While this is not really a weather hazard right now, DC forecasters have been watching the weather patterns and are predicting storms in the evening over the next couple days. Residents of Virginia already know that a hot a humid day typically turns into a stormy and wet night so this prediction is not out of the ordinary for the state. What is different is the fact that there is a chain of storms heading this way from the South (Texas).
The same storm that has spurred tornadoes in Texas and dumped endless rain in Missouri and Arkansas is heading this way. Forecasters in that region are expecting this chain of thunderstorms to make it to New York by Monday evening which puts the chance of thunderstorms for us somewhere between Monday evening and early Tuesday morning.
A LOOK AHEAD
Out ahead of a storm system wrapping up over the central part of the country, we stay in the warm air going into Monday. Skies should start off with plenty of sun, but clouds increase during the afternoon as a front approaches from the west. There could be a line of showers and storms in the afternoon, although at this point, it looks as though that risk could hold off until the evening or overnight, which would diminish the intensity. Highs should reach at least 80 most spots, and perhaps as high as the mid-80s. Confidence:Medium
The main storm and front have passed for Tuesday, but cooler air lags a bit. With a west wind off the mountains, it’s still warm. Highs are near 80. Clouds may increase in the afternoon with cold air floating by aloft. Confidence: Medium
At the time this article was written (Saturday morning), the storm was passing through Kentucky and Tennessee. In Virginia (or DC, to be more specific), we experienced a very hot a humid day with overcast skies. An early morning shower added to the humidity in the air. By the end of the day, the sun came out strong to finish the day. Sunday morning was equally hot and humid but more sunny. Since the storms are expected to arrive Monday evening, the article mentioned that the cooler temperatures will lessen the intensity of our expected impact.
After tornadoes ripped through northern Texas on Saturday evening, the states of Alabama all the way up to Indiana can expect to see sever thunderstorms going into Sunday night. The storm, the same one who generated the tornadoes for Texas and Oklahoma, is moving in a northeast direction and is expected to bring storms into New York by Monday evening. With this system, the hazards expected are as follows:
- Blinding rain
- Strong Winds
- Possible river-flooding on side-streets
The storm is fueled from the heat and humidity typical to these states. Unfortunately, this storm is coming on the heels of another one that passed through the same projected regions last weekend.
Last night (Saturday evening), five people were killed in the four confirmed tornadoes in Texas. All of the deaths occurred in Van Zandt county. In addition to the five deaths, fifty people were injured while the storm caused significant property damage to houses and businesses.
People in the projected path are being urged to keep track of the storm and the weather radar to know if and when they can expect any weather hazards.
Multiple tornadoes were spotted today in Arkansas and Georgia as a serve thunderstorm continues to make its way across the south today. One EF0 tornado passed through Yell county, Arkansas with sustained winds of 85 mph. “The tornado’s path was half a mile long and it measured about 50 yards in length.” The tornado caused some damage but most the knocked down trees and damaged homes were the result of stronger straight line winds. Two other tornadoes occurred in Montgomery and Pike counties. The tornadoes knocked over trees and damaged power lines and homes. One person was injured when a tornado touched down in Talbot County, Georgia. Three homes were damaged and a large amount of trees were snapped in half or knocked down. A small EF0 tornado touched down in Holdenville, Oklahoma Thursday evening with sustained winds of 68-85 mph.
Severe thunderstorms and accompanying hail, winds, and tornadoes are expected to move through the South, Plains, and Midwest, tonight and through the weekend. Heavy rain could also produce dangerous flash flooding.
A large low-pressure system is beginning to move through the southern Plains, and is expected to move through the rest of the midwest along with areas along a very active jet stream. April is usually a very active month for thunderstorms and tornadoes, and 2017 was no excuse.
As of 7:45 pm on April 27, a tornado watch has been issued for parts of middle Georgia. Other parts of Georgia and Alabama have reported tornadoes throughout the day Thursday. More tornadoes are expected throughout the weekend, as as the storm system moves east, severe and regular thunderstorms will follow and are expected to effect states as far east as Virginia by Sunday.
Look out southern Midwest!
The past couple weeks have been very stormy in the East Coast, Gulf Coast, and Midwestern regions of the US. Severe thunderstorms are expected to pass through eastern Texas, Arkansas, Missouri, Tennessee and Kentucky and up into Indiana and Illinois. These storms could bring huge, damaging chunks of hail, and as much as 7 inches of rainfall in some areas. Forecasters are warning residents in these regions to watch for flashfloods. There is also talk of potential tornado formations, giving sections of Tornado Alley the chance to live up to its name.
Tornadoes rely on severe differences in air mass temperatures to form. The succession of specific air conditions during a severe thunderstorms makes the formation of tornadoes and ground contact generally unlikely, but the risk associated with them is so great that potential warnings in advance are the duty of forecasters. Although the path of a tornado once it actually does make contact is wildly unpredictable, the conditions leading to the tornado itself are very easy to identify, thus issuing tornado watches and warnings are not hard to do.
