Saturday, May 04, 2013

Setting Record Lows at 4 PM

We're benefiting majorly with our current dry, sunny pattern in the Delaware Valley.  While temperatures are comfortably cool, record lows are being set in the middle of the afternoon in the heart of the South.

Yes, in mid afternoon.

Memphis dropped to 43 degrees at 4:23 PM yesterday afternoon, tying a record low for the date.  Temperatures in Memphis, St. Louis, and other places throughout the middle of the country were anywhere from 20 to 30 degrees below average at 6 PM Central time last night.

A number of sites throughout the middle of the country, especially in the Deep South, were dealing with some of the coolest temperatures on record for May as a result of an anomalous blocking pattern that's dominating our weather.  A large ocean storm in the Atlantic and a pair of sprawling high pressure ridges are putting the squeeze on a deep trough of low pressure in the middle of the country.  The two highs (outlined in red on the graphic below) are blocked in place and preventing any escape for the low in the middle of the nation while the ocean storm (in the Atlantic in the blue shaded areas) is preventing any eastward progression of the high pressure ridges.

The result, for us, is near weather perfection.  As is the case for the Northwest and West Coast, who are also dealing with great weather although portions of California are dealing with wildfire threats.  However, the middle of the country is paying the price with the squeeze play of record snow and cold.