QCOSTARICA – The morning warming and the entry of humidity formed cumulonimbus clouds that originated a whirlwind Tuesday afternoon in Santo Domingo de Heredia, prior to the downpours that later fell.
According to Pamela Rojas, Bomberos (Fire Department) supervisor, at 2:13 pm, they received the warning of the gale in San Vicente de Santo Domingo, 300 m north of the square, where several metal sheets of the roof of a house were pulled off by the wind, as well as several telephone cables.
“They called us because of a whirlwind that partially affected a house. We sent the M-111 unit from Santo Domingo, which attended to the emergency and gave recommendations to the family,” she said.
According to Daniel Poleo, from the national weather service, the Instituto Meteorológico Nacional (IMN), the cloud that generated this phenomenon also produced hail falls in other sectors west of the Central Valley.
He stated that intense downward gusts like the one in Santo Domingo usually reach more than 100 kilometers per hour and, although in this case the whirlwind was not formed, the gusts unroofed part of a house and affected wiring.
He added that in the morning, the muggy environment in San José caused the temperature to reach 28 degrees Celsius around 2 pm.
Douglas Salgado, from the Risk Investigation and Analysis Unit of the National Emergency Commission (CNE), affirmed that apart from that storm, they had reports of floods in Barva de Heredia, Alajuela and San José.
He says there are no reported incidents greater than the typical flooding from culverts that collapse from heavy, focused rain.
In some sectors of the Ruta 27 (San José – Caldera), the rains generated some waterfalls on walls that led to regulated traffic of vehicles in some sections.
During most of this week, isolated but intense precipitations, with lightning, is expected, mainly during the afternoons and first hours of the night.
Intense lightning
Regarding electrical discharges, Daniel Poleo affirmed that they are part of the huge cloud formed by the warming of this month that, together with October, constitute the rainiest of the year in the Central Valley and the Pacific coast.
The IMN detector for the Central Valley registered 800 electric discharges during the afternoon downpours.
For her part, Ileana Mora, from the Department of Atmospheric Discharges of the Instituto Costarricense de Electricidad (ICE), said that the total number of lightning strikes between 11:50 am and 4:44 pm in the county was 4,320.
“They were distributed in various regions of the country, with greater influence on the Pacific slope, the Central Valley and the northern zone,” said Mora.
Only between September 1 and this Tuesday (14th), ICE sensors have detected a total of 52,127 lightning strikes, while the same period last year was 75,127.
So far this year the figure is 409,733, while last year it was 490,078 in the same period.
The influence of the La Niña phenomenon during the past year made the amount of rains, lightning and hurricanes greater than that projected for this 2021, characterized by the neutral phase of the El Niño Southern Oscillation phenomenon (ENSO).
The IMN asks to seek refuge in a safe place from the moment the first lightning is perceived when out in the open. They should be dry places and you should never take shelter under a tree.
Dry mass weakens wave
Although the passage of a new tropical wave (No. 35) through our territory is foreseen for Friday, the IMN says that it will not represent a significant increase in the usual rains.
The above, because the atmospheric conditions do not favor its development.
“Over the weekend, there would be an increase in the intensity of the trade winds in the Caribbean Sea, bringing with this a mass of dust from the Sahara to Central America, which would mean a general decrease in rainfall in the country for those days.,” says a statement from the IMN.
Allergy sufferers should be extremely careful when they are outdoors and the presence of Saharan dust in the atmosphere is warned.
