Weather Wise: The weather of Sept. 11, 2001

Posted at 4:01 PM, Sep 11, 2023

“Never forget” is the phrase to honor the lives lost in the September 11, 2001 attacks. In this week's weatherwise, I'll never forget the weather on this day 22 years ago and its effects on the tragedy.

September 11, 2001, is a day that is burned into the minds of many Americans, as the details of that fateful day remain vivid no matter the years that have passed. Plumes of black smoke with a backdrop of a cloudless blue sky are etched in memory.

A strong cold front crossed the New York City metro area on the night of September 10. At the time, Hurricane Erin was lashing out on the Atlantic Ocean several hundred miles away. The cold front kept Erin out over the open waters with no impact on the northeast.

September 11, 2001, started out as a gorgeous September morning. It was crisp and clear and high pressure moved in, and there were no weather issues for planes leaving the airports that morning.

After the planes hit the towers, plumes of billowing smoke preceded the dust cloud of the collapse. Behind the cold front, and the pressure gradient between the approaching high and Hurricane Erin, a strong northwest flow developed. Wind of up to 20-25mph took smoke and pollutants out to sea rather than linger over the city, the coast of New Jersey, or adjacent Long Island.

Many people suffered from pulmonary and cardiovascular diseases after breathing in toxic pollutants in the dust and smoke from the World Trade Center collapse, and even brief exposure to the dust and products in the air was found to cause numerous diseases. However, the weather and the wind on that fateful day lessened the potential impact if the wind was not as strong or blowing in the direction it did.