Seguimento Europa 2009

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Previsão do Estofex para Hoje dia 1 de Maio:




SYNOPSIS

The pattern over Europe features a strong ridge over NW-Europe and an upper low over SE-Europe. In between those systems, cold air at mid-levels advects southwestwards, augmenting the thunderstorm risk over most parts of central Europe. Another outbreak of frigid air over extreme NE-Europe suppresses deep convection for at least the following 24h.

DISCUSSION

... Parts of Slovenia, Croatia, Bosnia and Herzegovina , Serbia, Montenegro, Macedonia, parts of central Romania and NE Italy ...

Latest soundings from Slovakia and Ukraine sample the airmass downstream of those areas well with very steep lapse rates to near 500hPa. GFS sticks to its solution for the past few runs that 2-4km lapse rates of 8-9K/km overspread those regions from the NE already during the morning hours with slightly lower values over Romania. ECMWF and GFS both forecast dewpoints at the surface running from 9-12°C in a concentrated swath just along the Dianaric Alps and those values look reasonable compared to current surface analysis. Strong insolation will push temperatures to well above 20°C, so beside weak capping/the nocturnal inversion, initiation will start during the late morning hours/noon.
Aforementioned environment results in MLCAPE release of 500 - 1500 J/kg. Steep lapse rates, combined with 10-15m/s DLS and some directional shear all point to a large hail risk. This risk is the highest during the early life time when storms are still more discrete. Rising LCLs during the afternoon hours and a dry subcloud layer also augment the risk of severe downbursts.
Betimes, thunderstorms cluster over the mountains and the main hazard then shifts to heavy rain and local flash flooding. Thunderstorms weaken after sunset.

The same over Italy but either shear or instability will be more conditional and hence isolated large hail will be the main risk.

... Parts of Austria and parts of Germany ...

A tongue of rich 0-1km mixed Theta-e runs from W-Germany southeastwards all the way to E-Austria. Furthermore, a pronounced wind shift zone from E-Germany and W-Czech Republic continues southwestwards with 0-2km deep convergence signals present mainly over SE-Germany and extreme NW-Austria. ECMWF remains more reluctant regarding surface dewpoint with GFS running a couple of degrees higher. We lean to the more agressive GFS solution due to a moist soil and strong evaporation.
As mid-levels stay cold, up to .5-1 KJ/kg MLCAPE are likely to evolve with highest values just along the SW-ward shifting convergence zone. Shear is weak at best, but nevertheless good instability release in the hail growth zone and steep lapse rates are available, so large hail will be possible, mainly over SE-/S-Germany and the level-1 area of Austria. Thunderstorms start to cluster betimes and predominantly northerly winds ought to push the storms slowly to the south/southwest.

Winds at all levels become very weak/variable over SW/W-Germany/E-France,Belgium and Luxembourg during noon/afternoon hours. Again, 500-1000 J/kg MLCAPE are forecast and mainly during the early/discrete thunderstorm stage, large hail is likely. However, thunderstorms tend to cluster rapidly in time and the environment is prime for locally excessive rain amounts...even training over the same spot can occur.

After sunset, thunderstorms decrease rapidly apart from SW/S-Germany, where a plume of strong MUCAPE persists well into the night. Winds back during the night and increase in strength, so the heavy rain risk increases along the N-Alps of W-Austria as cluster of showers/thunderstorms move to the south.

... NE-Algeria and extreme N-Tunisia ...

As strong high level streak curves in from the NW during the day, divergence at upper levels overspreads the level-1 area. Moist onshore flow persists during the forecast with cold mid-levels above that airmass. A cluster of showers/thunderstorms is forecast by GFS and AFWA-MM5 for the past few runs with intense rainfall amounts. A level-1 was issued, covering the region, where highest rainfall amounts will occur. Thunderstorms decrease during the night hours, but the precipitation keeps going well into the night.

... NW-Turkey /NE-Greece and parts of Bulgaria ...

An eastward sliding upper trough affects those regions during the day and widespread showers/thunderstorms are possible in a weakly capped airmass. Global models evolve small clusters with high precipitation rates but run-to-run consistency of those models is bad. There is a chance for local flash flooding beneath those storm clusters, especially over NW-Turkey and NE-Greece, but confidence is too low for issuing a level-1.
 
