10:30 p.m. – Weather Service says it restores tornado damage
The Weather Service says it restores just before 9 p.m. near the intersection of Quietree and Crosswind drive. One house was reportedly condemned as a tree fell on the roof.
Bayfield Court is on the Bay of Main Street
Farther northeast, multiple trees were reported down in Reston on Center Harbor and Baron Cameron roads at 8:56 pm
Fairfax and eastern Loudoun counties at 8:16 am, which expired at 9:15 pm
10:00 p.m. – Severe storm and heavy rain risk ends
The evening band of rain and thunderstorms was intensely thunderstorm and tornado warnings, but it so moved through the heart of the region sooner. It has moved to the north. Rainfall totals have been varied, with Dulles picking up more than an inch, and D.C. less than half an inch.
Additional showers are possible overnight, but there is no more threat of flooding or severe weather locally. Temperatures settle through the 60s for lows.
Saturday features plenty of clouds, but it should be fairly dry.
Detailed storm briefing from the afternoon
An intense, daylighting Dynamic storm system sweeping up the Appalachian Mountains in the Washington region on Friday afternoon and evening.
At the beginning of the afternoon and evening a second – possibly a more intense – wave in the evening.
The National Weather Service
Some storms could contain damaging wind gusts (up to 70 mph) and isolated tornadoes are not out of the question Storm Prediction Center has issued a tornado watch for much of the Washington / Baltimore region through midnight. A tornado watch means conditions are conducive to tornadoes;
If a tornado warning is issued, it means radar is indicating a tornado or a twister has been observed on the ground ,
A flash flood watch is also in effect due to the possibility of storms with very heavy rainfall tracking over the same areas repeatedly.
Approximate arrival time for storms:
- Round one: 2 to 5 pm, generally hitting south / southwest areas first
- Round two: 6 pm to midnight, generally hitting southwest areas first
All clear: Midnight to 2 a.m. Saturday
Storm duration: 45 minutes, but longer than storms track over the same areas repeatedly
Chance of measurable rainfall in any location: 80 percent
Storm motion: Southwest to northeast
Likely storm effects: Heavy rain, gusty winds,
Possible storm effects: Damaging wind gusts, flash flooding, lightning, a few tornadoes
Rainfall potential: 1 to 1.5 inches but highly variable.
Severe storm discussion
Storm this afternoon through Saturday morning will erupt in the energetic warm sector of a cyclone (low-pressure system) tracking to the west, along the spine of the Appalachians.
The high-resolution forecast models are advertising multiple rounds of storminess over the next 12 to 18 hours. The first batch is expected to develop during the afternoon, pushing from south to north. The second round is timed from 6 p.m.
Through the afternoon, clouds should be widespread and persistent enough to prevent a strong and unstable air mass from developing. The lack of solar heating in this case, however, wants to be offset by the high low level moisture content of air.
The exceptionally strong winds are used as ingredients for thunderstorms. Winds just 5,000 feet above ground will be screaming at 60-70 mph, and may approach 90-100 mph around 15,000 feet.
But the wind fields and shear are even stronger across the Carolinas and central Virginia / Tidewater, so where the air mass is expected to be more unstable. Accordingly, the National Weather Service Prediction Center has issued a moderate risk of severe storms, level 4 out 5 on its 1 to 5 scale.
But even in
The slight risk of severe storms (level 2 out of 5) indicates a 15 percent chance of damaging winds within 25 miles of any location.
The slight risk of severe storms is common in the Washington region. However, the moderate risk zone from central Virginia to the Carolinas is uncommon. In the Carolinas, this is the most significant severe thunderstorm risk since 2016 .
The zone of heavy rainfall from this storm is vast, with flash flood watches from North Carolina through New England.
While the amount of available moisture is abnormally high, there is still considerable uncertainty.
- GFS: 0.8 inches
- European: 0.5 inches
- NAM: 0.6 inches
- High resolution NAM: 0.6 inches
- Canadian: 0.9 inches
- High resolution Canadian: 0.7 inches
- HRRR: 1 inch
Throughout the entire event (through about 1-2 on Saturday), training storm cells will likely lead to localized flash flooding in several spots, with the potential for a relative quick 3 to 4 inches of rain. The heavy rainers are due to become very hot in the air, and are beginning to show signs of cloud failure.
To summarize, during Round 1 of storms this afternoon, any strong to severe storms wants to be isolated to scattered. They want to be heavy rainers though, with the greatest serious threat being isolated damaging wind gusts. However, given the amount of wind shear in the atmosphere – which can not be ruled out
Round 2 may be the more intense of the two, and impact more people in the Washington Baltimore region. Like last Sunday night, we can expect one or multiple, parallel bands of intense showers and thunderstorms … including short bowing segments. These segments can create small corridors of damaging, straight-line wind. Small areas of rotation may develop along these wavy lines, triggering a weak tornado or two.
