(WHTM) – On Thursday, October 19, NOAA released its annual winter weather outlook. Details from the outlook are more of a national/broad scale, however, the forecasting trends are important to realize and what those trends could mean for the Midstate.
It has been established through research and reviews of past winters, that El Niño winters (warmer than average eastern equatorial Pacific Ocean waters in winter) lead to a very active southern jet stream.
Translation – increased storm activity along the Deep South and ultimately the Mid-Atlantic.
You can see this reflected in the outlook for a wetter-than-average winter in the Deep South and Southeastern US. This southern jet stream can oftentimes join up or phase with the northern jet stream when a trough of low-pressure swings through the eastern United States.
If the timing is right this can lead to large coastal storms or Nor’easters. Some of our largest Midstate snow storms come from such occurrences.
While increased storm chances are great to have in winter, the supply of cold air has to be a large focus too. Before the moisture from any storm arrives, a cold air mass should be in place over Pennsylvania if there is any good shot at accumulating snow.
The Midstate/Mid-Atlantic is also notorious for mixed precipitation events. These types of storms can take place even when there is cold air ahead of a winter storm because warm air often accompanies the arrival of a storm originating from the south.
The other glaring piece of information from the NOAA outlook is the high confidence of a warmer than average Northeast/New England. Again the research on El Niño winters is clear- the northern United States tends to be very warm. This feature does then affects the availability of cold air to produce snow. So if you are a snow-lover, this does make the process of getting cold air established ahead of coastal storms more difficult.
Even during our recent stretch of three consecutive La Niña winters, the lack of cold air has been the major downfall or missing piece in getting snow locally.
In conclusion, the NOAA winter weather outlook leans heavily on the research of El Niño winters and the broad impact warmer than average weather across the northern United States can have for snow potential. The active southern storm track though should keep things interesting throughout most of winter locally. Even with marginally cold days ahead of a large Mid-Atlantic storm, we still may get some larger snow storms.
As always it is about timing! Look for the official abc27 Weather Team winter outlook in mid-November!