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 Subiectul mesajului: Prognoza ESTOFEX
MesajScris: Mie Feb 11, 2009 2:49 am 
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Membru din: Vin Dec 05, 2008 1:00 pm
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Am pornit acest topic pentru a posta de fiecare data cand o situatie foarte periculoasa este prognozata pentru Europa(> cod 2) sau cand o situatie potential periculoasa este prognozata pentru teritoriul Romaniei.
Incep cu un cod 1 care este dat pana aproape de granitele de sud ale tarii noastre.

Imagine

Storm Forecast
Valid: Wed 11 Feb 2009 06:00 to Thu 12 Feb 2009 06:00 UTC
Issued: Tue 10 Feb 2009 23:17
Forecaster: PUCIK

SYNOPSIS

An amplifying mid and upper level trough will influence the weather conditions over Europe as a cold airmass is being advected from northern Scandinavia to the Mediterranean. Strong flow is surrounding the base of the trough and several impulses are rotating around it. The strongest impulse is forecast to affect the eastern Mediterranean and develop into a closed circulation as it reaches the western coast of the Black Sea. At the surface, a large low pressure system is affecting most of Central Europe and as its cold front progresses across the Mediterranean to the east, a separate low pressure center will develop in the trough, travelling with the above mentioned impulse. This separate low will deepen significantly and its central pressure will fall under 992 hPa by Thursday morning.

DISCUSSION

...Central Mediterranean...

A cold airmass, characterized by high mid-level lapse rates will be advected over the sea. This will even increase the high vertical temperature gradient present in the airmass. Synoptic scale lift associated with the trough should result in the destabilization and few hundred J/kg of MLCAPE are anticipated over the large parts of this region. Low level wind field convergence should result in the thunderstorm initiation. Strong mid-level jet ( having speed of more than 45 m/s ) will yield high values of DLS over the southern half of the area. However, mid and low level shear should be insignificant, implying that the increase in the wind speeds will be mostly confined to the mid-levels. As storms should stay relatively low-topped, most of the shear will be probably realized in their upper levels, not aiding in the storm organisation.

Scattered thunderstorms are expected, with possibility of sub-severe hail. Moreover, high values of low level CAPE and lapse rates in the lowest km, low LCLs and surface convergence fields suggest that few waterspouts are possible across the area. Nevertheless, risk is too low to warrant a threat level.

... Aegean Sea, Turkey, Bulgaria...

As the cold front will approach the area, destabilization is expected due to the strong synoptic scale lift of the moist and warm air advected ahead of the front. Still, only few hundred J/kg of MLCAPE are expected. As the surface low will deepen thanks to the impulse, low level wind field is forecast to strenghten. Very high values of DLS are expected ( 25 - 30 m/s) thanks to the strong mid-level jet. Significant SWly flow will establish ahead of the surface low, with 20 - 25 m/s at 850 level. Shear in the lowest 3 km should increase to more than 20 m/s and LLS will reach 15 m/s ( especially inland, thanks to the frictional reduction of the wind speed close to the surface). Moderate values of SREH are also anticipated, ranging between 150 - 300 J/kg. The highest values of both the low level shear and SREH are forecast over Turkey.

Thunderstorms will be easily initiated by the cold front and a strong surface convergence. We expect mostly well organised multicells with tendency for back-building, as the mean flow will be roughly parallel to the boundary. Briefly rotating cells are also possible, thanks to the moderate values of SREH and high values of DLS. Marginally severe hail might occur, especially with the brief supercells, as overall vertical temperature profiles will be quite cold ( below -24°C at 500 hPa). Some severe gusts are also anticipated thanks to the strong low level wind field. A well pronounced overlap of LLS/SREH and instability will exist, especially in the coastal areas of Turkey. With such favourable environment supported by the low LCLs, an isolated tornado event can not be ruled out. Due to the combination of these threats a Level 1 is issued for this region. The severe weather risk should increase from 18Z and will cease with the front leaving the area by Thursday morning.


Sus
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 Subiectul mesajului:
MesajScris: Joi Feb 12, 2009 7:55 pm 
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Ploicica
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felicitari pentru idee.e super ca asa am putea avea o arhiva
mai la indemana :)


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 Subiectul mesajului: Re: Prognoza ESTOFEX
MesajScris: Mie Mar 04, 2009 12:45 am 
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Desi teritoriul tarii noastre inca nu este inclus nici macar in aria cu oraje, am decis sa postez prognoza valabila in intervalul 4 martie 2009 ora 06 - 5 martie 2009 ora 06 deoarece este inceputul unui interval care poate fi periculos pentru Romania, asa putand vedea intreaga desfasurare a evenimentelor.

