Brrrrrrr, it's cold out here!

In the wake of the 2 systems that have passed through the past 48 hours we will be getting some very cold, arctic air filtering down into the region.  This cold air has been positioned over much of the central United States after it moved down from Canada early in the week.  It has brought some very cold single digit highs, highs in the 20s and even Phoenix, AZ experienced a high of 53 on Monday, a temperature very unlikely for this time of year.  These will be the coldest temperatures we've felt in quite some time; with high temperatures only reaching the lower 30s and lows in the teens.  One positive of these colder temperatures is that it will bring some sunshine back for the weekend.  How long will these temperatures last you might be asking?  Temperatures will return to the 40s again early next week and it has also been forecasted that the average December 2011 temperature will be above normal.  One of the reasons for this is the position of the jet stream.  The jet stream has not dug too far south below us yet and it isn't expected to either as there is no blocking system set up and there seems to be no drastic pattern change in sight to bring us significantly colder temperatures.

Here's a really cool image showing the temperature changes in the US over the past 24 hours or so:

Image from: The Weather Channel (www.weather.com)

Snow on the way....

A stalled cold front off the east coast will help to bring some cold temperatures to the region as a rapidly intensifying low pressure system quickly moves through our region tonight and early tomorrow morning.  We will remain rain for the rest of the day but we will change over to snow around 1-2am overnight as some colder air filters in to the region and temperatures begin to fall below freezing.  As the bulk of the system moves through in the early morning hours we could see some heavier snowfall rates (up to an inch an hour).  So exactly how much snow will we expect to get?  Right now I'd say we will end up with an accumulation around 3", even though the snow will be coming down it won't accumulate as much because the ground is so soggy from the rain and relatively warmer temperatures.  After the system moves out tomorrow morning the wind will pick up (could see gusts up to 40mph) and there will be some slick spots on the roads.  The National Weather Service has issued a Winter Weather Advisory in effect from midnight tonight through 8am tomorrow morning. So if you're heading out somewhere late tonight or early tomorrow morning make sure you leave some extra travel time as roads will be slick and slushy and probably a bit icy in higher elevations.
For updated information regarding this storm go to: http://forecast.weather.gov/MapClick.php?CityName=Plymouth&state=NH&site=GYX&textField1=43.7386&textField2=-71.6983&e=0

A Tad Bit on the Warm Side...

     A new statement from the National Weather Service in Buffalo, NY (http://www.erh.noaa.gov/buf/) states that this past November has been the 6th warmest on record for both Rochester, NY and Buffalo, NY.  In the month of November Buffalo was found to be 5.8 degrees above the average temperature for the month and Rochester at 5.3 degrees above average (see climate data).  Another interesting finding is that Buffalo almost tied the record for the latest date of measurable snow, December 3rd.  This record is a record set way back in 1899.  Buffalo missed this record today by recording 4" of snow so far today associated with a cold front moving through the region.
     So what exactly does this mean for our snow season this year in Upstate/Western NY?  Well, with the warmer temperatures the Great Lakes will stay warmer but that doesn't necessarily mean a more intense lake effect season as there are many other variables that come into play with lake effect (i.e. presence of very cold air, proper wind direction, lifting mechanisms).  The climatology has shown that even with warmer November temperatures and a late snow, a winter with normal winter temperatures and snowfall amounts has pursued, but there have been a few times where it was below normal for both.  So it will certainly be interesting to see how this winter rounds out!
     The climatology report for Plymouth, NH has states that we have also had above average temperatures at 4.1 degrees above normal.  While we ended the month of November on the warm side, we are starting off December on the cool side.  Although it may seem like a cold start, it is actually right around the normal for this time of year in Plymouth (normal high: 39, normal low: 19).  And today we even have a slight change of snow as a cold front passes through later this afternoon/evening! So it's a pretty good start to December!


Climate Data:
Rochester, NY - http://www.nws.noaa.gov/climate/getclimate.php?wfo=buf
Buffalo, NY - http://www.nws.noaa.gov/climate/getclimate.php?wfo=buf
Plymouth, NH - http://www.nws.noaa.gov/climate/getclimate.php?wfo=gyx