Sunday, February 28, 2016

Snowy Start to March in the Midwest and East?

Linda Lam
Published: February 28,2016

March may come in like a lion for portions of the Midwest and Northeast with the possibility of wintry weather in the first several days of the month.
The first round of snow and some ice will target parts of the Midwest, Great Lakes, and New England early this week. Then, late in the week, we are watching portions of the Midwest and East for another potential snowmaker. However, forecast guidance at this time is very uncertain for this possible late week system with a wide range of scenarios from just a minor snowmaker to a more impactful round of accumulating snow.
Let's start with the details of the early week snow first and then given an overview of why we are also watching late this week.

Early Week Snow For Midwest, Great Lakes, New England

This early week system does not appear to be a major snowstorm with the potential to dump over a foot of snow over a widespread area.
This is mainly because the jet stream is in what is called a progressive pattern, meaning disturbances propagate through the jet stream rather quickly from west to east, rather than being blocked and persisting over any given area.
The next disturbance has arrived in the Pacific Northwest and will push eastward into the Rockies and then into the Plains Monday and Midwest by Tuesday.
Low pressure at the surface will organize along the arctic frontal boundary and gain some strength as it sweeps through the eastern two-thirds of the country.
Moisture from the Gulf of Mexico will be pumped in and over the cold air at the surface, wringing out some snow, and even, potentially, a little freezing rain or sleet. Here is the forecast timing and snowfall forecast for this early week system.
(MAPS: 10-day Forecast Highs/Lows and Conditions)
Timing: Monday Night - Tuesday
  • Accumulating snow arrives in parts of the Midwest and southern Great Lakes Monday night and continues Tuesday while spreading into western New York.
  • Both air and road travel could be affected in the region, including in Chicago, Detroit and Cleveland.
  • A narrow zone of mixed precipitation, including some ice, may affect parts of central and southern Iowa, northern Illinois, northern Indiana, southern Michigan and northern Ohio, leading to slippery travel conditions.
  • FORECASTS: Chicago | Detroit | Cleveland

Tuesday's Forecast
Timing: Tuesday Night - Wednesday
  • Accumulating snow spreads across much of northern New England Tuesday night, including Vermont, New Hampshire and Maine.
  • Snow or a wintry mix also continues as far west as northern Indiana, Ohio, western Pennsylvania and Upstate New York.
  • On Wednesday, snow and a wintry mix continue in New England and Upstate New York. Rain may change to snow in parts of southern New England and the central Appalachians.
  • FORECASTS: Burlington | Syracuse | Pittsburgh

Tuesday Night's Forecast
Snowfall Forecast Early Week
  • Generally less than 6 inches of snow is expected in the southern Great Lakes, including Chicago and Detroit. A few locations, however, could locally pick up more than 6 inches of snow in the southern Great Lakes region.
  • Total snowfall of 6 inches or more is possible from western and northern New York to northern New England. 

Snowfall Forecast

Late Week Snowmaker to Watch?

As mentioned at the beginning of this article, the potential for snow from another storm system late this week in the Midwest and East is far from certain.
Some computer model forecast guidance such as the European ECMWF model has suggested in recent days that we could see a swath of accumulating snow from the Ohio Valley to the central Appalachians, mid-Atlantic and possibly the coastal Northeast in the Thursday through early Saturday timeframe. Other forecast guidance like the American GFS model has depicted that high pressure will dominate those regions in the same exact period of time with little or no snow at all.
This, of course, is a huge forecast difference for millions of residents that live in those respective regions. So, why is the uncertainty so high you might ask?
The batch of energy in the upper atmosphere that would be responsible for developing this snowmaker is still over the north-central Pacific Ocean. That is a long way from North America and the models must make a forecast for that energy and other features in the lower and upper atmosphere over the course of several days into the future. This can, and often does, result in different outcomes for various computer model runs several days in advance of a particular weather event since the models may handle those features differently over the course of time.
We will continue to monitor this potential late week snow, so stay tuned for daily updates the next several days.

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