|January 04 2022|
Tennessee Valley to Mid-Atlantic Winter Storm: (1/2 - 1/3)
By: Rich Otto, WPC Meteorologist
A significant winter storm impacted portions of the Tennessee Valley into the Mid-Atlantic region from 2-3 January 2022, producing 4 to 8 inches of snow over parts of Alabama into Tennessee and 6 inches to over a foot of snow for the Mid-Atlantic. The storm was fairly quick moving, only producing 6-12 hours of snowfall at any given location but high snowfall rates ended up producing major travel disruptions, especially for locations east of the Appalachians.
The storm began as a 500 hPa trough crossed the lower Mississippi River Valley from the Southern Plains around 0000 UTC 3 January. The trough was preceded by a cold front which divided an anomalously warm maritime tropical air mass over the southern U.S. from a modified-arctic air to the northwest of the front. High temperatures were 20 to 30 degrees above average for early January in advance of the snow storm with several record high temperatures reported across the Tennessee Valley and Mid-Atlantic, including 79 degrees Fahrenheit at Huntsville, AL on 1 January and 72 at Richmond, VA on 2 January. A significant decrease in temperature was observed following the cold frontal passage which supported a changeover from rain to snow for locations across northern Mississippi, Alabama into Tennessee.
The 500 hPa trough over the lower Mississippi Valley at 0000 UTC 3 January continued to strengthen over the next 12 to 24 hours, developing into a compact but strong closed low while the trough acquired a negative tilt as the system tracked into the Mid-Atlantic states. Low pressure organized over the southeastern U.S., with a 12 hPa drop in pressure analyzed between 0000 UTC and 1200 UTC 3 January as the low tracked into North Carolina. Aloft, a powerful jet at 250 hPa developed across the Northeast, downstream of the trough axis, with 180-190 kt measured at Gray, ME on their 1200 UTC sounding on 3 January. Divergence aloft was augmented across the Mid-Atlantic region within the right-entrance region of the powerful jet maximum aloft. Meanwhile, strong 850-700 hPa frontogenesis was analyzed over the central Appalachians into northern North Carolina and Virginia, located just north of the south-southwest to east-northeast oriented surface cold front which was slowing its forward progression to the south across Virginia and North Carolina as a strengthening surface low approached from the southwest.
A combination of dynamic cooling and low-level cold air advection helped to support the changeover from rain to snow over the Mid-Atlantic region, with snowfall rates amplified early in the morning on 3 January across the Mid-Atlantic region due to a combination of factors described above. Snowfall rates between 2 and 3 inches per hour were observed from Virginia to the Delmarva Peninsula and southern New Jersey. The high rate of snowfall helped to overcome previously warm ground temperatures, allowing for moderate to heavy accumulations to occur. While the surface low quickly tracked out to sea through 0000 UTC 4 January, with snowfall only clipping southern New England, there was enough time to allow for 12 to 15 inches of snow from north-central Virginia into southern New Jersey.
While totals were not unusually high for a January snow storm, a local storm total of 15.5 inches of snow was reported in Huntingtown, MD ending 3 January. Daily maximum snowfall records were also set across the northern Mid-Atlantic region on 3 January including 13.0 inches at Atlantic City, NJ, 6.9 inches at Ronald Reagan Washington National Airport just outside of Washington, D.C., 6.8 inches at BWI airport near Baltimore, MD and 3.9” at Washington-Dulles International airport in Dulles, VA.
One of the more notable impacts from this winter storm was to transportation. Given precipitation started off as rain for many areas in the Mid-Atlantic region, road crews were not able to provide pre-treatment to roadway surfaces in preparation for wintry precipitation. When rain changed to heavy snow, roadways quickly became impassable and a 40-mile stretch of I-95 between Richmond and Washington, D.C. becoming blocked due to stranded vehicles. Snowplows were not able to clear the roadway causing some motorists to remain trapped in their vehicles for over 12 hours.
There were many traffic accidents (at least 800 in Virginia alone) and at least 5 deaths attributed to the storm from the southern to eastern U.S. Accumulating snowfall was heavy and wet, which stuck to trees causing them to fall when combined with a period of gusty winds in the immediate wake of the storm system. Power outages were widespread as a result, many of which were in Virginia where close to 500,000 customers lost power during the storm. Two days after the storm ended, over 180,000 customers were still without power in Virginia.
Other impacts to transportation included delays and cancellations to railway service along with thousands of flight cancellations in the eastern United States, many of which were in the Washington D.C. to New York City area airports.
Across the southern U.S., besides impacts from heavy snow, severe weather in the form of damaging straight line winds and tornadoes were observed on 2 January in southern Alabama, Georgia into the Florida Panhandle as well as portions of North and South Carolina. The strong to severe weather on the warm side of the storm system also resulted in downed trees as a result of strong winds along with power outages.