Single Digits to East Coast – Monday Night 01/06/14

Here in the Greensboro area the temperature is now 16 with occasional gusts of 21kph.   It is clear and cold with a random wisp of cirrus jetting by on it’s way to England and abroad.   It seems that these systems keep passing every three to four days.  

The term I am about to use is ‘Atmospheric Priming’.  Especially across the Southeast you need a pool of cold air stacking more or less vertically and in sufficient supply to keep that part of the airmass frigid.

Instead of freezing rain you get snow.   In Greensboro, those systems coming in from the west get supersaturated going up the mountains while losing a lot of that moisture going down hill.  These adiabatic processes are responsible for snow on one side and little or no precipitation arriving to Greensboro/High Point.

Infrared Satellite Image

Satellite imagery backs up my forecast but you can see by all the yellow that another system is not far behind.   Initial temperature forecasts will be suspect.   How much cloud clover and how much moisture are the critical questions.   In the Miller Type Climate Model is playing out and now a surge of cold air is mixing the weather up even more.

The Cape Hatteras Low is a wild card.  This system is called the Cape Hatteras Low because the geography in that area is prone to cyclogenesis (low formation) or a push from the south.  The storms from the south bring warming and most likely rain.

http://ww2010.atmos.uiuc.edu/(Gh)/guides/maps/fcst/sppth.rxml

The link above is a powerful tool for Meteorologists,  to determine what an airmass consists of.  Is there enough cold air and more importantly how dry or wet the atmosphere is.

Meteorologist Jeff Haby helps with the definition of thickness,  the parameter that gives the suggestion of rain or snow.   5400 Meters.  

http://www.theweatherprediction.com/habyhints/97/

I want to give you as many explanations that you need or want to clarify what this all means.   But forecasters should never think these values are 100%,  in fact their reliability is only 50%. Other fields need to be considered.   Such as warm overrunning along the surface front.

Winds along with temperatures are the signature parameters for the location of fronts.  Warm moist areas ahead of the front and dry or drier weather behind it.  

Looking at the surface chart you can see where winds and pressure define where the weather might be along with the pressure gradient that determines how fast winds might be.  Note: There are different frontal parameters as you go aloft.  It is not until the 250mb front passes that all weather generally ceases.   At least for a few hours to a few days if High pressure becomes ensconced over your area.

When the high moves off the coast winds will return to the south and bringing relatively warmed conditions.   Kind of like a Yo-yo,  up and down with regards to pressure and guided generally by jet streams.

The wave pattern suggest where weather patterns may lie.   This is like a virtual highway depicting the ebb and flow of weather.   The arbitrary climate change argument is merely rhetorical because the earth’s climate is always changing,  above and below.

 

 

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