Terry’s Take: The perfect fireworks forecast

Posted on: 9:43 pm, July 2, 2013, by

Terry Swails Weather Blog

Independence Day couldn’t be better timed. It falls in early summer, when the days are usually hot and sunny and the nights are comfortably warm. That’s perfect weather for parades, family gatherings, baseball games, picnics, barbecues, watermelon, and…after dusk, fireworks. (Thomas Jefferson and the boys planned it that way back in 1776)!

fireworks

THE PERFECT FIREWORKS DISPLAY

Of course good weather is the key to these special times and events, but did you know it’s also the key to “spectacular fireworks”?

Nothing puts a damper on a fireworks display like a muggy day. George Zambelli of the Zambelli Fireworks Company of New Castle, Pa., explains that “The brilliance of fireworks is better in low humidity, moist air due to higher humidity will cause the smoke to lay closer to the ground and appear more dense, and ultimately it will decrease the brilliance.

4TH OF JULY FIREWORKS, A CLASSIC AMERICAN TRADITION

4TH OF JULY FIREWORKS, A CLASSIC AMERICAN TRADITION

“The most brilliant fireworks are in low humidity when you have the winds carrying the smoke away from the spectators. In large displays you have a lot of pyrotechnic material going off at once, so you need something to dissipate that smoke,” he said.

What about other weather conditions?

Lightning storms can be too dangerous to set fireworks off, and they usually cause a delay in the program. Oddly, rain isn’t a problem. Fireworks can be fired right through it.

LIGHTNING AND FIREWORKS, THE DOUBLE WHAMMY

LIGHTNING AND FIREWORKS, THE DOUBLE WHAMMY

“Rain doesn’t cause an issue and it doesn’t impact how fireworks look because the colors are so vibrant,” says Julie Heckman, executive director of the American Pyrotechnics Association, the fireworks industry’s main trade association.

Wind, on the other hand, can be a problem — especially if it affects the safety of spectators.

“Winds will change the direction of where the fallout is,” Heckman said. “Winds are typically monitored all day long up until they push the fire button on fireworks shows. When winds exceed 20 to 30 miles per hour, fireworks companies won’t shoot [the shows] off.”

WIND AND FIREWORKS, A DANGEROUS COMBINATION

WIND AND FIREWORKS, A DANGEROUS COMBINATION

Shows can also be canceled because of overly dry conditions and the fire danger posed by falling sparks. Several shows have already been scrubbed in drought stricken parts of the country for this very reason.

So from the experts and my personal observations, the optimal weather conditions for fireworks displays are clear skies, low humidity and a light breeze that’s moving the opposite direction of the spectators.

Here in the Quad Cities, 61.7 percent of our 4th of July’s have no measurable rain and all told average a high of 86 and a low of 65. Humidity levels tend to be moderate to high. High temperatures have ranged from 102 in 1911 to 67 in 1967. The wettest 4th occurred in 2007 when 3.56″ of rain put a real damper on festivities.

Here is a link with the times of some festivals and fireworks going on around the area.
http://wqad.com/2013/06/28/july-4-events/