Tag Archives: Forecast models

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.