The next in a parade of powerful January storms will slam the D.C. area with downpours and gusty winds Tuesday into Tuesday night. The heaviest rain and strongest winds are expected Tuesday evening, when flooding, downed trees and some power outages are possible. Another round of wind-swept rain could come through Friday afternoon into Friday night as the third storm in a week charges through.
In advance of the storm, the National Weather Service has issued a flood watch and wind advisory for the region. The Weather Service has categorized most of the region at Level 3 out of 4 risk for excessive rainfall. At that level, numerous flash floods are likely, according to the scale. It would be a good idea to clear debris from gutters and storm drains and secure or bring inside loose outdoor objects before the storm arrives.
The rain and wind are part of a powerful storm system that will sweep through the eastern United States just a few days after a weekend storm dumped heavy rain and inland snow across the Mid-Atlantic and Northeast. Like that storm, this one will draw up enough warm air from the south to ensure that the vast majority of precipitation falls as rain in the D.C. region, except for perhaps a few wet snowflakes or pings of sleet early Tuesday well north and west of District.
With a general 1.5 to 2.5 inches of rain expected, and potentially some pockets of higher amounts, many locations could see their January rainfall approach or surpass 3 inches after this storm. The hefty rain totals, after a very wet December, have saturated the soil, increasing the risk of flooding and leaving trees vulnerable to being toppled by strong winds.
7 to 10 a.m. Tuesday: Rain arrives from west to east. Winds: 10 to 15 mph from the southeast. Temperatures: mid-30s to low 40s.
10 a.m. to 2 p.m. Tuesday: Rain, moderate at times. Winds: 15 to 20 mph from the southeast, gusts near 30 mph. Temperatures: rising through 40s and 50s.
2 to 6 p.m. Tuesday: Rain, moderate to heavy at times. Winds: 20 to 25 mph from the southeast, gusts near 30 to 40 mph. Temperatures: upper 40s to mid-50s.
6 to 11 p.m. Tuesday: Rain, heavy at times, thunder possible. Winds: 15 to 25 mph from the southeast, gusts 35 to 55 mph. Temperatures: 50s to near 60.
11 p.m. Tuesday to 2 a.m. Wednesday: Rain exits from west to east, diminishing winds. Temperatures: 50s to upper 40s.
The wind advisory is in effect from 3 p.m. Tuesday to 1 a.m. Wednesday. “Gusty winds could blow around unsecured objects. Tree limbs could be blown down and a few power outages may result,” the Weather Service said. “Use extra caution when driving, especially if operating a high profile vehicle. Secure outdoor objects.”
Winds are forecast to be roaring at 60 to 100 mph about 2,500 to 5,000 feet up in the atmosphere Tuesday evening, potentially breaking record wind speeds for this time of year at those altitudes. The heavy rain and vertical motions of the storm could bring a portion of those winds down to ground level, where we expect gusts of approximately 40 to 55 mph. The strongest gusts should occur east of D.C., especially near the Chesapeake Bay, where a few 60 mph gusts can’t be ruled out.
“Low-level winds from the south will be screaming between 1,500 to 5000 feet at speeds that may have no precedent in our data record. The concern is that pockets of this momentum will mix down to ground level as damaging gusts,” said Jeff Halverson, the Capital Weather Gang’s severe-weather expert. “At this point, forecasters are making their best educated guess in stating max gusts 45 to 55 mph are possible. But we can’t rule out that this event will overperform.”
The flood watch is in effect Tuesday afternoon through Wednesday morning because of “rainfall totals of two to three inches expected with localized amounts up to four inches possible,” the Weather Service said. “Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Creeks and streams may rise out of their banks. Flooding may occur in poor drainage and urban areas. Low-water crossings may be flooded.”
The Capital Weather Gang is predicting a general 1.5 to 2.5 inches across the region, but localized amounts near or over 3 inches are possible in areas that see repeated bursts of heavy rain.
Here’s how much is predicted by different forecast models:
High-resolution NAM: 1.2 inches
NAM: 1.4 inches
HRRR: 1.4 inches
High-resolution Canadian: 1.4 inches
Canadian: 1.5 inches
European: 1.5 inches
United Kingdom (UKMET): 2.1 inches
German (ICON): 2.2 inches
American (GFS): 2.3 inches
While flooding is possible in any low-lying areas typically prone to high water, including urban zones with poor drainage, the threat is enhanced near streams and creeks.
Because of high winds from the southeast pushing water up the Chesapeake Bay and Potomac River, tidal flooding is also possible, prompting coastal flood watches. Here are flood forecasts and estimated times of high tide, when the risk of flooding is highest, along the Potomac River in D.C. and Alexandria, along D.C.’s Southwest Waterfront and in Annapolis:
The Potomac River at Alexandria is expected to reach at least minor flood stage and could be close to the moderate flood stage, with water levels about 2 feet above normal. At the forecast water level, water approaches buildings near the intersection of King and Union streets. High tides are expected at 7 to 8 p.m. Tuesday and 5 to 6 a.m. Wednesday.
The Potomac River at Georgetown is expected to reach minor flood stage late Tuesday night into Wednesday morning, with water levels about 2 feet above normal. At that water level, low-lying areas near Fletcher’s Boathouse begin to flood, water begins to overflow the banks near the mouth of Rock Creek, and portions of the Swamp Trail on Roosevelt Island are flooded. In some cases, water may begin to bubble up through storm drains near Washington Harbour. High tides are expected at 7 to 8 p.m. Tuesday and 6 a.m. Wednesday
The Washington Channel at the Southwest Waterfront is expected to reach minor to moderate flood stage Tuesday evening into Wednesday morning, with the water level over 2 feet above normal. At that level, the unprotected area at the D.C. seafood market begins to flood and water approaches parts of Hains Point Loop Road. High tides are expected at 7 to 8 p.m. Tuesday and 5 to 6 a.m. Wednesday.
The Severn River at Annapolis is expected to reach at least a moderate flood stage Tuesday afternoon into Wednesday morning, with the water level about 2.5 feet above normal. At that level, the boardwalk at the Annapolis City Dock is underwater and water also impacts locations near the city dock, including portions of Compromise Street and several streets on the Naval Academy campus. High tides are expected at 5 p.m. Tuesday, 2 a.m. Wednesday and 4 to 5 p.m. Wednesday.
Wednesday could see a lingering isolated shower with winds still gusting as high as 30 to 40 mph. Otherwise, we’ll be mainly dry and not too chilly Wednesday through Friday morning, with highs each day near 50 to the mid-50s. Another storm looks likely to bring more moderate to heavy rain and gusty winds starting sometime Friday afternoon lasting through Friday night.
