Winter Ain't Over Until It's Over

We have had quite the interesting stretch of weather throughout the month of March.  We've received a taste of spring and even early summer when we had several days make their way into the 70's with a few locations hitting the 80F mark.  We've also been reminded that winter is not yet over as we have had bursts of colder air and even snow.  As we move into the end of March and into the first week of April it appears that winter will yet again make a comeback.  There are several signals that the final week of March and first week of April will feature well below-average temperatures across much of the continental United States.

Below is a graphic from the Extended CPC Analogs Model (EXCAM) taken from Al Marinaro's website (models.wxmidwest.com).  The graphic is showing projected surface temperature anomalies across the continental United States for the week of March 31st to April 6th:

Long-range computer forecast models have been very consistent with the degree of below-average temperatures across the continental United States.  

If we look at Wednesday evening's projected 8-10 day 500mb pattern both the GFS and European forecast models develop a massive ridge in the Gulf of Alaska and into western Canada.  The response to this is for a deep trough to dig into the United States and open the flood gates for much colder air from central Canada to work into the United States:

If we look at several various teleconnection indices we can see there is definitely some merit for this type of pattern development across the United States.

Looking below we will discuss several of the more prominent global teleconnection indices and discuss why the projected pattern has a great deal of merit.

**(Note:  PNA = Pacific North-American, NAO = North Atlantic Oscillation, AO = Arctic Oscillation, EPO = Eastern Pacific Oscillation)**

Finally, given how there will be a source for cold air around this also means there could be some chances for snow, especially across the higher elevations of interior New England.  While it certainly is tougher to get snow and big snows as we move into April it certainly isn't unprecedented.  This doesn't mean we will see snow but the potential will be there.  April snows certainly have happened before.  Looking even longer range, hopefully after mid-April we should finally start to see a transition to spring and we can put winter in the rear view mirror!