Category Archives: Severe Weather
With all the news about hurricanes over the past couple of weeks we’ve been asked a lot of questions about the various threats posed by these storms.
Hurricane Harvey is a clear example of the damage that long-duration heavy rains can inflict. Hurricane Irma provides an example of the destructive power of the winds associated with these storms. Continue reading
Lightning is a huge electrical discharge.
Static charges form in a storm composed of ice crystals and liquid water drops. Turbulent winds inside the storm cause particles to rub against one another, causing electrons to be stripped off, making the particles either negatively or positively charged. Continue reading
Hurricane Harvey is the first hurricane to make landfall in the United States since Wilma hit Florida in October 2005.
Harvey made landfall early Saturday morning as a Category 4 storm with estimated sustained winds of 130 mph and gusts to 150 mph. Continue reading
July was the month of revolution in both America and France in the late 18th century as we declared independence from Britain on July 4, 1776, and the French Revolution began with the assault on the Bastille in Paris on July 14, 1789. It is interesting to examine the extent to which weather may have influenced the passions that led to these seismic events.
The author of our Declaration, Thomas Jefferson, was such an avid weather observer that he brought his instruments with him from Monticello to Philadelphia that summer. He recorded a mild day on July 4 with a high temperature of 76 degrees. Phineas Pemberton, a prominent citizen, independently recorded the same high temperature – nearly 10 degrees Fahrenheit below normal. Pemberton also noted a wind shift from northerly to southwesterly with a falling pressure as often accompanies passage of a surface high-pressure system. Thus, the great revolutionary act in America was birthed in benevolent weather conditions. Continue reading
A derecho (pronounced deh-RAY-cho, a Spanish word meaning “straight ahead”) is an hours-long windstorm associated with a line of severe thunderstorms.
It is a result of straight-line winds, not the rotary winds of a tornado — hence its name. Derechos in the United States are most common in the late spring and summer (May through August). Continue reading