Drought and Precipitation Statement
For Stations Across
Belize – March 2014
Rainfall assessment of the country monthly average rainfall for March 2014 showed that most stations received rainfall below their climatological (1981-2010). normal.
Of the seventeen stations that was used for the assessment, only three stations recorded above normal rainfall; Melinda Forest station( South) 105.3% or 59.5mm, Pomona (South)104.4% or 69.0mm and Philip Goldson International Airport with 102.4% or 47.9mm.
Three stations received more than 70% of their normal; Big Falls Plantation (South)98.8% or 67.3mm, Spanish Lookout (Cayo) 97.3% or 43.1mm, Middlesex(South) 74.2% or 50.3mm.
Eleven stations recorded below 60% of their Normal, with Central Farm ( Cayo district) recording the lowest percentage; Central Farm 17.4% or 7.9mm
Assessment of the drought conditions showed that, although most of the country received rainfall below their normal for the month of March 2014, the December 2013through to March 2014 assessment showed normal to above normal rainfall. The entire country is NOT experiencing any sort of drought.
The seasonal precipitation forecast for the period April-May-June 2014 is going for equal chance of normal to below normal rainfall for the entire country.
Drought is a deficiency of precipitation over an extended period of time--usually a season or more.
National Meteorological Service of Belize is now using the Standard Precipitation Index to monitor the likely hood of drought across Belize.
The Standardised Precipitation Index (SPI) was developed by T.B. Mckee, N.J. Doesken and J. Kleist (McKee et al. 1993) of Colorado State University is an index that, if used carefully, can provide early warning of an extended drought period and aid in assessing drought severity. It can also provide similar information at the other end of the spectrum- extremely high precipitation. SPI is basically a representation of rainfall in units of standard deviation. Positive values indicate greater than median rainfall; negative values indicate less than median rainfall. The severity classes are shown in Table 1.
This Category of classification, that is used in the Caribbean since January of 2011 was develop by Caribbean Institute of Meteorology & Hydrology in Barbados.
Table 1 SPI classification used from January 2011
This article is courtesy of Caribbean Institute of Meteorology & Hydrology.
The SPI is flexible and can be calculated for different time scales. A time scale analysis reflects the impact of drought on the availability of the different water resources. A one-month SPI analysis reflects short term soil moisture and crop stress especially during the growing season. A three-month SPI analysis reflects short to medium term moisture and can give an indication of available moisture conditions at the beginning of the growing season. A six-month SPI analysis reflects medium term trends in rainfall and is effective in showing rainfall distribution over distinct seasons as well as being associated with anomalous stream flows and reservoir levels, which takes longer to manifest itself than does agricultural drought. A twelve-month SPI can indicate potential periods of shortfall in groundwater amounts.
Standardized Precipitation Index Outlook for a few stations across Belize is being done by using the historical records and seasonal precipitation April-May-June 2014outlook generated by Caribbean Regional Climate Outlook Forum (CariCOF).
The Results of the Standard Precipitation Index calculations for a few stations across Belize
With rainfall projected to be normal to below normal for April-May-June 2014, the country have a higher chance of experiencing abnormally to moderately dry condition.
The information contained herein is provided with the understanding that The National Meteorological Service of Belize makes no warranties, either expressed or implied, concerning the accuracy, completeness, reliability, or suitability of this statement. The information may be used freely by the public with appropriate acknowledgement of its source, but shall not be modified in content and then presented as original material.
Next Drought Statement will be issued in the first week of May 2014.