12:00 PM | **Heavy rainfall today and then an historic cold blast with an amazing current nationwide snow cover extent**

[Current snow cover extent in the US is 50.4%; courtesy NOAA]

Discussion

Today's heavy rainfall The evening rush hour up and down the I-95 corridor from DC-to-Philly-to-NYC will likely be quite a mess with heavy rainfall likely through much of the afternoon and early evening hours in many of these locations. All of this rainfall comes ahead of an Arctic blast that’ll arrive in the overnight hours and it will turn out to be an historic cold blast in many areas of the eastern half of the nation over the next couple of days.

Historic Arctic blast In this part of the country, several records are in jeopardy during this upcoming cold snap that will feature the coldest air seen around here since February. What is coming our way? It is currently 12 degrees in Minneapolis, Minnesota with winds gusting to 26 mph - and its only mid-November. The most likely time for record-challenging cold around here is likely to come on Wednesday as temperatures should bottom out in the teens in the overnight hours leading into the early morning. The record low at Philly Airport (PHL), for example, on Wednesday, November 19th is 20 degrees set in 1936 and this one is in jeopardy. Dulles (IAD), VA has a chance to break the record for its coldest low and high temperature on both Tuesday and Wednesday. BWI Airport in Maryland has a good chance to have its coldest November 18 on record (Tuesday), as well as its coldest low and high temperature on November 19 (Wednesday). Amazingly, the high temperature expected tomorrow in DC (maybe only as high as freezing) is 10 degrees colder than the average high temperature in mid-January. State College, PA will be lucky to see their high temperature reach the lower 20's on Tuesday and their record low maximum is 27 degrees set in 1903.

This historic Arctic outbreak will not only affect the Mid-Atlantic region, but will extend from the northern Plains to the Deep South over the next few days. In fact, record lows will be challenged on multiple occasions through midweek from eastern Texas to the Carolinas with lows near freezing along much of the Gulf Coast. Parts of northern Florida may even have their first freeze of the season as lows dip down into the 20s in cities such as Jacksonville and Tallahassee.

Amazing current US snow cover Not surprisingly, the snow cover across the country has expanded significantly during the past 7 days or so. In fact, the current snow cover extent across the nation is around 50.4% which is the most we’ve seen (by a long shot) in the first half of November since 2003, when the National Snow Analysis archive begins. Only the year 2012 comes close to this year’s 50.4 percent coverage — on Nov. 12, 2012, 31.5 percent of the lower 48 was covered in snow. The normal snow cover extent nationwide at Christmas-time is around 33%. By the way, ice is already starting to appear on Lake Superior and it should expand significantly over the next few days. Last winter's relentless cold caused some record ice cover amounts in all five of the Great Lakes.

Looking ahead Milder weather is in sight for the eastern half of the nation. It looks like it’ll turn milder late this weekend and early next week; however, that warm up is likely to be accompanied by some more rainfall.

[Clouds associated with the Arctic front extend from the Gulf of Mexico to New England; courtesy NOAA]