Tuesday, November 12, 2013

Wild Temperature Swing


By this time next week, we'll have had temperatures ranging from the 20s, back into the 70s, then into the 20s again.  Unusual?  Not really.  As the cold air masses start their move south out of Canada, they often battle some residual warm and moist air.  This is why we have our secondary severe weather season.  As all this takes place, the severe threat will have to be watched.  At this time, the threat appears low.

As mentioned on the previous blog post, I'm already looking at the weekend into next week.  I think showers will move through the area Friday with one wave of moisture.  It could be one of those cold, dreary, and rainy days.  Then as we move along into the weekend, the Gulf of Mexico really begins to open up and the humidity and warmth starts to advance northward.  At the same time, there's another blast of cold air coming out of Canada.  It has the potential to be just as cold as this one and maybe even colder.  I'm going to once again stick with the data from the European model.

This is the European model valid Monday morning at 6AM November 18th.  Remember, when we're dealing with the long range, there will be changes.  The surface low is the black circle just north of Wisconsin.  The front trails that low through Illinois into eastern Arkansas.  Behind the front, the isobars (black lines) are tightly packed together indicating a strong pressure gradient (wind).  The greens and yellows indicate precipitation over the previous 6 hours.  There's an extensive area of rain and storms along and ahead of the front.  Look at the high pressure over Montana.  It's 1040+mb.  That's some very cold air once again behind the front.  If this verifies, it's one of those situation where the high is reached early in the day with cold and windy weather.

This is the Euro from weatherbell.com.  I have never shown this product, but it really depicts the wild temperature ride we're about to go on.  Both graphs are read from left to right.  On the top graph, the red line is the 6 hour max temperature.  Look how it really goes up to near 70 by this weekend.  You can see it crash as the front slides through and temperatures take a nose dive Monday.  Now look at the bottom graph.  That's total rainfall for each time period.  Look at the spike Sunday night into Monday morning.  That's the rain and storm activity with the cold front.  The Euro says we could get more than 1 inch of rain out of it.  I'll keep everyone updated.

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