Weather forecast for Thursday February 9

February 10, 2011

By JOHN LINDSEY from PG&E

SEA SWELL:

Today’ 4 to 6-foot west-northwesterly (285-degree deep-water) swell (with an 8 to 17-second period) will continue at this height and period along our coastline through tonight, decreasing to 3 to 4-feet (with an 8 to 14-second period) on Friday.

This west-northwesterly swell will further decrease to 2 to 4-feet on Saturday.

Increasing northwesterly winds along the coastline will generate a 4 to 6-foot northwesterly (310-degree deep-water) sea and swell (with a 5 to 14-second period) along our coastline on Sunday, becoming a 3 to 5-foot northwesterly swell (with an 11 to 13-second period) on Monday.

Fresh to strong (19 to 31-mph) southerly winds will generate a 2 to 4-foot southerly (180-degree shallow-water) seas (with a 4 to 6-second period) Monday afternoon and night, building to 5 to 7-feet on Tuesday morning.

An 8 to 10-foot westerly (285-degree deep-water) swell (with an 8 to 12-second period) will arrive along our coastline by Tuesday afternoon, shifting out of the west-northwest by
Wednesday morning.

A series of storms in the Gulf of Alaska will produce an 11 to 13-foot northwesterly (320-degree deep-water) swell (with a 15 to 17-second period) along our coastline Wednesday
afternoon and should continue at this height through most of next week.

PG&E San Francisco Met Office predicted temps:

Inland Temperatures, Paso Robles

Actual                    Predicted

Wed           Thu         Fri         Sat         Sun         Mon         Tue         Wed        Thu
27-64      26-65    35-70  34-71   34-71     34-66     42-59     41-58    35-59

Coastal Valleys Temperatures, San Luis Obispo

Wed          Thu         Fri         Sat         Sun         Mon         Tue         Wed         Thu
38-70     47-73   37-74   37-74 37-72    39-67     45-59      45-57     40-61

ATMOSPHERIC CONDITION:

Gusty night and morning northeasterly (offshore) winds will continue to produce clear skies with mild overnight low’s and warm afternoon high’s through Friday in the coastal valleys and along the beaches.

However, in the North County overnight low temperatures will be cold. The Paso Robles Airport is reporting a low temperature of 26 degrees this morning.

High temperatures in the afternoon will reach the 70s in most areas.

Increasing northwesterly (onshore) winds over the weekend will allow the marine layer to redevelop along the coastal areas during the night and morning hours. This condition will give cooler afternoon high’s but warmer overnight low’s, especially in the North County.

A major change in the weather pattern will develop next week, finally bringing an end to our long dry period.

The Eastern Pacific High will slide southward towards the Baja Peninsula. At the same,  the strong high pressure ridge responsible for the dry weather during the first part of February will gradually weaken and migrate westward. This condition will open the door to a series of low pressure systems next week.

A 1,001 millibar low pressure system will develop about 300 miles to west of San Luis Obispo on Monday and the associated cold front will pass our area Tuesday morning with fresh to strong southeasterly winds and rain.  an upper-level trough will follow about 24 hours later producing scattered rain showers into Wednesday.

At this time, rainfall totals should range between 0.75 and 1.25 inches. Heavy snow is expected across the Sierra, with snow levels initially at 6,500 feet, then dropping to 3,000 feet or possibly lower by Wednesday.

Another low pressure system will likely follow by the end of next week and into the Presidents’ Day Holiday weekend for another round of rain, gusty winds, and heavy mountain snow
as the storm door should be wide open for the second half of February.

DIABLO CANYON AIR TEMPERATURES:

Diablo Canyon Meteorological Tower Air Temperature Data

Yesterday’s         Today’s          Tomorrow’s
Min    Max        Min    Max         Min     Max
52.1°   58.4°     55.1°   67.0°      53.0     65.0

WINDS:

A pattern of moderate to fresh (13 to 24 mph) northeasterly (offshore) winds developing during the night and morning hours, shifting out of the northwest during the afternoon hours will continue through Saturday morning.

Moderate to fresh (13 and 24 mph) northwesterly winds are forecast on Saturday afternoon through Sunday.

Increasing southerly winds are forecast on Monday morning, reaching fresh to strong (19 to 31 mph) levels by Monday night into Tuesday morning.

These winds will decrease and shift out of the southwest later on Tuesday and remain at this direction through Wednesday.

DIABLO CANYON METEOROLOGICAL TOWER WIND DATA:

Today’s winds:

Max peak winds:      NE       33.8 mph at   6:30 a.m.
Max sustained wind:  NE       17.9 mph at   6:30 a.m.

Yesterday’s Maximum Winds:

Max peak winds:      NE       33.6 mph at   2:15 a.m.
Max sustained wind:  NE       24.4 mph at   2:30 a.m.

SEAWATER TEMPERATURES:

The Diablo Canyon waverider buoy is reporting a sea surface temperature of 53.2 degrees while the Nortek AWAC current meter is reporting 53.0 degrees.

Intake seawater temperatures will range between 52 and 54 -degrees through Friday, increasing to 53 and 55 degrees over the weekend.

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 next week.

SEAWATER VISIBILITY:

Seawater visibility was 12 to 14 feet at the Diablo Canyon Intake.

