Most Wonderful Time of the Year

JAN was a huge disappoint with above average temperature departures and below normal snow fall. Nor'easters affecting the coast have been all but non-existent with most storms...the abominable hybrids of mainly rain and snow on the north edge of the precipitation shield such as they were...going straight up St. Larry/s Waterway or saving their best dynamics for offshore interests.

All that misery will be forgotten quickly if FEB manages to get its act together.

The second and third week of FEB are the heart of snow season for many stations along the EC. An important event leading to a notable change for the better could have been caused by a relatively minor stratospheric warming around the 23rd of JAN. Now...almost three weeks later...the Arctic Oscillation has gone negative...which is often the result of these warmings...especially during winters when the QBO is negative. Forecasts from four LR models suggest the AO index will remain below zero the next six days.


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The Pacific-North American index has also come around. It...too is forecast to persist for about a week. The focus is often on the ridge-W aspect of a +PNA configuration which delivers cold air masses into the Lower 48...but of equal importance at the very least is the negative geo-potential height anomaly off the SE coast where conditions for cyclogenesis are most favorable.


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By and large...New England has had a good run so far this winter. No so much for the mid-Atlantic; however...the forecast combination of -AO and +PNA could change all of that in a hurry.