10:00 AM (Tuesday) | ***Severe weather outbreak next couple days likely to include numerous tornadoes… significant snow in the cold sector…strong storms possible near east coast on Thursday***

One of the key ingredients in this upcoming severe weather outbreak will be the intensification of an upper-level jet (300 mb) which will combine with an low-level jet (850 mb) to generate deep-layer wind shear in the atmosphere. Map courtesy ECMWF, Pivotal Weather

Overview

There have been back-to-back weeks with severe weather outbreaks in the US and another one is on the way. Severe weather including the threat for tornadoes is likely from later today into the overnight hours across the Mississippi Valley and then the risk shifts to the Ohio Valley on Wednesday.  One of the key ingredients for the severe weather outbreak will be a strong surface cold front and it reaches the east coast later Thursday and there can be strong-to-severe storms in that region as well.  Other ingredients include multiple jet streaks in the atmosphere which will enhance the chance for rotation and tornadic activity.  In the cold sector of the storm, significant snow is going to fall during the next couple of days from the Rockies to the Dakotas/northern Minnesota. Looking ahead, this may be the end of the severe weather outbreaks for awhile warm air may finally flood the central and eastern states later next week.

One of the key ingredients in this upcoming severe weather outbreak will be the intensification of a low-level jet (850 mb) which will combine with an upper-level jet (300 mb) to generate deep-layer wind shear in the atmosphere. Map courtesy ECMWF, Pivotal Weather

Details

There is a risk of severe thunderstorms and tornadoes from later today into the overnight hours across the Mississippi Valley region from Iowa/Illinois to the north and eastern Texas/Louisiana in the south. In much the same manner as with recent severe weather outbreaks, a vigorous upper-level trough will help to spawn cyclogenesis in the middle of the nation at the same time high-level ridging intensifies over the eastern states.  An intensifying upper-level jet streak (southwesterly) will push into the Great Plains and then the Mississippi Valley region and a low-level jet (southerly) will become involved as well.  The combination of these two jet streaks will lead to deep-layer wind shear in the warm sector of the surface low pressure system potentially leading to supercells capable of producing tornadoes. In addition, torrential rain and hail will be on the table with this severe weather outbreak.

Severe weather is a threat from later today into the overnight hours across much of the Mississippi Valley region and this risk will shift to the Ohio Valley/Great Lakes/Midwest on Wednesday. Map courtesy NOAA/Storm Prediction Center

By tomorrow, the threat of severe weather will shift slightly to the east with thunderstorms capable of producing tornadoes extending from the Great Lakes to the Ohio Valley and southwestward back into the Lower Mississippi Valley. As the cold front pushes to the east on Wednesday, the cold and dry air mass on its backside will clash with warm and humid air all the way up into the Great Lakes region from the Gulf of Mexico.  This same front will push towards the eastern seaboard on Thursday and there can be strong-to-severe thunderstorms in the I-95 corridor later in the day or early Thursday night. 

The cold front clears the east coast by Friday and sets the stage for quieter weather in the northeastern states on Friday and through the upcoming Easter weekend. It will turn cooler on Friday with a chilly air mass moving into the Northeast US/Mid-Atlantic anchored by high pressure with its origins in Canada. There should be plenty of sunshine on both days; however, it’ll feel quite cool in the shade or during the nights. Looking ahead, there are signs for a widespread warm air surge later next week into the central and eastern US - eliminating that “battleground” region in the middle of the country - and this could very well make this upcoming severe weather outbreak the last one in an extended period of time.

There will be significant accumulating snow over the next couple of days in the cold sector of this storm from the Rockies to the Dakotas/northern Minnesota. Map courtesy ECMWF, Pivotal Weather

One final note, this unfolding weather pattern will not only produce numerous tornadoes from later today into Wednesday in the latest in a series of severe weather outbreaks, it is likely to also result in significant accumulating snow. Specifically, the region from the Rockies to the Dakotas/northern Minnesota will see some substantial snowfall during the next 72 hours or so with as much as 1-2 feet in some locations. Ultimately, the accumulating snow will reach the northern part of New England with Maine, for example, likely to receive several inches by late in the week.

Meteorologist Paul Dorian
Arcfield
arcfieldweather.com

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