Tag Archives: Cyclogenesis

IT IS THAT TIME OF THE YEAR: BE PREPARED! MITIGATE!

Today is Saturday 27 May 2017. Just a couple of days ago the National Oceanographic and Atmospheric Administration (NOAA) released its updated forecast for the 2017 Atlantic Hurricane season, which officially starts this coming Thursday 1 June 2017.

Available names for tropical cyclones forming in the Atlantic basin during upcoming 2017 hurricane season. (World Meteorological Organization)

NOAA’s forecasters have called for an above average Atlantic season with a possible 17 named-storms this year. An ‘average’ season, if there is such a thing, usually produces 11 named-storms. Just to be ready for what eventually will happen, or not, the World Meteorological Organization (WMO) has prepared a list of 21 names for tropical cyclones in the Atlantic.

Ocean waters are getting warmer already, having reached 30 degrees Celsius over large areas as shown on this sea surface temperature map of 26 May 2017. (NOAA)

While NOAA’s forecast has several caveats regarding the various factors that may contribute to this year’s Atlantic hurricane season, such as whether or not El Niño will stay away, we are already seeing some of the contributors begin to fall in place. For example, the tropical waters in the northern Atlantic are already getting rather warm, with sea surface waters over large  regions reaching 30˚ C, thus the heat energy content of the ocean is conducive to feeding tropical cyclones.

Several storms cells and areas of disturbed weather are already present in regions of the tropical northern Atlantic as seen in the GOES EAST satellite view of 05/27/2017 (NOAA)

We are also seeing the trains of tropical waves over equatorial Africa, ‘hurricane alley’, and the eastern Pacific starting to line-up north of the equator as they march toward the west. A sign that conditions are favorable for thunderstorm and rain cell formation, another contributor to cyclogenesis.

The train of tropical waves over Equatorial Africa, marching west toward the Atlantic, is already in place. (NOAA)

Elsewhere, we have already had the first named-storm  of the 2017 Eastern Pacific Hurricane Season, tropical storm ADRIAN formed on 10 May 2017 off the Pacific coasts of Central America and Southern Mexico becoming the earliest named-storm of record in that basin. Farther west, over the northwestern Pacific near the Philippines there are currently two large areas of disturbed weather that are showing some potential for tropical cyclone formation.

Tropical storm ADRIAN became the earliet named-storm of record over the northern eastern Pacific, when it formed last 10 May 2017 off the coasts of Central America and Southern Mexico (NOAA)

So, it is that time of the year in the northern tropics.  The 2017 Atlantic Hurricane Season is right upon us, ready for its ‘official’ starting date of 1 June 2017. Beyond the Atlantic, conditions appear already favorable for tropical cyclone generation throughout the Pacific ocean, to the northern Indian ocean and the Arabian sea.

It is time to be prepared, and remain alert. It is time TO MITIGATE!

Official start: the 2015 Atlantic Hurricane Season!

Here we go again imposing human constraints on what Mother Nature does well on her own, by declaring the 2015 Atlantic Hurricane Season if officially open today 1 June 2015! This despite the fact that ANA marked an early start of the 2015 Atlantic season when it became the first named storm of 2015 in the Atlantic basin early in May of this year.

So, how is Mother Nature behaving in terms of cyclonic activity as we give her the ‘green light’ to begin the 2015 Atlantic hurricane season?

Infrared satellite image of 1 June 2015 showing Hurricane ANDRES and Tropical depression #2 over the Eastern Pacific off the coast of Mexico
Infrared satellite image of 1 June 2015 showing Hurricane ANDRES and Tropical depression #2 over the Eastern Pacific off the coast of Mexico

Taking a worldwide look at the northern tropics on this 1st day of June 2015 we see a strengthening Hurricane Andres, the first-named tropical cyclone of the East Pacific 2015 hurricane season, which is moving WNW toward the area of Hawaii. Also in this area and not far from ANDRES we see a nearly stationary Tropical Depression #2 some 500 kilometers west of the resort of Acapulco, Mexico. So the East Pacific season is off to a busy start.

Projected track for Hurricane ANDRES {courtesy of the U.S. Naval Research Laboratory)
Projected track for Hurricane ANDRES {courtesy of the U.S. Naval Research Laboratory)

Also in the Pacific basin, but farther south from where Andres and TD #2 are located, we see an expanding and strengthening  El Niño reaching from the central Pacific to the coastline of South America. This anomaly will undoubtedly have effects on weather patterns in regions as far away as India, where the annual monsoon has already been delayed leading to a  heat wave that has claimed more than 1500 lives, to the Atlantic where the hurricane season is expected to be dampened somewhat.

Chart showing anomalies in sea surface temperatures generated by the growing El Nino during the month of May 2015
Chart showing anomalies in sea surface temperatures generated by the growing El Nino during the month of May 2015

Elsewhere the various sub-basins where cyclogenesis takes place are quiet today, but there are plenty of tropical waves, rain and storm cells that presage the possibility of future cyclonic activity in regions such as the Northwest Pacific, where the Philippines and other nations have already been impacted this year, or the northern Indian Ocean.

Closer to us here in Florida, the Atlantic is already showing elongated areas of  rain and disturbed weather populating the southern fringe of ‘Hurricane alley’ pushed westward by tropical waves emerging from Equatorial Africa. This pattern will gradually shift northward as summer approaches and the season progresses allowing potential future storms to aim for the Caribbean and the several vulnerable coastal regions in Central America and the Yucatan as well as island nation.

Infrared satellite image of 1 June 2015 showing disturbed weather activity along the soyhtern fringe of 'Hurricane Alley' from near the east coast of South America to the west coast of Africa
Infrared satellite image of 1 June 2015 showing disturbed weather activity along the southern fringe of ‘Hurricane Alley’ from near the east coast of South America to the west coast of Africa

To highlight the ‘official’ start of the 2015 Atlantic Hurricane Season we have recently seen the seasonal forecasts issued by NOAA, the folks in Colorado and others, which all coincide in projecting as a ‘below normal’ season, whatever the meaning of ‘normal’ is. In the end, as most of us well know, Mother Nature will do what it takes to balance the extremes that may emerge over the next six months in the coupled ocean-atmosphere environment.

So, this is the worldwide picture of cyclonic activity today. What the 1 June official start of the 2015 Atlantic hurricane season really is,  is a reminder that all of us in hurricane vulnerable communities to be prepared, remain alert, and to practice mitigation in order to reduce the potential for damage from the expected impacts of tropical cyclones generated over the waters of the Atlantic.