11:45 AM | ***Strong cold front to bring some heavy rainfall to the eastern US later Saturday into Saturday night and there can be severe thunderstorms as well***
Paul Dorian
A line of strong-to-severe thunderstorms is possible in the eastern US late Saturday/early Saturday night with the arrival of a west-to-east moving strong surface cold frontal system. Map courtesy NOAA, tropicaltibits.com
Overview
Cold air outbreaks from Canada into the US continue on a regular basis as we progress through the month of April and this has led to occasional accumulating snow across parts of the northern US and to severe weather outbreaks farther to the south. The leading edge of the latest cold air outbreak pushed into the middle of the nation last night resulting in some tornadic activity across Oklahoma and several inches of snow can fall later today/tonight in the Northern Plains. This strong cold front will slide across the Ohio Valley early Saturday and then impact the eastern states from later Saturday into Saturday night. The impact in the I-95 corridor from DC-to-Philly-to-NYC can include some heavy rainfall and there is the potential for severe thunderstorm activity as well.
Tornadoes broke out late yesterday across Oklahoma and there can be some strong-to-severe thunderstorm activity in the Mississippi Valley region from later today into tonight. Map courtesy NOAA/SPC
Details
The overall weather pattern across North America appears quite favorable for the continuing influx of cold air masses from Canada into the US right into the early part of May. As a result, the overall weather pattern will remain quite active given this expected push of cold, dry air from the north and west across the nation combined with increasingly warm and humid conditions in the southern states. Currently, much colder-than-normal air is flooding the middle of the nation on the heels of yesterday’s strong cold frontal passage which resulted in tornadic activity across the state of Oklahoma. This same strong cold front can produce more strong-to-severe storms later today and early tonight across the Mississippi Valley.
A “negatively-tilted” upper-level trough axis will enhance upward motion across much of the eastern US later Saturday and early Saturday night this will increase chances for heavy rainfall and strong-to-severe thunderstorms. Map courtesy Canadian Met Centre, tropicaltidbits.com
By Saturday, the strong surface cold front that wreaked havoc yesterday in the nation’s mid-section will slide across the Ohio Valley and into the eastern US. At the same time, the associated upper-level support will evolve into a “negatively-tilted” trough orientation (i.e., extends from the upper-level low in a NW-to-SE fashion) which will enhance upward motion in the eastern US including in the Mid-Atlantic’s I-95 corridor region. As a result, heavy rainfall will be possible ahead of and along the cold frontal boundary zone late Saturday and Saturday night and there can be the formation of some strong-to-severe thunderstorms. The likely time period of concern in the DC-to-Philly-to-NYC corridor for the potential active weather will be 3-10pm as the cold front edges from west-to-east and towards the eastern seaboard.
A strong cold front at the leading edge of the latest cold air outbreak will reach the eastern states late Saturday and it can result in some heavy rainfall ahead of and along its boundary zone and strong-to-severe thunderstorms as well. Map courtesy Canadian Met Centre, tropicaltidbits.com
The surface cold front will likely clear the east coast on early Sunday paving the way for cooler, breezy conditions in the Mid-Atlantic region, but it’ll remain somewhat unsettled during the day with plenty of clouds and a possible additional shower or two. A secondary cold front seems destined to arrive on Sunday night and its overnight passage will usher in even cooler air for the first part of next week.
The overall weather pattern looks pretty wet for much of the eastern half of the nation during the next ten days as depicted here by the 00Z GEM. The Mid-Atlantic region has been quite dry in recent weeks and soil moisture is low, but that may begin to markedly improve with this next cold front this weekend and additional decent rain events are likely as we head into May. Map courtesy Canadian Met Centre, tropicaltidbits.com
Looking ahead, it certainly appears additional colder-than-normal air masses will drop from Canada into the US and an active weather pattern is likely to be the result with more rain/thunderstorms and snow across the nation. Soil conditions have actually become quite dry in parts of the East such as in the Mid-Atlantic region, but the heavy rainfall expected there late Saturday will alleviate the situation and additional strong low pressure systems are likely to become part of this evolving active weather pattern with more soaking rains possible as we head towards and then into the month of May. In addition, these on-going cold air outbreaks are quite likely going to result in additional accumulating snow events into May across portions of the northern US.
Not quite time yet to turn off nature’s snow machine across the northern US…the next ten days features more accumulating snow in many areas as depicted here by the 00Z GEM. Map courtesy Canadian Met Centre, tropicaltidbits.com
Meteorologist Paul Dorian
Arcfield
arcfieldweather.com
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