Tell Mother Nature Hurricane Season Starts in Six Days!

That would be the 2011 Atlantic Hurricane season! Does Mother Nature know she has to punch a time card on 1 June 2011 and start working on her cyclogenesis?

Nine weeks ago as Earth’s mid-section crossed directly under the Sun during the spring equinox the oceans and atmosphere north of the equator started growing warmer. As the coupled ocean-atmosphere system in the northern hemisphere deals with more heat there has been a gradual increase in the number of so-called weather events, as Nature uses its arsenal of processes in a continuous balancing-between-extremes act, which is often punctuated by extreme events when conditions reach levels of critical instability.

So far in 2011, anecdotally at least, there appears to be a continuous chain of weather events punctuated by extremes especially as winter gave way to spring, and now as we approach summer in the northern hemisphere. The pulses of large storm systems that have spawned East of the Rockies to then proceed eastward creating havoc across the great plains, and the south and the central regions, as well as in the northeast with hurricane force winds, extreme rain, hail, thunderstorms and devastating deadly tornado swarms, in addition to record-breaking spring flooding in the Mississippi, Missouri, Ohio, Red River and other basins, certainly bear witness to the frequency with which these extreme events are happening.

Confronted with these events and as the media have continued to bombard the national public with reports of death, destruction and damage, and at times all too graphic imagery of despair and human suffering, the inevitable questions of: why is this happeningIs this related to global warming?  and others, are on the table to be debated and pondered by everyone. 

Not surprisingly, as the debate of these issues heats-up and the scientific community takes positions on both sides of them, there are few or no answers as to what it all mean or what can be done. While technical explanations have been provided as to what has caused given events, by and large  we are seeing more of the same with respect to the discussion on global climate change and global warming.

With this as a backdrop here we are just six days from what we call the 2011 Atlantic Hurricane Season seeing plenty of hurricane guidesbeing distributed through various means, special reports in the electronic and printed media, and the conferences and reminders to be prepared, to have a plan, to have a hurricane kit and in general the obvious one: to deal with the fact we live in Florida otherwise known as hurricane country.

Today 26 May 2011 we see plenty of signs that various components of cyclogenesis [the generation of tropical cyclones – hurricanes] are already in place or at work in the northern hemisphere.

Far away in the northern western Pacific category 4 typhoon SONGDA is approaching the Philippines even as it turns toward the north by northwest in the general direction of Taiwan and southern Japan. This is the same region that less than 3 weeks ago was hit by tropical storm AERES, and which saw several tropical cyclones in 2010. The color-enhanced infrared satellite image [courtesy of NASA] below illustrates how typhoon SONGDA is affecting a large region of the western Pacific:

On the opposite side of the Earth, over in the eastern Atlantic we see the tropical wave assembly line busy over equatorial Africa, with several strong tropical waves already forming a train over the southern extreme of hurricane alley and moving toward South America and the Caribbean; this is illustrated by the color-enhanced infrared satellite image of the region taken today 26 May 2011:

Tropical waves similar to those shown of the satellite image above have contributed to heavy rains and flooding over the northern regions of Venezuela and Colombia earlier this year. Also, some of these waves traverse over the isthmus of Panama and emerge over the eastern Pacific to interact with La Nina influenced waters and atmosphere, which has led to a pattern of large rain and thunderstorm cells generated over the area and affecting several countries in Central America similar to what took place in 2010 over the same region. The eastern Pacific 2011 hurricane season officially started on May 15 2011.

Some of the conditions described before are evident of the composite satellite image of Earth’s full disk showing the western hemisphere on 26 May 2011 as we near the ‘official’ start of the 2011 Atlantic hurricane season:

Only time will tell how “busy” the 2011 Atlantic Hurricane season will turnout to be or if global warming contributes in any way to exacerbate the impacts of tropical cyclones that do form over the Atlantic in 2011. What is clear is that Mother Nature will continue on its quest for balance between extremes in response to that which is a constant: change!

Are Tropical Cyclones around the Corner?

