In a pattern more reminiscent of Winter, a nor’easter is forecast to track northward just off the East Coast the end of this week and into the weekend. It’s a little early in the year for this storm to produce the intense snow often associated with a nor’easter, but we can expect plenty of rain and cooler temperatures along much of the eastern seaboard. And we might see a little snow in some mountainous areas as well.
The low pressure center that will become the storm is currently situated over the Mississippi/Tennessee border. It will move eastward and off the South Carolina coast by tomorrow morning before turning northeastward and racing up the coast. (Note: the Nor’easter is given its’ name not because it moves northeast or often affects the northeast US; rather, it usually produces northeast winds along the coast as it passes by, producing heavy precipitation.)
Right now, it appears the heaviest rain will fall in the mid-Atlantic states during the day on Thursday. Around an inch of rain can be expected from Washington, DC to New York, NY, with the heaviest rain (1.5+ inches) falling in Delaware and southern New Jersey. The chance of precipitation will continue through the weekend for much of the east coast with the probability of rain diminishing each day. The 5-day rain totals (ending Monday morning – see map below) could exceed 3 inches in parts of eastern PA, NJ, DE, MD, and southern NY.
In addition to heavy rain, snow may fall at higher elevations in central PA and southern, but upstate, NY. The NWS office in State College, PA has created this web site regarding the upcoming event. On the site, they mention just how unusual October snowfall is in parts of PA. It’s not unheard of, but it is very rare. If the table is complete (and I’m not entirely sure it is), this could mark the 2nd-earliest snowfall on record in the region. Here’s a map depicting the forecast for at least 4 inches of snow between Thursday morning and Friday morning:
Finally, as you might expect, colder-than-normal temperatures are forecast along much of the east coast. As the nor’easter moves northward, cold, Canadian air will move southward on the west side of the storm and settle into much of the eastern US. Average temperatures will run about 15 degrees below normal with high temperatures struggling to hit the 50 degree mark on Thursday and Friday. (As a reference, the average high in Washington, DC this time of year is in the upper-60s. New York City usually tops out in the low- to mid-60s.)
Peering into the future, it looks as if temperatures will begin rebounding throughout much of the country next week. This doesn’t necessarily mean it’s going to be balmy, just a return to more normal temperatures – for at least a little while.