George Hiotis

Severe Storm Sunday — Stay Alert

by George Hiotis on November 17, 2013 at 6:59 am

The Storm Prediction Center has placed almost the entire state under a moderate risk for severe weather for this evening. For anyone who does not know much about SPC, it takes a lot of confidence for them to issue even slight risks for severe weather. Therefore, this shows this storm means business.

The risk is a widespread, damaging wind event with gusty winds around 50 mph. The National Weather Service has issued a Wind Advisory for many counties to our west, and I believe we will be issued an advisory in the near future.

The Cause:
?An upper level low, or a trough, is strengthening and is being helped to grow by a strong jet streak.
?There is also, a deep service low pressure that will begin its move today and tonight north towards Lake Superior.
?Associated with this low, and our real concern, is a cold front that will swing through this evening.


Winds, as said above, are the main threat due to a packed pressure gradient. Which is a fancy way of saying: the low is strong and with tighter isobars (contour lines of constant pressure), winds are able to increase and become more dangerous. During today’s “Thunderstorm”, actual thunder will be isolated but it is still shaping up to be a significant weather event. Luckily, there is low instability for the frontal passage, which will occur around 7 to 9, this evening. Low instability will prevent the storm from being even more severe.