Imagine

Storm Forecast
Valid: Wed 04 Mar 2009 06:00 to Thu 05 Mar 2009 06:00 UTC
Issued: Tue 03 Mar 2009 21:23
Forecaster: GROENEMEIJER

SYNOPSIS

Wednesday at 0600 UTC... a longwave trough is located over western Europe. A sharp embedded shortqave trough stretches from the western Mediterranean across NW Algeria into eastern Morocco. As a strong 80-90 m/s north-northwesterly jet across the eastern North Atlantic propagates southward, the longwave deepens and the embedded shortwave moves east-northeastward as a rather intense feature with a strong 40-50 m/s mid-level-jet ahead of it until 00-03 UTC. At the same time cyclogenesis occurs over the Tyrrhenean Sea.

DISCUSSION

Sicily, south Italy, parts of the Balkan west coast...

The 12 UTC GFS as well as a majority of the WRF runs available, simulate significant amounts of convective precipitation to occur along a cold front passing Sicily and southern Italy in the 18-00 UTC time frame. About 300 m2/s2 of storm-relative helicity is also predicted ahead of the front, so that rotating updraughts are possible. Considering low-level wind shear will be well in excess of 10 m/s, some threat of tornadoes will be present. A few marginal large hail events appear possible as well. Limiting factor will be the overall instability which will probably not exceed a few 100s of J/kg, and the likelihood of linear convection. These keep me from upgrading to level 2 for Sicily and extreme south Italy at the moment in a situation that appears to have good forcing and wind shear. The Balkan coast will probably not be affected by storms until after 0000 UTC.


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 Subiectul mesajului: Re: Prognoza ESTOFEX
MesajScris: Mie Mar 04, 2009 1:25 am 
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Perioada 5 mar. ora 18z - 6 mar ora 00z poate fi chiar periculoasa, deoarece convectia va fi foarte puternica ( chiar exploziva in unele locuri ).
Momentan nu se stie unde vor fi pp cele mai intense, pt. ca GFS-ul variaza foarte mult de la o rulare la alta, iar descarcarile electrice vor fi posibile, deoarece gradientul termic va fi foarte apropiat si deja s-au semnalat oraje la temperaturi scazute in tara noastra, pe o miscare sud-sud-vestica


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 Subiectul mesajului:
MesajScris: Mie Mar 04, 2009 1:32 pm 
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Ar fi fain sa fulgere. La mine a fulgerat in Martie undeva prin 1998, apoi in 2007, cand a cazut si grindina. Si credinta populara este ca daca tuna in Martie este an bogat. Insa daca fulgera in Februarie, e de culturi distruse de grindina la vara. :D


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 Subiectul mesajului: Re: Prognoza ESTOFEX
MesajScris: Joi Mar 05, 2009 2:15 am 
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Imagine

Storm Forecast
Valid: Thu 05 Mar 2009 06:00 to Fri 06 Mar 2009 06:00 UTC
Issued: Wed 04 Mar 2009 22:57
Forecaster: GATZEN

SYNOPSIS

A deep long-wave trough is placed across western and southern Europe. At its western flank, a strong mid-level jet streak moves into Portugal region and further into northern Algeria. The trough is filled with well-mixed polar air mass characterized by lapse rates of more than 8K between from 2000 to 4000 metres over British Isles, Bay of Biscay, eastern Iberia and west Mediterranean Sea. Polar air mass is relatively dry at low levels. To the south and east of this cold air mass a couple of cold front occlusions are present moving across west Mediterranean Sea, southern Mediterranean, and the Balkans.

DISCUSSION

Bay of Biscay, eastern Iberian Peninsula, and west Mediterranean

Focus of expected convective activity will be mid-level troughs filled with deeply mixed polar air mass. The cold front occlusions ahead of these troughs may also lead to convection, but instability will be limited due to rather poor lapse rates. The easternmost trough axis is expected to cross the Balkans and Adriatic from the south in the morning hours. Given rather moist low-level air mass due to southerly winds, some instability will likely develop in the range of the Mediterranean Sea. Although widespread clouds are expected given quite strong QG forcing and moist air mass, embedded convection is forecast. Chance for some lightning is highest along the southern coasts where upslope flow will likely lead to some additional low-level forcing. Severe threat is limited given weak low-level instability, but strong mid-level winds may pose a risk of some organized storms. Sever wind gusts and tornadoes are not completely ruled out in the morning hours. Low thread will even decrease during the day, and a threat level seems to be not necessary.

