In the DC area, we may see stormy rains and thunderstorms starting to rise around 5pm and continuing at intervals until nightfall. They may be hit or lose. The story goes on under the ad A strong storm means that the conditions are favorable for strong storms, but no guarantee and that you should stay alert. If a strong storm (or tornado) is issued, it means that a storm is imminent in your area and you should seek refuge immediately. Heavy rains have been reported in the District of Columbia, Maryland, New York, Pennsylvania, Virginia and West Virginia by 10 p.m. EDT pic.twitter.com/B68lZ0nqoD – NWS Severe Tstorm (@NWSSevereTstorm) March 31, 2022 The Meteorological Service also increased the area’s storm risk level from “light” (level 2 of 5) to “enhanced” (level 3). To our south, emerging storms have already triggered tornado warnings on the west and north sides of Richmond. At this point, we have not seen any reports of confirmed tornado or damage. Note that while our discussion below shows that the most intense thunderstorms are possible later this afternoon, when the cold front passes, showers and thunderstorms that will develop before this afternoon and afternoon can be intense and cause catastrophic gusts. wind and maybe a short tornado. The story goes on under the ad We will post updates in case the weather progresses in the area. Original article from 1:20 p.m. After an outbreak of severe weather in the South on Wednesday until the early hours of Thursday, the cold front responsible for the dangerous storms is moving towards the East Coast. As the front encounters mild, humid winds blowing northward, strong to strong storms may break out in the Washington area, especially this afternoon and tonight. The Storm Forecasting Center (SPC) has placed much of the eastern United States in a low-risk lightning zone. This is Level 2 out of 5 on the seriousness threat scale. The main threat with any storms will be catastrophic winds, although a tornado or two short-lived is not ruled out. It is possible that the thunderstorms and the storm will pass through parts of the area without much fanfare. Although severe thunderstorms are not certain, it would be wise to stay up to date until late at night. The story goes on under the ad In the face of any storms, strong winds from the south – with gusts of up to 50 miles per hour – led to a wind warning for the area until 8 p.m. “Stormy winds could blow around unsafe objects,” the Meteorological Service wrote. “Individual damage to trees and some power outages may occur.”
Interstate 81: Between 4 and 8 p.m. Germantown / Dulles / Warrenton: 6 to 10 p.m. Interstate 95 and Beltway area: 8 p.m. and midnight. South Maryland to Annapolis: 9 p.m. and 1 p.m.
Note that short, thunderstorms are possible before the main line of rain and thunderstorms late this afternoon. All OK: Midnight west of the Beltway, around 1 p.m. around the Beltway and at 2 p.m. near Chesapeake Bay.
High (2-in-3) probability: Stormy winds (30 to 50 mph), short rainfall. Moderate (1-in-3) probability: Catastrophic winds (50 to 65 mph). Low (1 in 10 or less) chance: Short tornado, light hail, catastrophic winds (over 65 mph), lightning, floods.
Possibility of rainfall: Average 0.25 to 0.5 inches. locally it is up to 1 inch or so. A look at the forecast map of the day reveals that a warm front pushed our area last night, bringing wind from the south and a milder and wetter gas mass. This front is connected to a deeper low pressure system north of the Great Lakes. Our area will remain in the hot zone of this storm all day and night as it approaches a cold front from the Ohio Valley. In the upper levels, a strong low pressure bottom approaches the east coast. The air rise is expected to intensify throughout the DC area as the cavity is strengthened. With the inflow of moisture to the south and the rise of the wind, waves of thunderstorms will develop and cross our area in the afternoon and evening. The story goes on under the ad Our anxiety shifts early in the evening as the front approaches and an unstable air pocket develops just along it. The early morning weather balloon at Dulles Airport shows that the atmosphere – at the moment – is quite stable and does not favor deep storms. However, with the arrival of milder air from the south (and the cooling of the middle levels from the approaching threshold), some instability is expected to develop, at least through the middle atmosphere, by early evening. Extensive cloudiness during the day will probably prevent the strong sun of the end of March from destabilizing the atmosphere to a great extent. While instability may be somewhat absent from a deep layer, low level wind fields are extremely strong and ideally designed so that any deeper cells can rotate. A look at these very strong winds about a mile above the surface is shown below. note that it is in the range of 70+ mph. Even with shallower synagogue clouds (without significant lightning and thunderstorms), we are concerned that downstream currents in the clouds may cause strong winds to blow in local catastrophic gusts. Strong wind shear (change in speed and direction with altitude) can also promote transient, rotating storm cells with the possibility of a short-lived tornado or two. The following two images show radar snapshots as simulated by various forecasting models. In the first, the high-resolution NAM model suggests that a small line, with integrated strong to severe cells, will pass through the area between 10 p.m. and 1 p.m.
The second simulation (the HRRR model) presents an older scenario, with a series of thunderstorms crossing our area between 8 and 11 p.m.
The Capital Weather gang will stay on top of this scenario throughout the day and will post updates if storm monitoring is issued and local alerts are generated.
