****”Clippers” galore...Friday system weakens, but can produce snow in DC, VA...potential of accumulating snow this weekend in Mid-Atlantic with the most impressive system...a major Arctic blast****

December 10, 2025Paul Dorian

The next several days will feature multiple “clipper” low pressure systems across the northern US which are typically rather quick movers from northwest-to-southeast. One such system will track well to the north and west of the DC-to-Philly-to-NYC corridor later today bringing windy and slightly milder conditions to the I-95 corridor along with the threat of a few rain showers. A second “clipper” system will push towards the Mid-Atlantic region on Friday from the Ohio Valley. While this system may begin to weaken upon its approach, it can still produce some snow on Friday in parts of the Mid-Atlantic region including the DC metro and parts of Virginia (a hot spot so far this winter season for snowfall).

Over the weekend, yet another “clipper” system will push east-southeast towards the Mid-Atlantic region from the Ohio Valley, and this one will feature some strong support in the upper atmosphere with a vigorous jet streak. As a result, this is the most impressive to me of all of these “clipper” systems with the highest potential of producing accumulating snow in the Mid-Atlantic region (late Saturday into early Sunday). One final note, the Arctic blast that reaches the north-central US by early this weekend and then the Mid-Atlantic/Northeast US by early next week will feature some of the coldest air yet in this relentless cold weather pattern that began around Thanksgiving Day. Temperatures can drop to twenty degrees below zero by Sunday morning across a wide portion of the Upper Midwest from Minnesota-to-Iowa-to-Wisconsin.

***Multiple cold air outbreaks in an active pattern...light snow event likely across southern Mid-Atlantic on Friday...a possible east coast storm signal for down the road***

December 03, 2025Paul Dorian

The month of December has gotten off to a cold start across much of the eastern half of the nation and there will be multiple cold air outbreaks in coming days. Two signals that have foreshadowed a cold period include an unusually early season stratospheric warming event and the movement of a tropical disturbance into a position that favors colder-than-normal weather across much of the nation. In fact, there appears to be a second burst of stratospheric warming in the offing for later this month resulting in a “stretched” polar vortex, and the tropical disturbance will likely persist in much of the same “cold” position” for awhile longer...both of these favor the idea of additional cold air outbreaks as we progress through the month.

The cold pattern has been quite active as well and multiple systems will have to be watched in coming days. On Friday, low pressure will develop over the Deep South and head in an northeasterly direction. This system is likely to produce some accumulating snow in the southern half of the Mid-Atlantic region and looks like a light-to-moderate snow event. Another low pressure system may pull out of the southeastern states by early next week and head in an northeasterly direction at the same time a “clipper” moves southeastward across the Great Lakes…we’ll monitor this activity as it could result in some accumulating snow for the northern Mid-Atlantic and Northeast US. Later next week, it appears a couple of other “clipper” systems will drop southeastward from southwestern Canada into the Great Lakes and ultimately, to the Northeast US. Finally, the significant change in recent days of an index value known as the “Southern Oscillation” is raising a red flag that the chance of an east coast storm will be on the rise somewhere down the road as the sub-tropical jet stream likely becomes activated.

****Great Lakes snow event...Great Lakes/Midwest snowstorm...Mid-Atlantic/NE US early week storm threat...wild weather coming Thanksgiving-to-Christmas****

November 26, 2025Paul Dorian

The period between Thanksgiving and Christmas will begin with a major Great Lakes snow event from Thursday to Friday and an Great Lakes/Midwest snowstorm this weekend and it could end with a White Christmas in many parts of the country. Two of the factors that have been highlighted here, likely leading to a cold and active stretch of weather, include an unusual early season stratospheric warming event and the likely movement of a tropical disturbance into a location that favors colder-than-normal conditions across a large part of the nation. Both of these phenomena – stratospheric warming and tropical forcing – will likely lead to a “buckling” of the polar jet stream which can lead to the unleashing of multiple Arctic air masses from northern Canada into the US (with intense cold in the table), and an activation of the southern branch of the jet stream which will likely produce multiple snow/ice threats.