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Cold fronts (CF) are the synoptic systems of mean latitudes that, after moving first to the southeast on the Gulf of Mexico and then to the east, affect Cuba. They show up in the denominated not very rainy or dry period, which extends from the month of November until April, although these synoptic situations have occurred in the months of September (7 CF’s) and June (4 CF’s). The period in which CF’s affect Cuba, is also denoted as the fronts season.
The average cold front in a season is of the classic type and moderate intensity (with maximum winds between 36 Km/h and 55 Km/h). The type of classic CF, is the one that is associated to a center of low pressures, which moves from West to East over the Gulf of Mexico or the southern states of the United States. It is also preceded by winds of South region on the occident of Cuba, well known as " SOUTH ".
Cuba has been affected by very strong CF’s, with average winds registered of 98 Km/h and maximum gusts of 115 Km/h.
In presence of the ENOS event, a positive anomaly reveals in the number of the CF’s that affect Cuba.
The shortest seasons are those in which CF’s have only affected in a period of six months, beginning in October - November and ending in March - April. While those of more duration extend until June and may begin as early as September - October, embracing a winter period of nine months.
CF’s are preceded by throughs, denominated prefrontal throughs. In occasions they are very active bringing in severe weather, in which hail, precipitation of the order of the 100mm/24 hours and Severe Local Storms occur. An example of a very active prefrontal through, is the so-called Storm of the Century (March 1993).
| Based on the Chronology of the Cold Fronts (Rodríguez et al., 1984) and in the Climatology of the Cold Fronts (González, 1999), the characterization of these synoptic systems was elaborated for the period from 1916-1917 to 1999-2000 embracing 84 front seasons. From this characterization you will learn the following: | |
| Total of cold fronts (CF) that have affected Cuba (from 1916 until May 2000) | 1663 |
| Average of CF’s per season that affect the Cuban archipelago | 19.8 |
| Season with the smaller number of CF’s that have affected Cuba | 1996 - 1997 |
| Amount of CF’s in the season with smaller number of CF’s that have affected Cuba | 11 |
| Season with higher number of CF’s that have affected Cuba | 1976 - 1977 |
| Amount of CF’s in the season with higher number of CF’s that have affected Cuba | 35 |
| Months with higher number of CF’s | January and February |
| Amount of CF’s in the months with higher number of cold fronts | 9 |
| Month in that the CF’s has always affected (the only one) | February |
| Bigger number of serial days without CF’s affecting, once the season has begun | 61 |
| Amount of seasons with 30 CF’s or more | 1 |
| Amount of seasons with an amount of CF’s between 25 and 30 | 10 |
| Provinces more affected by CF’s | Pinar del Río, La Habana and Ciudad de la Habana |
| Provinces less affected by CF’s | Granma, Santiago de Cuba and Guantánamo |
| Minimum temperature registered during the step of a CF (date, place and registered value) | 10/02/1996 - Bainoa, La Habana - 0,6°C |
Rodriguez, R. M., et al. (1984): Cronología de los frentes fríos que han afectado a Cuba desde la temporada de 1916-17 hasta la temporada de 1982-83 (67 temporadas) ACC, Reporte de Investigación, No.9. pp. 15.
González, P. C. (1999): Climatología de los frentes fríos que han afectado a Cuba desde 1916-17 hasta 1996-97. Rev. Cub. Met. vol. 6, no.1. pp. 15-19.
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