Weather forecast for Monday February 28

February 28, 2011

By JOHN LINDSEY from PG&E

SEA SWELL:

Today’s 3- to 4-foot northwesterly (310-degree deep-water) swell (with a 9- to 14-second period will continue at this height and period along our coastline through 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 westerly (270-degree deep-water) swell (with a 10- to 12-second period) on Thursday.

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

Increasing northwesterly winds will generate 8- to 10-foot northwesterly (310-degree deep-water) sea and swell (with a 7- to 11-second period) later on Sunday through next Tuesday.

ATMOSPHERIC CONDITION:

Clear skies and a cool air mass has allowed air temperatures to reached a low of 31 degrees at the Paso Robles Airport and 34 degrees at the San Luis Obispo Airport this morning.

Fair and warmer weather will continue into Tuesday with temperatures reaching the low 60s by Tuesday afternoon.

A 1,006 millibar low pressure system currently about 1,000 miles to the west of San Luis Obispo will move towards Cape Mendocino and intensify to 983 millibars by Tuesday afternoon.

The associated cold front will pass over the Central Coast on Wednesday around noon with strong to gale force (25 and 38 mph) southeasterly winds and moderate to heavy rain.
The jet stream will be directly over the Central Coast during frontal passage.

Rain will turn to scattered showers by Wednesday night, ending by Thursday morning. Rain fall amounts with this system could range between 1 and 2 inches.

Fair and warmer weather will develop later on Thursday into Saturday with temperatures reaching the high 60s and maybe even the low 70s by Friday and Saturday afternoon.

A weakening cold front will pass the Central Coast on Sunday with increasing clouds and a few rain showers. The main effect of this system will be to set up a steep pressure along the California coastline. This pressure gradient should produce strong to gale force (25 and 38 mph) northwesterly winds along our coastline later on Sunday through next Tuesday.

DIABLO CANYON AIR TEMPERATURES:

Diablo Canyon Meteorological Tower Air Temperature Data

Yesterday’s         Today’s          Tomorrow’s
Min    Max        Min    Max         Min     Max
38.7°   52.8°     46.2°   54.0°      47.0     56.0

PG&E San Francisco Met Office predicted temps:

Inland Temperatures, Paso Robles

Actual                    Predicted

Sun      Mon   Tue   Wed   Thu   Fri   Sat   Sun   Mon
28 55    31 58 31 61 40 58 41 62 34 65 35 68 41 67 42 59

Coastal Valleys Temperatures, San Luis Obispo

Sun      Mon   Tue   Wed   Thu   Fri   Sat   Sun   Mon
32 57    34 59 33 60 45 60 45 61 42 68 40 69 42 65 46 59

WINDS:

Gentle to moderate (8 to 18 mph) variable winds are forecast today through Tuesday afternoon.

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

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

Increasing southerly winds are forecast on Saturday into Sunday morning, followed by strong to gale force (25 to 38 mph) northwesterly winds on Sunday afternoon through next Tuesday.

DIABLO CANYON METEOROLOGICAL TOWER WIND DATA:

Today’s winds:

Max peak winds:      SE        8.9 mph at   8:45 a.m.
Max sustained wind:  SE        7.2 mph at   8:45 a.m.

Yesterday’s Maximum Winds:

Max peak winds:      NW       23.0 mph at   4:30 p.m.
Max sustained wind:  NW       19.9 mph at   4:30 p.m.

SEAWATER TEMPERATURES:

The Diablo Canyon waverider buoy is reporting a sea surface temperature of 52.5 degrees while the Nortek AWAC current meter is reporting 52.2 degrees.

Intake seawater temperatures will range between 52- and 54 -degrees through Tuesday, increasing to 53- and 55-degrees on Wednesday through Friday.

OCEAN CURRENTS:

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

This northerly (onshore) flowing current will continue to flow northward through Friday.

SEAWATER VISIBILITY:

Seawater visibility was 18 to 20 feet at the Diablo Canyon Intake.

