thursday morning. Total rainfall
amounts will range between 1.00 and 1.75 inches. Snow
levels will lower to 5,000 feet.
A break in the weather looks possible Thursday afternoon
and night, before another cold front moves in Friday
morning with moderate gale-force to fresh gale-force
(32 to 46) southerly winds along the coastline and heavy
rain. Rain will turn to showers Friday afternoon into
Saturday morning as strong to gale-force (25 to 38 mph)
northwesterly winds develop along the coastline. Total
rainfall amounts will range between 1.25 and 1.75 inches.
Snow levels are expected to range around 3,500 feet on
Friday into Saturday.
The last installment in a three part trilogy of storms
and likely the strongest will tap into huge plume of
subtropical moisture "Atmospheric River" and will produce
fresh gale-force to strong gale-force (39 to 54 mph)
southerly winds along the coastline and heavy rain on
Sunday. Rain to turned to showers on Monday. Total
rainfall amounts with this system will range between
2.00 and 4.00 inches.
High pressure is then expected to build back into the
region Tuesday and should produce night and morning
Santa Lucia (offshore) winds and dry weather through
Weather graphics and power outage information are available
Yesterday's Today's Tomorrow's
Min Max Min Max Min Max
50.1° 59.5° 47.7° 58.0° 51.0° 58.0°
PG&E Weather Office in San Francisco predicted temperatures
for San Luis Obispo County
Inland Temperatures, Paso Robles
Tue Wed Thu Fri Sat Sun Mon Tue
29 62 37 54 46 55 46 53 42 56 48 55 38 52 35 55
Coastal Valleys Temperatures, San Luis Obispo
Tue Wed Thu Fri Sat Sun Mon Tue
36 67 42 59 50 60 45 56 45 60 51 58 44 57 39 60
Strong to gale-force (25 to 38 mph) southerly winds are
forecast this afternoon, increasing to moderate gale-force
to fresh gale-force (32 to 46 mph) levels tonight. These
southerly winds will decrease Thursday morning into Thursday
Moderate gale-force to fresh gale-force (32 to 46 mph) southerly
winds are forecast on Friday morning, followed by strong to
gale-force (25 to 38 mph) northwesterly winds on Friday
afternoon into Saturday morning. decreasing Saturday afternoon.
Moderate to fresh (13 to 24 mph) southeasterly winds are
forecast Saturday night, increasing to fresh gale-force to
strong gale-force (39 to 54 mph) levels along the coastline
on Sunday morning, decreasing Sunday afternoon and night.
Moderate gale-force to fresh gale-force (32 to 46 mph)
northwesterly winds are forecast on Monday, decreasing
and shifting out of the northeast next Tuesday and Wednesday.
DIABLO CANYON METEOROLOGICAL TOWER WIND DATA:
Today's Maximum Winds:
Max peak winds: SE 8.9 mph @ 5:30 a.m.
Max sustained wind: SE 6.7 mph @ 5:30 a.m.
Yesterday's Maximum Winds:
Max peak winds: NE 12.8 mph @ 3:15 a.m.
Max sustained wind: NE 8.7 mph @ 3:15 a.m.
Seawater temperatures will range between 54 and 56 degrees
Today's northerly (onshore) flowing current will continue to
flow northward through Sunday, becoming a southerly (offshore)
flowing current on Monday.
Seawater visibility was 14 to 16 feet at the Diablo Canyon Intake.
24-Hour Ocean Condition Outlook for Wednesday 01/18 to Thursday 01/19
SEA/SWELL: DIR. NW HT. 4-6 PER. 8-15 This morning
Increasing to: DIR. NW HT. 5-7 PER. 8-15 This afternoon
Remaining at: DIR. NW HT. 5-7 PER. 9-14 Tonight
(Combined with: DIR S HT 5-7 PER. 4-6 Tonight)
WINDS: DIR. SE SPEED 10-15 This morning
Increasing to: DIR. SE SPEED 25-30 + 35 This afternoon
Increasing to: DIR. SE SPEED 35-40 + 45 Tonight
48-Hour Ocean Condition Outlook for Thursday 01/19 to Friday 01/20
SEA/SWELL: DIR. WNW HT. 8-10 PER. 11-13 Thursday morning
Increasing to: DIR. WNW HT. 9-11 PER. 12-14 Thursday afternoon
Remaining at: DIR. WNW HT. 9-11 PER. 12-14 Thursday night
(Combined with: DIR S HT 4-6 PER. 5-7 Thursday morning)
WINDS: DIR. SW SPEED 25-30 + 35 Thursday morning
Decreasing to: DIR. SW SPEED 15-20 + 25 Thursday afternoon
Decreasing to: DIR. W SPEED 10-15 + 20 Thursday night
Extended Ocean Condition Outlook:
A west-northwesterly (290-degree, deep-water) swell is expected
to peak at 18 to 20 feet (with a 16- to 18-second period) Saturday
morning, decreasing to 16 to 18 feet by Saturday afternoon and
night with the same period.