15 May 2011 marked the official start of the 2011 Hurricane Season in the eastern Pacific basin, and in less than two weeks on 1 June 2011 we will officially inaugurate the 2011 hurricane season in the Atlantic basin.

As we keep an eye on the tropics for any signs of potential tropical cyclone development along hurricane alley, the Caribbean, the Gulf of Mexico and the west-central Atlantic, as well as the eastern east Pacific, we note tropical waves on the move from equatorial Africa toward the west and areas of disturbed weather, which may eventually become threats to communities through the larger basin. Geostationary (GOES) satellites provide frequently updated imagery 24 hours a day year round, such as the one shown above [courtesy of NASA] where a large region of disturbed weather is clearly seen to the north of the U.S. Virgin Islands moving westward toward the USA mainland, which will collide with a front pushed by the jet stream toward the northeast by north. This image also shows quite a bit of tropical activity further south near the equator.

A color-enhanced infrared GOES satellite image, shown below [courtesy of NASA], also taken on 18 May 2011 shows the cell of disturbed weather mentioned above in more detail.

 On the image above notice how the large cell of disturbed weather over the west-central Atlantic is moving generally westward toward a collision with a storm system near the USA Atlantic coastline, which is being pushed by the jet stream toward the east by northeast. From this image it may be deducted that in the absence of a jet stream coming so far south and pushing toward the east by northeast, the cell over the west-central Atlantic might very well continue moving toward USA land where it may cause copious rain and possibly coastal flooding over the next 36-48 hours.

Meanwhile over the far eastern Atlantic, to the south of the Cape Verde islands, we are more and more everyday seeing tropical waves generated by the assembly line that is active over equatorial Africa, which eventually feed into the hurricane alley that channels them toward the Caribbean and the western Atlantic. Some of these tropical waves are shown on the satellite image of 18 May 2011 shown below:

A better overall perspective of tropical activity over the eastern Pacific and Atlantic-wide basin, which may at some point have the ability to impact the USA as well as several other countries, can be gained by the full-disk satellite image of Earth’s western hemisphere on 18 May 2011 that is shown below:

On the satellite image above the yellow outline across the Earth’s disk identifies the belt of tropical weather that circles the planet, and which when this image was taken on 18 May 2011 was clearly positioned to the north of the equator where it may already be capable of affecting the trajectory of tropical waves, which may impact the USA and other interests in the Caribbean and Gulf.

The overall perspective of tropical cyclone risk can be complemented by the map of sea surface temperature from 17 May 2011, which shows hurricane alley, the Caribbean and Gulf as well as the eastern-east Pacific have already reached a thermocline that is favorable for cyclogenesis. This map of sea surface temperature is shown below:

The above sea surface temperature map [courtesy of NOAA] also shows the effect of the La Nina [ENSO] event still active off the coast of Peru, where the green and yellow color identify the much cooler waters of the La Nina event. The historical record has shown that a La Nina event creates an atmosphere-ocean environment that is more conducive toward tropical cyclone generation in the Atlantic basin.

Finally, I believe it is important to take a closer look at tropical activity over the eastern Pacific off the coasts of Central America and Mexico where a satellite image on 18 May 2011 shows several large cells of rain and storms and otherwise disturbed weather that are active in that region. This region of the Pacific has seen quite a bit of storm activity the same as the junction between Panama and northern South America (Colombia and Venezuela), which has resulted is repeated incidents of heavy rains and thnderstorms over most of the area over the past several weeks. This is a pattern that developed in 2010 driven by La Nina, which appears to be repeating in 2011. The satellite image that follows below, showing the eastern Pacific near Central America on 18 May 2011 illustrates the commentary made before:

With such widespread tropical activity, and so many of the triggers for tropical cyclone development already present in these basins, i.e.: warm and warming surface waters, tropical waves and areas of disturbed weather, areas of low atmospheric pressure etc., it is clear possible tropical cyclone development may occur at any time from now on, so it becomes imperative we remain prepared, pay attention and continue to practice mitigation!