Weather forecast for Monday February 22

February 22, 2011

By JOHN LINDSEY from PG&E

SEA SWELL:

Today’s 3 to 5-foot northwesterly (300-degree deep-water) sea and swell (with a 5 to 11-second period) is forecast to continue along our coastline through Tuesday morning, increasing to 4 to 6-feet (with a 7 to 12-second period) on Tuesday afternoon and remaining at this height and period through Friday morning.

A 6- to 8-foot northwesterly (300-degree deep-water) sea and swell (with a 7- to 13-second period) is forecast along our coastline on Friday afternoon through Sunday, decreasing
to 3 to 5-feet on Monday through next Tuesday.

PG&E San Francisco Met Office predicted temps:

Inland Temperatures, Paso Robles

Actual                    Predicted

Mon          Tue         Wed         Thu         Sat         Sun         Mon         Tue         Wed
37-54     36-59     27-58     30-58    38-56    38-52     28-55     30-59    33-60

Coastal Valleys Temperatures, San Luis Obispo

Mon          Tue          Wed         Thu         Sat          Sun         Mon         Tue         Wed
35-57      37-60     34-59      35-59    40-57    39-52     34-57     34-59      37-62

ATMOSPHERIC CONDITION:

Partly cloudy and slightly warmer weather has developed this afternoon. Cold temperatures will develop in the North County tonight into Wednesday morning with temperatures reaching into the high 20s. Overnight lows in the coastal Valleys will reach the low to mid 30s with areas of frost developing throughout the county.

Wednesday is forecast to be mostly sunny with a few passing clouds and a little warmer, but still below normal for February.

Clouds increase again on Thursday leading to rain showers and cold daytime temperatures as an upper-level low drops out of the Gulf of Alaska and moves southward along the
California coastline. Rain showers should start Friday afternoon and continue into Saturday morning. Total rain fall amounts should range between 0.25 and 0.75 inches.

If showers develop early Saturday, there could be snow down to 1,250 feet, including the possibility of snow showers on the Cuesta Grade.

Heavy snow is a good bet across the Sierra on Friday and into Saturday with a few feet possible at the upper elevations and many inches in the Sierra foothills.

Clearing is forecast for Sunday, then the next round of precipitation moves into the Central Coast next week and while it doesn’t appear nearly as cold, it may be wetter.

DIABLO CANYON AIR TEMPERATURES:

Diablo Canyon Meteorological Tower Air Temperature Data

Yesterday’s         Today’s          Tomorrow’s
Min    Max        Min    Max         Min     Max
44.2°   50.7°     41.9°   55.3°      40.0     58.0

WINDS:

This afternoon’s fresh to strong (19 to 31-mph) northwesterly winds will decrease on Wednesday morning, than build to strong to gale force (25 to 38 mph) levels on Wednesday
afternoon and night, decreasing somewhat on Thursday.

Moderate to fresh (13 and 18 mph) southwesterly winds are forecast on Friday into Saturday morning.

Strong to gale force (25 to 38 mph) northwesterly winds are forecast on Saturday afternoon, decreasing on Sunday.

DIABLO CANYON METEOROLOGICAL TOWER WIND DATA:

Today’s winds:

Max peak winds:      NW       29.9 mph at  11:15 p.m.
Max sustained wind:  NW       24.6 mph at  11:15 p.m.

Yesterday’s Maximum Winds:

Max peak winds:      SE       19.2 mph at  11:15 p.m.
Max sustained wind:  SE       14.5 mph at  11:15 p.m.

SEAWATER TEMPERATURES:

The Diablo Canyon waverider buoy is reporting a sea surface temperature of 56.1 degrees while the Nortek AWAC current meter is reporting 54.6 degrees.

Intake seawater temperatures will range between 54- and 56 -degrees through Friday.

OCEAN CURRENTS:

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

A northerly (onshore) flowing current will continue to flow northward through Wednesday morning, becoming a southerly (offshore) current on Wednesday afternoon through Thursday.

SEAWATER VISIBILITY:

Seawater visibility was 11 to 13 feet at the Diablo Canyon Intake.

