Sunday, January 24, 2016

What's Ahead This Week After Jonas

Quincy Vagell
Published: January 24,2016





 
While much of the East is still digging out from Winter Storm Jonas, other parts of the country may see more snow to start the new week. By midweek, a frontal system is expected to move toward the East Coast with a touch of wintry weather, followed by the possible development of a coastal storm to end the week.
(MORE: Winter Storm Central)
For those hoping for snow in the Upper Midwest, a quick-moving system may leave a fresh coating of snow early in the week. This does not look like a major storm system, as moisture will be limited and the disturbance will swiftly race from the nation's heartland into Canada.

Current Radar
Before we look ahead to the late week setup, let's discuss what can be expected at the beginning of the week.

First Snowmaker: Plains, Upper Midwest, Great Lakes

Low pressure develops over the central Plains Monday morning and quickly moves northeast across the Midwest and Great Lakes.
Light snow advances east across the Dakotas, Nebraska, Minnesota, northern Iowa and Wisconsin during the day. NOAA's National Weather Service has posted winter weather advisories for parts of the region.

Winter Weather Alerts
To the south, a wintry mixture of rain and snow, with perhaps a bit of ice, reaches northern Missouri, southern to eastern Iowa and far southern Wisconsin.
Scattered rain showers are likely on the warm side of the system, from parts of Missouri into Illinois, Indiana and western Kentucky. Here, temperatures will rise into the 40s, with some 50s possible across parts of the lower Ohio Valley.

Monday's Forecast
Precipitation tapers off across the Midwest Monday night, with some lingering snow showers and flurries pivoting into the Great Lakes for Tuesday. Chicago may see rain briefly end as a few snowflakes, but no appreciable accumulation is expected.
A swath of 1 to 3 inches of snow is likely across much of the north-central states and Great Lakes, mainly north of I-80. A few locally higher amounts are possible over parts of northern Nebraska, South Dakota and Minnesota, otherwise this looks like a modest snowfall event.
Forecast: Milwaukee | Omaha | Sioux City

Snowfall Forecast Through Tuesday

Midweek Front: Rain, Some Snow in the East

On Tuesday, low pressure moves from the Great Lakes into Canada, with a trailing cold front approaching the Appalachians and Deep South.
Rain showers will move from the lower Ohio Valley into parts of the Northeast and Mid-Atlantic. Although a few snow showers are possible across the higher terrain of Pennsylvania, Upstate New York and northern New England, temperatures should rise into the 40s across the region, supporting mainly rain from this next round of precipitation.

Tuesday's Forecast
Since rain is forecast to be fairly light, most of the fresh snowpack should be able to absorb the rainfall without any significant flooding concerns.
Forecast: Baltimore | Nashville | New Orleans
To the south, showers and a few rumbles of thunder will be possible from the Tennessee Valley to the Gulf Coast. The threat for any severe thunderstorms is fairly low, although a few storms could feature gusty winds and briefly heavy rainfall.
By Wednesday, the frontal boundary slowly moves toward the East Coast.
Enough cold air may be in place for a mixture of snow and ice across the Appalachians from western Virginia to western North Carolina and eastern Tennessee, especially where the most snow remains on the ground from Winter Storm Jonas. Portions of I-81 could become slick, but with precipitation remaining light and temperatures near or above freezing, accumulations of any snow and ice should be minimal.

Wednesday's Forecast
Across the Mid-Atlantic from Maryland, D.C., and the Virginia piedmont, rain showers could mix with or change to sleet or snow late Wednesday, but no significant accumulations are expected.
Forecast: Charlotte, North Carolina | Richmond | Washington, D.C.
Since there will likely still be solid snowpack in place across the region, it is possible that some of the computer-generated model forecasts could be underestimating the amount of cold air locked in near the ground. This could have an impact on how much wintry precipitation ends up accumulating.
Since this is still a few days out, check back for updated forecasts for more details in the coming days and be prepared for at least the potential for a touch of wintry weather.
Across the Southeast, rain showers with temperatures rising into the 40s and 50s are expected. Warmer, somewhat unstable air across Florida may support a few thunderstorms, some of which could become severe.
(MORE: Severe Weather Forecast This Week)
A combination of snowmelt and additional rainfall could lead to some ponding of water and spotty poor-drainage flooding in parts of Virginia and North Carolina. While this is not a major concern at this time, the situation will continue to be monitored.

Late Week: Possible Coastal Storm

The progression of the lingering frontal boundary becomes very important for the forecast along the East Coast come Thursday into Friday.
With the front located near or just offshore, a dip in the jet stream is expected to dig a trough of low pressure into the Northeastern states at the end of the week. Low pressure may develop and rapidly intensify off the coast, especially if the approaching trough can catch up with the front.

Late Week Setup
If this "capture" of energy occurs too late or well offshore, then any coastal storm would likely pass out to sea, largely missing the Eastern Seaboard.
However, if low pressure gets pulled back toward the East Coast, then a higher-impact nor'easter could affect parts of the Mid-Atlantic and Northeast.
The forecast is further complicated by a probable lack of a fresh supply of cold air on the northwest side of any such storm. The computer models are suggesting that a weak secondary area of low pressure may ride north into the eastern Great Lakes, a scenario somewhat similar to a nor'easter earlier in January. That storm featured mainly rain for the I-95 corridor, only dropping heavy snow across parts of Maine.
(MORE: Odd January Storm Without Much Snow)
This setup is not exactly the same though, as this airmass should be somewhat cooler and with snow still on the ground in the Mid-Atlantic and southern New England, temperatures in the low levels of the atmosphere may be cold enough for wintry precipitation.
Since this potential storm is still several days out, a lot of scenarios are still on the table. Be prepared that if another nor'easter does develop, snow, sleet or freezing rain could affect parts of the East Coast.
This storm, if it does develop, is unlikely to be another historic snowmaker, due to the expected lack of strong high pressure to the north. Still, some areas recently affected by Winter Storm Jonas could have more wintry weather to deal with, less than a week after the record-breaking storm departed.
Check back often with weather.com for the latest forecasts and information through the week.
MORE: Photos from Winter Storm Jonas

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