The storm clock, accompanied by thunder and lightning, will continue until 10 PM. Some storms can cause damaging gusts and create power outages.
At 6:15 PM, the severe Chesapeake Bay storm is intensifying towards the Bay’s direction from Waldorf.
A severe storm, Colert-Arnold Line, is rotating around Waldorf and moving northeastward and eastward. An alert for severe storms with thunder and lightning is in effect for this area until 7 PM.
A few hours ago, a storm that started in Fairfax County, VA, produced gusts of wind at a speed of 44 miles per hour while passing through Fort Belvoir, and radar suggests that it could generate smaller tornadoes.
Furthermore, the radar is concerned about the Washington area, except for southern central Pennsylvania where some storms have spread. So far, the storms have avoided the immediate vicinity of Washington and are concentrated in the south of Beltway.
The storms were approaching closely; however, a beautiful rainbow appeared, and it even produced a double rainbow visible at the National Mall.
Although the storms have veered away from the immediate DC area, there is still a chance of some storms popping up this evening (as models indicate). If more severe weather develops, we will update this article. Otherwise, stay tuned to our PM update for the rest of this evening.
At 5:20 PM, the majority of storms are remaining south of Beltway, but there is a possibility of some spreading this evening.
Storms are being tracked along Interstate 66, from just south of Central Fairfax County to southern Prince George’s County, along the Beltway. So far, while there have been a few storm warnings with thunder and lightning, the storms are not particularly severe, and we haven’t seen any indications of severe weather.
Currently, the most intense storm is located near Dale City and is crossing Interstate 95 before possibly affecting far northern Charles County and southern Prince George’s County.
Short-term models show storms slightly veering northward during the evening hours, but they should still be monitored or dodged. The best chance for severe storms might be east of Interstate 95.
At 4:30 PM, a storm in Southern Prince George’s County intensified towards the southern part of Prince George’s County. Overall coverage is very limited.
The storm that originated in Fauquier County and moved from Warrenton and Manassas has entered Southern Prince George’s County, affecting areas like Brandywine and Springdale, and continued towards Fort Belvoir and Alexandria. It has chosen a more southerly path than predicted and should head towards Southern Prince George’s County, reaching Friendly and Fort Washington by around 5 PM. The storm has diminished in intensity but still has sporadic heavy rainfall, strong winds, and occasional lightning.
In central Fauquier County, another storm is trailing behind and can take a similar path, potentially reaching Central and Northern Prince William and then Southern Fairfax County for the next hour or more.
As of recent days, the overall coverage of storms has been lower than the threat posed by severe storms, and a significant portion of the area has been spared from the storms. We will continue to monitor and provide updates during the next couple of hours.
3:40 PM – A strong storm in Northern Prince William County has advanced towards Fairfax County.
The areas from Knox Village to Manassas have been affected by a powerful storm that originated in Fauquier County and traveled across Warrenton. It is moving northeast along Interstate 66 and could likely impact Centreville, Fairfax, Burke, and Annandale throughout the next hour with heavy rain, lightning, and strong gusts. Although it is not now thought to be severe, as it moves east-northeast, it has the potential to become more powerful.
At 3 PM – The thunderstorm clock with intense thunder and lightning continues until 10 PM.
Storms with thunder and lightning, accompanied by heavy rain, have been ongoing in Northern and Western Virginia, Western Maryland, and Southern Pennsylvania. The National Weather Service has issued a thunderstorm clock until 10 PM for the Washington-Baltimore area. The clock extends from south of Fredericksburg to as far north as Interstate 81, and from the Delaware and New Jersey coasts to the east. The clock indicates the potential for wind gusts up to 75 miles per hour, similar to bowling balls hitting pins.
The storm, currently progressing, has been forecasted to expand its coverage during the evening hours, mainly towards the east-northeast.
Keep in mind that a thunderstorm clock with intense thunder and lightning does not guarantee severe storms, but it indicates the presence of some ingredients. When there is a clock, you should monitor weather alerts and be prepared to seek shelter, preferably in a sturdy building.
From 2:30 PM to an actual article:
This afternoon and evening in the DC area, scattered showers and thunderstorms are likely with good conditions for thunder and lightning. Some storms can become severe, with damaging winds, frequent lightning, heavy rain, hail, and possibly one or two isolated tornadoes.
Around 2 PM, a thunderstorm had already erupted near the Virginia-West Virginia border close to the Interstate 81 corridor, and the coverage is expected to expand towards the east during the possible upcoming hours. The greatest chance for storms in the metro area is between 4 PM and 8 PM, although some lingering instability can last a bit longer.
Considering the weak cold front moving eastward through the region, increased humidity, and rapidly rising air, the National Weather Service’s Storm Prediction Center has placed the entire area in a high-risk area for severe storms.
Interstate 95 corridor and eastward, the threat level is 3 or “enhanced.” In the immediate vicinity of I-95, it is level 2. The levels indicate the extent of the expected storm. Level 3 risks occur only a few times on average in a year in larger areas, making them noteworthy for storm hazards.
A glance at the storm threat:
Timing: From 2:30 PM to 8 PM, progressing from west to southeast, continuing with additional but potentially non-severe storm possibilities.
Coverage: Somewhat scattered or patchy. It appears that scattered storms form within a broken line, which then intensifies as it progresses eastward.
Main risks: Damaging winds, isolated tornadoes, and possibly some hail.
Bottom line: Monitor the storm hours and warnings and have a plan ready for seeking shelter if a storm is approaching your location.
Deep dive: Monday’s setup is concerned with a weak surface boundary and jet stream riding atop, causing the air mass over the entire area to become rapidly destabilized.
Furthermore, an increase in wind shear through the lower atmosphere enhances the change in wind speed with height—a common requirement for severe weather.
The juxtaposition of mixed clouds and a high sun angle assists in further destabilizing the environment, aiding in the development of storms. However, the quantities we use to gauge these amounts are immediately apparent to be notably higher southeast of DC, where values range from 1500-2000 J/kg, which is sufficient for strong to severe storms, to 3000-5000 J/kg over the southern Delmarva Peninsula.
Wind shear represents changes and increases in the wind with height. It is generally needed for robust storm development.
The range of 30-40 knots (approximately 35 to 45 mph) for Monday’s shear means that potential storm cells could evolve into larger, organized, and longer-lived multi-cell clusters—except for some isolated higher shear pockets in the vicinity and just south of our coverage area.
Our concern is that the combination of shear and instability could contribute to scattered incidents of severe weather, including heavy rain and repeated lightning strikes, gusty winds, and isolated tornadoes.
Any storms that obtain rotating updrafts are not ruled out, even if they are brief tornadoes.
Rainfall amounts could be localized on a broad scale, with some areas experiencing very little and others possibly seeing localized flooding at the surface level. It may rain at a pace of 1-2 inches per hour.
Current observations and model guidance suggest that storms will occur as more of a squall line rather than a discrete cellular mode, hence the potential for severe to robust weather to be somewhat more scattered or patchy. However, storm interactions that divide into separate behaviors can also be indicative, with one storm to the left and another to the right, though typically with an east-to-west orientation.
We will post updates as the storm intensifies throughout the afternoon.