Choveu aqui ontem, dia 1, em Viena. Uma trovoada, um aguaceiro.
Mas nada doutro mundo.

Um bom ínicio para as "monções" europeias. :thumbsup:
 
Previsão do Estofex para Hoje dia 7 de Maio:




A level 1 was issued for southern France and north-eastern Iberian Peninsula mainly for severe hail.

A level 1 was issued for western Black Sea region mainly for severe hail.

SYNOPSIS

The geopotential will further rise across south-western Europe in the range of a broad subtropical ridge. As a new Atlantic trough amplifies into north-western Europe, weak upper disturbances will affect portions of west Europe during the period. To the east, an quite intense short-wave trough cuts off over the Baltic Sea region and moves to the Black Sea during the period. A strong mid-level jet will be present along its western flank.

DISCUSSION

North-eastern Iberian Peninsula, southern France

At the southern flank of the main westerly jet, a relatively weak upper trough migrates eastward during the day reaching the west Mediterranean Sea in the evening hours. Rather cool mid-level air mass is present in the range of the trough and spreads across the Iberian Peninsula and southern France. While cool low-level air mass is expected to spread into the western portions of the Iberian Peninsula, the approach of the mid-level trough will likely be associated with destabilization further east as diurnal heating will be in place over the Iberian plateau, and steep lapse rates will likely spread across eastern Iberian Peninsula and southern France.

Main uncertainty concerns the content of low-level moisture. Latest observations indicate relatively poor mixing ratios below 10 g/kg over most places with the highest values across southern France and north-eastern Iberian Peninsula. A significant increase in low-level moisture is not expected on Thursday, and current thinking is that diurnal heating will lead to dry inverted-v profiles. With decreasing mid-level temperatures, CAPE in the order of 500-1000 J/kg seems to be likely in the afternoon hours, though.

Given a weak thermal low across the Iberian Peninsula, slightly veering winds are expected across southern France, and the development of weak convergence lines is likely north of the Pyrenees. Upslope flow along the eastern coasts of the Iberian Peninsula will also cause some low-level forcing. A few storms are likely in the afternoon and evening hours that will have a potential of severe hail with the stronger storms. Especially in the southern portions, a severe wind event is not ruled out given locally large downdraft CAPE.

Storms will likely cluster given only weak vertical wind shear and cool downdrafts in the afternoon hours. In the evening, models indicate increasing 700 to 500 hPa westerly winds at the southern flank of another trough across northern France. Over most places, this is not expected to increase the chance of severe weather significantly due to decreasing low-level convergence and weak QG forcing, although vertical veering profiles may slightly improve. However, latest models indicate low-level convergence north of the Pyrenees to continue in the evening hours, leading to low-level moisture flux convergence as well as increasingly favourable veering profiles. Supercells are not ruled out along and east of this boundary when it really develops and severe hail may be a threat in the evening hours as well. Although a tornado is not completely ruled out, lack of rich low-level moisture and instability will be a strong limiting factor. Over the Iberian Peninsula, weak forcing will likely suppress convection in the evening hours.

Central France to western Alpine region, western Germany

On Thursday, a short-wave trough will move into France in the evening hours and will reach western Germany on Friday morning. At low levels, rather warm air masses originating from southern France will spread north-eastwards. Showers and thunderstorms are likely given rather steep mid-level lapse rates and QG forcing. Limiting factor will be the cool and dry boundary-layer, and storms will likely be elevated. The best potential for surface-based storms exists over central France, where low-level moisture will be sufficient in the evening hours. Given rather strong westerly winds in the 700 hPa level, some storms may organize, but threat of severe hail seems to be too weak for a level 1.

Eastern Ukraine

As the cut-off low moves southward into the Black Sea region, warm air masses spread northward ahead of a cold front reaching the eastern Ukraine in the late morning hours. Warm air mass will likely be characterized by rather moist low levels and moderate mid-level lapse rates, and CAPE is expected to develop in response to some diurnal heating. Given strong forcing along the cold front, showers and thunderstorms will likely develop. As vertical wind shear is moderate, organized storms are not ruled out, capable of producing large hail. The chance seems to be too marginal for a level 1, though.

