DISCUSSION: Following the impressive heatwave from earlier this week, thunderstorms have formed along a boundary draped across Germany which has led to some very nasty thunderstorms. Photos and videos posted to Facebook captured beautiful wall clouds, hailstones, and very heavy rainfall across the country. One video even shows a downburst, which is a strong downdraft typically associated with strong thunderstorms and heavy rainfall. According to Lightning Maps, and as of this writing (around 4:30 PM EST), nearly 6,000 lightning strikes were detected. These storms are associated with a low pressure system passing by to the north along a cold front cutting through the country. Behind the front, much cooler and drier air will replace the record setting heat.
Now for a little meteorological lesson. A downburst occurs when heavy rain inside a thunderstorm significantly cools the air and forces it to the sink to the surface. When the downdraft (current of air that falls to the surface) reaches the ground it spreads out in all directions and causes what is known as straight-line winds. These winds can be very powerful and damaging to everything in their path. The damage seen from straight-line winds can be equivalent to a tornado, however in straight-line winds the direction is uniform, hence the name straight-line, whereas in a tornado one can tell where the center of the cyclone was due to the rotation of the damage surrounding it.
No damage, injuries, or fatalities have been reported so far from Germany following these thunderstorms. High pressure will move into the area tomorrow and bring with it dry and sunny conditions that will last into the weekend when a weak storm system looks to impact the country on Sunday, according to local meteorologists. To learn more about other high-impact weather events from across Europe, be sure to click here!
DISCUSSION: As a strengthening Tropical Storm Gaston continues moving off to the northwest at between 5 and 10 MPH, there continues to remain a strong potential for this tropical storm to reach hurricane status by the mid/late-morning hours tomorrow. That being said, fortunately the current mid/upper-air pattern across the Western-to-Central Atlantic Ocean has prevented Tropical Storm Gaston from taking any more of a jog further to the west. This has consequently spared the island nation of Bermuda as well as the Eastern United States from any direct impact from Gaston.
Nonetheless, as reflected by the projected forecast cone-of-uncertainty graphic (courtesy of @ScottDuncanWX), there is a large portion of far Western Europe which will almost certainly lie in the path of what will likely be a strong (or possibly even a strengthening) extra-tropical cyclone as the core circulation of Gaston moves toward and over the colder waters of the North and Northeast Atlantic Ocean. As a result, those who are vacationing, visiting, or even living across any parts of Ireland, the British Isles, northern sections of France, and points further to the north and east should prepare for a hard (if not direct) hit from this future extra-tropical cyclone as it marches across the Atlantic Ocean over the next several days! To learn more about other high-impact weather events from across Europe, be sure to click here!
DISCUSSION: An impressive heatwave is currently affecting Western Europe, bringing with it temperatures well above the 30°C (86°F) mark. Countries from Portugal to Poland are experiencing temperatures that are well above average, which is adding stress to the power companies. It has been a very hot summer thus far, globally July 2016 was the hottest month ever recorded since the Satellite Era. So far, August appears to shatter that record as the heat continues on across the Northern Hemisphere. Back to Europe, this current heat wave is due to a large upper-level ridge (area of high pressure) that has parked itself over the region. An upper-level ridge is responsible for sinking air, which air as it sinks becomes compresses and heats up. The sinking air also prevents storms from rolling through as rising motion leads to clouds and eventually precipitation. The coolest places during this latest heat wave have been confined to the coast where typical daily sea breezes provide a nice relief during the early afternoon. Also, the Northwestern British Isles are on the periphery of the ridge which has allowed temperatures to remain cool at around 16°C (61°F). London, on the other hand, is expected to reach 32°C (90°F) over the next several days as the ridge doesn’t appear to be breaking down anytime soon. Even on mainland Europe, southerly surface winds have allowed warm air to make its way North into the European continent. Places such as Paris, France are expected to surpass 35°C (95°F), which can become deadly for the young and the elderly if precautions aren’t taken seriously. During episodes of intense heat like this, it is very important to stay hydrated and limit your time outside during the hottest part of the day (which is typically between 10am-2pm). Check on your neighbors to ensure that they are okay and not in need of any medical assistance. Central air-conditioning is not very common in Europe as it is in the United States, so extra caution must be taken at night when temperatures fail to drop below 27°C (80°F).
The United Kingdom and France are not alone, places in Spain like Madrid, have failed to record a high temperature less than 30°C since the month began. Temperatures have soared well above 40°C (104°F) in many places throughout Spain and Portugal since August 1st, which has led many weather forecasters to issue heatwave warnings to prepare and warn residents of the persistent heat. Even further East places in Germany, Poland, and the Ukraine had the potential to reach 30°C for several days earlier this week.
As is typical when heatwaves break, severe thunderstorms tend to erupt along potent cold fronts, bringing with them heavy rainfall, hailstones, and damaging winds. Thankfully, behind the storms comes much cooler and drier air. The heatwave is set to break later this week, according to local forecasters. To learn more about other high-impact weather events from across Europe, be sure to click here!
DISCUSSION: As strong storms fired up over parts of Western Europe during the past few days, there were a few particularly impressive storms with truly incredible storm structure! In this one example attached below, you can clearly see a truly gorgeous shelf cloud bearing down this particular beach along the shores of Southern France (specifically in Varlas-Plage). Shelf clouds typically develop as a result of warmer air being lifted up and over the incoming cloud deck which causes rapid condensation in the form of the visually-evident shelf cloud. In this particular case, you can clearly see how there was a rather long shelf cloud indicating that there was very efficient displacement of cooler air above the deeper incoming convective storm(s)! Just a very neat case to say the least considering the incredible size of this shelf cloud! To learn more about other high-impact weather events from across Europe, be sure to click here!
DISCUSSION: Powerful thunderstorms erupted over France yesterday which brought ping-pong sized hailstones, heavy rainfall, and damaging winds. It was an active severe weather day over Southern France, Northern Italy, and Austria yesterday. At one point 400 lightning strikes were recorded in just one minute! Eerie looking shelf clouds moved through several towns as residents captured the storms rolling through. Several reports of hail came in from Switzerland where the scenery looked more like winter than summer. No reports of damage or injury have been reported as crews tried to clean up the mess left behind by the storms. Dangerous lightning strikes were captured on video in Austria as heavy downpours snarled rush hour traffic. An impressive shelf cloud moved across the northern coast of Italy as residents began to run for cover. A weak area of low pressure was responsible for the severe weather observed over Central Europe yesterday. All these events can be tied to the same weather event that caused a train to crash into an uprooted tree yesterday evening.
A commuter train traveling to the east of the French city Montpellier, in far Southern France, collided with an uprooted tree, and injured several dozen people. Eight of the people were listed in critical condition last night by emergency officials, who said that all patients should survive. Many people were treated for minor injuries and shock on the scene of the incident. Initial reports claimed that the train had derailed, but later reports confirmed that the train never derailed, however the front of the train sustained extensive damage. One witness claims that she and her fellow passengers believed that the initial impact has something to do with terrorism, but that was quickly ruled out and the incident is currently being blamed on the weather. Officials believe that the hail and heavy winds led to the uprooted tree and caused the accident. Local meteorologists confirmed that an intense thunderstorm was located over the region at the time of the incident. Two trains traveling along the same route were cancelled to allow emergency officials access to the scene. Crews eventually reopened the route shortly after the evening rush. Pictures posted to social media show what the area looked like shortly after the accident (shown below).
The storm system responsible for the severe weather yesterday, slowly trekked to the east on Thursday as it began to weaken. High pressure will move over the area in the upcoming days, as a powerful coastal storm moves across the British Isles. To learn more about other high-impact weather events from across Europe, be sure to click here!
DISCUSSION: A very hot and dry summer across Western Europe has set the stage for wildfires to quickly grow and advance. These wildfires have mostly been set by arsonists, according to local police who have promptly arrested several suspects in the wake of the ongoing fires. Firefighters are having trouble getting these forest fires under control as conditions have remained very windy and dry across the region. Several firefighters battling the blazes have been injured in the process. Several hundred people have been treated for smoke inhalation, while one report of a severely burned person has emerged as well. Unfortunately, 16 people are also dead from the fires raging across Portugal. As of August 9, multiple news sources confirmed that over 500 individual wildfires (which make up about 15 major blazes) are currently burning across Portugal and the Madeira archipelago, which is a chain of islands located to the southwest of mainland Portugal. Looking at Portugal’s climatological past, summer fires are common across the region each year, but this year’s drought situation coupled with unusually strong surface winds are only making matters worse.
