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 28th of November to 94ºF in multiple locations across the island. Temperatures across the U.S. Virgin Islands ranged from 71ºF, November 16th, 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 16th
94ºF in Ponce on November 4th  
94ºF in Gurabo on November 16th  
93ºF in Guayama on November 4th    
93ºF in Rincon on November 25th
92ºF at Corozal, Dos Bocas and Manati

Other Notable November 2009 Low Temps:

59ºF in Toro Negro on November 30th    
59ºF in Cerro Maravilla on November 28th
62ºF in Maricao on November30th   
63ºF in Aibonito on November 28th
64ºF in Lajas on November 29th  
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 17th of the month. The highest weekly rainfall total occurred in Rio Piedras, where 7.83” of rainfall accumulated the week ending November 20th. 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 11th 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 10th, 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 15th.

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 13th & 21st         
73ºF – November 9th
Saint Thomas
89ºF – November 1st  
 
71ºF – November 16th
Saint Croix
89ºF – November 4th & 6th
73ºF – November 11th & 16th

 
November Historical Statistics:
 
Highest November Temperatures on record:
 

San Juan              
96ºF – November 6th, 1981
95ºF – November 7th, 1981
94ºF – November 20th, 1994*
*Most recent occurrence   
Saint Thomas     
95ºF – November 25th, 1995 & November 1st, 1993
94ºF – November 23rd, 1995*
*Most recent occurrence
Saint Croix
93ºF – November 8th, 1993*
*Most recent occurrence

 
Lowest November Temperatures on record:
 

San Juan              
66ºF – November 20th, 1969*
*Most recent occurrence
Saint Thomas
67ºF – November 22nd, 1956*
*Most recent occurrence
Saint Croix
62ºF – November 13th, 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 1st, 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 1st 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 31st, 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 21st, 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 1st 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 2nd 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 16th of the month at 8:02 am AST. The first quarter of the moon will be observed on the 24th of December and the last quarter of the moon will be observed on the 9th 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.
 

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