11 February 2015
Coldest Air of The Winter Headed For the NE U.S. and Midwest
Posted by Dan Satterfield
Numerical models are estimating temps to be running up to 30 degrees below normal for mid February by early Friday. The GFS model tends to run too cool, but it’s often about right in true Arctic outbreaks, and sometimes too warm even! This is a new and improved model, so we forecasters are not exactly sure how it will behave.
A true outbreak of Polar air is headed for the northeastern quarter of the U.S. beginning Thursday. It will actually come in at least two and maybe 3 waves. The first wave will bring snow showers and plunging temps on Thursday to the East Coast from Virginia to Maine, and another surge will arrive Saturday evening with even colder air.
Wind chills along the U.S.Canada border are forecasted at -50F Sunday! Below zero wind chills are likely into North Carolina and Kentucky.
A true Polar air mass often brings a dusting of snow and we may see some Bay effect snow over the Delmarva Peninsula as the frigid air crosses the Chesapeake Bay. There will not be as much lake effect around the Great lakes because they are rather frozen now. Anytime you have this much Arctic air in place, you have to watch out for a surprise snow event, and the models tend to not do well in these situations. Cold air tends to be tougher to move out than the models forecast, and what may look like a rain event becomes an ice and snow event.
It looks like Boston will get more snow on Thursday night and early Friday, but this will be a rather light few inches. A much more powerful storm may be coming toward the early part of next week though, and this one may be a widespread snow and ice event from Virginia northward. From Maryland northward the temperature will stay below freezing from Thursday evening until at least Tuesday afternoon, and even then it will be only a few degrees above 0 C.
WARM OCEANS EQUAL SNOW
You used to hear people make climate change jokes when we had cold winter weather, but have you noticed how that has mostly disappeared now? I think this shows that we are making progress in educating the public about the science, and the image below shows just how warm the oceans are off the U.S. East Coast. This certainly is a factor in the heavy snow events in New England over the past month.
From WX Bell. Click for LARGE version. These are anomalies showing above and below normal water temps.
There was a good piece in USA Today about the Boston snow and warm ocean waters this week. Look for the quote by Dr Kevin Trenberth at NCAR.
Dan Satterfield has worked as an on air meteorologist for 32 years in Oklahoma, Florida and Alabama. Forecasting weather is Dan's job, but all of Earth Science is his passion. This journal is where Dan writes about things he has too little time for on air. Dan blogs about peer-reviewed Earth science for Junior High level audiences and up.
Dan – this is a fascinating post. Its interesting to see the impacts of global warming unfold. I was at OSU in the late 70s and used to listen to Lonnie Thompson talk about it during “Brown Bag Seminars”…where we all sat around eating lunch and listening to talks by various scientists at noon every Thursday. The predictions of Thompson, John Mercer, Ian Whillans have proven to be pretty accurate.
Although I took a course on climatology in college (1980) and worked in the weather lab – I have forgotten most of what I learned. Is there a book you can recommend? I am looking for something on a college level that’s substantial.
Thanks for your posts –