‘Unusual’ hurricane season spares Cayman

Doppler radar to be ready by next hurricane season

A hurricane season that had “highly anomalous tropical cyclone activity” according to two noted climatologists ended last Saturday with the Cayman Islands receiving little effect from the 
19 named storms. 

In a report issued last week, Colorado State University scientists Phil Klotzbach and William Gray said the 2012 hurricane season had more tropical cyclone activity than they predicted in their forecasts. 

“The 2012 hurricane season was one of the most unusual seasons on record in terms of its very high frequency of weaker cyclones in combination with the almost complete lack of major hurricane activity,” the duo’s report stated.  

“It was notable for having a very large number of weak, high latitude tropical cyclones, but only one major hurricane.” 

Mr. Klotzbach and Mr. Gray predicted 10 named storms in their 4 April forecast, 13 storms on 1 June and 14 storms on 3 August, all well below the actual number of 19, which tied for the third most in recorded history for the Atlantic Basin.  

The scientists also significantly underestimated the 10 hurricanes that occurred in 2012, predicting four, five and six in their three forecasts.  

Conversely, they predicted two major hurricanes but only one occurred – Hurricane Michael, which was only a Category 3 hurricane for only 12 hours. 

 

Effects on Cayman  

Because most of this year’s tropical cyclone activity was concentrated in the northeast subtropical Atlantic Ocean, Grand Cayman was hardly affected by any of the storms, getting only some wind and rain when Tropical Storm Ernesto passed about 200 miles south of Grand Cayman on 6 August and mostly wind and rough seas when Hurricane Sandy made landfall near Kingston, Jamaica on 25 October before heading on its deadly track along the United States East Coast.  

Ernesto triggered a Tropical Storm Watch for the Cayman Islands, as did Tropical Storm Isaac on 24 August before it passed over Haiti and Eastern Cuba. Isaac had little effect on Grand Cayman, but did bring heavy rain to the Sister Islands of Cayman Brac and Little Cayman. 

 

2013 outlook  

Mr. Klotzbach and Mr. Gray will issue their first outlook for the 2013 hurricane season on 7 December.  

Last year, the duo stopped making quantitative forecasts in December in terms of predicting tropical cyclone numbers for the following hurricane season because of a lack of demonstrated accuracy. However, the December outlook will discuss the qualitative factors likely to impact the 2013 hurricane season.  

One of those factors is the El Niño/La Niña–Southern Oscillation – also known as ENSO – in the equatorial Pacific Ocean, which impacts wind shear in the Atlantic Basin and particularly in the Caribbean Sea.  

As of 3 December, most of the forecasting models predict ENSO neutral conditions to persist through August of next year. ENSO neutral conditions generally do not create cyclone inhibiting wind shear in the Atlantic Basin. 

 

Doppler radar  

When the next hurricane season rolls around 1 June, 2013, the Cayman Islands should have another weather forecasting tool to rely on, the new Doppler radar. 

Doppler is a specialised radar that uses microwave signals to determine factors such as the exact location, movement and wind speed of storm systems, the presence of wind shear and expected rainfall. 

The pedestal building for the Doppler radar, which has been built in the High Rock area of East End in Grand Cayman, has been completed and the radar unit is set to be installed this month. 

Once installed, the radar will undergo testing in January and February, Cayman Islands National Weather Service Director General Fred Sambula said. 

“We’re aiming for February for the official opening of the radar.” 

Mr. Sambula said technicians have already been sent to Germany, where the radar was manufactured, for training. 

“The radar requires three technicians,” he said. “It requires a 24/7 watch to operate properly.” 

Only one of the trained technicians, Michael Carey, is officially assigned to the National Weather Service.  

“We’ve managed to borrow two technicians,” he said, noting that one of them, Earl Lindo, is with the Cayman Islands Airports Authority and another one, Mark Ross, is with the Office of Telecommunications.  

Mr. Sambula said that situation is not ideal and that it would be difficult for the men not assigned to the Weather Service to do both their regular jobs and the onerous daily, weekly and monthly tests that need to be run on the Doppler radar. 

“We have to start to think about getting at least another technician [with the National Weather Service]. Two would be better,” he said. “It’s a lot of work to operate this radar and keep it going.” 

Although the radar is being paid for partially with a grant from the European Union, the responsibility for its operation and maintenance falls to the Cayman Islands government, Mr. Sambula said. 

However, Mr. Sambula said the Doppler will be extremely useful for a variety of reasons. 

“I feel very good about this because Cayman will be better prepared and better served through having this radar because we should be able to see things we weren’t able to see before,” he said. “We’ll be able to monitor the weather a lot better. We’ll be better able to warn people.” 

The Doppler will also be a useful tool for air and marine traffic and for Hazard Management Cayman Islands. 

“It’s not just a tool to be used for warnings when hurricanes are coming,” he said. “It will be used all year round.” 

The signal from the radar will be transmitted wirelessly to the tower near Her Majesty’s Prison at Northward and then transmitted from there to the government administration building in George Town. That signal will be carried by a fibre optic cable to the National Weather Service’s office near Owen Roberts International Airport. In addition to the monitor at the National Weather Service’s office, there will be another at the offices of Hazard Management, which will serve as a backup should the airport office have to be abandoned because of hurricane conditions. 

The radar will also send the information it gathers to the National Hurricane Center in Miami to help that organisation better analyse tropical cyclones or areas of disturbed weather within the 200-mile radius range of the radar.  

Once a storm is within the Doppler radar’s range, the radar becomes an even better analysis tool than one of the Hurricane Hunter aircraft that investigate storms, Mr. Sambula said.  

The Cayman radar will fill in a blind spot in the network of Doppler radars across the Caribbean Sea that includes installations in Guyana, Trinidad, Barbados, Martinique, Guadeloupe, Puerto Rico, Dominican Republic, Jamaica and Belize. 

“Now we’ll be covered through the entire Caribbean,” Mr. Sambula said. “We should not miss anything.” 

 

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  1. I though that sole purpose of the doppler radar was to help to detect wind shear in order to enhance the safety of aircraft landing and taking off.

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