Western Black Sea region

Ahead of the approaching cut-off low, a strong mid-level jet streak moves southward into the western Black Sea region in the afternoon hours, providing QG forcing. At lower levels, models indicate that a tongue of relatively warm and moist air mass remains ahead of the surface cold front reaching the Black Sea in the evening. Ahead of this front, veering profiles are forecast to overlap with strong deep layer vertical wind shear in the afternoon hours. Current thinking is that showers and embedded thunderstorms will likely form along the cold front, and the stronger storms may pose a weak threat of large hail. Limiting factor is the weak instability, and the level 1 may be too optimistic. Storms will likely weaken when moving over the rather cold Black Sea.

Hoje é que vai ser um grande festival em França:shocking::

http://www.wetterzentrale.de/topkarten/fsavneur.html
 
Está defacto uma tarde muito animada, quer para os Espanhóis, quer para os Franceses!

Registo, em média, de 242 DEA/h, e 2 DEA/min!:D

radartrovoadaseuropa070.png


radartrovoadaseuropa070c.png
 
Previsão do Estofex para Hoje dia 8 de Maio:



A level 1 was issued for N-Germany, NW-Poland and S-Sweden mainly for large hail and severe wind gusts.....

A level 1 was issued for SW-France mainly for large hail and strong to severe wind gusts.....

A level 1 was issued for S-Germany and NW-Austria mainly for large hail and strong to severe wind gusts.....


SYNOPSIS

A sub-975hPa cyclone is situated north of Scotland during the period. Strong ridging and WAA occurs downstream, affecting most parts of the W/CNTRL Mediterranean and SW/W-Europe. Stable conditions therefore persist in that regions. A cut-off low over the W-Black Sea results in unsettled conditions over the E-Ukraine, whereas mostly stable conditions occur over NE-Europe.

At the surface, an active boundary runs from SW-Europe all the way to Sweden and serves as a focus for thunderstorms. A cold front approaches from the W/NW during the period and stalls out over S-France, while remaining progressive over NE-Germany/Sweden.

DISCUSSION

...E-France, N-Switzerland and SW/CNTRL/E-Germany between 06Z-roughly 09Z...

A pronounced lead impulse, embedded in a moderate southwest flow, is placed over central/east Germany at 06Z whereas the position is a compromise between AFWA,GFS,WRF and ECMWF, the latter one being the most aggressive one. Nevertheless, the impulse outruns axis of highest theta-e over SW/W-Germany, so just a very isolated thunderstorm is forecast over E/SE and central Germany during that time. Ongoing upslope flow and a near uncapped warm/humid airmass assists in scattered showers/thunderstorms over SW/W-CNTRL Germany and NW-Switzerland, which build northward betimes along a pronounced theta-e tongue. Winds at mid-levels are already on the increase, but the risk of severe remains low due to limited instability/weak synoptic forcing and probably elevated nature of storms. Strong wind gusts and marginal hail are possible with stronger storms.

... N-Germany, NW-Poland and S-Sweden from 09Z onwards ...

An eastward moving cold front is situated over NW-Germany during the morning hours/noon and showers/thunderstorms will start by that time. Initiation should occur both along the cold front and in the prefrontal airmass, where surface pressure falls. Persistent SW-flow keeps moisture advection going over N/NE-Germany all the way up to S-Sweden. The lack of better mid-level lapse rates ought to limit instability release but 200-500 J/kg MLCAPE look reasonable.

Beside aforementioned early initiation along the front, thunderstorms also evolve further east(NE-Germany) as we hit the convective temperature during the day. Shear constantly increases from the west, so an isolated supercell, embedded in the predominant multicell mode, is possible with an attendant large hail/severe wind gust risk. Abundant 0-3km CAPE release is forecast, but very slim directional shear in that layer keeps tornado probabilities very low.

