November 2009 Climate Report

November 2009 Climate Report for Puerto Rico and the U.S. Virgin Islands

November 2009 Highlights:

Temperatures across Puerto Rico ranged from 54ºF in Adjuntas on the 28^th of November to 94ºF in multiple locations across the island. Temperatures across the U.S. Virgin Islands ranged from 71ºF, November 16^th, at the Charlotte Amalie Airport on Saint Thomas, to 89ºF, observed at Red Hook Bay, Charlotte Amalie as well as Christiansted during the course of the month. Other notable temperatures for November 2009 are listed below:

Other Notable November 2009 High Temps:

94ºF in Rio Piedras on November 16^th

94ºF in Ponce on November 4^th

94ºF in Gurabo on November 16^th

93ºF in Guayama on November 4^th

93ºF in Rincon on November 25^th

92ºF at Corozal, Dos Bocas and Manati

Other Notable November 2009 Low Temps:

59ºF in Toro Negro on November 30^th

59ºF in Cerro Maravilla on November 28^th

62ºF in Maricao on November30^th

63ºF in Aibonito on November 28^th

64ºF in Lajas on November 29^th

65ºF in Arecibo, Ponce and Gurabo

^{*If multiple occurrences, all dates above reflect the most recent occurrence of the month.}

The highest 24-hour precipitation total for the month of November was 4.60”, which fell at Toro Negro on the 17^th of the month. The highest weekly rainfall total occurred in Rio Piedras, where 7.83” of rainfall accumulated the week ending November 20^th. While just under five inches of rain fell on Saint Croix during the month of November, this was still nearly an inch below normal for the month and also marked the 11^th consecutive month with below normal rainfall recorded at the Christiansted Airport on Saint Croix.

Figure 1A – Island wide precipitation for January-November2009

Figure 1B – Graphical Display of November 2009 precipitation across Puerto Rico and the U.S. Virgin Islands derived from a combination of rain gage and radar data.

Monthly Weather Summary:

November 2009 began with the remnants of an old frontal boundary just northeast of the local islands and associated area of low pressure across the northern Atlantic that brought scattered showers and large seas to the forecast area. Weather events associated to the proximity of old boundaries are regular during the late fall and winter season months. The major threats related to these old boundaries are brief periods of moderate to heavy rainfall and large seas generated by the associated areas of low pressure to the north.

On November 10^th, maximum temperatures across the island were well below normal due to another, stronger, frontal shearline (old boundary). Maximum temperatures only reached 79°, 78° and 75° at WFO San Juan, Vega Baja and Arecibo respectively. By mid November, an unusual south to southwest wind flow brought scattered to numerous showers across the north and northeast sections of Puerto Rico. For this particular event, measurements indicated 2.62",3.15" and 2.36" of rainfall accumulated at the Adjuntas Substation, Orocovis and the WFO San Juan respectively. Also, a new record river stage was set along the Rio Piedras River in the San Juan Metro area after several very wet days, when it crested at 26.30 feet on November 15^th.

November 2009 ended as the third wettest November on record at Luis Muñoz Marin Airport in San Juan when 12.14 inches of rain was recorded. To put this in perspective, LMM airport normally averages only 6.17” of rain in a typical November. The two wettest Novembers on record remain 1979 and 1977, when 15.96” and 12.44” inches of rain were recorded respectively. Across the island, precipitation totals varied between 1.29" and 12.90" for the month.

November 2009 marks the end of the 2009 hurricane season. The tropical cyclone activity during this season was below normal. A total of nine named stormed were observed in the Atlantic basin, three of which became hurricanes and two of which were major hurricanes.

November 2009 Statistics:

Average November Temperatures/Precipitation (NCDC 1971-2000 averages):

High:

Low:

AvgT:

Pcpn:

San Juan

85.1ºF

74.0ºF

79.6ºF

6.17”

Saint Thomas

87.8ºF

74.9ºF

81.4ºF

5.28”

Saint Croix

87.0ºF

74.3ºF

80.7ºF

5.55”

November 2009 Observations:

High:

Low:

AvgT:

Pcpn:

San Juan

86.8ºF (+1.7ºF)

75.8ºF (+1.8ºF)

81.3ºF (+1.7ºF)

12.14” (+5.97”)

Saint Thomas

86.5ºF (-1.3ºF)

76.4ºF (+1.5ºF)

81.5ºF (+0.1ºF)

9.96” (+4.68”)

Saint Croix

86.9ºF (-0.1ºF)

75.5ºF (+1.2ºF)

81.2ºF (+0.5ºF)

4.72” (-0.83”)

November 2009 Extremes:

High:

Low:

San Juan

91ºF – November 13^th & 21^st

73ºF – November 9^th

Saint Thomas

89ºF – November 1^st

71ºF – November 16^th

Saint Croix

89ºF – November 4^th & 6^th

73ºF – November 11^th & 16^th

November Historical Statistics:

