S232 | August 2013

in February 2012 was 65% higher than the long-term 

mean and the seventh wettest.

A total of six tropical cyclones reached Mexican 

territory in 2012 [two (four) of them in the Atlantic 

(Pacific) basin]. Of those, two storms had significant 

impacts: on 15 June, Hurricane Carlotta made land-

fall on the Mexican Pacific coast and followed a tra-

jectory to the northwest from Oaxaca and Guerrero 

to Michoacán. Despite bringing an important amount 

of rainfall at the initial stage of the rainy season, it 

damaged national infrastructure and set a new record 

for total daily precipitation at Tuxtepec, Oaxaca, of 

350.0 mm (16 June 2012), surpassing the previous 

record of 342.0 mm (9 July 1956). The second storm, 

Hurricane Ernesto, made landfall on 7 August on the 

Caribbean coast and tracked through the country 

to reach the Pacific coast. Significant precipitation 

associated with Hurricane Ernesto was reported at 

various locations in the states of Tabasco, Veracruz, 

and Puebla. New daily precipitation records were set 

in at least two locations: Naranjal, Veracruz (353 mm), 

and Jacatepec, Oaxaca (344 mm), breaking records of 

332.0 mm day-1 (18 September 1960) and 324.5 mm 

day-1 (25 July 1973), respectively.

In terms of agriculture, 2012 was considered a 

good year at the national scale, with a low incidence in 

crop losses due to a near-normal rainy season. When 

it comes to livestock, bovine milk production grew up 

by ~2% in comparison to 2011, though beef produc-

tion still decreased as a result of a reduced population 

in cattle due to the long-term drought in 2011.

c. Central America and the Caribbean

1) Central aMeriCa—J. A. Amador, E. J. Alfaro, B. Calderón, 

A. M. Durán-Quesada, H. G. Hidalgo, and i. L. Rivera

For this region, nine stations from five countries 

were analyzed. The stations located on the Caribbean 

slope are: Phillip Goldson International Airport, 

Belize; Puerto Barrios, Guatemala; Puerto Lempira, 

Honduras; and Puerto Limón, Costa Rica. The fol-

lowing stations are located on the Pacific slope: 

Tocumen International Airport and David, Panamá; 

Liberia, Costa Rica; Choluteca, Honduras; and San 

José, Guatemala. The analysis follows Amador et al. 

(2011) for all variables, except that the base period for 

computing anomalies was 1981–2010.

(i) Temperatures

The mean temperature (Tm) distributions for all 

stations are shown in Fig. 7.11. There was little de-

parture from mean values at Phillip Goldson, Puerto 

Lempira, and Puerto Limón. Puerto Barrios presented 

a significant decrease in mean temperatures of the 

order of 2°C. The Tm skewness to the left at Phillip 

Goldson and Puerto Barrios on the Caribbean slope 

in both the climatology and for 2012 is remarkable, 

and is most likely a result of frequent cold front intru-

sions during the winter months. In all stations except 

Puerto Limón, the median Tm had a greater (15% to 

30%) frequency than its corresponding climate value, 

and as a consequence, Tm presented less variability 

and lighter tails. 

(ii) Precipitation

All stations showed normal wet season (May–

November) values of maximum 5-day precipitation, 

wet season interquartile range (an indicator of vari-

ability), and wet season mean precipitation. During 

the wet season the total number of dry pentads was 

normal for all stations in 2012. In terms of the number 

of dry pentads during the wet season, Puerto Limón 

was on the cusp of being characterized as wetter-

than-normal (p=0.05). Across the isthmus, the Pacific 

slope stations David, Liberia, Choluteca, and San 

José, showed a similar pattern of late starts and early 

ends of the rainy season. Tocumen was not consid-

ered in this analysis because of the large amount of 

missing data during 2012. The start and end of the 

rainy season is calculated as follows: starting from 

the beginning of the year, if in any particular pentad 

at time “t” the precipitation was greater or equal to 

25 mm, and the precipitation of pentad t+1 was also 

greater or equal to 25 mm, and the precipitation of 

t+2 was greater than zero, it was considered that the 

rainy season started at time t. A similar procedure 

was used for computing the end of the rainy season, 

with the exception that the procedure was applied 

from the end of the year backwards.

The region was under the influence of El Niño con-

ditions, based on positive values of the Multivariate 

ENSO Index, especially from April to September with 

stronger than average 925 hPa winds during July (in-

serted arrows in map in Fig. 7.11), a characteristic of El 

Niño events in the region and a condition unfavorable 

for tropical cyclone formation (Amador et al. 2006). 

During March–May 2012, large low-level conver-

gence anomalies were found over the Caribbean and 

northern Central America increasing precipitation, 

whereas drier conditions were observed over southern 

Central America (mainly Costa Rica). Summer was 

characterized by a decrease in the moisture avail-

ability over the Caribbean Sea where the intensity of 

low-level winds increased compared to the base pe-

riod (see inset map in Fig. 7.11), which resulted in the 



S233stAtE OF tHE CLIMAtE IN 2012 |August 2013

decrease of the moisture transport that contributes to 

precipitation over Central America. Note that the in-

tensification of the Caribbean low-level jet enhances 

the trans-isthmic transport. The second part of the 

rainy season started with a marked decrease in the 

moisture availability for southern Central America 

(September). A generalized drier-than-normal peak 

during the second part of the rainy season (October) 

was observed in the interim reanalysis data. 