Parts of Oklahoma, Texas, Missouri, and Arkansas have been experiencing tornados, flooding and hail. The tornados went through parts of Oklahoma while not particularly strong they still amassed damage. Parts of Missouri have been and are expected to receive more flooding as the severe weather moves in. Parts of Texas reported golf-ball sized hail.
Today there are expected severe storms bringing in thunder, hail, heavy rain and a small chance of tornados. The strong storm surge is expected to enter the warm air system in west Michigan this morning. There will be around 3 different storms passing through, the first is expected to just be light showers and will end mid morning. The next storm to arrive in Michigan is likely to be more brutal. The second storm will come along the cold frontal passage and will likely last until 9pm tonight. Threats of this storm include heavy rain, hail and severe lightening; many people who live where the storm is expected to hit are advised to stay indoors and take precautions. There is a slight chance of tornados but not very likely.
The Storm Prediction Center predicts that the West Michigan is at slight risk for severe whether, which means that some aspects of the storm can be severe but not all.
Based on another weather forecast website, the region expecting to get hit by severe weather is now under marginal risk for severe weather, which means the risk is gradually decreasing. Areas such as Flint and the Northern Thumb are at highest places of risk based on levels of poverty but also the path of the storm.
Washington DC’s weather gang put together a report explaining the types of tornadoes that hit DC on Thursday. The Weather Gang was seeking to explain that these tornadoes are not the ones that we are used to seeing, or hearing about. The tornadoes which touched down in and around Washington were not tornadoes caused by a super cell thunderstorm that are created by a spiral updraft also called a mesocyclone, but instead were “squall line tornadoes” which form along a bow-shaped series of thunderstorms. These squall lines, called quasi-linear convective systems (QLCS) are reported as being responsible for 20% of all tornadoes in the U.S., and are smaller, weaker and shorter-lived than their super cell counterparts.
This specific squall line approached the DC area from the southwest. However the Weather Gang report that this squall line was unusual in nature. Firstly there was no lightening, the line itself was very wavy in nature- arching and bowing in several areas, and lastly it formed in area of only relative instability. An extremely supportive upper atmosphere compensated for the low instability ultimately allowing for the squall line to be formed. In this case the supportive upper-atmosphere was a vorticity maximum, which is characterized by an extremely vigorous ascent of air beneath the jet stream. The squall line is a direct reflection of the violently rising air along the outer edge of the vorticity maximum.
This particular squall line had the appearance of a regular QLCS, which is why multiple tornado warnings were issued for areas around DC. However meteorologists are still learning and researching about the way in which these systems form, and develop. What is known about these QLCS systems pose real problems for detection because their parent storms, misocyclones are shallower and shorter-lived than the mesocyclones which cause super cell tornadoes. This means that they can easily fool Doppler radar, and they are also hard to see visually because they are often embedded within storms and are hidden by the heavy rain that falls along the squall line. They are even hard to determine post-mortem because the strong rotary winds become embedded within the powerful straight-line winds of down bursts.
The squall line that formed along Washington, showed the counter-clockwise rotating couplets which are products of a misocyclone system. These rotating couplets were able to be observed because of the highly sensitive radar located at Andrews Air Force Base, south of DC. The rotating couplets of air were seen 10,000 feet over the ground, and while it is likely that these vortical circulations likely extended to touch the ground and became weak tornadoes which caused spotty wind damage across the district. While the spinning column of air characteristic of tornadoes were not present in many of the videos that the Weather Gang studied, but in the case of the likely tornado which hit the Tidal Basin and H. St. Corridor showed a spinning column of water spray on the river, and also rotation in the in the cloud base as well. The reason that the characteristic funnel cloud was not present in this case is most likely due to the fact that the pressure drop at the center of these rotating air columns was not sufficient enough to cause enough the right amount of condensation for a funnel cloud to form.
This morning, the National Weather Service confirmed that two tornadoes touched down in the DC Metro area yesterday afternoon.
One tornado hit my hometown of Herndon, Virginia at 1:36 p.m. while the other hit a few minutes later at Joint Base Anacostia-Bolling in Southeast D.C.
Both tornadoes were EF-0 with estimated peak winds at 60 to 70 miles per hour and there were no reported injuries from these tornadoes.
The weather service has confirmed that the tornado to hit Herndon was the first to hit in almost 15 years, saying that “The tornadoes were spawned by a line of northward-moving thunderstorms. Tornadoes that form from linear storms are generally weak and last on the order of only a couple of minutes.”
Update of Severe Weather outbreak in the South April 6th, 2017
The Carolinas are bracing themselves for severe weather that has crossed the southern portion of the US leaving damage from tornadoes and flooding. The first round of severe weather produced snow, hail, and heavy rains that lead to flooding in areas. Coastal areas are to be on the lookout for waterspouts and high storm surge.
The NWS is asking residents to keep radios and cell phones with them ahead of these storms to get immediate warnings and updates. Schools have delayed opening to avoid students traveling during until the storms have passed.
Luckily throughout the southeast there have been limited death and injury reports follow these storms. However, residents are without power and the damage from possible, and known, tornadoes is significant.
The image below shows flooding in Atlanta from the storm that is bound for the Carolinas. Severe flooding is a factor in these severe storms.