Heat Ends as Rain Elevates Flooding Threat Across Central America

By Eric Leister, Meteorologist

April 27,2015; 9:08PM,EDT

 

 

Big changes are on the way for parts of Mexico and Central America this week.
Following a stretch of dry weather and record heat, a cold front will push across the Gulf of Mexico causing rain and thunderstorms to soak southeast Mexico, Guatemala, Belize and Honduras.
Much of April saw scorching heat from Villahermosa to Merida while rainfall was extremely scarce.
While April is typically warm and dry across this region, no rainfall was reported in both cities while temperatures soared well above normal.
In Villahermosa, there have been nine days with temperatures at or over 37.8 C (100 F) this month. The normal high is around 34 C (93 F).
Even more extreme is that 21 of the first 26 days of April had a temperature of 37.8 C (100 F) or higher in Merida, with a sizzling high of 110 degrees on the 25th and 26th.
This unrelenting heat will finally come to an end during the middle of the week as a cold front brings cooler air and widespread rainfall to the region.

The high temperature in Merida on Tuesday is expected to reach 41.7 C (107 F) prior to the arrival of this cooler air. By Wednesday, rain and thunderstorms will lead to a high temperature of 29 C (84 F). A similar drop in temperatures is expected across the entire region.
While cooler air will be one impact of this approaching cold front, the heavy rain and thunderstorms will cause an elevated risk for flooding.
The greatest threat for flooding will be across the Mexican states of Tabasco and Chiapas, while also extending across much of Guatemala, Belize and western Honduras.
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Mexico Weather Center
Detailed Forecast for Merida, Mexico
Central America Weather Center
These areas can expect rainfall amounts of 25-50 mm (1-2 inches) from Wednesday into Thursday. While these areas have been extremely dry, this amount of rainfall in a short period of time can result in flash flooding. Localized rainfall amounts can exceed 100 mm (4 inches).
This front will stall across Central America during the second half of the week prompting additional showers and thunderstorms; however, the threat for flooding will diminish as the front weakens late in the week.
This same frontal boundary will lead to showers and thunderstorms across Cuba from Wednesday into the weekend. While much of this rain will be beneficial, there will also be the threat for flash flooding.
Farther east, record heat will continue across Puerto Rico through at least Friday as dry weather prevails and the cold front stalls well to the northwest.