(iii) Notable events

The year 2012 was near average for tropical storms 

in the Caribbean Sea (6°N−24°N, 92°W−60°W). In 

this basin there were four named storms, two hur-

ricanes, and no major hurricanes. Hurricane Ernesto 

made landfall in Belize, but the main impact was to 

Guatemala where it produced intense rain, forcing 

150 people to evacuate their homes due to f loods 

and power cuts and damaging 30 houses. Guatemala 

reported drought conditions July–August with esti-

mated losses over $10 million (US dollars). A low pres-

sure system (18–29 May) and an upper-level trough 

(16–20 June) impacted Honduras, causing six and two 

fatalities, respectively. Costa Rica suffered through 

a “temporal” (a period of rain of variable intensity, 

lasting for several days and affecting a synoptic-scale 

region), that caused three fatalities during 27–30 June. 

Two more casualties were reported in early August 

due to the passage of an intense tropical wave. The 

indirect effects of Hurricane Isaac (see Peña and 

Douglas 2002 for mechanisms) were felt in Costa 

Rica around 15 October, causing floods in the north, 

the Central Pacific, and the Central Valley. Temporal 

conditions in Costa Rica (21–25 October), associated 

with the indirect effect of Hurricane Sandy, produced 

intense rainfalls over the nation’s Pacific coast, caus-

Fig 7.11. mean surface temperature (tm) frequency and accumulated pentad precipitation (P) time series shown 
for the 9 stations (blue dots depict station location) in Central america: (1) Phillip goldson international air-
port, belize; (2) Puerto barrios, guatemala; (3) Puerto lempira, Honduras; (4) Puerto limón, Costa Rica; (5) 
tocumen international airport, Panama; (6) David, Panama; (7) liberia, Costa Rica; (8) Choluteca, Honduras; 
and (9) san José, guatemala. the blue line represents the 1981–2010 mean and the red line shows 2012. Wind 
anomaly vectors at 925 hPa, based on 1981–2010 base period for July, are also shown. map also shows regional 
elevation (m). (source: noaa/nCDC.)



S234 | August 2013

ing overf lowing rivers, landslides, and damage to 

roads and houses. These conditions affected more 

than 3000 people due to floods, landslides, obstructed 

roads, fallen electrical wires and trees, and also dam-

aged 922 houses in Panama. Heavy rainfalls resulted 

in three casualties in Panama on 25–29 November.

2)  the Caribbean—M. A. Taylor, J. Campbell, T. Stephenson, 

and A. Trotman

This report covers the island chain of the Carib-

bean basin. Unless otherwise noted, records set are 

with respect to the following years for the following 

territories: Jamaica, 1952; Puerto Rico, 1898; St. Croix, 

1972; St. Thomas, 1953; Antigua, 1928; Grenada, 

1985; Dominica, 1982; and Barbados, 1942. Normal 

conditions for these and other territories discussed 

are estimated from the 1981–2010 base period, unless 

otherwise noted.

(i) Temperatures

The Caribbean was warmer than usual in 2012, 

particularly over the Greater Antilles (Fig. 7.12a). 

This was due to an unusually warm second half of 

the year (Fig. 7.12b). Summer 2012 (June–August) 

was the third warmest in the San Juan metro area, 

Puerto Rico, with June being its warmest month ever 

recorded. San Juan also had its eighth warmest July, 

warmest August, fourth warmest October, warmest 

November, and ninth warmest December. St. Thomas 

had its eighth warmest June, seventh warmest Octo-

ber, and ninth warmest November. St. Croix had its 

ninth warmest October. In Jamaica, mean maximum 

temperatures for November through December 

exceeded the 1992–2011 average. Prior to sum-

mer, the tendency was for normal to below-normal 

temperatures. Antigua had its 3rd coldest May and 

Puerto Rico had its 11th coolest May. The temperature 

variations were due in part to dramatic sea surface 

temperature (SST) anomaly changes over the tropical 

Atlantic during 2012. Positive 2011 anomalies rapidly 

disappeared during the winter (December–February) 

months. A dramatic upswing in the North Atlantic 

Oscillation (NAO) around 1 May resulted in weak 

trade winds and anomalous warm SSTs that lasted 

through October.

(ii) Precipitation

The Caribbean experienced a dry 2012. The 

northwest Caribbean and northern Lesser Antilles 

were drier than normal (Fig. 7.13). This would also 

have been true for the southern Caribbean had it not 

been for an anomalously “wet” dry season (Decem-

ber–April) at the start of the year.

Weak-to-moderate La Niña conditions at the 

start of the year resulted in a dry north-wet south 

rainfall gradient. Consequently, January–May was 

much wetter than normal for Trinidad, Tobago, 

and Grenada. January rainfall was 156%, 184%, and 

Fig. 7.12. (a) 2012 and (b) Jun–nov 2-m temperature 
anomalies (°C) for the Caribbean basin. anomalies are 
with respect to 1981–2010 base period. (source: nCeP/
nCaR reanalysis.)

Fig. 7.13. 2012 rainfall anomalies (mm) with respect 
to 1981–2010 base period. (source: nCeP/nCaR 
reanalysis.)