Article written for EarthSky by meteorologist Rachel Duensing.

An Alberta Clipper is a fast-moving low strain system that strikes out of west-central Canada and, usually, skirts throughout North America’s Nice Lakes. It brings chilly climate and, if situations are proper, snow. A clipper developed in central Alberta this week and shortly moved southeast towards the Nice Lakes. Because it’s been transferring over the Nice Lakes – headed towards the U.S. Northeast immediately (December 4, 2024) – the probabilities for snow have been going up.

Plus, there is perhaps one other clipper to look at within the coming week. It’s known as the Panhandle Hooker, and it’s simply as complicated – if no more so – than its Canadian neighbor, the Alberta Clipper. Generally known as a Texas Hooker, the Panhandle Hooker is one other fast-moving low strain system that will get its identify from the area the place it develops: the Panhandles of Texas and Oklahoma.

A Panhandle Hooker hasn’t but developed. However world forecasting fashions are suggesting one may develop early within the week of December 9. What occurs after that, if it develops, remains to be to be decided … because the timing of chilly air is important for snow formation with the hookers.

Nationwide Climate Service forecast

As of two:52 a.m. EST (6:52 UTC) on December 4, the Nationwide Climate Service Prediction Middle in School Park, Maryland was saying:

A strengthening clipper storm will shift throughout southeastern Canada Wednesday and Thursday with an arctic chilly entrance crossing the Nice Lakes and Northeast which is able to produce intense bursts of snow and gusty winds. Localized short-duration blizzard situations can be potential with a number of ft of extra lake impact snow within the Nice Lakes. Dry and heat situations are anticipated within the West.

And the NWS was calling for:

…Heavy snow for the Higher Peninsula of Michigan and the northern Decrease Peninsula on Wednesday…

…Heavy lake-enhanced snow downwind from Lakes Erie and Ontario on Wednesday and Thursday; Heavy snow over components of Northern New England; mild to reasonable snow over components of the Central Appalachians on Wednesday…

What’s an Alberta Clipper?

A clipper by itself received’t convey snow. A number of situations must be in place, and a type of situations is chilly air. On Sunday and Monday – December 2 and three – chilly excessive strain moved south from Canada and settled into the US. Wind round a excessive strain zone flows clockwise (or anticyclonic). In order the excessive strain moved southeast, winds across the excessive strain zone got here out of the south. Within the Northern Hemisphere, these winds can usher in simply sufficient moisture to gasoline an opportunity for snow.

So the components are ready: chilly air, moisture, and a racing Alberta Clipper to assist create the prospect for wintry precipitation.

As a result of clippers are fast-paced programs, they have a tendency to drop some snow earlier than shortly transferring on. However on this occasion, the snow from the clipper is just the start.

By Thursday, the Alberta Clipper can be transferring by means of southern Ontario, northern New York and southern Quebec. As chilly wind strikes over the (comparatively) heat waters of the Lakes, the hotter, moister air will rise, condensing into clouds within the course of. Precipitation will kind and fall out of the clouds, and because of the chilly air in place something that falls out of the clouds can be within the type of snow.

Lake-effect snow bands will be persistent and impactful, generally dropping as much as 3 inches (8 centimeters) of snow per hour! With this lake-effect snow occasion, components of Michigan’s Higher Peninsula expect 10 to 16 inches (25 to 41 centimeters) of snow by means of Thursday evening. Different communities close to the Nice Lakes – like Cleveland, Ohio and Erie, Pennsylvania – count on an extra 2 to 4 inches because of lake-effect snow.

One other clipper system: The Panhandle Hooker

Right here’s one other clipper-type system to look at within the coming week. Panhandle Hookers will be complicated storm programs. Regardless of forming within the southern United States, because the identify implies, this low strain zone doesn’t keep there. It will definitely “hooks” shortly to the northeast, the place impacts are felt in quite a lot of methods on its path.

Because it develops farther south, a Panhandle Hooker has the benefit of hotter, moister air feeding into it from the Gulf of Mexico. The upper moisture content material provides it a greater likelihood to supply vital precipitation in many alternative kinds, relying on the situations.

In the course of the winter, and particularly when chilly air has spilled south from Canada, these hookers can faucet into that chilly air and produce snow – generally heavy – on the northern facet of the low strain zone. On the southern facet of the low strain zone is the place issues will be extra attention-grabbing, as this space is usually hotter for Panhandle Hookers. Sturdy, chilly air crashing in when hotter air is in place is a recipe for thunderstorms, a few of which will be extreme! It’s not unusual for snow to fall north of extreme thunderstorms in winter, because the complicated nature of low strain programs work together with the totally different temperatures throughout the nation.

As winter goes on, these programs with distinctive names are positive to maintain us all on our toes, as we put together for regardless of the climate throws at us.

Backside line: An Alberta Clipper developed in Canada this week and shortly moved southeast towards the Nice Lakes. In the meantime, the probabilities for snow have been going up.

Through Nationwide Climate Service

Through Authorities of Canada