10:45 AM (Monday) | *Powerful storm system impacts the eastern third of the nation…significant snow in portions of the Ohio Valley…colder pattern emerges post-storm in the central/eastern US*
Paul Dorian
Strong low-level winds with today’s powerful storm system will raise the chances for gusts past 50 mph; especially, in areas close to the east coast. Map courtesy NOAA, tropicaltidbits.com
Overview
A powerful storm system is churning northward today through the Appalachian Mountains and is having an important impact on a large part of the eastern third of the nation. The DC-to-Philly-to-NYC corridor has had steady and heavy rainfall this morning and the afternoon will present the possibility of some severe thunderstorm activity. Meanwhile, it is cold enough in the Midwest for snow to fall at mid-day and portions of the Ohio Valley will receive significant snowfall during the next 24 hours or so. An especially hard hit region may be northeastern Ohio where more than a foot of snow is possible in localized areas later tonight and Tuesday. This storm system is coming at the front end of an overall pattern change that will bring persistent colder conditions to the central and eastern US as we transition from the month of November to December.
Another contributing factor to today’s strong storm system are jet streaks high up in the atmosphere (250 millibar level) where winds are in excess of 110 mph in parts of the eastern US. Map courtesy NOAA, tropicaltidbits.com
Details
A storm system centered over West Virginia’s mountains at mid-day has a lot going for it with strong energy aloft and multiple jet streaks in the atmosphere which are contributing to its overall strength. Heavy rain inundated the I-95 corridor region this morning ahead of a warm front and the precipitation pattern in the DC-to-Philly-to-NYC corridor will become more “showery/convective” this afternoon with the chance of strong-to-severe thunderstorms. As it turns milder and becomes quite windy this afternoon in the wake of the warm frontal passage, any thunderstorm that forms can produce damaging wind gusts and additional heavy rainfall. In fact, isolated tornadoes cannot be ruled out for later today in the region from southeastern Virginia-to-the Delmarva Peninsula-to-central New Jersey as some dry air aloft potentially makes the atmosphere extremely unstable.
Heavy snow potential exists later tonight and on Tuesday in places like northeastern Ohio where there will be “lake effect” winds and deep, slow-moving energy aloft. Map courtesy NOAA, tropicaltidbits.com
The upper-level feature associated with this storm system will be a slow-mover as it encounters blocking high pressure ridging over central and eastern Canada. As a result, conditions will remain unsettled in much of the Mid-Atlantic region and Northeast US well into Tuesday and it’ll be noticeably colder than what we’ll experience this afternoon before the colder air arrives. In fact, the colder conditions that develop later tonight and on Tuesday will be part of an overall pattern change that will result in persistent colder weather for the foreseeable future in much of the central and eastern US following our warm finish to the month of November.
The combination of “lake effect” winds and a slow-moving upper-level storm system raises the chances of significant snowfall in the next 24-48 hours across places like northeastern Ohio. Map courtesy Weather Bell Analytics, NOAA
In terms of snow, this unfolding situation is setting up favorably for some very significant snowfall amounts during the next day or so in places like northeastern Ohio and this includes in and around the Cleveland metro region. The combination of strong winds crossing over Lake Erie and the slow-movement of the overall strong storm system will allow for snow to pile up in some localized spots with more than a foot possible in the northern part of Ohio. Snow accumulations are likely elsewhere over the next day or so including across West Virginia, western Pennsylvania and New York. Looking ahead, another storm system is likely to form later this week across the middle of the nation and it could impact the eastern states at week’s end, but there are still many questions that remain on its potential.
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com
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