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24-Hour Ocean Condition Outlook for Thursday 02/10 to Friday 02/11

Swell           DIR. WNW     HT.   4-6   PER.   8-17  This morning
Remaining  at:  DIR. WNW     HT.   4-6   PER.   8-17  This afternoon
Remaining  at:  DIR. WNW     HT.   4-6   PER.   8-15  Tonight

WINDS:          DIR. NE      SPEED 15-20 + 35         This morning
Decreasing to:  DIR. NW      SPEED 10-15              This afternoon
Increasing to:  DIR. NE      SPEED 10-15 + 20         Tonight
===========================================================================
48-Hour Ocean Condition Outlook for Friday 02/11 to Saturday 02/12

Swell           DIR. WNW     HT.   3-5   PER.   8-15  Friday morning
Decreasing to:  DIR. WNW     HT.   3-4   PER.   8-14  Friday afternoon
Remaining  at:  DIR. WNW     HT.   3-4   PER.   8-13  Friday night

WINDS:          DIR. NE      SPEED 10-15 + 25         Friday morning
Decreasing to:  DIR. NW      SPEED 10-15              Friday afternoon
Decreasing to:  DIR. N       SPEED  5-10              Friday night
===========================================================================

Extended Ocean Condition Outlook:

Another low pressure system will likely follow by the end of next week and into the Presidents’ Day Holiday weekend for another round of rain, gusty winds, and heavy mountain snow
as the storm door should be wide open for the second half of February.

===========================================================================
The 24 – Hour Ocean Data From The Diablo Canyon Wave rider Buoy
MONTH  DAY  TIME  SIG.HEIGHT   PERIOD   SWELL DIRECTION     SST
02    06    0543     6.4       11            282          54.0
02    07    0743     4.3       11            279          55.9
02    08    0913     8.5       10            295          56.3
02    09    1513     4.9       11            285          53.1
02    10    0413     4.4       17            261          53.2

(cm) (sec)  22+   20    17    15    13     11    9    7
———————————————————————–
02 06  0543  195    9     1     5    16   123   238   620   674  281
02 07  0743  132    9     1     5     4    37   151   272   279  163
02 08  0913  259    9     5    17   102   277   462   992  1420  448
02 09  1513  150   11     8    35     6    46   151   401   277  246
02 10  0413  133   17     5    46   258    87    70   254   126  135

Daily Swell Inspection Program

NAME                      DAY   TIME    HEIGHT   PERIOD     SST
(PST)   (FEET)  (SECONDS) (DEG. F)
# 166  Ocean Station Papa      10    0402       9       11       42.8
# 06   SE Papa                 10    0450       7       13       54.7
# 59   California Buoy         10    0450      10       13       55.2
# 01   Point Reyes Waverider   10    0446       7       15       50.7
# 15   Monterey Waverider Buoy 10    0450       5       15       53.4
# 28   Cape San Martin, Ca     10    0450       7       16       54.3
# 50   DCPP Waverider Buoy, Ca 10    0413       4       17       53.2
# 63   Harvest Buoy            10    0420       7       17       54.5
# 01   NW Hawaii               10    0450       7       12       74.5

* 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.

Tuesday    1500 through Wednesday  1500   0.00 inches
Wednesday  1500 through Thursday   1500   0.00 inches

Precipitation this rain season (July 1 – June 30): 17.67 inches
Average season rainfall at DIP to date:            14.54 inches

Ocean Lab Barometer:   30.11 in/Hg or 1019.7 mb  -0.4 mb (Falling)

Sunrise and Sunset

Today’s         Sunrise 6:54 AM      Sunset 5:40  PM
Tomorrow’s      Sunrise 6:53 AM      Sunset 5:41  PM

Tides:
Low Tide                 High Tide
AM          PM           AM          PM
10 Thursday    9:58  1.4    7:36  2.5    2:11 4.7    4:19  2.7
11 Friday     11:16  1.0    8:46  2.7    3:07 4.8    6:31  2.8
12 Saturday  (12:16  0.5)  10:28  2.9    4:10 5.0    7:26  3.1
13 Sunday     (1:02  0.0)  11:46  2.7    5:13 5.3    7:57  3.4
14 Monday     —–  —    1:42 -0.5    6:09 5.6    8:24  3.7
15 Tuesday    12:46  2.4    2:19 -0.8    7:00 6.0    8:52  4.0
16 Wednesday   1:39  2.0    2:55 -1.0    7:49 6.2    9:22  4.3
17 Thursday    2:30  1.6    3:31 -1.0    8:37 6.2    9:53  4.7
18 Friday      3:20  1.2    4:06 -0.8    9:25 6.1   10:27  5.1
19 Saturday    4:12  0.8    4:42 -0.4   10:15 5.7   11:03  5.4
20 Sunday      5:07  0.5    5:19  0.2   11:08 5.1   11:43  5.6
21 Monday      6:06  0.4    5:58  0.8   —– —   12:07  4.5
22 Tuesday     7:13  0.4    6:40  1.5   12:26 5.7    1:17  3.8
=========================================================================

This day in weather history

1978 – As much as eight inches of rain drenched southern California resulting in widespread flooding and mudslides. The heavy rainfall produced a wall of water which ripped through the mountain resort community of Hidden Springs drowning at least thirteen persons. The storm was one of the most destructive of record. (David Ludlum)

1982 – Bismarck, ND, experienced its 45th consecutive day of subzero temperature readings which tied the previous record long string of subzero daily lows ending on the same date in 1937. (David Ludlum)

1988 – Bitter cold arctic air gripped the north central U.S. International Falls MN was the cold spot in the nation with a low of 35 degrees below zero.

Record warm readings were reported in southern California, with highs of 78 at San Francisco and 88 at Los Angeles. San Juan Capistrano CA was the hot spot in the nation with a high of 92 degrees. (The National Weather Summary)

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