In this second round, lightning activity may not play out everywhere. , , so the normal visual and audible cues that could be impending storms could be absent. Accordingly, everyone should have access to a device that provides automated weather alerts and warnings, or be tuned to radio or TV.
Expired updates (no longer relevant)
9:15 p.m. – Tornado warning for parts of Montgomery County
Another tornado warning has been issued, this time for parts of Montgomery County until 9:45 p.m. Take cover in the area highlighted below.
8:58 p.m. – Tornado warning for parts of the area
Parts of Loudoun and Fairfax counties are under a tornado warning until 9:15 p.m. Centered on Herndon, seek shelter or cover in an interior room.
8:43 p.m. – Damaging wind threat progressing through the western parts of the area
A severe thunderstorm warning for the western part of the Beltway, 9:15 p.m. Storms have taken on a bit of a bow shape as they move through the area.
Other intense storms.
Other intense storms Tornado warnings have been put into effect recently.
8:28 pm – Damaging wind threat in southwest parts of the area
Rain is moving in the southwest. A big chunk of the southwestern part of our area is under severe thunderstorm warning until 9 pm, and storms are moving northeast at 30 mph.
The main threat from these storms is damaging winds. An area of strong winds is approaching a corridor from Manassas to Stafford, and will continue to move northeast from there. Fairfax and Dumfries wants to be in line near and after 9 p.m.
8:15 p.m. – Main evening band moving in the immediate area
The final volume of heavy activity for the evening is moving through the western parts of the area. For the most part, severe weather has remained south and southeast of the area. There is still some potential for wind damage or a tornado. A tornado warning is up near Boonsboro, Md. Through 8:30 p.m.
6:10 p.m. – Showers redeveloping locally, [more]
Most of the area has taken over a quarter to a half an inch of rain so far, and has extended to a few hours now. Shower coverage has increased again lately, but it remains hit-or-miss at this time. Rain becomes more widespread again.
Over the next hour or two, the heaviest and most widespread rain and storms may focus west of Interstate-95 overall. The storm motion is a bit east of north, most of the storms around here go from west to east. In other words, eastward movement may be slower than usual.
For now, the closest severe weather is west of Richmond. The northward expansion of more unstable air has been a little less than modeled thus far. With some luck that may lower the severe risk, but it's too early to say that yet. Damaging winds and tornadoes remain possible through the evening. Heavy rain is the primary threat.
4:10 p.m. – Awaiting the evening of storms, likely to arrive between 6 and 8 pm.
The first wave of rain and storms was pretty tame, with just a few rain and letter downpours.
The activity to watch is currently in southwestern Virginia and western and north central north carolina. It wants to sweep northeastward towards our area, and some new storms may develop out ahead of it. This issue has a history of triggering flash flood, severe thunderstorm and / or tornado warnings.
The time frame of concern for these storms is roughly 6 p.m. to midnight, arriving and departing first in our west / southwest areas and last in our east / northeast areas.
We'll post our next update around 6 p.m. or as storms start closing in, whichever is first.
3:25 p.m. – First round of rain exiting, pollen washington
The first wave of rain and storms is lifting north of the Beltway, with the heaviest activity now being north of Interstate 70 in Maryland. No severe weather was reported from this first round. Generally around 0.1 to 0.5 inches of rain fell (0.22 inches at Reagan National Airport).
The rain did help wash the tree out of the air, which on Thursday reached its highest level of 2570.93 grains of pollen per cubic And it's now possible to pollen has peaked for 2019.
Even though this first round of rain and storms have passed, some very scattered trailing showers and storms are possible before the next wave expected to start moving in around 6 pm
2:15 pm – Moderate to heavy rain approaching Beltway, but no severe storms for now
Rain, moderate to heavy in some areas, is moving into the immediate Washington area from the south. At the moment, there are no severe thunderstorm warnings in effect. However, some gusty winds and thunder are possible as some of the heavier activity moves through the region over the next couple of hours. And so, we want to be monitoring closely. Interstate 95.
We'll expect this initial wave of rain and storms to be between 4 and 5 p.m (south to north). before another wave starts to move in the southwest between 6 and 8 p.m. or so.
1:25 p.m. – A large area of rain with embedded thunderstorms is approaching the Washington region from the southwest. A severe thunderstorm warning is in effect for parts of Fauquier, Stafford, Spotsylvania and Culpeper counties until 1:45 pm
This whole area of rain and storms should overspread the Washington area, especially along and west of Interstate 95, over the next hour. In the atmosphere triggering tornado activity.