11:45 AM (Friday) | ***Wintry mix this weekend in the Mid-Atlantic to include some icing…two more storms to deal with next week and icing on the table for both...historic cold for southern Plains***

The potential exists for significant icing in the Mid-Atlantic region during the next 7 days beginning with a system this weekend. Map courtesy NOAA, Pivotal Weather

Overview

The overall weather pattern remains quite active as we end the work week and it will remain so right through next week.  The pattern is also evolving into one that increases the chances of icing (sleet, freezing rain) in the Mid-Atlantic region.  In fact, significant icing is possible this weekend as the next system brings some moisture into the area with low-level cold remaining air in place. In addition, there will likely be two significant storm systems to deal with next week and there is the potential for some icing during both events in at least parts of the Mid-Atlantic region. 

Elsewhere, an Arctic plunge later this weekend will result in historic cold for the southern Plains with many low temperature records to be broken across Texas and Oklahoma and they’ll have to contend with snow and ice as well. In fact, there are some spots in the southern Plains that will approach or even break their all-time low temperature records during this blast of Arctic air. The longevity of this on-going cold wave across the northern and central US has been quite amazing.

A change in wind direction across the upper part of the atmosphere in coming days will increase the odds of icing in the Mid-Atlantic region and other parts of the nation (i.e., warmer air aloft, cold dense air remains at ground-level). Map courtesy NOAA, tropicaltidbits.com

Discussion

The upper-air wind flow has been rather zonal (west-to-east) in recent days across the Midwest and Mid-Atlantic region, but that will evolve into one with southwesterly winds aloft.  As a result, there will be some warming in the upper parts of the atmosphere during the next several days, but cold, dense Arctic air at ground-level will be reluctant to give up its ground.  The combination of some of this warming aloft and stubborn cold (and generally below-freezing) air at ground-level increases the chances of sleet and freezing rain in coming days and this can produce some big problems in at least parts of the Mid-Atlantic region.

Arctic air will plunge from the northern US to the southern Plains later this weekend likely resulting in a historically cold temperatures for that part of the nation. Map courtesy NOAA, tropicaltidbits.com

The first threat for some icing in the Mid-Atlantic region will come this weekend as weak low pressure pushes up along the east coast.  Moisture will flow northeastward on Saturday and run into a cold, dense air mass at ground-level in the Mid-Atlantic/Northeast US.  While there can be some snow from later tomorrow into Sunday, the odds for sleet and freezing rain will climb as the warming begins in the upper part of the atmosphere and significant icing will be possible; especially, across the DC metro region and Delmarva Peninsula where precipitation amounts might be a bit higher than elsewhere in the Mid-Atlantic.  While the total precipitation amounts will not be all that high this weekend, it won’t take much in the way of icing to cause problems; especially, on untreated surfaces where there can be a significant buildup of ice. In addition, trees will be quite vulnerable to an icy buildup this weekend which will raise the chance for some broken limbs and power outages.

An unusually widespread area of the nation will experience average temperatures of at least 20 degrees (F) below-normal over the next 7 days. Map courtesy BAMWX, NOAA

Another storm will begin its trek across the nation early this weekend and it’ll become quite a news making system as it will end up producing significant snow and ice along its path - and in some unusual places.  In addition, extremely cold Arctic air will plunge southward this weekend from the northern Plains to the southern Plains and it could turn out to be an historic Arctic air outbreak for that part of the nation with numerous records likely broken - perhaps even all-time temperature records in some spots. 

NOAA has posted “watches and warnings” all across the nation in this very active weather pattern.

This storm system will generate as much as 6-10 inches of snow in the Pacific Northwest including in the region from Seattle-to-Portland.  It’ll then push over the Rocky Mountain States with significant snowfall there and wind up over Deep South by the end of the weekend.  Accumulating snow of 6+ inches will be possible from this storm in such unusual places as Dallas, Texas by late Sunday night and icing can take place all the way down to the Gulf coast (e.g., Houston area). Early on Monday, this strong storm will take a turn to the northeast and it’ll continue to produce significant snow and ice along its path from the Deep South to the Ohio Valley.

Many spots in the northern and central US experienced record or near record lows this morning. Numerous records will be broken by Monday morning across the southern Plains to include much of Oklahoma and Texas. Map courtesy coolwx.com, NOAA

Later Monday, strong cold high pressure will expand from the Northern Plains into the southeastern part of Canada and this will ensure that low-level cold air remains in place across the Mid-Atlantic/Northeast US. Moisture associated with this storm system will begin to spread into the Mid-Atlantic/Northeast US and the result could be significant snow in some interior sections and significant ice in other areas. The exact details as to how much snow and/or ice will fall in the Mid-Atlantic region will have to be ironed out over the next couple of days when the ultimate storm track is better determined.  The storm system is likely to head towards the Appalachians and ultimately wind up off the Mid-Atlantic/Northeast US coastline.  A track farther to the north and west, however, would result in a warmer solution for the Mid-Atlantic region (i.e., better chances for some plain rain) and a track farther to the south and east would likely result in a better chance for more snow and ice. Another strong storm is likely to follow rather closely behind later next week and this too can produce some icing in the Mid-Atlantic region and snow and plain rain may be involved as well.

Buckle up…the next 7 days will be very active and potentially historic in some parts of the nation.

Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com

Follow us on Facebook, Twitter, YouTube

Video discussion: