Posts made by pavelneuman
Albania and Greece to get excessive rainfall, severe wind gusts, large hail, and tornadoes
Valid: Tue 19 Nov 2019 6:00 to Wed 20 Nov 2019 6:00 UTC
Issued: Mon 18 Nov 2019 21:29
- A level 2 was issued for Albania and Greece for excessive rainfall, severe wind gusts, large hail, and tornadoes.
- A level 1 was issued for Croatia, Bosnia and Herzegovina, Montenegro, Albania, S Italy, and Greece mainly for excessive convective precipitation and severe wind gusts.
The largest part of western and Central Europe is under the influence of a long-wave trough and as a result, strong WAA is found in eastern parts of the continent with unseasonably warm conditions.
Several embedded short-wave troughs can be found in the forecast maps, one of them is about to create favorable conditions for severe weather in Mediterranean. Another trough is approaching from the Atlantic, reaching Ireland by the end of this forecast.
A few storms will develop at the leading edge of this trough, reaching Portugal in the early morning of Wednesday.
Croatia, Bosnia and Herzegovina, Montenegro, Albania, S Italy, and Greece
The axis of the trough over the Mediterranean becomes negatively tilted, with a jet streak extending from Tunisia towards the Balkans. The mid/low-level vorticity maxima will provide large-scale lift of very moist air masses (9-11 g/kg mixing ratio) over the Ionian Sea and steep mid-level lapse rates will result in high CAPE values.
An environment SW of Albania and Greece, characterized by 1000-1500 J/kg MLCAPE, 15-25 m/s DLS and more than 150 m2/s2 SREH0-3km will be conducive for the development of severe storms. A few supercells are expected, able to produce severe wind gusts, large hail, tornadoes, and excessive rainfall. Large hail is expected in the southern part of the level-2 area, with the least favorable environment in Albania (lower NCAPE).
The most intense convective activity is expected to reach Greece and Albania in the late afternoon or night of Tuesday, while in the morning, storms will affect mostly offshore areas and the coasts of S Italy. In southern Italy, flash floods will be the main threat, as well as in the rest of the Balkan States during the early morning of Wednesday marked with a level-1.
Tornadoes are expected mostly in the level-2 area where low-level shear and helicity will be maximum, but also waterspouts are expected in South Italy.
Skier or snowboarder? You’ll love this…
As @idefix37 pointed out, there’s better metric for that and Windy already has the feature. It's the Snow depth forecast map, although it has it's limits - namely the grid of the forecast models (9 km for ECMWF, 7 km for ICON).
If you cumulate the snowfall over several days, it will not give exactly the depth of snow, because the snow compacts gradually: Its density increases.
On Windy the Snow depth layer gives you directly the information as well as the snow density.
But because of the low resolution of the weather models, this information is very rough and quite inaccurate in mountains.
Catastrophic effects of ‘unprecedented’ Australian bushfires
With the raging wildfires, widespread air quality issues, caused by very high surface particulate matter values, will affect many people over the coming days, latest Copernicus Atmosphere Monitoring Service forecasts reveal.
As significant numbers of bushfires burn in New South Wales and Queensland, Australia, the Copernicus Atmosphere Monitoring Service (CAMS), monitors their intensity and emissions. Data collected by CAMS shows that the fires are unprecedented when compared to the previous 16 years for New South Wales.
CAMS, which is implemented by the European Centre for Medium-Range Weather Forecasts on behalf of the European Union, provides daily estimates of global fire emissions with its Global Fire Assimilation System (GFAS), which assimilates fire radiative power (FRP) observations from satellite-based sensors.
Recent satellite imagery shows massive smoke plumes over New South Wales and Queensland, turning day into night in some areas. The fires have even been burning in the kind of intensity never experienced before in places usually not seriously affected such as Northern New South Wales and tropical Queensland and according to scientists. Smoke from the fires has been transported beyond New Zealand and over the South Pacific Ocean with satellite observations showing that it may reach South America in coming days.
The monthly hydrological summaries of the Copernicus Climate Change Service (C3S), also implemented by ECMWF, showed August, September and October anomalies with high positive resp. dry values for eastern Australia, that are consistent with long-term drought conditions and are contributing to the current fire conditions. Most of the extratropical Southern Hemisphere, particularly in Australia and the southern part of Africa are currently experiencing drier than usual conditions.
Very high surface atmospheric particulate matter has also been causing air quality issues with New South Wales declaring a state of emergency in the wake of fires.
Fires, not only in Australia, but worldwide, can now be tracked by users of the App, Windy, which has added a new map “Active fires”. Input for the new layer is provided by the Copernicus Global Fire Assimilation System (GFAS) and displays the daily average of the fire radiative power (FRP).
CAMS Senior Scientist, Mark Parrington, comments: “We have been closely monitoring the intensity of the fires and the smoke they emit and when comparing the results with the average from a 17-year period, they are very unusual in number and intensity, especially in New South Wales, for being so early in the fire season.”
For further information visit atmosphere.copernicus.eu/global-fire-emissions
Copernicus Report: Precipitation, relative humidity and soil moisture for October 2019
In October 2019 most of western and northern Europe experienced wetter than average conditions, whereas drier than average conditions prevailed in eastern Europe and the Mediterranean region. Japan experienced much above average precipitation related to Typhoon Hagibis, but severe dry conditions prevailed in the western USA, creating a favourable environment for wildfires in the region, and drier than average conditions prevailed in most of the extratropical Southern Hemisphere, particularly in Australia and the southern part of Africa.
The surface hydrological variables are more difficult to observe and analyse than surface temperature. The data on soil moisture are currently of qualitative rather than quantitative value. This summary is intended to provide European and near-global views of conditions for the month. Specific information for many countries can be found on the websites of their weather or climate services.
Europe - October 2019
In October 2019, wetter than average conditions prevailed over large parts of northern and western Europe, as indicated by above average precipitation, soil moisture and relative humidity compared to the 1981-2010 average. This was particularly true over a band encompassing the southern parts of Ireland and the UK, most of France, the Benelux, Germany and most regions around the Baltic Sea. Some areas in the northeast of Spain, south of France and northern Italy experienced very heavy rainfall towards the end of the month.
Exceptions to the wetter-than-average northern and western Europe were Iceland and most of Norway, which saw drier than average conditions in general. In the south of France, soil moisture remained below average despite above average precipitation.
Drier than average conditions also prevailed in most of the Mediterranean region, eastern Europe and around the Black Sea, where soil moisture in particular was much below average.
Europe - Last 12 Months Hydrology Anomalies
For the last 12 months, ending in October 2019, most of Europe saw drier than average conditions, with above average temperature and all three hydrological indicators (precipitation, soil moisture and relative humidity) below their respective 1981-2010 average. During the same period, wetter than average conditions, marked by above average precipitation and soil moisture, prevailed only in eastern Iceland, Ireland, large parts of the UK, western and northern Scandinavia and northern Finland, and some regions along the Mediterranean Sea, including the southernmost parts of Italy, Greece and parts of Turkey. Some regions, such as the Alps, show mixed conditions.
Globe - October 2019 Hydrological Anomalies
Beyond Europe, in the Northern Hemisphere extra-tropics, October 2019 brought wetter than average conditions, with above average precipitation, soil moisture and relative humidity, to large parts of Canada, the northern USA, most of northern Siberia, parts of the middle east, Pakistan and northern India. Precipitation was above average also in the eastern USA and over Japan. Most notably, the latter was hit by typhoon Hagibis which brought large amounts of rain within a short period of time. Dry conditions prevailed over the western USA, where precipitation and even more so soil moisture were lower than average. This provided favourable conditions for the large wildfires that affected parts of California during October.
In the extra-tropical southern hemisphere, drier than average conditions prevailed overall, as has been the case for several months in a row. Most below average were south-eastern Australia, southernmost Africa, as well as large parts of Argentina and Chile and southern Brazil. However, parts of Argentina saw above average precipitation.
Globe - Last 12 Months Hydrological Anomalies
For the 12 months ending in October 2019, precipitation, soil moisture and relative humidity were below average (indicating generally dry conditions) within a belt stretching eastwards from Europe across large parts of Asia. This dry belt includes most of the regions to the north and east of the Black and Caspian Seas, as well as some parts of central Asia, Russia, Mongolia and northern China.
Southern Africa and Australia experienced much drier than average conditions, strengthening severe drought conditions. The exception is the remarkable extreme rainfall in Queensland during the past March, whose imprint is still visible in the 12-month average. Furthermore, in the southern and central parts of South America, conditions were drier than average.
On the contrary, precipitation and relative humidity were higher than average over most of the Middle East, central and eastern China. Generally wet conditions marked by above average precipitation, soil moisture and relative humidity prevailed in southern and eastern USA, Alaska, eastern Canada and central Argentina.
Longer term trends
Monthly Global humidity anomalies
Relative humidity averaged over all land areas globally has decreased over the last forty years and has remained below its 1981-2010 average since the early 2000s. The average relative humidity for October 2019 was also below average, but not by a particularly large amount.
Relative humidity averaged over Europe as a whole is more variable, but in general also shows a net decline over time. Relative humidity for October 2019 in Europe was slightly below average.
The observed drying is not associated with an appreciable reduction in precipitation, as shown below for four European regions. It may be a consequence of a period in which surface air temperature rose faster over land than it did over sea.
Continued monitoring is required to document behaviour over a longer period and refine the understanding of this aspect of climate variability or change.
The variation over time of the hydrological variables and temperature are shown below for averages over land areas for NW, NE, SW and SE Europe. Values are averaged over successive four-month periods in order to highlight variations on seasonal and longer time scales.
Regional differences are quite pronounced in the time series. Average precipitation rates are higher in the north, particularly the NW, but precipitation is more variable in the southern regions. This is partly a consequence of the smaller areas of the southern regions or the four-month averaging. Warming is largest in the NE, but the decrease in relative humidity is larger in the south.
The correlations between precipitation, relative humidity and soil moisture, evident in the maps of anomalies, can be seen to hold for the area averages on time scales up to a year or more. However, average precipitation does not show the marked longer-term decrease seen for relative humidity and soil moisture.
The four months to October 2019 saw somewhat drier than average conditions for NW and SW Europe with average precipitation, below average soil moisture and relative humidity and above average temperature.
The same four months saw drier than average conditions for NE and SE Europe with below average precipitation, soil moisture and relative humidity and above average temperature.
NW Europe Hydro Anomalies
NE Europe Hydro Anomalies
SW Europe Hydro Anomalies
SE Europe Hydro Anomalies
RE: Your map uploads
Europe (Global Heat Flow Database)
Upload your own KML, GPX, GeoJSON file at https://www.windy.com/uploader
Copernicus report: Smallest ozone hole in 35 years has closed early
Copernicus Atmosphere Monitoring Service (CAMS) reveals unusually small ozone hole closed much earlier than in previous years
The smallest Antarctic ozone hole to appear in 35 years made an unusually early disappearance, according to scientists from the Copernicus Atmosphere Monitoring Service (CAMS) who have been monitoring its activity since August. CAMS is implemented by the European Centre for Medium-Range Weather Forecasts (ECMWF) on behalf of the European Union.
The ozone hole forms annually over Antarctica during southern spring. This year it was smaller than average and has now virtually disappeared, according to the CAMS data. Most years, the ozone hole starts to appear in August, reaching a maximum size in October before finally closing again in late November to December. Its early closure at the beginning of November is unusual.
CAMS scientists noticed that the 2019 ozone hole did not grow as rapidly during late August than in previous years. “A sudden stratospheric warming over Antarctica led to a less stable and warmer polar vortex than usual, resulting in reduced ozone depletion,” explains CAMS Senior Scientist Antje Inness. This made the 2019 ozone hole one of the smallest since the mid-1980s and resulted in an unusually short ozone hole season.
“The facts that the 2019 ozone hole has been exceptionally small and that it closed early are no indication that the ozone layer is recovering faster than expected. It simply illustrates the very large variability of ozone holes from one year to another. The healing of the ozone layer will still take several decades and the international monitoring efforts of ozone and ODS play a crucial role in making sure that we keep on the right track,” comments Vincent-Henri Peuch, Head of the Copernicus Atmosphere Monitoring Service (CAMS).
The ozone layer protects all life on Earth from harmful solar ultraviolet (UV) radiation. In the late 20th century, human emissions of Ozone Depleting Substances (ODS), such as Chlorofluorocarbons (CFCs) and hydrofluorocarbons (HFC), adversely affected the ozone layer, resulting in annual ozone depletion events (“holes”) over Polar regions.
CAMS monitors and forecasts ozone hole activity by combining measurements from satellite with a numerical model to provide quality-assured information about the state of the ozone layer - in a similar way to weather forecasts. Thereby, CAMS contributes to international efforts to preserve the ozone layer by continually monitoring and delivering high quality data about its current state.
The ozone hole first appeared decades ago, caused by harmful man-made emissions into the atmosphere of chemicals arising from aerosols, refrigerants, pesticides and solvents. However, the 1987 Montreal Protocol has been signed by 196 states and the European Union, within which the main ozone-depleting chemicals were phased out. This worldwide action has led to the gradual repair of the ozone layer and ozone values are expected to return to pre-1980s levels by 2060.
More information and a 3D animation of the current status of the ozone hole is available on the CAMS website.
How the Antarctic ozone hole is formed
Chlorine and bromine-containing substances accumulate within the polar vortex where they remain chemically inactive in the darkness. Temperatures in the vortex can fall to below -78 degrees Celsius and Polar stratospheric clouds can form, which play an important part in the chemical reactions. As the sun rises over the pole, chemically-active chlorine and bromine atoms are released in the vortex and rapidly destroy ozone molecules, causing the hole to form.
In 2019, the polar vortex was unusually warm and was also weaker than normal allowing more mixing with ozone-rich air from outside the vortex. These two effects limited the extent of ozone destruction during September and October 2019 over Antarctica.