Weather forecast for Saturday February 26

February 26, 2011

By JOHN LINDSEY from PG&E

SEA SWELL:

Tonight 5- to 7-foot northwesterly (300-degree deep-water) sea and swell (with a 7- to 13-second period) will continue at this height and period through Sunday afternoon, decreasing
to 4- to 6-feet (with an 8- to 11-second period) by Sunday night.

A 3- to 5-foot northwesterly (300-degree deep-water) swell (with a 9- to 15-second period is forecast along our coastline on Monday and Tuesday.

Increasing southerly winds will generate 7- to 9-foot southerly (195-degree shallow-water) seas on Wednesday, followed by a 6- to 8-foot (270-degree deep-water) swell (with a 10- to 12-second period) on Thursday.

This swell will further lower to 3- to 5-feet (with an 8- to 11-second period) on Friday.

ATMOSPHERIC CONDITION:

Friday and Saturday’s rain fall totals as of 4 p.m.

Adelaida ……………………………..  1.85″
Arroyo Grande …………………………  0.61″
Arroyo Grande along James Way …………..  0.86″
Atascadero, Heilmann Regional Park ………  0.59″
Baywood Park ………………………….  0.36″
Camp San Luis  ………………………..  0.70″
Cambria ………………………………  0.36″
Cottontail Creek near Cayucos……………  0.75″
Condor Lookout Los Padres National Forest ..  1.57″
Creston at Rich’s Home …………………  0.35″
Davis Peak, north of Avila Beach…………  0.79″
Diablo Canyon …………………………  0.26″
Heritage ……………………………..  1.00″
Hog Canyon near Paso Robles …………….  0.37″
Islay Hill, San Luis Obispo, CA …………  0.93″
Los Osos, George’s home ………………..  0.39″
Nipomo ……………………………….  0.95″
Oak Shores at Jim’s House ………………  0.75″
Oceano ……………………………….  0.35″
Paul’s House (41 West & Toro Creek) ……..  1.30″
Paso Robles Airport ……………………  0.60″
PG&E Energy Education Center ……………  0.65″
Rocky Butte …………………………..  2.32″
Santa Margarita Fire Department …………  1.09″
San Luis Obispo Water Reclamation Facility .  1.07″
Santa Maria Public Airport ……………..  0.45″
San Luis Obispo County Airport ………….  0.84″
Shell Beach at Ken’s home ………………  0.37″
Shandon, CDF Yard ……………………..  0.35″
SLOWeather.com ………………………..  1.10″
Templeton …………………………….  0.83″

A very cold upper-level low pressure system moved over San Luis Obispo County today and produced snow flurries down to about 1,000 feet along with scattered rain showers and
hail.

Mostly clear skies and a very cold air mass will allow air temperatures to plummet into the mid 20’s in the North County and low 30’s in the coastal valleys and even along our beaches on Sunday morning with widespread frost throughout the county.

Fair and warmer weather will occur later on Sunday with maximum temperatures in the 50’s. Another cold morning is expected on Monday, but the minimums will be a little warmer than Sunday morning’s.

Warmer and mostly clear weather will develop on Monday into Tuesday with temperatures reaching the 60s.

The weather pattern will take a turn towards mild temperatures and wet and windy weather on Wednesday as a somewhat subtropical weather system crosses the Central Coast. A cold front is forecast to pass over the Central Coast later on Wednesday with strong to gale force (25 and 38 mph) southeasterly winds and moderate to heavy rain.

Showers will continue into Thursday morning with dry weather returning Thursday afternoon and Friday. Rain fall amounts with this system could range between 1 and 2 inches.

Another potentially very wet weather system will approach the Central Coast, with another round of heavy rain and gusty winds next weekend.

DIABLO CANYON AIR TEMPERATURES:

Diablo Canyon Meteorological Tower Air Temperature Data

Yesterday’s         Today’s          Tomorrow’s
Min    Max        Min    Max         Min     Max
48.5°   52.5°     40.1°   49.2°      38.0     54.0

PG&E San Francisco Met Office predicted temps:

Inland Temperatures, Paso Robles

Actual                    Predicted

Fri         Sat         Sun         Mon         Tue          Wed         Thu         Fri         Sat
46-52   34-48   27-52   30-56       31-61     40-56     43-60    35-62   34-68

Coastal Valleys Temperatures, San Luis Obispo

Fri         Sat         Sun         Mon         Tue         Wed         Thu          Fri         Sat
46-54   36-52   31-57   34-59      36-63     43-59      45-62     41-68   40-67

WINDS:

Today’s fresh to strong (19 to 31 mph) northwesterly windswill decrease to moderate to fresh (13 and 24 mph) levels on Sunday.

Gentle variable winds are forecast on Monday.

Increasing southerly winds will develop on Tuesday, reaching strong to gale force (25 to 38 mph) levels on Wednesday.

Moderate to fresh (13 and 24 mph) northwesterly winds are forecast on Thursday, decreasing on Friday.

DIABLO CANYON METEOROLOGICAL TOWER WIND DATA:

Today’s winds:

Max peak winds:      NW       34.2 mph at   6:00 p.m.
Max sustained wind:  NW       24.5 mph at   6:00 p.m.

Yesterday’s Maximum Winds:

Max peak winds:      SW       36.0 mph at   2:00 p.m.
Max sustained wind:  SW       21.9 mph at   2:00 p.m.

SEAWATER TEMPERATURES:

The Diablo Canyon waverider buoy is reporting a sea surface temperature of 56.7 degrees while the Nortek AWAC current meter is reporting 52.7 degrees.

Intake seawater temperatures will range between 52- and 55 -degrees through Friday.

