Seiche on Lake Erie??

By: 24hourprof, 4:06 PM GMT on December 24, 2014

The 16-hour forecast of 3-hour pressure change 11Z run of the Rapid Refresh (below, valid at 03Z this evening), shows a couplet of large pressure falls over Canada in concert with the 985-mb low and large pressure rises associated with high pressure over the western Gulf ridging northeastward (second image below).


The 16-hour Rapid Refresh forecast of 3-hour pressure changes from the 11Z run, valid at 03Z this evening. Courtesy of NOAA.

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Synoptic Meteorology Physics

Updated: 4:23 PM GMT on December 24, 2014

More Media Drivel

By: 24hourprof, 8:00 PM GMT on December 02, 2014

Media reports on Pacific storms like the one currently off the West Coast of the United States drives me crazy. Just this morning, a nationally known TV weathercaster pointed at the plume of clouds funneling toward California and said, "the jet stream is driving in lots and lots of moisture." Good grief!

First, this feature is the subtropical jet stream...typically located near 200 mb (about 12 kilometers up...see 00Z GFS model analysis from last even...

Updated: 8:02 PM GMT on December 02, 2014

The Deep, Deep Low in the Bering Sea

By: 24hourprof, 4:39 PM GMT on November 16, 2014

In the aftermath of the very intense, 924-mb extratropical low-pressure system in the Bering Sea, I read several historical accounts regarding the low's place in weather records. A scientific reference in one of the blogs caught my eye, but for dubious reasons.

For reference, the lowest central pressure of Hurricane Andrew (1992) was 922 millibars. Despite the potential of a similar pressure at its peak, wind speeds in extratropical cyclones such as the...

Updated: 4:55 PM GMT on December 01, 2014

Chesapeake and Delaware Bay-Effect Precipitation

By: 24hourprof, 3:08 PM GMT on November 15, 2014

This morning, there were two bands of bay-effect precipitation over Chesapeake and Delaware Bays (one band over each bay). Below is a loop of infrared satellite images spanning from 1015 UTC to 1345 UTC, which shows the two convective bands of clouds.


A loop of infrared satellite images from 1015 UTC to 1345 UTC on Saturday, November 15, 2014.

The bands tend to align themselves with the mean-layer wind in the lower half of the troposphe...

Updated: 4:12 PM GMT on November 15, 2014

The Polar Vortex...Blah, Blah, Blah

By: 24hourprof, 10:06 PM GMT on November 08, 2014

I had a dental procedure last week to fix resorption in one of my teeth. I first had a root canal, followed by surgery that exposed the root of the tooth, where my endodontist had to fill two holes caused by the resorption. The aftermath has not been pleasant.

The pain from my surgery was bad enough. Then I heard the media once again predicting the approach of the "polar vortex" from Canada and the associated Arctic air arriving over the contiguous sta...

Updated: 10:23 PM GMT on November 19, 2014

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About 24hourprof

Retired senior lecturer in the Department of Meteorology at Penn State, where he was lead faculty for PSU's online certificate in forecasting.