An Alberta Clipper that will cross the area and result in snowfall with total amounts of about 15 to 20 centimeters is expected. Snow at times heavy is expected to develop Monday morning or early afternoon and persist into Monday night. Some areas may see snowfall totals near 15 cm by Tuesday morning, although locally higher amounts are possible closer to the Great Lakes. very cold polar air will add to the dangers as extreme cold warnings are out for the entire area.
Low pressure moving north and east across the Great Lakes will spread precipitation across the region from west to east during the day on Tuesday. Models have come into better agreement on the overall timing of this system, with precip beginning north and west of New York City Tuesday morning, then spreading east across the rest of the region through the afternoon and evening.
A frontal system dropping from the northern Plains will move into the Upper Midwest and Upper Great Lakes later tonight and into tomorrow. Blizzard warnings are currently in effect for eastern portions of North and South Dakota--where 3 to 6 inches of snow can along with wind gusts up to 60 mph. These conditions will cause blowing snow and white out conditions.
A storm will bring intense precipitation to the entirety of the northeast. Due to a lack of cold air, most of the precipitation will fall as plain rain, but in the northern tier, wintry threats such as freezing rain are present, and are actually occurring right now. As a result of reports of ZR, WFO ALY has extended their WWAs. CAD in specific localized valleys could also present a localized threat.
A total lunar eclipse will be visible across the entirety of North America and South America on the night of January 20-21, 2019. An alternative name to this particular eclipse is the "Super Blood Wolf Moon" because it takes place during a supermoon, it could be a blood moon, and the moon during the period of January is colloquially called a wolf moon. It will be the last total lunar eclipse until May 2021, so be sure to "cash in" while it is visible!
... Major winter storm to impact the Northeast/Mid-Atlantic states into the weekend... The upper-level trough responsible for the ongoing storm over the western U.S. will generate a new surface low over the western High Plains by Friday morning. This system is expected to produce a vast area of heavy snow, heavy rain with pockets of freezing rain to the south-central states and much of the East Coast. Some thunderstorms will also be possible across the Gulf Coast region.
Across the far south, surface temperatures look to remain warm enough for just rain until sometime Saturday afternoon, when a change to snow will occur as colder air moves in. In the central part of the area, temperatures will be cold enough for freezing rain at times Friday night into Saturday, before changing to snow Saturday afternoon. Given this, the north could see 4 to 7 inches of snow, with central areas seeing 2-5 inches of snow with over 0.10 inch of ice.
A weak and broad area of low pressure will approach the East coast tonight along with some troughing aloft and shortwave energy. The energy in the southern branch of the jet stream is quite strung out and not all that impressive. The model consensus is for precipitation to start during the late evening, give or take a couple of hours from west to east. Not an impressive system with some of the BUFKIT profiles showing some gaps in the moisture, with the mid level forcing weak to say the least. Due to weak omega, in general snowfall amounts will not exceed two inches.
Blizzard warnings remain in effect for the highest elevations of the northern portions of the Sierras where snowfall amounts in excess of three feet expected. Winter Storm Warnings and Winter Weather Advisories are also in effect for the surrounding areas, as well as, Washington, the Great Basin, the Intermountain West and the Central/Southern Rockies. Coastal areas will have an increased risk for heavy rainfall and flash flooding-- especially along the stretch of coast from northern California to northwest Oregon and a small area in southern California.