ECMWF features the most interesting solution for the cold front passage right now, which affects NE-Germany and S-Sweden around 18Z. The progressive upper trough axis sweeps in from the west between 15Z-18Z and picks up the cold front, which is placed over N-CNTRL Germany. Dependant on the quality of the airmass ahead, a line of thunderstorms/showers (potential LEWP-type) can evolve with a severe wind gusts/isolated large hail risk. ECMWF still paints an atmosphere with some potential instability release ahead of the front and given the strong nature of the forcing, we went ahead and placed a wide swath in a level-1 for severe wind gusts. Beside rapidly diminishing instability over S-Sweden, cold front passage could still be active regarding not necessarily electrified deep convection and severe wind gusts are forecast,too. We have to monitor the degree of moisture advection as better LL moisture would culminate into an higher severe wind risk.

... S-France, Switzerland and parts of Austria all day long over highlighted regions in France and at the latest after 12Z-15Z over the rest of the area ...

Despite the exaggeration of GFS regarding surface dewpoints (locally more than 5°C overrated over SW-France), the boundary layer indeed yields dewpoints in the lower to mid tens. A weak Spanish plume fans out over the area, but lapse rates are not too steep, so MLCAPEs of 500-locally 1kJ/kg build along a SSW-ENE aligned convergence zone, later re-enforced by a southward sliding cold front, which also stalls out somewhere over S-France/W-Alps during the night. The airmass is weakly capped at best, so thunderstorms initiate over S-/SE-France and Switzerland all day long and also over S-Germany/most parts of the Alps during the early afternoon hours. The messy picture gets complete as initiation occurs due to ENE-ward traveling short-waves, upslope flow along the mountains and persistent convergence along the boundary over S-France.

Wind increases somewhat during the afternoon hours with DLS of 15-20m/s, so isolated large hail and strong wind gusts are likely, especially during the more discrete phase of those storms. Rapid clustering occurs and the main hazard then shifts to heavy rain with the following arguments:

i) flow at the lower levels is aligned normal to the boundary with mid-/upper winds blowing near parallel to it, so convergence along southward moving outflow boundaries favors new cell growth with some training possible

ii) ECMWF and GFS both hint on a moist atmosphere at the lowest 3km, especially over W/NW Switzerland with an increasingly deep warm cloud layer

iii)just weak to moderate shear occurs, which keeps entrainment effects low

A few spots just west of Switzerland and also along the W-Alps could indeed see rain amounts, which match our criterion, but this depends mostly on the location of those convective clusters, so we did not issue a level-1 for that hazard. The level-1 over S-Germany/NW-Austria and the other one over SW-France imply mainly large hail/isolated severe wind gusts. Especially over SW-France, thunderstorm coverage might be more sporadic, but more isolated nature should bring hail chances up. Thunderstorms diminish after sunset as CAPE vanishes.

... Ireland and N/CNTRL-UK...

A humid/well mixed postfrontal airmass affects those regions and daytime-driven thunderstorms are forecast. Beside weak directional/speed shear at all levels, 15-20m/s at 850hPa mix down easily, so showers/thunderstorm can produce strong to isolated severe wind gusts. Both the coverage and intensity of those thunderstorms remains too marginal for a level-1. Thunderstorms decrease around sunset.

... CNTL/E-Ukraine...

500-1000 J/kg MLCAPE develop over the area in a weakly sheared environment, so despite an isolated large hail risk, no severe risk will occur with that activity. Thunderstorms leave the area of responsibility during the late afternoon, while weakening.
 
Alemanha: Vinte e seis pessoas ficaram feridas no Domingo quando um raio caiu num campo de futebol em Baden-Württemberg

03/05/2009

Vingt-six personnes ont été blessées dimanche lorsque la foudre s'est abattue sur un terrain de football d'Ingolden, dans le Baden-Württemberg, en Allemagne. Trois victimes sont dans un état grave. L'une d'elles, un garçon de 17 ans, est maintenu dans un état de coma artificiel mais ses jours ne sont plus menacés. Selon les premières informations, la foudre a apparemment frappé un poteau d'éclairage au moment où deux équipes de jeunes s'échauffaient sur le terrain avant la tenue d'un match.

LE VIF.be
 
Viena, Áustria. Nestes últimos dias, as temperaturas já chegaram aos 26º, sendo as máximas mais elevadas do ano, bem elevadas para esta altura do ano que normalmente costumam ser de 20º. Ontem a mínima foi até 17º!!

