1:30 PM | An odd twist to Saturday's snow that can enhance snowfall amounts in eastern PA, more on next week's brutal cold, and some interesting tidbits on the recent cold and snow

Discussion

Another in a series of strong Arctic fronts will approach the Mid-Atlantic region on Saturday from the west and it has a fair amount of moisture associated with it along with gusty winds. As the front approaches the east coast on Saturday, winds should be quite noticeable out of the southwest which may cause an oddity to the eventual snowfall amounts. First of all, it is quite unusual to get snowfall around here with southwesterly winds in a “warm advection” type of weather pattern, but this air is so cold that snow will indeed fall on Saturday despite the milder air flow. Secondly, in an odd twist, southwesterly winds could actually enhance the snowfall amounts across eastern Pennsylvania as the air will blow over the Chesapeake Bay bringing slightly enhanced moisture content into this region (see above GFS forecast map of precipitation totals for frontal passage). As a result, a minimum accumulation of a coating to two inches can be expected on Saturday from DC-to-Philly-to-NYC; however, across eastern PA and perhaps into western NJ, it is likely that many areas receive 3 or 4 inch amounts as a result of the “Chesapeake Bay enhanced-moisture" flow of air ahead of the front. Also, expect some heavier snow squalls mixed in across eastern PA during the afternoon and evening hours.

Frigid air will follow this front for Sunday and then there will be a one-day “relaxation” in the severe cold on Monday just ahead of the next Arctic front. That next frontal system will usher in a painfully cold air mass into the central and eastern US for Tuesday and Wednesday of next week. This extremely cold air mass originated in Siberia, crossed over the North Pole, and is now dropping southward through central Canada towards the northern US. By the way, latest readings in Siberia had temperatures as low as nearly 70 degrees below zero. Tuesday and Wednesday promise to be brutally cold throughout the entire eastern half of the nation.

Some interesting notes about the recent cold and snow: - Philadelphia (PHL) has had 3 mornings in a row with single digit lows (still trying to find out when that has happened before). - Philadelphia (PHL) has had 5 single digit lows this month. - Philadelphia (PHL) has already reached its 18th snowiest winter ever (dating back to 1884) with 33.7 inches. Only 27 winters have had 30+” of snow since 1884 and 5 of those have occurred in the last 12 years. - Dulles Airport (IAD) in Virginia bottomed out at 2 degrees below zero on Wednesday morning which was the coldest reading there since 1996. - Raegan National Airport (DCA) has only recorded 4 single digit low temperatures since the year 2000 and 2 of them have been this month (1/7, 6°F; 1/22 9°F). - Central Park in New York City has already recorded 26.5” of snow which is way above the normal of 9.7” at this stage of the winter season. - Central Park reached a high of only 18 degrees on Wednesday, 1/22, which was the second “lowest” high temperature reading on that particular date since 1888. - If the winter ended today, it would be the coldest since the late 1970’s for the contiguous US (see NOAA map below).