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24-Hour Ocean Condition Outlook for Tuesday 02/22 to Wednesday 02/23

Sea/Swell       DIR. NW      HT.   2-4   PER.  11-13  This morning
Increasing to:  DIR. NW      HT.   3-5   PER.   5-11  This afternoon
Remaining  at:  DIR. NW      HT.   3-5   PER.   5-11  Tonight

WINDS:          DIR. SE      SPEED 15-20 + 25         This morning
Increasing to:  DIR. NW      SPEED 20-25 + 30         This afternoon
Decreasing to:  DIR. NW      SPEED 15-20 + 25         Tonight
===========================================================================
48-Hour Ocean Condition Outlook for Wednesday 02/23 to Thursday 02/24

Sea/Swell       DIR. NW      HT.   3-5   PER.   5-11  Wednesday morning
Increasing to:  DIR. NW      HT.   4-6   PER.   7-12  Wednesday afternoon
Remaining  at:  DIR. NW      HT.   4-6   PER.   7-12  Wednesday night

WINDS:          DIR. NW      SPEED 15-20 + 25         Wednesday morning
Increasing to:  DIR. NW      SPEED 25-30 + 35         Wednesday afternoon
Decreasing to:  DIR. NW      SPEED 20-25 + 30         Wednesday night
===========================================================================

Extended Ocean Condition Outlook:

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

===========================================================================

The 24 – Hour Ocean Data From The Diablo Canyon Wave rider Buoy
MONTH  DAY  TIME  SIG.HEIGHT   PERIOD   SWELL DIRECTION     SST
02    17    0243    11.7       14            268          54.0
02    18    0613     8.7       13            268          54.1
02    19    1443     7.9       12            270          55.0
02    20    1113     9.0       12            270          59.0
02    21    2113     3.3       11            278          57.2
02    22    0513     2.2       15            272          54.0
02    22    1413     3.7       11            263          56.1

(cm) (sec)  22+   20    17    15    13     11    9    7
———————————————————————–
02 17  0243  356   13    10    72   418  1588  1771  1312  1214  572
02 17  0543  312   13    10    79   331  1122  1127  1032  1087  570
02 18  0613  264    7     3    18    21   171   904   741   560  950
02 19  1443  241    4     3    28   153   124   385   789   525  858
02 20  1113  275   13     4     9    17   347  1334  1195   779  408
02 21  2113  101    9     1     2     6    34    36   140   160  120
02 22  0513   68    4     1     5     5    49    33    26    46   71
02 22  1413  114    7     1     6     7    40    62    93   163  210

Daily Swell Inspection Program

NAME                      DAY   TIME    HEIGHT   PERIOD     SST
(PST)   (FEET)  (SECONDS) (DEG. F)
# 166  Ocean Station Papa      22    1702       8        9       42.1
# 06   SE Papa                 22    2150       8       12       53.4
# 59   California Buoy         22    2150      12       12       54.7
# 01   Point Reyes Waverider   22    2146       8       11       52.0
# 15   Monterey Waverider Buoy 22    2150       6       11       53.4
# 28   Cape San Martin, Ca     22    2150       5       10       54.5
# 50   DCPP Waverider Buoy, Ca 22    2113       4       11       56.1
# 63   Harvest Buoy            22    2120       5       14       55.2
# 01   NW Hawaii               22    2150       8       12       74.3

* 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.

Sunday     1500 through Monday     1500   0.00 inches
Monday     1500 through Tuesday    1500   0.00 inches

Precipitation this rain season (July 1 – June 30): 19.41 inches
Average season rainfall at DIP to date:            16.88 inches

Ocean Lab Barometer:   30.10 in/Hg or 1019.2 mb  -0.9 mb (Falling)

Sunrise and Sunset

Today’s         Sunrise 6:41 AM      Sunset 5:52  PM
Tomorrow’s      Sunrise 6:40 AM      Sunset 5:53  PM

Tides:
Low Tide                 High Tide
AM          PM           AM          PM
22 Tuesday     7:13  0.4    6:40  1.5   12:26 5.7    1:17  3.8
23 Wednesday   8:29  0.4    7:30  2.1    1:15 5.6    2:47  3.3
24 Thursday    9:54  0.3    8:40  2.5    2:14 5.5    4:40  3.1
25 Friday     11:15  0.1   10:15  2.7    3:24 5.3    6:18  3.3
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

1986 – A twelve siege of heavy rain and snow, which produced widespread flooding and mudslides across Northern and Central California, finally came to an end. Bucks Lake,
located in the Sierra Nevada Range, received 49.6 inches of rain during the twelve day period. (Storm Data)

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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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