==========================================================================
24-Hour Ocean Condition Outlook for Monday 02/28 to Tuesday 03/01

Swell           DIR. NW      HT.   3-4   PER.   9-14  This morning
Remaining  at:  DIR. NW      HT.   3-4   PER.   9-14  This afternoon
Remaining  at:  DIR. NW      HT.   3-4   PER.   9-13  Tonight

WINDS:          DIR. SE      SPEED  5-10              This morning
Increasing to:  DIR. NW      SPEED 10-15              This afternoon
Decreasing to:  DIR. SE      SPEED  5-10              Tonight
===========================================================================
48-Hour Ocean Condition Outlook for Tuesday 03/01 to Wednesday 03/02

Swell           DIR. NW      HT.   3-4   PER.   9-13  Tuesday morning
Remaining  at:  DIR. NW      HT.   3-4   PER.   9-13  Tuesday afternoon
Increasing to:  DIR. NW      HT.   3-5   PER.   9-12  Tuesday night

WINDS:          DIR. SE      SPEED  5-10              Tuesday morning
Remaining  at:  DIR. SE      SPEED  5-10              Tuesday afternoon
Increasing to:  DIR. SE      SPEED 15-20 + 25         Tuesday night
===========================================================================

Extended Ocean Condition Outlook:

Today’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    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
02    27    0343     5.7       12            279          54.5
02    28    0643     3.4       14            229          52.5

(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
02 27  0343  173    9     1     3    11    49   225   500   511  259
02 28  0643  103    9     1     3    11    77    48    70   166  155

Daily Swell Inspection Program

NAME                      DAY   TIME    HEIGHT   PERIOD     SST
(PST)   (FEET)  (SECONDS) (DEG. F)
# 166  Ocean Station Papa      28    0402      19       13       41.7
# 06   SE Papa                 28    0650      14       13       52.7
# 59   California Buoy         28    0650      10       13       54.5
# 01   Point Reyes Waverider   28    0646       4       11       50.5
# 15   Monterey Waverider Buoy 28    0650       3        9       52.7
# 28   Cape San Martin, Ca     28    0650       5       10       53.1
# 50   DCPP Waverider Buoy, Ca 28    0643       3       14       52.5
# 63   Harvest Buoy            28    0620       7       10       54.0
# 01   NW Hawaii               28    0650       7       12       73.4

* 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.

Saturday  1500 through Sunday   1500   0.00 inches
Sunday    1500 through Monday   1500   0.00 inches

Precipitation this rain season (July 1 – June 30): 19.67 inches
Average season rainfall at DIP to date:            18.01 inches

Ocean Lab Barometer:   30.24 in/Hg or 1023.9 mb  +0.6 mb (Rising)

Sunrise and Sunset

Today’s         Sunrise 6:33 AM      Sunset 5:58  PM
Tomorrow’s      Sunrise 6:31 AM      Sunset 5:59  PM

Tides:
Low Tide                 High Tide
AM          PM           AM          PM
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
2 Wednesday   2:16  1.8    3:02 -0.2    8:14 5.3    9:25  4.3
3 Thursday    2:53  1.5    3:28  0.0    8:51 5.2    9:47  4.5
4 Friday      3:27  1.3    3:53  0.3    9:26 5.0   10:09  4.6
5 Saturday    4:02  1.1    4:16  0.6   10:01 4.7   10:31  4.7
6 Sunday      4:37  1.0    4:39  0.9   10:37 4.4   10:55  4.8
7 Monday      5:15  0.9    5:02  1.3   11:15 4.0   11:20  4.8
8 Tuesday     5:57  0.9    5:25  1.7   11:59 3.6   11:48  4.8
=========================================================================

This day in weather history

1988 – Thunderstorms in California produced severe weather during the early morning hours. Strong thunderstorm winds, gusting to 74 mph, downed trees in the Sacramento area. Unseasonably mild weather prevailed in the northwestern U.S. The afternoon high of 71 degrees at Portland OR was a February record. (Storm Data)

2006-  Yesterday’s storm produced gale force southerly winds but little rain along Diablo Canyon coastline. The DCPP rain gauge only recorded 0.36 inches or rain which was much less then expected. Areas south of Pt Conception received heavy rain.

=========================================================================
The National Weather Service will conduct Weather Spotter Training at the PG&E Energy Education Center (6588 Ontario Road, San Luis Obispo, CA 93405) this evening 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.

Replication of this email must be in its entirety. You may view and copy material from this forecast, provided you retain all copyright, trademark, and other proprietary notices displayed on the materials. Use of these materials in publications, radio, television, other media presentations, or other websites is prohibited without PG&E’s express written consent.

PG&E is a subsidiary of PG&E Corporation, one of the largest natural gas and electric utilities in the United States, delivering some of the nation’s cleanest energy to 15 million people in northern and central California. If you would like to subscribe or unsubscribe to this daily forecast, please send an email to PGEweather@pge.com. Any questions about this forecast please E-mail John Lindsey at jcl5@pge.com or contact by phone at 546-5265. For more information visit, www.pge.com.