Highest November Temperatures on record:

San Juan

96ºF – November 6^th, 1981

95ºF – November 7^th, 1981

94ºF – November 20^th, 1994*

*Most recent occurrence

Saint Thomas

95ºF – November 25^th, 1995 & November 1^st, 1993

94ºF – November 23^rd, 1995*

*Most recent occurrence

Saint Croix

93ºF – November 8^th, 1993*

*Most recent occurrence

Lowest November Temperatures on record:

San Juan

66ºF – November 20^th, 1969*

*Most recent occurrence

Saint Thomas

67ºF – November 22^nd, 1956*

*Most recent occurrence

Saint Croix

62ºF – November 13^th, 1983*

*Most recent occurrence

Wettest Novembers:

San Juan

15.96” November 1979

12.44” November 1977

12.14” November 2009

Saint Thomas

18.39” November 2003

14.73” November 1984

10.36” November 1987

Saint Croix

18.03” November 2003

16.34” November 1974

13.25” November 1987

Driest Novembers:

San Juan

1.91” November 1980

2.31” November 1971

2.65” November 2002

Saint Thomas

0.78” November 1962

0.90” November 1963

1.35” November 1980

Saint Croix

0.86” November 1995

1.09” November 1960

1.11” November 1976

2000-2009 Decade in Review:

Decadal Observations for San Juan, Puerto Rico:

Decadal November High Temperatures:

2000’s		1990’s		1980’s		1970’s		1960’s		1950’s*
*85.7ºF*		*86.4ºF*		*86.3ºF*		*86.0ºF*		*85.3ºF*		*85.2ºF*

Decadal November Low Temperatures:

2000’s		1990’s		1980’s		1970’s		1960’s		1950’s*
*74.6ºF*		*74.4ºF*		*74.2ºF*		*75.1ºF*		*72.5ºF*		*71.2ºF*

Decadal November Average Temperatures:

2000’s		1990’s		1980’s		1970’s		1960’s		1950’s*
*80.1ºF*		*80.4ºF*		*80.3ºF*		*80.6ºF*		*78.9ºF*		*78.2ºF*

Decadal November Precipitation:

2000’s		1990’s		1980’s		1970’s		1960’s		1950’s*
*6.51”*		*7.06”*		*4.86”*		*7.01”*		*5.89”*		*4.18”*

* Records for San Juan began on January 1^st, 1956

Figure 2 - Temperature deviations for San Juan, PR

Figure 3 - Temperature deviations for Saint Thomas, VI

Figure 4 - Temperature deviations for Saint Croix, VI

Figure 5 - November precipitation deviations 2000's

Figure 6 - Year-to-Date precipitation deviations for San Juan, Saint Thomas, and Saint Croix

Looking ahead toward the month of December:

Average December Temperatures/Precipitation (NCDC 1971-2000 averages):

High:

Low:

AvgT:

Pcpn:

San Juan

83.2ºF

72.1ºF

77.7ºF

4.57”

Saint Thomas

86.2ºF

73.2ºF

79.7ºF

2.74”

Saint Croix

85.0ºF

72.8ºF

78.9ºF

3.29”

Moon/Sun/Tide Data for the month of December:

The sun rises at 6:41 am AST on the 1^st of December and sets at 5:47 pm AST, in San Juan, Puerto Rico. This represents a total of 11 hours and 6 minutes of daylight. By December 31^st, the sun will rise at 6:56 am AST and set at 5:59 pm AST, providing a total of 11 hours and 3 minutes of daylight, or a total decrease of just 3 minutes over the course of the month (the winter solstice, the shortest day of the year, falls on December 21^st, 2009). At Charlotte Amalie on Saint Thomas, the sun will rise at 6:36 am AST and set at 5;42 pm AST on the 1^st of the month. By the end of the month, the sun will rise at 6:51 am AST and set at 5:54 pm AST, also representing a total decrease in daylight of just 3 minutes for the month.

For the month of December, a full moon will be observed on the 2^nd of the month at 3:30 am AST and a blue moon will be observed on New Years Eve at 3:13 pm AST. This marks the first blue moon since June 2007, and first blue moon to fall on New Years Eve since 1990. The next blue moon to fall on New Years Eve will not be until 2028! There will also be a new moon on the 16^th of the month at 8:02 am AST. The first quarter of the moon will be observed on the 24^th of December and the last quarter of the moon will be observed on the 9^th of the month.

Links to additional sunrise/sunset data, phases of the moon, as well as tide data can all be found by clicking on the climate link of the National Weather Service San Juan homepage (www.srh.noaa.gov/sju) and then clicking on the Astronomical tab.

National Weather Service Weather Forecast Office