Hoje notei alguma convecção, o ar esteve abafado, mas ainda não chegou cá nada de trovoadas. Noto algumas nuvens a oeste e a norte. Talvez a massa que passou agora na França chegue aqui... ;)

Sabiam que no ano passado aqui, segundo o IM local, foi o ano com o recorde de mais quantidade de raios/ trovoadas detectados! :w00t:
E bem se notou, pois a certa altura era trovoada a cada 3 dias! Lembro-me bem dumas quantas tempestades como nunca tinha visto antes...

Previsão Estofex Portugal:
Most thunderstorms decay after sunset despite the activity over Portugal. As the main trough finally approaches from the west, strong forcing and some MUCAPE could generate a few storms in a strongly sheared environment over NE Portugal/NW Spain after midnight, but confidence in anything organized is still too low for a level area. Otherwise, thunderstorms under the base of the trough affect Portugal during the night hours with marginal hail/strong wind gusts.
 
Nova Actualização do Estofex para Hoje:




A level 2 was issued for SW and central France mainly for large hail, tornadoes, severe winds and extreme rainfall.

A level 1 was issued for an area surrounding the level 2, across W France, a larger part of S France, N Spain, NE France, central and S Germany mainly for large hail, and severe winds and to a lesser extent for tornadoes.

A level 1 was issued for N Switzerland, N Austria, parts of the Czech republic, Slovakia, S Poland and W Ukraine mainly for large hail and severe winds.

SYNOPSIS

Refer to the convective forecasts...

DISCUSSION

SW and central France...

SBCAPE values of 1500-2000 J/kg have developed across SW France, where strong deep-layer shear on the order of 25 m/s in the 0-6 km layer is present. Along the warm front, which stretches from Bordeaux to Dijon, some 200 m2/s2 of 0-3 km storm-relative helicity should be present, and possibly somewhat more just north of the front.

Convective storms are now intiating near the coast of SW France. It is expected that these will include a number of supercells. Those storms will probably produce large hail and possibly giant hail with sizes of 5 cm or more. Additionally, damaging wind gusts are expected. One or two tornadoes are also possible. It is expected that the storms cluster and will translate northeastward along the warm front, possibly in the shape of a bowing convective system. The main threat of the system should then shift away from hail to severe winds. The threat of a few tornadoes will however persist. Some back-building of the system may however also occur, so that a threat of extreme convective rain will also exist in and around the Regions of Poitou, Pays de la Loire, Centre, and Limousin.

NE France, central Germany

Although deep-layer shear (0-6) km is with about 15-20 m/s, most of this shear is concentrated in a shallower 0-3 km layer, which has proven to be sufficient for the development of a couple of supercells. Along and just north of the surface warm front, which stretches from near Saarbrucken to Nuremberg, shear in the 0-3 layer is strongest, and -- given that strong low-level buoyancy should be in place here -- one or two short-lived tornadoes cannot be excluded. Otherwise, the main threat will be large hail and perhaps a few severe wind gusts.

S Poland, Slovakia

A complex of thunderstorms is currently moving NE wards across S Poland and N Slovakia. The complex has a history of producing hail and sub-severe wind gusts. Moderate instability and moderate deep-layer wind shear (15 m/s), along with a belt of enhanced SREH on the convergence line suggest that large hail will continue to be possible for a couple of hours, before instability decreases after sunset.

Imagem de satélite ( França):w00t::

 
Hoje continuou o calor aqui em Viena, Áustria. Mínima de 17º, Máxima de 26º. Ao fim da tarde uma pequena célula formou-se a norte da cidade mas apenas deu um ou outro trovão e um breve aguaceiro. Ainda nada de super-interessante!
Vamos a ver se a massa da França vem por aqui...
 
irpsit disse:
Hoje continuou o calor aqui em Viena, Áustria. Mínima de 17º, Máxima de 26º. Ao fim da tarde uma pequena célula formou-se a norte da cidade mas apenas deu um ou outro trovão e um breve aguaceiro. Ainda nada de super-interessante!
Vamos a ver se a massa da França vem por aqui...
Clique para expandir...

Mesmo no centro da Áustria, a animação parece marcar presença.
Embora não se possa comparar ao monstro francês.



