Retired senior lecturer in the Department of Meteorology at Penn State, where he was lead faculty for PSU's online certificate in forecasting.
By: Lee Grenci, 6:34 PM GMT on March 21, 2017
Each December (typically), an ice boom is deployed across 1.7 miles (8800 feet) of extreme eastern Lake Erie near the mouth of the Niagara River. The purpose of this boom is to prevent large chunks of ice from flowing down the river, where they might block water inflow to hydroelectric plants, cause ice jams and flooding, and damage private property.
A section of the ice boom. Courtesy of the Army Corp of Engineers.
On March 6, the New Y...
By: Lee Grenci, 3:35 PM GMT on March 16, 2017
Just a short blog about a few of my takeaways from the winter storm in the Northeast this week...I had no doubt that precipitation type would be an issue in some of the major cities, and I thought forecasters were aware of the difficulties with regard to predicting snowfall.
However, all the forecasts I saw were deterministic rather than probabilistic. And many forecasts were framed in the context of the European and GFS models (essentially, choosing th...
By: Lee Grenci, 8:13 PM GMT on March 12, 2017
To my dismay, I read a short-range discussion about the imminent winter storm along the Atlantic Seaboard tomorrow night and Tuesday. I quote: "A low pressure system crossing the Midwest states is expected to phase (sic) with another low off the southeast U.S. coast." I don't know about you, but the word, phase," in this context suggests two low-pressure systems merging along the East Coast. It's just not true.
For the record, I usually reserve "phasin...
By: Lee Grenci, 6:27 PM GMT on January 07, 2017
Last evening, while watching a national weather show on cable TV, a meteorologist began his presentation about the threat of heavy precipitation in California with an enhanced water vapor image (see below; Larger image). As I have preached and preached for years, using water vapor images to quantify atmospheric water vapor is just plain old bad science. And, yet, that's exactly what the meteorologist did.
The enhanced water-vapor image from GOES-1...
By: Lee Grenci, 4:41 PM GMT on October 16, 2016
All of my professional career, I have lobbied for the temperature, 32 degrees Fahrenheit, to be called the melting point of ice. Perhaps it was the stubbornness of youth that made me so insistent. As I have grown older, I now believe that trying to get this convention adopted is a losing proposition. Not even close.
That's because the common experience of almost everyone is that most liquid water does indeed freeze at temperatures close to 32 degrees Fah...
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.