Photos posted on Facebook (shown below) capture the devastating impacts of a wildfire on a local town. Visible satellite images obtained by the European satellite, Meteosat-10 on August 8, captured the smoke plumes over the Eastern Atlantic from space, as upper-level winds pushed the smoke and ash offshore. Local forecasters, looking at the various weather models, unfortunately do not see any substantial rainfall in the near-future, which will only make it more difficult for the firefighters already attempting to get these forest fires under control.
Support from neighboring countries such as Great Britain and Italy have begun to pour in, as Portugal remains hopeful in distinguishing the wildfires. Spain and Morocco have sent in five Canadair airplanes to help combat the flames. Several thousand people had to be evacuated from their homes as the flames moved closer on the mainland, meanwhile on Madeira island, 37 homes were destroyed due to a forest fire in the major city of Funchal. A state of emergency was declared in Northern Portugal as firefighters continue to battle ongoing wildfires in the Norte Region.
Portugal is not alone fighting against the flames; Southern France is battling a blaze that has threatened the city of Marseille, meanwhile Spanish officials are trying to contain nasty flames that have broken out in the northwest region of Spain, which is adjacent to Portugal. To learn more about other high-impact weather events from across Europe, be sure to click here!
DISCUSSION: Northern Europe was hit with bitter cold this past week and even snow was observed in the higher elevations across Sweden. Pictures and videos posted to Facebook have captured the heavy wet snow falling across many ski resorts throughout the country. For many ski resorts, this is the first snowfall of the season, which occurred earlier than normal. The first major snowfall typically occurs by late September, making this event nearly 2 months earlier than usual. Residents of the country were thrilled with the snowfall due to this being the time at which ski resorts begin preparing for the upcoming season. On top of the snowfall, cold air filtered down from the Arctic, shattering temperature records across the country. Ljungskile, a city in Western Sweden, dropped to 8.6°C (47°F) which broke a 100-year old record for the coldest day in August. This temperature was colder than that observed last Christmas Eve. Many residents were seen walking around with their winter jackets, an unusual sight for mid-August.
Sweden typically has a much milder climate than other countries at the same latitude due to the influences from the Gulf Stream which pumps warm/moist air into the region throughout the year. July is typically Sweden’s hottest month when temperatures approach 17°C (approximately 62°F). July is also the time when Northern Sweden experiences continuous daylight for several weeks, while Southern Sweden has daylight for nearly 20 hours each day during this same period of time. February is Sweden’s coldest month when temperatures drop to dangerous levels, with temperatures getting as low as -22°C (nearly -8°F). Snowfall generally covers the ground from December to April across the majority of the country, with the northern parts experiencing regular snowfall beginning in October. Just as continuous daylight occurs during the summer, the winter is usually defined by the sun failing to rise above the horizon for about 2 months across Northern Sweden. Meanwhile, places across Southern Sweden only see about 5 hours of daylight during this same period of time. Fall tends to be the wettest season for Sweden, while Spring is usually the driest season. However, the country receives ample precipitation throughout the year whether it is in the form of rain or various types of frozen precipitation.
Sweden was not alone during this brief cold spell, as records were broken across parts of Germany. In Carlsfeld, Saxony (a German state), the temperature tumbled to 1.3°C breaking the previously coldest day in August since records began in 1990. Frost was reported in several mountainous regions across the country early Thursday morning. In addition, it was a year ago this past week when Germany and other countries across Europe were sweltering from record-setting heat.
Local weather forecasters anticipate that the cold temperatures will not last. By the end of the weekend, temperatures were already beginning to moderate across the region. To learn more about other high-impact weather events from across Europe, be sure to click here!
