NADINE: The storm that just won’t quit!

Just about a month ago, on 1 September 2012, one of several large tropical waves generated by the tropical wave assembly line over Equatorial Africa approached the western coast of Africa to emerge the next day over the warm waters of the eastern Atlantic, to the south of the Cape Verde Islands.

Color-enhanced infrared satellite image (NOAA) of the western portion of Equatorial Africa and the Eastern Atlantic showing a tropical wave about to emerge over the warm ocean waters to the south of the Cape Verde Islands, which later became Tropical depression #14 and shortly thereafter tropical cyclone NADINE

A few days later, on 10 September 2012, this particular tropical wave became Tropical Depression #14 of the 2012 Atlantic Hurricane season, as it traveled along the northern fringe of Hurricane alley. Soon thereafter, on 12 September 2012, T.D. #14 strengthened and became the 14th named tropical cyclone of the season as Tropical Storm Nadine.

Color-enhanced infrared satellite image (NOAA) showing then Tropical Storm NADINE as it moved toward the open waters of the Atlantic some 1,200 kilometers from the Lesser Antilles

Initially Nadine tracked WNW in the general direction of the Virgin Islands, but it soon began to be steered first toward the NW and then more toward the north, as the system encountered the same atmospheric regime that had interacted with its predecessors, tropical cyclones Joyce, Kirk, Leslie and Michael, and before that short-lived Gordon. Soon a strengthening Nadine appeared to be aiming for Bermuda only to continue a sweeping arch over the central Atlantic to take aim toward the northeast and the Azores Islands. During the course of this maneuver Nadine became a hurricane.

Projected track for NADINE as of 15 September developed by the U.S. Navy Research Laboratory on the basis of observational data from NOAA

It is dizzying just trying to describe the exceedingly convoluted track tropical cyclone Nadine has followed up to today 30 September 2012, when it is yet again a hurricane (for the third time!), and continues to meander in the neighborhood of the Azores with no signs of letting off any time soon three weeks after being generated back in ‘hurricane alley’.

Panoramic view (from Google Earth) of the track followed by Hurricane NADINE since first becoming a tropical cyclone back on 10 September 2012

Although Nadine has been active over open waters without having had much of an impact over land areas, despite having affected the Azores, Madeira and the Canary Islands albeit from a distance, it is clear we are witnessing quite an extraordinary storm both in terms of longevity and the track it has followed since it emerged over the eastern Atlantic as one more tropical wave. Adding to this qualification of ‘extraordinary’ is the fact that NADINE has become a hurricane for the third time since its genesis even as it tracks over a region of the Atlantic Ocean with much cooler surface waters.

Projected track for Hurricane NADINE as of 30 September 2012, as it is making yet another cyclonic loop near the Azores before a expected move toward the NE and then N in coming days, developed by the U.S. Navy Research Laboratory on the basis of observational data from NOAA

In  summary: (a) Nadine has been a tropical cyclone for three weeks already; (b) It has reached hurricane strength three separate times during this period; (c) It has followed a continuously changing path that includes three full cyclonic loops where the storm has changed its direction of travel by 180 degrees or more; (d) It has stalled a couple of times during periods where its forward motion became stationary for several hours; (e) Nadine has traveled approximately 9,100 kilometers since it became a tropical cyclone, and close to 12,000 kilometers since it emerged as a tropical wave over the eastern Atlantic near the Cape Verde Islands; (f) To make it even more interesting, Nadine is not done yet, so we will have to wait and see until it decays a ceases to be a named-storm once and for all to determine just how extraordinary a storm it has been. For those interested in viewing an animation of the track followed by Hurricane NADINE the following links should be interesting: www.nhc.noaa.gov/archive/2012/graphics/al14/loop_3W.shtml or the following: www.nhc.noaa.gov/archive/2012/graphics/al14/loop_R.shtml

What else is happening in the tropical northern hemisphere, while we continue tracking Nadine?

Track for Tropical storm NORMAN developed by the U.S. Navy Research Laboratory on the basis of observational data from NOAA
Final projected track for what was Hurricane MIRIAM developed by the U.S. Navy Research Laboratory on the basis of observational data from NOAA

Over in the eastern Pacific the remains on what once was major hurricane (category 3) Hurricane Miriam is now a decaying low pressure system with sustained 30 kph winds some 1,100 km west of Puerto Vallarta, Mexico. To the north of that we have the remains of Tropical Storm Norman, the 14th named tropical cyclone of the season in that basin, now down to tropical depression status and weakening rapidly overland the Baja California peninsula some 100 km north of the town of San Marcos. Beyond this the only tropical activity in that region is in the form of a couple of tropical waves or areas of stormy weather over the Pacific waters off the coast of central America and Panama.

                      

Projected track for a now decaying Tropical Storm EWINIAR developed by the U.S. Navy Research Laboratory on the basis of observational data from NOAA
Projected track for recently generated Tropical Depression #20 in the western Pacific developed by the U.S. Navy Research Laboratory on the basis of observational data from NOAA

At the other extreme of the ocean over the Western Pacific, a region that has seen plenty of tropical cyclone activity over the last four months, also on 30 September Tropical depression #20 has generated and is strengthening while moving generally NNW some 500 km to the northeast of Guam.  Then, there is a weakening Tropical Storm EWINIAR  some 1,000 km east of the island of Hokkaido in Japan moving toward the NNE away from land. There is also a third active cyclone, a still strong Tropical Storm Jelawat, which is now overland Honshu the main island of Japan some 200 km west of Tokyo with the potential for causing some damage as it interacts with mountainous terrain and generates considerable amounts of rain as it continues to move toward the most densely populated urban area in the world.

