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, 9:27 PM GMT on May 21, 2016
In the year I graduated from high school, I became an avid fan of the television series, Mission: Impossible (1966-1973), starring Peter Graves, Barbara Bain, Greg Morris, Peter Lupus, and, one of my favorite all-time actors, Martin Landau. Grave's character, Jim Phelps, led this team of secret government agents called the Impossible Missions Force (IMF) (Stephen Hill played the leader during the first year of the series). Each episode began with Jim Phelps getting...
Updated: 1:15 PM GMT on May 23, 2016
By: Lee Grenci, 2:23 PM GMT on May 15, 2016
Early Sunday morning, the Cleveland office of the National Weather Service issued a Frost Advisory for some counties in northern Ohio and northwest Pennsylvania for Sunday night and early Monday morning. In part, it read:
...FROST ADVISORY IN EFFECT FROM 2 AM TO 9 AM EDT MONDAY...
THE NATIONAL WEATHER SERVICE IN CLEVELAND HAS ISSUED A FROST
ADVISORY...WHICH IS IN EFFECT FROM 2 AM TO 9 AM EDT MONDAY.
* TEMPERATURE...LOWS TONIGHT...
Updated: 7:48 PM GMT on May 21, 2016
By: Lee Grenci, 3:01 PM GMT on May 13, 2016
Today's 500-mb pattern really drives home the point I made in last week's blog, The Cheapening of Blocking Highs. I admit I'm old school, and I've always followed the criteria of the "Father of Blocking," Daniel J. Rex (with the exception of the duration criterion and the reference to the 45 degrees of longitude).
By way of review, Rex's criteria for a blocking high were:
a) the basic westerly current must split into two branches,
Updated: 5:14 PM GMT on May 13, 2016
By: Lee Grenci, 2:29 PM GMT on May 09, 2016
Just a short blog about my take on the devastating wildfire in Ft. McMurray, Alberta:
As Jeff Masters and Bob Henson expertly wrote in a recent blog, the antecedent lack of rain primed eastern Alberta for wildfires.
Local winds exacerbated wildfire conditions. The quasi-stationary, upper-level ridge that I wrote about last week (which wasn't an "omega block," contrary to television and internet pronouncements) fostered westerly winds that dow...
Updated: 2:30 PM GMT on May 09, 2016
By: Lee Grenci, 5:46 PM GMT on May 05, 2016
Some forecasters continue to describe the current 500-mb pattern as an “omega block.” Today's upper-air pattern (and yesterday's) is not a blocking pattern, in any traditional sense of the word (and, in my opinion).
The 06 UTC GFS model analysis of 500-mb heights on May 5, 2016, shows a long-wave, high-amplitude pattern over the contiguous states. Larger image. Courtesy of Penn State.
Granted, the 500-mb pattern over the contiguous ...
Updated: 12:48 AM GMT on May 07, 2016