RINA: A Complex Environment

Infrared GOES satellite image of Hurricane RINA in the early morning of 27 October 2011 also showing the remnants of a tropical wave in the Caribbean, now a large cell of stormy weather near the Nicaragua-Honduras border

It is now 8:00 a.m. EST on Thursday 27 October 2011. Early data from the GOES satellite and hurricane-hunter aircraft is that Hurricane Rina has continued to weaken during the night, a trend that started some 24 hours ago, as it feels the effects of wind shear resulting from its clash with a ridge of high pressure over the Gulf of Mexico, a rather dry atmosphere to the west and north of its path and the early effects of a cold front now moving south and east over the southern USA. Early reports from National Hurricane Center forecasters are that this tropical cyclone is barely a hurricane, with surface winds estimated at 110 kph. Visual clues empirically confirm what the data are telling us, the overall size of the system is perhaps half of what it was just 48 hours ago, the perimeter has a jagged appearance as wind shear is taking its toll, the eye is not readily discernible, and the outflow from the top of the storm is almost absent: all of these are signs of a weakening system.

GOES satellite image of Hurricane RINA on 27 October 2011 in the morning showing water vapor in the atmosphere to help illustrate the adverse environment around this storm, whcih has contributed to its recent weakening

RINA has shifted its track as it continues its progressive turn toward the north, and it is now moving northwest by north at 10 kph. At this rate and direction the storm appears headed for an impact over the general area of Playa del Carmen – Cozumel-Cancun, in the state of Quintana Roo in Mexico’s Yucatan Peninsula during the night tonight.

Regarding RINA’s track it is important to note that consensus among the various forecast models is now in closer agreement than we have had over the past couple of days. Most models are now forecasting the cyclone will come overland in the northeastern region of the Yucatan Peninsula, then exit over the southeastern Gulf of Mexico and under the effects of a high pressure system and cold front pushing south over the Gulf, start a ‘hairpin’ turn toward the east and then southeast by this weekend or early this coming week. This projected track appears to bring RINA back into the Caribbean or Cuba in 4 to 5 days from now. While this scenario reflects the consensus of  most model it should however be noted that at least two of the models project RINA will track over the Florida Straits or even the Florida Keys and extreme southeastern Florida around 5 days from now. This projected track is illustrated below:

Projected track for Hurricane RINA as of 27 October 2011 developed by the Navy Research Laboratory of the United States

In considering what this projected track might mean for various interests around the Caribbean sub-basin and in Florida, the main questions becomes: what will happen to RINA intensity-wise as it follows such convoluted path in 4 or 5 days from today? As a weakening system, which is projected to continue weakening, will RINA survive as a tropical cyclone in 4  or 5 days. From previous discussions we have seen that if predicting the track to be followed by a tropical cyclone is difficult, it is even more difficult to predict what the intensity of a storm may be 2 to 3 days hence, and extremely more so when we are talking about 4 or 5 days from today. The general thinking has RINA decaying to tropical storm strength as it interacts with land over Quintana Roo and continues to sustain the effects of the various external factors already mentioned here. What will happen as RINA re-emerges over waters in the Gulf of Mexico? Given the adverse environment that will prevail over that region over the next several days it appears unlikely the storm would regain strength at that time, consequently we might be might see only the remnants of RINA making the hairpin turn in the projected track 4 – 5 days from now.

What does it all mean for communities in the path of RINA, such as vulnerable communities in the coastal region of Quintana Roo, Mexico? What about Tulum, Xel-Ha, Playa del Carmen, Cozumel, Puerto Morelos, Cancun, Isla Mujeres and the numerous resorts along the so-called ‘Riviera Maya’? My recommendation to all those communities that will suffer, in varied measure, the impact of RINA, is do not let your guard down and be deceived by a weakening storm. Winds of 100-120 kilometers per hour, possibly gusting to 140-150 kph can be quite damaging generating considerable flying debris, with the potential for causing injury or even death as well as damage to buildings and structures. Storm surge and superimposed waves have the capacity of exerting tremendously strong impact loads on buildings and infrastructure in the coastal region in addition to causing severe beach erosion. From communications with contacts in Quintana Roo I know for a fact that Civil Protection authorities have activated emergency plans, which include evacuation of tourists from coastal resorts. Civil protection  authorities in Quintana Roo have an excellent record of proactively activating emergency plans, convening emergency committees at the municipal level, and of protecting the lives of visitors and residents alike from the impacts of tropical cyclones their state suffers with some frequency because of its geographic location.

Satellite image with superimposed wind analysis on 27 October 2011 developed by the Cooperative Institute for Meteorological Satellite Studies of the University of Wisconsin in Madison

What else is happening in the Caribbean or elsewhere in the larger Atlantic basin? For starters, the tropical wave of low-pressure that was active in the southeastern Caribbean and moving westward has become disorganized, and it shows low to no probability for further development. This system has been moving at a rather fast clip of 20 – 25 kph and it is now a large cell of disturbed weather, with plenty of thunderstorm activity and heavy precipitation, located to the east of the Nicaragua/Honduras border and continuing to move generally westward at approximately 20 kph. What is interesting about this system has been its fast  pace of forward movement especially when compared to the rather slow pace at which RINA has been moving, which raised a remote potential for some interaction between both systems. An interesting question would be, if the remnants of RINA as it recurves back into the Caribbean and those of this other system, may not generate some sequel should they happen to interact in the future? Relative to this, it wouldn’t be the first time we see the remnants of a system in the Caribbean interact with another and be re-energized to become something totally new, even a new tropical cyclone.

