While conditions are dry in the Mid Atlantic today, and should remain true tomorrow for much of the central and northern part of the region, the National Weather Service’s Mid Atlantic River Forecast Center (MARFC) has expressed concern with winter/spring river flooding in the coming weeks.
Yesterday, the State College, Pennsylvania based MARFC issued their first outlook of the new year, describing what they see as potential flood threats for the season. This first outlook of the year is valid for the period from today, January 7, through to January 21. The outlook explores past and forecast weather conditions, soil moisture, snow cover, river ice, and other factors to determine river flooding threats. While the outlook identifies the amount of risk that exists around flooding, it does not address the severity or extent of any future flooding. The MARFC region includes much of New Jersey, all of Delaware, portions of central upstate New York, the eastern two-thirds of Pennsylvania, most of Maryland, eastern West Virginia, and the northern two-thirds of Virginia.
According to the new outlook, the river flood potential is above average across southern and eastern portions of the MARFC service area. The balance of the area has a normal risk level.
Driving the risk level for the Mid Atlantic are recent precipitation, snow conditions, stream flow conditions, groundwater metrics, and soil moisture content. According to the MARFC, precipitation in the entire region has been above to much-above average. While the snow / no-snow line is close to Route 220 in the Appalachians, I-99, I-80 in Pennsylvania, and northeast to near I-84 in New York, snow and its water equivalent values are above normal for this time of year. Outside of Pennsylvania and New York, snow conditions are close to normal. USGS data shows streamflow conditions are above to much-above median levels for this time of year. Soils remain extremely moist across southern and eastern portions of the MARFC service area. Ground water is also average to above average in much of the region.