Winds of Change


Derek Segal, building consultant with GCI, was at the helm of the Everything Building Envelope podcast recently, hosting a fascinating discussion with meteorologist Rocco Calaci, of LRC Services.

Rocco Calaci was a meteorologist with the United States Air Force for 20 years and also an instructor for the Department of Defense. Rocco finished his career with the Air Force as manager of the military weather station at Eglin Air Force Base, Florida.

Following his retirement from the Air Force, Rocco started LRC Services, which provides after-the-fact, or forensic, reconstruction of weather events, as well as site-specific forecasting.

Location, Location, Location

Rocco assembles forecasts using a variety of resources, including federal databases dating back to 1980, surface observations taken at airports and for other agencies, and a repository of weather radar for the entire United States going back about 25 years.

The data analysis lets LRC predict weather events from large, or synaptic, scale to microscale level, pinpointing what happened at a specific location at narrow intervals — even, Rocco suggests, every four minutes.

In addition to data, Rocco evaluates the surrounding environment. Micro-climates are created around a structure by trees, tall buildings, nearby water bodies, or flat land where wind blows across without interruption. Such variables make a significant difference in how structures are impacted by weather events, even from one neighborhood to the next.

World of Wind

Rocco Calaci also gave listeners a glimpse at wind through a meteorologist’s eyes. For Rocco, many worlds are contained inside the word “wind”.

Pressure-gradient wind is what drives most wind across the globe, initiated by factors such as pressure and temperature. Thunderstorm winds are generated by thunderstorms and a wind gust is a sudden burst of wind speed that lasts three to five seconds.

A microburst occurs when a storm collapses, resulting in winds descending from the upper atmosphere, hitting the ground and spreading out, in a manner that’s similar to a bomb. A microburst has the power of a tornado, but where a tornado is vertical with a lot of shear over a short distance, a microburst has a horizontal tornado effect, creating havoc as it rolls across the ground.

Then there is the mighty mesocyclone. A mesocyclone is a large, rotating cluster of storms that can take the form of one large storm, extending six to eight miles across, or a cluster of storms, with each storm within it rotating. The mesocyclone may produce large hail, or heavy winds at 55 miles an hour or more, or microbursts. There might be a tornado in the mesocyclone, or heavy rain.

What’s Going On?

Hurricane Harvey in Texas, Maria in Puerto Rico and Florida, Matthew, Irma, and Michael in Florida — all category 4 events happening within three years, a rate of frequency for intense storms that hasn’t occurred in the last 50 years. What’s going on? That was Derek’s question to Rocco.

Rocco notes that in the last 25 years, we’ve had the hottest 10 years on record. Water continues to warm and the atmosphere is retaining heat at a higher rate. Polar caps are melting, putting more moisture in the air.

Moisture and wind are fuel for storms. With more of both in the atmosphere, the results are explosive category 4 events and Rocco expects that to continue for at least two or three more years, or until the cycle becomes less active. He further notes that the heightened intensity of storm events is a global phenomenon.

You can find the entire discussion between Derek Segal and Rocco Calaci — which also touched on storm chasing and alternative energy — at the Everything Building Envelope podcast. Don’t forget to subscribe while you’re there, so you don’t miss upcoming discussions between members of the GCI Consultants team and other building experts.

Rocco Calaci can be contacted through My Weather Search, where you will also find comprehensive weather maps.