Monthly Weather Summary, May 2020
National Meteorological Service of Belize
Climatologically May is the warmest month of the year in Belize. The first part of the month is typically characterized by warm, dry and hazy conditions. However, this month is also the transition month from the dry to the wet season across the country. Therefore, the rains usually start in the south after the first week of May and gradually make their way northwards.
May 2020 started mainly fair across the country with only isolated thunderstorms over the Maya Mountains in the afternoon on the first day. A light easterly to northeasterly surface flow prevailed due to a pre-frontal trough that was located just east of the country. However, the cold front only reached as far as southern Yucatan on the second where the tail end dissipated. Showers were generally isolated and affected coastal areas in the morning and mountainous areas during the afternoon. From the 3rd to the 4th, weather conditions continued mostly fair except for isolated showers along with isolated thunderstorms over the mountains in the afternoon and over the Toledo district at night. Rain and thunderstorms affected Punta Gorda on the morning of the 5th supported by relatively moist and divergent conditions aloft. Elsewhere generally fair weather conditions prevailed.
Moist and unstable conditions prevailed across the country from the 6th as a high pressure system behind a stationary front over the southern Gulf of Mexico induced a northeasterly and easterly to northeasterly airflow over the area. Skies were mostly cloudy with isolated showers over central areas on the 6th morning and isolated thunderstorms over the south and near the western border during the afternoon then several showers affected most areas overnight. The cloudiness persisted on the 7th and a few showers and thunderstorms affected inland areas in the morning and spread over most areas during the afternoon but were concentrated mainly over the south by nightfall. Skies remained cloudy on the 8th and 9th as showers and thunderstorms continued to affect the country but especially southern and coastal areas at night and during the morning then northern and inland areas during the afternoon and evening. The 10th saw a gradual decrease in moisture and instability with only isolated thunderstorms over the mountains, coastal Toledo and near San Pedro in the afternoon. Elsewhere only isolated showers developed.
Mainly fair weather prevailed during the daytime on the 11th and only isolated showers developed over the northern half of the country including the airport overnight. A low pressure system was over the northwest Caribbean Sea with a weak surface trough near the coast of Belize. This feature was shallow and did not produce any significant weather across the country. From the 12th to the 14th a light easterly to southeasterly airflow supported mostly fair and warm conditions with only isolated afternoon thunderstorms over the Maya Mountains.
The main feature on the 15th was a low pressure system near the western tip of Cuba that showed a high potential for tropical cyclone development. However, weather conditions continued warm and mostly dry over the country with only isolated afternoon thunderstorms over the Maya Mountains.
The 16th afternoon saw the formation of the first tropical depression for the 2020 Atlantic Hurricane Season off the central coast of Florida. Later that night the depression strengthened northeast of Florida and became Tropical Storm Arthur, the first named storm of the season. Meanwhile conditions remained generally fair and warm throughout the daytime of the 17th as a moderate easterly to southeasterly airflow dominated the country. However, overnight thunderstorm activity over the south resulted in close to an inch of rainfall in Placencia and almost two inches in Punta Gorda.
The 18th started off fair and warm across the country but by afternoon a few thunderstorms developed mainly over northern and central coastal areas as a relatively moist northeasterly surface flow prevailed supported by moist and divergent upper level conditions. Showers and thunderstorms increased overnight and affected the entire country resulting in one to two inches of rainfall over northern and central areas. The 19th to the 21st saw mainly fair and warm weather except for isolated showers and thunderstorms over the mountains during the afternoons and over the south at night.
Weather conditions continued fair and warm during the 22nd morning then intense thunderstorms developed along the northwestern and western border as well as over the Toledo district in the afternoon. This activity persisted and spread to northern and central areas during the night.
Moisture decreased from the 23rd to the 25th even though a weak tropical wave crossed the country on the 24th. Isolated thunderstorms developed over the mountains during the afternoons and over the north on the evening of the 24th then over the extreme south during the night of the 25th. Elsewhere hot and dry conditions prevailed during this period.
Moisture increased slightly on the 26th as another tropical wave approached the country. Skies were cloudy in the morning with mostly layered clouds but only isolated thunderstorms occurred over the mountains in the afternoon. However showers and thunderstorms affected inland and northern areas the first part of the night then southern areas later that night with the activity continuing over the Stann Creek district through to the morning of the 27th. The tropical wave crossed the country before midday on the 27th with isolated showers and thunderstorms just south of Belize City in the morning and along the coast during the night. Cloudy conditions persisted over the country through to the 28th with isolated showers and thunderstorms affecting northern districts in the afternoon and the Toledo district during the night.
The last few days of the month saw the development of a broad cyclonic gyre over the eastern Pacific that supported the advection of deep moisture into Central America. Weather conditions remained generally fair during the daytime on the 29th with a few showers and isolated thunderstorms that affected mainly the north and some central areas of the country. However, later that night intense thunderstorms and heavy persistent showers affected Belmopan and its surrounding areas as well as areas along the Hummingbird Highway as far south as Middlesex. This activity produced excessive rainfall that resulted in extreme flooding in Belmopan and along portions of the George Price Highway on the morning of the 30th.
Tropical Depression Two formed over the eastern Pacific on the 30th afternoon and was projected to move northward and dissipate over southern Guatemala. The system continued to support moisture advection over the country resulting in cloudy conditions along with a few showers and thunderstorms especially over the south at first then showers and thunderstorms increased over central areas during the night.
Tropical Depression Two-E was upgraded to Tropical Storm Amanda early on the morning of the 31st before making landfall in southern Guatemala where it quickly dissipated over the mountains. However, its remnants continued to track slowly northward resulting in cloudy to overcast skies across the country and heavy rains with severe thunderstorms especially over central and northern portions of the country. Flooding conditions were reported in some areas including Belize City and municipalities in the north.
In summary two tropical waves crossed the country and two tropical cyclones formed outside the conventional June to November time period, namely Tropical Storm Arthur on May 16 and Tropical Storm Bertha on May 27. Tropical Depression Two-E/Tropical Storm Amanda that developed over the eastern Pacific basin dumped 12-13 inches of rain over the interior of the country at the end of May 2020.
The graphs and maps below summarize the total rainfall and average maximum and minimum temperature recorded during the month of May 2020. They also give an indication of how these readings compare to the normal for the month across the stations sampled. As can be seen, rainfall was well above normal over most of the country with Belmopan receiving almost five times the normal amount of rainfall for May. Meanwhile rainfall was slightly below normal along the coast of the Stann Creek district. Both daytime (maximum) and nighttime (minimum) temperatures were above normal for most of the stations sampled with only Punta Gorda recording cooler than normal nighttime temperatures.Monthly Rainfall SummaryMonthly Maximum TemperaturesMonthly Minimum TemperaturesRainfall Observed: January 2020 (mm)Rainfall Observed: January 2020 (% Above/Below Average)