Monday, October 01, 2012

"Octo-brrrrr" Coming To A Town Near You Soon!


Have you noticed how there has been a major flip in our weather since the middle of August?  The entire year up to that point was well above average in terms of temperature with well below average precipitation.  It seems like these patterns can snap like a rubber band and I would NOT be surprised to see a rainfall surplus by the end of the year.  We have gone from rainfall deficits of more than 8 inches in Little Rock to deficits around 1-2 inches.  It will not take much to put us in the "plus" category now.  That's just incredible considering the historic drought and hot weather we all experienced this summer!

The effects of the developing El Nino pattern usually brings wetter and cooler weather against the averages and this should take us right through winter.

This week will feature a warm up, but it will not last long and it should not be too strong.  The upper level wind flow pattern is undergoing a strong amplification.  A large ridge of high pressure will develop over the eastern Pacific into western Canada with a strong corresponding trough across the central and eastern United States.  This will dislodge cool, Canadian air and send it south.  We can expect well below average temperatures by the end of the week into the following week.  As far as precipitation is concerned, there should not be much with the actual front.  However, at times, the models do show periods of wet weather developing after the front passes as disturbances flow through the region.

If you watched the blog video in the previous post, you know there are model differences concerning the timing of the cool air.  There is a little better agreement and I expect the front to sweep through the state Thursday night or into Friday.  The Global Forecasting System forecast numbers indicate highs only in the lower 60s Sunday in Little Rock.  This would be almost 15-20 degrees below average!  IF there were clouds and showers around, this may be too warm, but it's too early to speculate about that.

Let's look at the model information below...

The GFS shows warming ahead of the front Thursday with highs going into the 80s especially across the southern half of the state.  Look at the colder air poised to move in from the north.  There will be widespread 40s and 50s just north and west of Arkansas.  Do you see the closed white line near Yellowstone Park?  That's an area of freezing temperatures.  Keep an eye on that white line in the maps below.
By late Friday, the colder air is establishing itself across Arkansas with readings only in the 50s and 60s.  The freezing temperatures are still wayyy to the north.  Look at the warm air.  It has moved to the southeastern United States.
This is the GFS next Sunday morning.  The 35 degree line is situated across far northern Arkansas with the freezing line in southern Missouri.  This indicates lows around 40 degrees in central Arkansas.  Do I buy this?  It's too early to tell!  There are some indications we could have some cloud cover and wind which would keep temperatures from reaching these chilly levels.  Nevertheless, it will be MUCH colder regardless.  STAY TUNED!!!!!


Anonymous said...

This is the most exciting post I've read all year!

Anonymous said...

Not even remotely "brrr." I don't know about you guys, but my comfort zone is between 25-50 degrees.

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