Projected track for now Tropical Storm JELAWAT over Central Japan, developed by the U.S. Navy Research Laboratory on the basis of observational data from NOAA
Color-enhanced infrared satellite image (NOAA) of 30 September 2012 showing Tropical Storm JELAWAT over land on the island of Honshu, Japan approaching the urban area of Tokyo

Closer to our neck-of-the-woods here in Florida there are numerous disturbed weather cells and storms along ‘hurricane alley’, in the central Caribbean, in the Gulf of Mexico, over the Atlantic, and a large storm system reaching from Texas to the northeastern USA. So, in addition to the possibility of some bad weather coming our way, there is always the potential for cyclonic activity to develop in the larger basin, especially considering there are still a couple of months left in the ‘official; 2012 Atlantic hurricane season.

Infrared color-enhanced GOES satellite image of the eastern USA showing several storm systems over the Atlantic, the Caribbean, the Gulf of Mexico, and over the mainland USA on 30 September 2012

While we wait and see what develops in the various basins mentioned here, it is important for all of us to remember to pay attention, to be prepared and above all to keep practicing Mitigation!

New tool for hurricane hunting

Hurricane hunting, the deliberate act of flying into some of the most extreme and turbulent weather on Earth generated by tropical cyclones, is a critical tool for the mission of NOAA’s National Hurricane Center of tracking and forecasting hurricanes from the time they form in order to issue warnings. These tools also include satellites, ships’ observations, buoys and in some cases, ground level observations of surface winds and collection of other data.

Hurricane hunting emerged from weather reconnaissance flights carried out by the U.S. military during World War II in the early 1940s using a variety of aircraft, which included observations of hurricanes and typhoons over the Atlantic and the Pacific initially carried-out with on-board weather instrumentation relayed by radio, which soon thereafter included the use of newly developed radar. This hurricane hunting capabilities carried over during peacetime using a wide collection of military aircraft such as B17, B24, B25 and even B29, and even the B50s, which were nothing more than souped-up/enhanced B29s that were lighter, faster and had considerably more range than the B29s, bombers especially outfitted for these purposes.

Logo and uniform patch of the Hurricane Hunters 53rd Weather Reconnaissance Squadron of the Air Force Reserve

When the Air Force Reserve 53rd Weather Reconnaissance Squadron was formed, its mission included hurricane hunting, which it carried out using aircraft such as Seahawks and Neptunes, and even the Lockheed Constellations with their distinctive triple-tail. These aircraft were outfitted with radar and especial antennas that were mounted on external pods or pedestals giving the airplanes quite a peculiar look. Eventually hurricane hunting activities settled on the P3 ORION and eventually of a workhorse of an airplane, the Lockheed WC-130 HERCULES, which now carries out the full load of hurricane hunting missions.

The Lockheed WC-130, workhorse of hurricane hunting missions carried out by the Air Force Reserve 53rd Weather Reconnaissance Squadron

More recently a new tool was added to complement the work of the WC-130s, in the form of a Gulfstream Jet that actually flies at much higher altitude than the WC-130s, but rather than penetrating the cyclone it flies around its periphery to measure outflow and collect complementary high altitude data.

The ‘old’ P3 ORION and the ‘new’ Gulfstream Jet hurricane hunting aircraft reflect the evolution of hurricane hunting missions

Using these aircraft and improved instrumentation and data-collection tools, such as dropsondes, combined with much improved satellite remote sensing have allowed the National Hurricane Center to achieve considerable improvement in forecasting hurricane tracks, which has resulted in also much improved warnings for vulnerable communities.

Despite these vast improvements if hurricane track forecasting, considerable challenges remain regarding the forecast of hurricane intensity, especially when it comes to rapidly intensifying storms that considerably reduce the amount of advanced warning that can be given to vulnerable communities in coastal locations. It is clear much work remains to be done in this respect.

To tackle the need for improving the forecasting of tropical cyclone intensity NOAA has recently started to use unmanned  aircraft loaded with all sorts of instrumentation and data acquisition sensors, which are capable of flying into tropical cyclones and of staying aloft for much longer periods than the WC-130/Gulfstream teams can. One critical objective of using such pilot-less aircraft is to collect much needed data that can be used to enhance existing models to enhance intensity forecasting.

Picture of the NASA operated unmanned aircraft the Global Hawk in its hangar in eastern Virginia being readied for a special hurricane hunting mission

The most recent addition to this arsenal of unmanned aircraft is known as the Global Hawk and it is actually operated by NASA. As this article is being written the Global Hawk is engaged on a month-long mission that started in early September, known as Severe Storm Sentinel, to look at the environment of tropical cyclones to collect data that has been difficult to collect using traditional methods of hurricane hunting. Scientists will use those data to gain enhanced understanding of tropical cyclone formation, but more importantly how these cyclones intensify from tropical depression/tropical storm stage to intense Atlantic hurricanes, which will in turn enhance the capability of forecasters to make better predictions for the benefit of emergency managers in vulnerable coastal locations.

Hurricane hunting, a critical component of hurricane mitigation and emergency management, is also an excellent example of how the dedication and work of so few benefit so many without most of them even knowing about it. Those of us who live in hurricane vulnerable communities are privileged to benefit from the work of hurricane hunters, and should thank them often and loudly.