OCEAN CURRENTS:

Both the DCPP Cal Poly CODAR stations and the DCPP Nortek AWAC meter are indicating a southerly (offshore) flowing current.

This southerly (offshore) flowing current will continue to flow southward through Monday, becoming a northerly (onshore) current on Tuesday through Wednesday.

SEAWATER VISIBILITY:

Seawater visibility was 10 to 12 feet at the Diablo Canyon Intake.

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24-Hour Ocean Condition Outlook for Saturday 02/26 to Sunday 02/27

Sea/Swell       DIR. NW      HT.   5-7   PER.   7-13  This morning
Remaining  at:  DIR. NW      HT.   5-7   PER.   7-13  This afternoon
Remaining  at:  DIR. NW      HT.   5-7   PER.   7-13  Tonight

WINDS:          DIR. NW      SPEED 15-20 + 25         This morning
Increasing to:  DIR. NW      SPEED 20-25 + 35         This afternoon
Decreasing to:  DIR. NW      SPEED 15-20 + 30         Tonight
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48-Hour Ocean Condition Outlook for Sunday 02/27 to Monday 02/28

Sea/Swell       DIR. NW      HT.   5-7   PER.   7-12  Sunday morning
Remaining  at:  DIR. NW      HT.   5-7   PER.   7-12  Sunday afternoon
Decreasing to:  DIR. NW      HT.   4-6   PER.   7-11  Sunday night

WINDS:          DIR. NW      SPEED 10-15              Sunday morning
Increasing to:  DIR. NW      SPEED 15-20 + 25         Sunday afternoon
Decreasing to:  DIR. NW      SPEED 10-15              Sunday night
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Extended Ocean Condition Outlook:

Today’s longer range models are not indicating any high-energy swell events over the next two weeks.

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The 24 – Hour Ocean Data From The Diablo Canyon Wave rider Buoy
MONTH  DAY  TIME  SIG.HEIGHT   PERIOD   SWELL DIRECTION     SST
02    22    1413     3.7       11            263          56.1
02    23    0643     5.6       11            286          56.1
02    24    1643     3.7        8            292          57.0
02    25    1643     7.5        7            268          59.0
02    26    1713     5.0       13            264          56.7

(cm) (sec)  22+   20    17    15    13     11    9    7
———————————————————————–
02 22  1413  114    7     1     6     7    40    62    93   163  210
02 23  0643  172    7     1     6     8    51   183   338   290  445
02 24  1643  114    4     1     6    19    15    43    67   162  266
02 25  1643  228    7     2     3    13    46   108   170   521 1022
02 26  1713  153    4     1     2    18    73   225   183   318  350

Daily Swell Inspection Program

NAME                      DAY   TIME    HEIGHT   PERIOD     SST
(PST)   (FEET)  (SECONDS) (DEG. F)
# 166  Ocean Station Papa      26    1202      12       10       42.1
# 06   SE Papa                 26    1750      12       10       42.1
# 59   California Buoy         26    1750      13       10       54.5
# 01   Point Reyes Waverider   26    1746      11       10       51.1
# 15   Monterey Waverider Buoy 26    1750       6       11       53.8
# 28   Cape San Martin, Ca     26    1750       9       12       53.4
# 50   DCPP Waverider Buoy, Ca 26    1713       5       13       56.7
# 63   Harvest Buoy            26    1720       8       11       54.5
# 01   NW Hawaii               26    1750       4        8       74.1

* Note: Height (significant swell height) is the average height of the waves in the top third of the wave record. Maximum wave height may be up to TWICE the height in the data shown in the above table.

Precipitation at the Diablo Canyon Ocean Lab.

Thursday  1500 through Friday   1500   0.07 inches
Friday    1500 through Saturday 1500   0.19 inches

Precipitation this rain season (July 1 – June 30): 19.67 inches
Average season rainfall at DIP to date:            17.64 inches

Ocean Lab Barometer:   29.85 in/Hg or 1010.9 mb  +0.7 mb (Rising)

Sunrise and Sunset

Today’s         Sunrise 6:36 AM      Sunset 5:56  PM
Tomorrow’s      Sunrise 6:35 AM      Sunset 5:57  PM

Tides:
Low Tide                 High Tide
AM          PM           AM          PM
26 Saturday  (12:21 -0.2)  11:41  2.6    4:40 5.2    7:19  3.6
27 Sunday     —–  —    1:14 -0.3    5:48 5.3    8:01  3.9
28 Monday     12:46  2.4    1:56 -0.4    6:45 5.3    8:33  4.0
1 Tuesday     1:35  2.1    2:32 -0.3    7:33 5.3    9:01  4.2
=========================================================================

This day in weather history

1910 – Parts of Washington State were in the midst of a storm which produced 129 inches of snow at Laconia between the 24th and the 26th, a single storm record for the state. A series of storms, which began on the 23rd, led to a deadly avalanche on the first of March. By late on the 28th, the snow had changed to rain, setting the stage for disaster.

2004 – Westerly swell peaked at 19.5 feet with a 17 second period this morning. This was the highest significant swell height measured at the Diablo Canyon since December 2002.

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The National Weather Service will conduct Weather Spotter Training at the PG&E Energy Education Center this Monday February 28, 2011 at 6:30 p.m.

The National Weather Service Storm Spotter Program is a volunteer organization of people with an interest in the weather.

This training session is free and open to the public. Anyone interested in volunteering to become a storm spotter for the National Weather Service is welcome to attend.

This weather forecast is a service provided by Pacific Gas and Electric Company (PG&E) to our energy customers. The forecast is valid only for the Diablo Canyon Power Plant coastline area (approximately a one-half mile radius surrounding the plant). Some of the information in this forecast is provided by Pacific Weather Analysis, with their permission.

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