****Strong storm pounds western US...reaches northeastern states this weekend...very cold next week...mid-week east coast major storm threat****

A very cold air mass will flood the northeastern states at the end of the upcoming weekend and next week looks very cold on average across the eastern 2/3rds of the nation. Map courtesy ECMWF, weathermodels.com (Dr. Ryan Maue, X)

Overview

A major storm system will pound the western states during the next couple of days and it will then trek across the nation and wreak havoc in the eastern states this weekend. In California, the rainfall in coming days will be heavy all along low-lying coastal sections from Oregon to the Mexican border, and snowfall will be measured by the foot in the Sierra Nevada Mountains. By the early part of the upcoming weekend, this same storm system will bring flooding rainfall to the Ohio and Tennessee Valleys and then significant snow is likely on Sunday across interior New York State and New England.

In the Mid-Atlantic region, there will be plenty of rainfall this weekend; however, it is likely to be preceded on the front-end by snow and accumulations are possible; especially, to the north of the PA/MD border. Cold air will pour into the eastern states following this weekend storm system and next week is indeed looking very cold across the eastern two-thirds of the nation. Low pressure is likely to gather strength in the southern states by the middle of next week aided by an influx of Gulf moisture and it could become a major east coast storm system by later Wednesday or Thursday.

A major storm will impact the western US during the next couple of days with significant rainfall in low-lying coastal sections and substantial snowfall in higher elevation locations. In fact, the snow will be measured by the foot in coming days across the Sierra Nevada Mountains of eastern California and substantial snow will fall in many of the Rocky Mountain States. Map courtesy NOAA, tropicaltidbits.com

Major storm crosses the country next few days

A strong storm system will pound California during the next couple of days with significant rainfall along low-lying coastal sections from Crescent City in the north to San Diego in the south. Substantial snow will fall across the higher elevations of the Sierra Nevada Mountains during this event with several feet in some spots by the latter part of the weekend. This same storm system will then cross the nation and reach the eastern states this weekend bringing flooding rainfall on Saturday to some areas such as the Ohio and Tennessee Valleys and significant accumulating snow to others on Sunday including interior New York State and New England.

The weekend will feature plenty of rainfall in the DC-to-Philly-to-NYC corridor; however, there can also be a quick thumping of snow on the front-end with accumulations on the table; especially, to the north of the PA/MD border. Any snow or sleet that does fall at the onset of the weekend event will change to rain by Saturday night and continue Sunday and some of the rain may be heavy at times. Map courtesy NOAA, tropicaltidbits.com

In the Mid-Atlantic region, the weekend weather event will range from cold and possible accumulating snow on the front-end to mild with plenty of rainfall in the middle and back-end. All of this will be followed by an influx of very cold air on Sunday night and Monday and the first half of next week will be very cold across much of the nation including the Mid-Atlantic region. On Saturday, precipitation may begin as a quick thumping of snow; especially, to the north of PA/MD border. Accumulations of a couple to a few inches are possible across eastern PA, central and northern New Jersey, and in the New York City metro area likely from the late morning to early afternoon hours. Even the DC metro region can experience some snow and/or sleet at the onset of the weekend event around mid-morning on Saturday and a coating or so is on the table. Later in the day, the precipitation will mix with and then changeover to rain and the rain will continue on Saturday night and Sunday morning. Some of the rain that falls on Saturday night and Sunday morning can be heavy at times and a rumble of thunder cannot be ruled out. By later Sunday, strong low pressure to the north will drag a cold front through the region and temperatures are likely to plunge late Sunday/Sunday night from the mild levels achieved earlier in the day.  

The Madden-Julian Oscillation or MJO is predicted to push through phase 8 and into phase 1 during the next couple of weeks (indicated by arrows, left plot) and these particular phases are typically correlated with colder-than-normal conditions across the central and eastern states (boxed regions in temperature composite maps, right). The colder-than-normal weather pattern that begins in earnest next week could last all the way into the month of March. Plot courtesy ECMWF, NOAA

Very cold next week across much of the nation...major east coast storm threat mid-to-late week

The first half of next week looks to be very cold across much of the central and eastern US with particularly cold air centered over the central states. This outlook for colder-than-normal weather next week in the eastern half of the nation is supported by the movement of a tropical disturbance that is tracked by meteorologists using a teleconnection index known as the Madden-Julian Oscillation or MJO. Depending on its location (or “phase”) for the given time of year, it can provide clues as to the temperature patterns across the nation.

Next week is destined to be very cold across much of the nation and this colder-than-normal pattern could take us all the way into the month of March. The 2-meter temperature anomaly forecast map shown here for the 7-day period of February 20 - February 27 depicts much below-normal temperatures across the eastern half of the nation with a focus on the Midwest/Ohio Valley. Map courtesy ECMWF, Weather Bell Analytics

At this stage of the winter season, when the MJO moves into phases 8 and 1, temperatures are typically below-normal across the central and eastern states. Indeed, it appears the MJO will push into phase 8 during the next day or so and then into phase 1 around February 22nd or so...this colder-than-normal pattern may even last right into the month of March.

The overall active weather pattern across the nation in recent weeks will continue through at least much of next week and one of the supporting factors has been powerful “jet streak” activity in the upper part of the atmosphere. This forecast map of 250 millibar winds for next Wednesday evening, February 19th, suggests strong surface low pressure may develop somewhere near the Mid-Atlantic coastline. Map courtesy NOAA, tropicaltidbits.com

By later Tuesday of next week, moisture will push northward into the Mississippi Valley resulting in snow to the north and rain down south.  Low pressure over the northern Gulf region will then make a move to the northeast and head towards the Atlantic seaboard and it will encounter plenty of cold air across the Mid-Atlantic region. Exactly how far this system moves up along the east coast remains to be seen, but the threat is there for a major storm system to impact the Mid-Atlantic region by the middle or latter parts of next week...stay tuned.

Meteorologist Paul Dorian
Arcfield
arcfieldweather.com

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