THEWEATHERMOGIL:: Out of balance temperatures rule the eastern U.S.
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It’s important to realize that cold air masses tend to form over higher latitude regions due to snow cover, shorter days and lower sun angles. Similarly, warm air masses develop over lower latitudes. Air masses are just large volumes of air with similar temperature and moisture characteristics.
When upper-level troughs and associated storm systems develop, these air masses get transported far their homes. This means that cold air travels far south from its “source” region and warm air travels far north from its origin location. Such was the case early this Thursday morning.
Fig. 1 shows the upper level wind pattern at 7:00 p.m. E.D.T. yesterday that was associated with the low-pressure (or storm) system responsible for the deadly and destructive severe weather events of the past two days. Early this morning, that double-barreled surface low (with its counter-clockwise wind flow) was centered near western New York State.
To the east of the low, winds were blowing from the south and temperatures across southern New England were in the upper 50’s to lower 60’s. Fig. 2 shows that at 4:00 a.m. E.D.T., Boston, MA (BOS) was reporting a 61-degree reading (with thunderstorms). Far to the south of the low, where colder air had moved southward on northerly and northwesterly winds, Tampa, FL (TPA) was only at 57 degrees.
A similar scenario existed between Minneapolis, MN (MSP) and Amarillo, TX (AMA). Both cities had readings in the upper 20’s this morning.
© 2016 H. Michael Mogil
Originally posted 2/25/16