 
Chegou cá André.
O céu encobriu e vejo relâmpagos a cada 5 segundos a sul, já desde há uns 20 minutos. Finalmente :)
Já chove mas pouco...
O centro da supercélula está a uns 50-100 km a sul

Aquela massa da França ou é de mim ou vai direitinha para Londres!
 
Previsão do Estofex para Hoje dia 12 de Maio:



A level 1 was issued for parts of France and NE Spain mainly for large hail.

A level 2 was issued for E France, S Germany, N Switzerland, and NW Austria mainly for large hail, and severe winds.

A level 1 was issued for an area surrounding the level 2, across Germany and the Alps mainly for large hail, and severe winds.

A level 1 was issued for the Dinaric Alps, the Pannonian Plain, Romania mainly for large hail.

A level 1 was issued for the W and central Ukraine, SE Belarus and W Russia for large hail and severe winds.

SYNOPSIS

Tuesday at 0600 UTC, mid-level charts feature an intense trough from northern Scandinavia to W Poland. During the forecast period, a low cuts off from the trough and becomes established over Smolensk Oblast. There, intense surface cyclogenesis is also expected as the upper-level systems interacts with a frontal zone. Upstream of the trough, a ridge stretches from the Shetlands to W Germany. Further upstream, a low is situated over the Bay of Biscay. On the SE flank of that low, a 30 m/s jet streak is present from SW Iberia to the Alps. While being well-defined in the lower troposphere also, it tends to propagate downstream somewhat during the period. A subtle shortwave ridge over Iberia moves NE ward and connects with the Shetland-W Germany ridge. A baroclinic zone stretches across eastern Spain towards central France. A clear surface front stretches eastward across Europe, from the Paris region eastward across southern Germany to N Hungary, to E Belarus -- where the surface cyclogenesis is expected -- and onwards along the Valdai Hills to the northern Russian Plain.

DISCUSSION

E France, S Germany, Switzerland, Austria, N Italy...

A rather moist air-mass that has become stagnant south of the warm front mentioned above. As this air-mass is warmed during the day, CAPEs well in excess of 1000 J/kg, possibly up to 2000 J/kg are expected to form north of the Alps. This, in combination with strong 20-25 m/s shear, will lead to a situation in which rotating storms can develop with ease. Scattered storms will probably form in the early afternoon in response to diurnal heating. They will bear a threat of large hail. A risk of severe winds will also exist. The risk of tornadoes appears not to be exceptionally large, because of the relatively low 0-1 km shear. However, high amounts of low-level buoyancy and locally enhanced shear may still allow for one or two tornadoes to develop, especially in vicinity of the front.
The storms may continue into the evening, but will gradually subside.

Across the Alps and on the southern flanks of the Alps, storms are also expected to occur. Instability will be less, so the threat of large hail will be a bit lower, but still significant. Some severe wind gusts are possible in addition to the hail threat.

N Dinaric Alps, Pannonian Plain, Romania...

Scattered storms are expected to form in this region also, under somwhat weaker shear. Hence, rotating updraughts will be rarer. Still a few events of large hail are possible.

Central France...

Weak capping just south of the aformentioned warm front will likely lead to widespread initiation of storms across central France. Shear will probably be rather weak across central and western parts of France, but will be higher in the east and south, and across northeastern Spain. CAPE on the order of 1000 J/kg is expected, which suggest that a couple of storms that manage to become well-organized multicells could produce some severe hail.

S France, NE Spain...

As a subtle shortwave ridge approaches during the day, convective initiation is inhibited across southern France and NE Spain, until in the evening. Then, convective initiation is still possible, and some storms will porbably form. The environment may be able to sustain a few supercells as 0-6 km bulk shear should be around 20 m/s. A few large hail events will be possible.

Ukraine, Central Russian Upland, Smolensk-Moscow Upland...

In response to the approaching trough, upward vertical motion is expected to occur increasingly within the warm air-mass east of the front, and convective storms are expected to form in the morning. Moderate deep-layer shear, around 15 m/s, and CAPE around 1000 J/kg indicate that soem threat of large hail will exist.
Additionally, as low-level winds increase in response to pressure falls, the storms may produce a few severe wind gusts, It is expected however, that the convection will cease during the evening as instability diminishes.
 
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