12:00 PM | ***Nationwide colder-than-normal conditions on the table by late next week...active pattern to bring multiple rain/snow threats to the Mid-Atlantic/Northeast US***

Widespread colder-than-normal conditions are possible across the nation by late next week. Map courtesy NOAA (GFS Ensemble)

Overview

While the western US may experience an extended quieter weather pattern beginning later this week, it’ll remain quite active across the central and eastern US.  The break in the action in the western US will be due to the development of an upper-level ridge of high pressure that will ultimately extend from the eastern Pacific Ocean northward into Alaska.  In response to this ridge, an upper-level trough of low pressure will form over the central US and Canada by later next week. The combination of the eastern Pacific-to-Alaska ridge and the trough over the central US/Canada will result in upper-level winds that can easily transport cold air masses from northern Canada into the US. In fact, signs point to widespread colder-than-normal conditions across most the nation by late next week. Nationwide colder-than-normal weather in late January is quite impressive considering this is when climatological averages are close to their lowest levels of the year.  

Meanwhile, the southwestern Atlantic Ocean will feature a ridge of high pressure in coming days that will intensify at times and the corridor region between the upper-level low (cold) over the central states and the Atlantic Ocean ridge (warm) will become a “battle zone” region with multiple storms riding through it from southwest-to-northeast. Accumulating snow has been virtually non-existent so far this winter season in the immediate DC-to-Philly-to-NYC corridor, but this active pattern will at least be able to raise hope for snow lovers in that part of the country with a couple of storm systems next week.

Widespread colder-than-normal conditions are possible across the nation by late next week. Map courtesy Canadian Met Centre (GEM Ensemble)

Details

Yet another in a series of storms will impact California later today and tonight, but this will be the last likely through the remainder of the month as a large-scale pattern change across North America brings about upper-level ridging to the eastern Pacific Ocean. The development of high pressure ridging over the eastern Pacific Ocean will have ramifications to the overall upper air pattern across the US and Canada. While the ridge over the eastern Pacific Ocean expands northward to Alaska, an upper-level trough of low pressure will develop over the central sections of the US and Canada and colder-than-normal air will overspread these areas. In fact, signs point to widespread colder-than-normal conditions virtually from coast-to-coast by the latter part of next week.  In addition, a persistent ridge of high pressure over the southwestern Atlantic will tend to intensify as we progress through the second half of January.

Widespread colder-than-normal conditions are possible across the nation by late next week. Map courtesy ECMWF (EPS Ensemble)

The region between the trough (cold) over the central states and ridge (warm) over the SW Atlantic will become a “battleground” zone and it’ll act as a conduit for low pressure systems to move through in a general southwest-to-northeast fashion. In fact, a couple of storms are in the cards for the eastern US next week with this unfolding pattern change across North America. The first storm is likely to arrive in the Mid-Atlantic/Northeast US in the Sunday/Monday time frame with the threat of rain and/or snow and the second around mid-week.

An active pattern will likely produce two storms next week for the Mid-Atlantic/Northeast US. The first storm (left) is likely to arrive for the late Sunday/Monday time period and the second (right) during the mid-week. Maps courtesy NOAA, tropicaltidbits.com

In terms of the potential for accumulating snow in the DC-to-Philly-to-NYC corridor where it has been virtually non-existent this winter season, it’ll be a struggle - at least initially - to get sufficient cold air.  Odds favor rain for the immediate I-95 corridor during the late weekend/early next week event although this is still a close-call and needs to be closely monitored. A little bit of a shift in the expected storm track to the southeast can raise the chance of snow in the I-95 corridor. For now, snow is looking more likely in those interior, higher elevation locations to the north and west of I-95.

The passage of this early week storm system can help to “push-back” the western Atlantic ridge of high pressure potentially allowing for better established cold air in the Mid-Atlantic region just in time for the mid-week follow-up storm. This impact from the first storm could raise the chances significantly for snow in the DC-to-Philly-to-NYC corridor for the second storm. Following the mid-week storm system, cold air may very well spread farther to the south and east so that virtually all of the nation could experience colder-than-normal conditions by week’s end. Nationwide colder-than-normal weather in late January is quite impressive considering this is about the time climatological averages are at their lowest levels of the year.

Stay tuned…just about all of the “potential” snows” this winter season have turned into disappointments for snow lovers in the immediate I-95 corridor, but there is some hope for next week.

Meteorologist Paul Dorian
Arcfield
arcfieldweather.com

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