T&T’s Eyes In The Skies – The Doppler Radar

For years, any Trinbagonians with internet access could look at incoming weather in near real-time before even looking out the window. To some extent, we still can. Satellites have made significant strides in recent history worldwide, updating every few minutes and allowing anyone with an internet connection to see weather systems near you. But, Trinidad and Tobago had another tool in our arsenal, a Doppler weather radar.

This specialized, expensive equipment is predominantly used to detect the motion and intensity of rain droplets. These two critical pieces of data allow meteorologists to determine the structure of showers or thunderstorms and their potential to cause hazardous weather. With strides in technology, radars can detect strong winds, whether thunderstorms are producing rain or hail, how tall clouds extend into the sky, take vertical cross-sections of showers or thunderstorms, and even calculate how much rain has fallen and accumulated.

Since February 2020, Trinidad and Tobago’s Doppler radar has been out of service. Come the 2022’s Wet Season, the Trinidad and Tobago Meteorological Service is not only hoping to have it back in commission but a new, smaller radar is expected to join T&T’s radar coverage.

T&T’s Weather Radar History

The RC-32B weather radar (manufactured by Mitsubishi) was installed on the Great Stone, Cuba, in 1973. (Image: Blog Radares looking south)

In 1967, the first Doppler weather radar was installed at Crown Point, Tobago, through the partnership of the World Meteorological Organization (WMO) and the United Nations Developmental Program. This RC-32B radar, manufactured by Mitsubishi, became the longest-serving radar in the English-speaking Caribbean of its type, according to Christopher St. Clair, a Meteorological Supervisor and Officer-in-Charge of the Meteorological Services in Tobago. This specific radar model was installed in Cuba in the early 1970s and is still in use today by the Cuban Meteorological Services after modernization in 2006 and again in 2021.

By the turn of the 21st century, the Tobago radar was no longer operational. However, talks began in 1994 through an initiative between the WMO and the Caribbean Meteorological Organization (CMO) to develop the Caribbean Radar Network. This project eventually became the CARIFORUM initiative for a radar network warning system in the Caribbean. It directly led to Doppler radars being installed in T&T, Guyana, Barbados, and Belize at the cost of 13.2 million Euros.

Following a detailed technical study of six potential sites in Trinidad and Tobago by the CMO and the French Meteorological Service, a site at Brasso Venado on the Central Range was chosen to construct the Doppler radar.

The 20-meter reinforced concrete tower housing the radar was completed in January 2008, the radar was physically installed in March 2008, and testing began in early April 2008. However, by July of that year, testing ceased due to the failure of a Pulse Transformer, leading to a months-long delay in commissioning. By November, Trinidad and Tobago now had a powerful, high-precision METEOR 600 S-band Doppler radar.

On October 2nd, 2014, Radar observations during the passage of a tropical wave that produced severe winds, ripping off 25 roofs. Radial velocities are displayed on the left, reflectivity on the right. Vertical cuts above and plan views, with the vertical cut lines below. (Image: Baker et al. 2017, Early Hazard Warning Potential of Trinidad and Tobago’s Weather Radar.)

The Brasso radar was capable of detecting surface rainfall intensity, locations of showers (reflectivity) and thunderstorms, cloud heights, and horizontal and vertical winds (wind velocity). Meteorologists were also able to create cross-sections to see further atmospheric detail. The radar extended 400 kilometers away from Central Trinidad in all directions, capable of detecting rain as far north as St. Lucia and Barbados, as far west as Tortuga Island, Venezuela, and as far southeast as northeastern Guyana.

T&T’s Brasso Venado Doppler weather radar captured Tropical Storm Bret’s landfall in June 2017. (Image: Trinidad and Tobago Meteorological Service)

The Doppler radar ran 24/7, year-round, only down for brief routine maintenance, for nearly ten years. The Brasso radar saw tornadoes, tropical cyclones, flooding rainfall, and many other hazardous hydro-meteorological events. However, significant wear and tear persisted. Chief Climatologist at the Trinidad and Tobago Meteorological Service (TTMS), Kenneth Kerr, said during the TTMS’ 2022 World Meteorological Day webinar that even with the frequency of corrective maintenance, the wear became too much for the system.

On February 12th, 2020, the multi-million dollar Doppler weather radar system went down. Until last Wednesday, the Met Office has been relatively mum on the issue.

“You do not find a radar sitting on a shelf”

Since February 12th, 2020, if you visited the Trinidad and Tobago Meteorological Service’s website looking for the latest radar imagery, you’d be greeted with this image. (Trinidad and Tobago Meteorological Service)

At the time of this article, it has been two years, one month, and sixteen days since the Brasso Venado Doppler radar has been out of operation. The Met Office is adamant that this prolonged outage is not a result of a lack of trying.

Kerr, speaking virtually, explained, “We have a bigger problem now because you do not find a radar sitting on a shelf like a bookbag anywhere on the globe.”

“And when you manufacture this radar, sometimes the company that manufactured the equipment is not manufacturing that particular level of radar anymore. So when you need a part, it means that they have to go and rebuild that particular part because, as I said, technology is constantly changing.”

The METEOR 600 S-band Doppler radar at Brasso Venado was manufactured by Selex-Gematronik Company of Germany and is no longer produced. The company now manufactures the 700 S-Band model. Barbados, which also had a METEOR 600 S-Band radar, recently upgraded to at the cost of US$3.5 million.

According to Kerr, even the replacement parts are quite expensive. Compounding issues, “every time we find and fix one problem, another one pops up given the complexity of it,” Kerr explained.

However, he added that they hope to have the radar running sometime this year. “Most likely, we are trying to get it running for the start of the hurricane season.”

Is cost also an issue?

The Meteorological Service Division’s Recurrent Expenditure for Maintenance and Repairs from 2018 to 2022 (Data: Ministry of Finance of Trinidad and Tobago)

Given that the repairs to the existing radar would fall into recurrent expenditure rather than capital expenditure if the Met Office were to purchase a new radar system, we took a look at the Meteorological Services Division’s budget from 2018 through 2021.

The Meteorological Services Division (MSD) has spent a fraction of its annual maintenance and repair budget allocation based on the last several budgets. In fact, since 2018, only $400,876 has been spent on repair and maintenance, 1.27% of the total (and estimated total) budget from 2018 through 2022.

However, funds from another arm of the government, the Central Administrative Services of Tobago, have been used to provide the Trinidad and Tobago Meteorological Services in Tobago with new equipment.

Decades Later, Tobago Gets New Radar, Satellite Equipment

Capella-GR GOES-16 (GOES-East) satellite ground station in Crown Point, Tobago (Image: Enterprise Electronics Corporation)
Capella-GR GOES-16 (GOES-East) satellite ground station in Crown Point, Tobago (Image: Enterprise Electronics Corporation)

Through the government’s Public Sector Investment Program, TT$36.7 million has been allocated to constructing the new meteorological office at Crown Point and the procurement of meteorological equipment. The central government has invested in upgrading Tobago’s meteorological capabilities so that the Crown Point meteorological office can act as a backup to Piarco.

The Tobago MSD has also been allocated TT$4.6 million for the 2021/2022 fiscal year to purchase a climate management system, more automated weather stations at A.N.R Robinson International Airport, in Buccoo, Tobago, and Flagstaff, as well as a voltage regulator and an ultraviolet monitoring system. The island also now has a Capella-GR GOES-16 direct receive ground station, allowing the Tobago Met Office to receive GOES-16 satellite images directly.

Radial extent of Tobago's new Doppler radar
Radial extent of Tobago’s new Doppler radar

As of 2022, Tobago now has a Ranger X-5 ICAO Compliant X Band Portable Doppler Weather Radar System but a much smaller range of 150 kilometers from Crown Point. This dual-polarization radar is a marked upgrade, allowing forecasters to have more accurate estimates of precipitation, the ability to discern between rain and hail, and better detection of non-meteorological hazards in the sky as birds or tornado debris.

This new radar can also operate in sustained winds up to 120 KM/H, gusts to 144 KM/H, and can survive winds up to 240 KM/H. To date, the strongest winds that have impacted Tobago originated from Hurricane Flora in 1963, with maximum sustained winds at 90 knots (167 KM/H) with gusts to 110 knots (205 KM/H).

According to the Met Office, they hope to make the radar imagery available to the public via the TTMS website eventually and expect the new and old radars to be operational before the 2022 hurricane season.

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