Time may be ticking for prolonged cold air and an active winter storm track here in Central PA. If you follow winter weather often you may know the major global forecast models, the European model (ECMWF) and the American model (GFS), have both shown opportunities for coastal storms or Mid-Atlantic snow storms for the final week of January. At one point this week in the outlooks next Tuesday appeared to have the potential for storminess locally and for the coastline. Then another possible storm followed by the end of the week in the Friday-Saturday time frame. Unfortunately for winter weather lovers those phantom storms have come and gone in the model guidance. But the nonetheless there are signals for storm activity before we hit February!

We often look for overall pattern changes to help generate storms. Large areas of low pressure are created by differences in temperature and pressure. So when a pattern flips from warm to cold or cold to warm that often generates a large storm. Our weather team has been tracking this prolonged stretch of colder than average or near-average January weather and how we will likely transition to a warmer than average February. In the maps below our weather will likely go from a colder trough of low pressure over the East Coast to a warmer ridge of high pressure, which will help pump warmer air into the region. This pattern existed during our remarkably warm stretch of weather in December. We see indications of this warmer pattern starting next Thursday through next weekend:

This Sunday’s weather pattern with colder air locked in for southern Canada and the Northeast.
By middle to late next week warmer weather begins to work its way back north, possibly creating a storm system too.

The GFS model does show some type of storm activity by next weekend in association with the mild air streaming north, but the colder air at the ground holding out to help create snow:

GFS model depiction for next weekend

The European model also shows a storm next weekend, but the colder air is flooded by warm air and more of a mixed precipitation storm is portrayed:

European model depiction for next weekend

We show these models as evidence that something may be brewing around the time the milder air moves in, but this is no absolutely no guarantee for wintry weather. As explained above, storms come and go in the model guidance. These are also just snapshots of one model run at a time, and there is never much run-to-run consistency this far out into the future.

There is a little more confidence that some type of precipitation is likely next weekend because of the pattern shift, but it is certainly no lock. What is more and more likely is a milder month in February compared to January. Already the Climate Prediction Center is calling for above average warmth in their 3-4 week outlook for the East Coast and this is likely only the start of milder conditions: https://www.cpc.ncep.noaa.gov/products/predictions/WK34/gifs/WK34temp.gif

As always stay with the abc27 Weather Team and we will keep you updated about any winter weather changes, and we will of course follow this trend toward warmer weather as well.

-Meteorologist Dan Tomaso