Satellite image on 27 October 2011 showing water vapor in the atmosphere over most of the tropical North Atlantic basin

Farther east other than a couple of areas of rain over ‘hurricane alley’ and the eastern Atlantic there is nothing, for now at least, showing potential for cyclonic development. Tropical waves over equatorial Africa continue to develop, and although such activity has shifted southward toward the equator there is still some potential for any one of these waves to emerge over the eastern Atlantic and head toward the Caribbean. So, as I always say: pay attention! Be prepared!! MITIGATE!!!

In the Caribbean!

GOES satellite image for the aviation industry on 24 October 2011 showing category 1 Hurricane RINA, to the north of Cabo Gracias a Dios in Nicaragua, moving generally northwest toward the coastal region of Quintana Roo state in Mexico

Historically in the late Fall, say late mid-October through mid-November, more often than not the annual Atlantic hurricane season appears to shift most activity to the Caribbean sub-basin. True to form, and after trying for three weeks in a row, by generating three low-pressure systems that were characterized by the vast amount of rain generated, the Caribbean saw yet one more low pressure system that reached tropical storm strength on 23 October and barely 24 hours later is now category 1 Hurricane RINA.

When RINA was still a tropical storm, early forecasts projected slow and gradual strengthening with the cyclone reaching hurricane strength possibly by late Thursday 27 October or Friday 28 October. This forecast was based, among other criteria, on the generally quite dry atmospheric environment throughout most of the Caribbean, and the also quite dry environment and a ridge of high pressure dominating the Gulf of Mexico ahead of most of the projected cyclone tracks. As it happens, as if to illustrate the uncertainty associated with predicting the intensity of tropical cyclones, RINA has already reached category 1 hurricane strength on Monday 24 October 2011 and appears primed for further strengthening.

Visible light GOES satellite image RINA during the morning hours of Monday 24 October when the cyclone was still categorized as a tropical storm just north of the Nicaragua-Honduras border

Such rapid strengthening has now contributed to a modified forecast that has Hurricane RINA reaching category 3 strength within the next 48-60 hours with maximum sustained winds of 200 kph, and higher gusts, while moving toward the coastline of Mexico in the state of Quintana Roo.

On Sunday 23 October 2011 the consensus track had tropical cyclone RINA moving in the general direction of Belize City and Chetumal Bay, in Quintana Roo, Mexico, but new data and aircraft observations  now have Hurricane RINA on Monday 24 October 2011 still moving northwestward, but anticipated to make a gradual turn toward the north by northwest or even northward pointing it toward the northeastern region of the Yucatan Peninsula in the vicinity of Tulum, Playa del Carmen, Cozumel and  Cancun in Quintana Roo, Mexico.

Projected track for Hurricane RINA as of Monday 24 October 2011 developed by the Navy Research Laboratory

The projected track for Hurricane RINA carries quite a bit of uncertainty although it is based on a consensus of the various forecast models used by the Tropical Prediction Center, National Hurricane Center of NOAA. Typically, most of the models appear in agreement regarding RINA’s track over the next 24-36 hours, but beyond that they start to diverge widely with some models taking RINA west across Central America, others moving it into the Gulf of Mexico and yet others have RINA impacting South Florida. The image that follows shows such widely diverging results from the various models, and illustrates the difficulties faced by NOAA forecasters as they try to keep emergency managers and the general public as well informed as possible so that they may take precautionary measures in order to reduce the potential for damage and protect life and property ahead of a possible impact by the approaching cyclone.

Projected tracks for tropical cyclone RINA as of the early morning hours of 24 October 2011 based on the several forecast models used by NOAA

Relative to the forecast track, with all of its associated uncertainty, it is important to note that even with the rapid intensification experienced by RINA, the preferred track remains as shown above for what is now Hurricane RINA.

Looking beyond Hurricane RINA toward the east, there are a few weather systems including one just west of the Lesser Antilles in the eastern Caribbean, and a couple more along ‘Hurricane Alley’ that appear ready to contribute to a potential continuation of tropical cyclone activity in the Caribbean during what remains of the month of October and perhaps into early November. Take a look at the satellite image that follows:

Atlantic-wide GOES satellite image showing water vapor in the atmosphere on Monday 24 October 2011

The satellite image above by showing water vapor in the atmosphere emphasizes the very dry atmospheric environment dominating most of the Caribbean and Gulf sub-basins as well as the open Atlantic. The solid-yellow outlines identifies Hurricane RINA to the north of the Nicaragua-Honduras border as the system moves generally west by northwest. Also visible is the ridge of high pressure cutting across the Gulf of Mexico and South Florida, which is expected to influence the track that RINA will follow toward the end of this week. Over the far eastern Caribbean the dashed outline identifies a system of disturbed weather that developed over ‘Hurricane Alley’ and is now to the west of the Lesser Antilles moving toward Central America and Belize. Two other for now minor weather systems continue to move along “Hurricane Alley’ and may penetrate into the Caribbean over the next few days.

In summary, on Monday 24 October 2011 we have the 17th-named tropical cyclone and 6th hurricane of the 2011 Atlantic hurricane season, also the expected activity in the Caribbean and the potential for continued activity if the sub-basin as the annual season enters its late phase. All interest around the Caribbean sub-basin, Florida, the Bahamas and in the Gulf need to monitor Hurricane RINA closely as well as the system now over the eastern Caribbean over the next few days to bar any surprises over the late phase of the 2011 Atlantic Hurricane Season.