Special Weather Discussion

Latest Weather Discussion by Kyle Elliott

* Major pattern change leads to persistently cold conditions *

11:30 a.m. Tuesday, January 13, 2026:

The second full week of January kicked off on a partly sunny, breezy and seasonable note across the Lower Susquehanna Valley. West-southwesterly winds of 10-20 mph with gusts up to 25 mph accompanied high temperatures in the upper 30s to low 40s Monday afternoon. After a mainly clear and crisp Monday night, strengthening, southerly flow in advance of a complex but disorganized storm system and its associated cold front has ushered milder air into the mid-Atlantic States late this morning. Despite increasing clouds this afternoon, high temperatures will be around 10°F above normal, or generally in the upper 40s to perhaps low 50s, across northern MD and southeastern PA. If you can, get outside and enjoy the pleasant weather! It may be awhile until we get another day this nice..

After a mostly cloudy and relatively mild Tuesday night with lows in the mid-to-upper 30s, the aforementioned storm system will trek into the Ohio Valley, eastern Great Lakes region and central Appalachians during the middle of the week and bring periods of light rain to the region from Wednesday into Wednesday night. Light rain will first develop across central PA Wednesday morning and then spread into northern MD and southeastern PA during the afternoon and evening hours. There is still notable disagreement between numerical computer models regarding the strength and evolution of the storm system, but the upper-level low will stay well to our north and move through New England on Thursday. Thus, a "big snowstorm" is simply not in the cards along the I-81 and I-95 corridors (see below). Instead, light rain may briefly mix with or change over to wet snow before tapering off later Wednesday night, but I expect no more than a dusting of snow on some non-paved surfaces. In fact, precipitation could just as easily end as plain rain with no accumulating snow whatsoever. Regardless of the eventual outcome, rainfall amounts should not exceed one third of an inch in most locations through early Thursday morning (see below). Due to the ongoing drought and lack of substantial rainfall this past Saturday, the wet weather will be largely beneficial. Use caution on the wet roadways during the Wednesday afternoon commute, but I certainly don't expect this system to have much of an impact on travel across the Lower Susquehanna Valley. Despite the clouds and rain, high temperatures will still be slightly above average Wednesday afternoon and range from the low 40s north/west of I-81 to low 50s in the I-95 corridor.

The trailing cold front will sweep through the Commonwealth Wednesday night and signal the arrival of a persistently cold pattern. Behind the front, west-northwesterly winds of 12-25 mph with gusts up to 40 mph will usher much colder and drier air into the mid-Atlantic States on Thursday. Temperatures will "fall off the cliff" later Wednesday night and bottom out in the low-to-mid 20s Thursday morning. They will then hover in the mid-to-upper 20s throughout the day, and wind chills won't get out of the teens (see below). Some wet roadways may briefly freeze before drying out Thursday morning, so there could be some areas of "black ice" during the Thursday morning commute. Dress in layers and bundle up before heading out the door to work or school, and be alert for blowing objects and minor debris on roadways. Keep a tight grip on the steering wheel, as well, especially on north-south oriented highways. Skies should be partly-to-mostly cloudy throughout the day, and I won't rule out a few additional flurries either. 

Looking ahead into the weekend and beyond, a major, large-scale pattern reconfiguration.. featuring a massive, Jet Stream ridge across Alaska and western North America and deep trough, or dip in the Jet Stream, over eastern North America.. will lead to multiple, Arctic air outbreaks during the second half of the month. A piece of the Tropospheric Polar Vortex (TPV) will basically settle over Hudson Bay and central Canada late this week and move very little through at least the end of next week. The counterclockwise flow around it will combine with clockwise flow around the Jet Stream ridge in the eastern Pacific to create "cross-polar flow." Unfortunately, that cross-polar flow will have a direct line at the Central and Eastern States and be the culprit for multiple bouts of frigid air over the next 2 weeks. Residents across the Upper Midwest and Great Lakes region will bear the brunt of the Arctic air, but high temperatures from Thursday through the end of next week will largely be in the 20s/30s across northern MD, southeastern PA and the Lower Susquehanna Valley with overnight lows in the teens/20s (see below). The upcoming pattern will actually be similar to and mimic the pattern from early-to-mid December. Thus, the "good news" is that it should be relatively dry with a lack of snow and significant storm systems. Instead, a slew of moisture-starved, clipper type disturbances will dive southeastward out of Canada and swing through the Great Lakes region, northern mid-Atlantic States and Northeast from Friday through early next week. Attempting to finesse the timing of each disturbance and their associated snow flurries/showers more than 2-3 days in advance is a fool's errand, so I won't do so until Friday. However, each disturbance will more than likely track north of the PA/NY border, so any snow showers from Saturday-Monday will likely be of the "intermittent" and "non-accumulating" variety across south-central PA. Any brief, heavier snow shower could put down a quick coating of snowfall in some spots, but I expect this to be the exception rather than the rule.

At this point, Friday appears to be a cold but dry day with high temperatures around freezing (32°F) following a brisk and unseasonably cold Thursday night with lows in the teens. Winds should turn southerly Friday afternoon, and that southerly flow will persist into Saturday ahead of one of the clipper disturbances. Thus, high temperatures may actually be "near normal" (upper 30s to perhaps mid 40s) again Saturday afternoon, but they'll peel back into the upper 20s to low 30s both Sunday and Monday following another cold frontal passage Saturday night. Per the usual in a pattern like this, gusty, west-to-northwesterly winds will accompany each blast of colder air and make it feel even worse outside. Wind chills may bottom out in the single digits this Friday morning and again Sunday and/or Monday mornings, and MLK Day should turn out brisk and unseasonably cold this year. Whether or not any snow showers accompany the frigid conditions on the holiday remains to be seen. Either way you slice it, Old Man Winter is about to make a roaring comeback, and plenty of tears will be shed by warm-weather lovers like myself.. -- Elliott