DISCUSSION: Torrential rainfall in Skopje left nearly 2 dozen people dead late Saturday night. Nearly 4 inches of rainfall was recorded in a very short amount of time. The city typically receives about 3 inches of rain for the entire month of August, and 35 inches for the entire year. Warnings were issued earlier in the day on Saturday, however many were caught off guard by the intensity of the rainfall. Underpasses quickly became lakes as the rain continued to fall, trapping motorists in their cars. Macedonia’s top weather official called this storm a “water bomb”, as he described the ferocity of the rainfall. The Mayor of Skopje claimed that this was “a disaster we have never experienced before.” He also promised financial aid to all of those affected by the flooding. Officials say that this is the worst flooding to strike the region in over 50 years. A slow moving weak trough, or area of low pressure, is being blamed for the rainfall.
Volunteers began to setup donation centers across the capital as residents began to survey the damage. Health officials advised people to only drink out of bottled water until a complete health assessment can be conducted on the city’s water quality. Authorities have declared a crisis situation in the nation’s capital for at least the next 15 days to aid in the recovery efforts. The Macedonian Army was also called in to assist those in need following the flooding. According to local media, the government has declared Monday to be a day of national mourning, as the capital continues to cleanup in the aftermath of the storm.
Showers and thunderstorms were in the forecast for today, but thankfully the city escaped more heavy downpours. Officials are worried about any additional rainfall as the ground is now completely saturated and unable to hold any more water.
To learn more about other high-impact weather events from across Europe, be sure to click here!
DISCUSSION: As very strong thunderstorms erupted over the weekend across parts of Central Italy such as this shot of a very majestic storm in Ancona, Italy! These storms were a consequence of very robust and efficient moisture transport associated with a tropical low-pressure system (which formed over the Northern Adriatic Sea). This low-pressure system dramatically increased the amount of convective instability across much of East-Central Italy as well as the amount of vertical wind shear. The combination of the enhanced convective instability and the more pronounced wind shear acted to created an environment conducive for the development of severe thunderstorms. As observed in the image below (courtesy of Gianfranco Petraccini), there was a classic shelf cloud structure associated with the evolution of this particular severe thunderstorm moving ashore from over a small bay located just to the east of Ancona, Italy.
Shelf clouds form as a result of cooler outflow from the outer portions of strong to severe thunderstorms being forced to rise up and over warmer air downstream (i.e., in this case to the west of incoming severe thunderstorm coming in from east-to-west off the Northern Adriatic Sea). When the aforementioned process is coupled with additional large plumes of warm/moist air coming into eastern portions of the Italian Peninsula, this facilitates the development of thunderstorm-based structures such as this shelf cloud observed just two days ago in Ancona, Italy! To learn more about other high-impact weather events from across Europe, be sure to click here!
DISCUSSION: Earlier this week, electromagnetic radiation from the Sun collided with the Earth’s magnetic field to put on quite the show for many across Northern Europe. People in Estonia and Denmark captured some breathtaking photos, and shared them onto Facebook for all to see and enjoy. Auroras occur when a sunspot on the surface of the Sun emits charged particles out into space via a solar flare. These charged particles get carried towards Earth by the solar wind where they then collided with the Earth’s magnetic field, specifically at the North and South poles where the magnetic field is weaker. At the poles, photons and electrons from the sun collide with gas particles in the Earth’s atmosphere to give us what we know as auroras. Oxygen lower in the atmosphere gives us the typical green auroras as seen in the majority of pictures, while oxygen higher up in the atmosphere gives us bright red auroras. Nitrogen on the other hand, gives us a very vivid blue and violet light show. A variety of colors were shown in various photos seen on Facebook across Northern Europe.
As forecasted, a mild G1-class geometric storm reached the Earth’s surface late in the day on August 2nd, and lasted well into the early morning hours on August 3rd. NOAA breaks down the scale into 5 distinct levels to describe the intensity of the solar flare, with G1 being the mildest up to G5 becoming extreme. Auroras are quite common near the North and South poles throughout the entire year. It’s been a while since we have seen a G5 geometric storm, however a G4-class storm did occur in March of last year and threatened to damage satellites and transformers, but that did not occur. This most recent geometric storm comes after the Sun was in a relatively peaceful “sunspot free” period. NOAA forecasters say that there is no need to panic as this is quite normal in the Sun’s 11-year natural variability cycle. Do you have any pictures of the recent auroras? Please feel free to share in the comments below! To learn more about other high-impact weather events from across Europe, be sure to click here!