* Heavy thunderstorm clock for Washington and Baltimore region for 8 p.m. *
3:35 p.m. TORNADO WARNING for Columbia, Md. Until 4 pm; Severe thunderstorm warning for immediate Washington area.
Radar indicates a possible tornado just west of Columbia, moving toward Columbia itself. Seek medical attention immediately if in this area in an interior room at the lowest level, away from windows.
Elsewhere, there are severe thunderstorm warnings in force for much of the immediate area, including the district, through 1
They are fast-moving, moving about 40 mph, and must push east of Beltway at 4:30 am
3:30 pm – Severe thunderstorm warning extended to cover all of Washington's northern suburbs. All of Washington's northern and western suburbs under storm alerts.
In addition to the thunderstorm alerts that apply to Montgomery, Fairfax and Prince William, a new warning has been added through Howard, Northern Anne Arundel, and Northern Prince George's County until 11:00. 16.00
The storm of storms moving through the area has solidified and becomes intense. Very strong winds are indicated on radar along its leading edge from Columbia southwest to Chantilly. 3:15 p.m. – Severe thunderstorm warning added for northern Virginia
Almost all Washington western suburbs are now under a severe thunderstorm warning as a new warning has just been posted for eastern Loudoun, central and western Fairfax, central and western Prince William and central Fauquier counties , in fact until noon. 15.45.
Storms with heavy rain, lightning and gusts up to 60 km / h push southeast at 35mph.
They were supposed to hit the western part of Beltway between 10am 3:30 and 3:45 pm and then moving within Beltway and through the district between about 3:45 and 4:30 pm
3:00 pm – Severe thunderstorm for Montgomery County
As this storm road heads east, much of Montgomery County is now under a severe thunderstorm warning until 3:30 pm This warning also includes Northwestern Howard, Southeastern Frederick, and Northeast Loudoun counties.
This storm contains very heavy rain and can produce gusts of 60 mph.
Storms still seem to be moving within Beltway between 3:30 and 4:00 am
(Scroll down to the bottom of the expired update record)
Original story from kl. 13.25
In less than 24 hours, our weather has shifted from pleasantly cool to summer-like and sticky. The new humid air over Washington can burn thunderstorms like a cool front cover approaching the region Thursday afternoon and early evening.
An unstable atmosphere and strong winds increase the chances of some storms becoming severe with harmful gusts and hail.
The National Weather Service issued a severe thunderstorm watch for the region until A clock means that the terms are favorable to the development of severe storms, but they are not guaranteed and you should pay attention . But if a serious thunderstorm is issued to your location, it means there is a serious thunderstorm nearby and you must seek shelter.
The Weather Service Clock says that some storms could produce scattered harmful gusts of wind
The storms can be hit or miss, with a greater concentration of them in our northern areas.
Approximate arrival time for storms: 2 to 4 pm western areas
All ready: 6 to 8 p.m. from west to east
Storm duration: 30 to 45 minutes or so
Possibility of measurable rainfall at any location: 40-60 percent (highest north, lowest south)
Storm movement: northwest to southeast
Likely storm effects : Heavy rain, lightning, gusts
Possible storm effects: Damaging gusts of wind, hail, short tornado
Very small chance: Large hail
Rain potential: Very variable. Locally up to an inch or so in heaviest storms.
Thursday morning a warm front is lifted northwards across the D.C. region. This will pave the way for mostly sunny skies in the afternoon, along with an increase in heat and humidity when a southwind catches up.
Meanwhile, a cold will slowly try south-east across Ohio and then Pennsylvania. In front of the front is a slanted line moved out of Ohio and into West Virginia. The system has produced spotty reports of wind damage in the morning.
In the upper atmosphere, strong winds have caused wind shift (increase in wind speed with height) of about 45-50 mph. This windbreak is quite robust at the end of May, across the Middle Atlantic.
The question is whether the nearby crooked line poses a direct threat to D.C. in the middle of the afternoon. Three out of three forecasting models that explicitly solve convective storms say this system will fizzle as it crosses the appalachians.
If so, two of these three models rebuild parts of the convex line when the impulse has moved east of The Blue Ridge in Maryland. One of these models, the NAM, is shown below. It suggests storm remodeling as early as 3 pm
Another model, HRRR, has been a holdout against hardly storms late on Thursday afternoon and evening.
This leaves us in a difficult situation.
We know that the atmosphere will be primed for convective storms – a lot of instability is expected, and the wind cut is very favorable for organized, intense and long-lasting storms. The Storm Prediction Center has therefore raised the threat level of severe storms to Enhanced Risk (level 3 out of 5) for most of Central Maryland (including Baltimore). The district and northern Virginia are in the next threat category, which is lower (small risk).
While two of the models argue for least scattered storms, one predicts essentially a bust. This model, HRRR, has the greatest ability to solve individual thunderstorms, but has proven to be "hit or miss" for its skill in some days.
Arguing against widespread major activity is the somewhat diffuse nature of "Trigger" or mechanism needed to help lift the air. The cold front does not enter our area until Friday morning. The hot front will have lifted into far northeastern Maryland. This leaves the DC region dependent on localized triggering mechanisms such as the mountains in our west or an energetic enough residue (outflow limit) generated by the weakening quay approaching the region.
We're called about 60-40 storms will trigger in 3-6 pm time frame. Any storm that develops finds itself in an environment that is capable of reaching serious levels.
The most likely form will be one or more arc storm clusters or short lines moving rapidly to the east southeast. There are reasonable prospects for scattered, heavy gusts, along with small to moderate size hail (up to quarter size). An isolated tornado cannot be excluded due to the significant "rotational energy" contained in the wind deflector.
The scrutiny between "strong" (limit of injury) and "severe" (probably causing damage) storms should rise towards the north, across the DC-Baltimore metro corridor.
CWG will monitor conditions for any weather conditions issued.
2:35 pm – Severe thunderstorm warning for Washington's far-western suburbs, including northern Fauquier and Loudoun counties
Storms in northwest Virginia approaching Washington's far western suburbs have intensified, causing serious thunderstorm warnings. These warnings cover much of Loudoun and Northern Fauquier counties, including Leesburg, until about 3 pm Gusts of up to 60 mph and small hail are possible with these storms.
These storms continue to transport together at about 35 to 40 mph and should be close to Beltway at 4 PM
2:15 p.m. – Storms crossing Interstate 81; serious warnings between Hagerstown and Thurmont, Md. and around Frederick
Radar shows a thunderstorm right from east of Hagerstown, Md. south through Winchester and Strasburg in Va.
The most intense activity is in northern Maryland, approaching Thurmont, which is during a severe thunderstorm warning until 2:30 pm A another severe thunderstorm warning is in force for its south, including Frederick, Md. Until 3 pm
These storms, passing through northern Maryland, can produce areas of harmful wind up to 60 mph in addition to heavy rain and lightning.
South and southwest of northern Maryland in northwest Virginia, these storms are not so intense, but still produce crashes, lightning, and wind.
The storms are moving rapidly eastward about 35 km / h and will approach Washington's far-western suburbs, including Loudoun and Upper Montgomery counties in the next hour.