Central Mediterranean

Another trough axis follows to the west and crosses the central Mediterranean. Polar air mass will likely be well-mixed, but boundary-layer moisture will be quite dry as indicated by latest observations across the Iberian Peninsula. Instability will likely be limited. Given low-level cold air advection, strong forcing is also not expected. Some showers may develop, and the chance for waterspouts is not forecast to be significant although weak vertical wind shear and good low-level lapse rates will be present.

Bay of Biscay to south Mediterranean

A third upper trough axis will move from the Bay of Biscay across the Iberian Peninsula and west Mediterranean into northern Algeria. It is also accompanied by a strong mid level jet streak moving south-eastward. Strong DCVA is forecast underneath the cyclonic flank of the mid-level jet. At lower levels, cold air mass spreads southward across the Iberian Peninsula behind a cold front occlusion that crosses northern Africa during the period. This air mass will be characterized by steep low- to mid-level lapse rates in excess of 8 K/km. Although low-level moisture will be rather limited, diurnal heating will likely contribute to significant buoyancy and CAPE in the order of a few 100s J/kg. Showers and thunderstorms are forecast to spread southward during the period and will likely produce soft hail. Given strong vertical wind shear underneath the jet streak, organized convection is possible and linear segments are forecast capable of producing severe wind gusts. Although tornadoes are not ruled out completely, chance seems to be low given rather poor low-level moisture. Best potential seems to exist near the casts, where low-level moisture is more favourable.

Over the Mediterranean, additional thunderstorms will likely develop lat in the period and spread southward reaching the Algerian coast. Better moisture and good low-level buoyancy will overlap with strong low-level vertical wind shear and forcing, and thunderstorms may be severe capable of producing severe wind gusts. Tornadoes and marginally severe hail are not ruled out, but potential is limited given weak low-level veering profiles.

Greece, Aegean, western Turkey

Cold front that has crossed most of the Mediterranean will become parallel to the flow over Greece during the period. While southerly low-level winds will advect rather moist air masses, a mid-level trough moves northward across the region, leading to some QG forcing. Given mid-level cooling and steepening lapse rates, instability will likely develop along nd ahead of the cold front. Embedded convection is forecast specially along the western coasts, where low-level convergence is expected. Strong low-level vertical wind shear near the coasts is likely, and a few rotating storms are not ruled out as well as bowing segments embedded in the cold front. Chance of tornadoes is slightly enhanced until the evening hours, while the threat will likely decrease from the west during the night. Severe wind gusts and large hail seem to be rather unlikely.


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 Subiectul mesajului: Re: Prognoza ESTOFEX
MesajScris: Joi Mar 05, 2009 2:49 am 
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Supercelula
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Deja se-nfierbanta situatia in mediterana...inca un pic si prindem si noi ceva :D


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 Subiectul mesajului: Re: Prognoza ESTOFEX
MesajScris: Vin Mar 06, 2009 1:28 am 
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Estofex procnozeaza fenomene severe in Romania ! [ COD 1 ]

Imagine
Imagine
Storm Forecast
Valid: Fri 06 Mar 2009 06:00 to Sat 07 Mar 2009 06:00 UTC
Issued: Thu 05 Mar 2009 20:05
Forecaster: TUSCHY
SYNOPSIS

A cold cyclonic vortex is centered over the central Mediterranean and steers the weather over most parts of Europe. Conditions over the warm Mediterranean and SE-Europe are supportive for scattered thunderstorm activity. A dry/cold continental airmass over far NE-Europe suppresses any convection, while an eastward building high pressure area over SW-Europe brings warmer/stable conditions to Portugal and Spain.

DISCUSSION

... Tyrrhenian Sea, Adriatic Sea and Ionian Sea ...

An active thunderstorm day is in store for parts of the central Mediterranean as the upper low and attendant pool of cold mid-levels remains parked over that area. The quality of the surface airmass is passable as airmass already made a complete loop around the cyclonic vortex and had time to ingest moisture from the warm Mediterranean. However, largest temperature spread between mid- and lower levels is present along the southern fringe of the vortex, and that's where strongest thunderstorm activity is forecast. A few isolated thunderstorms are well possible around Corsica or the N-Adriatic Sea but we decided to highlight the area with the strongest activity. This is a winter-like moderate CAPE/weak shear environment, so scattered thunderstorms are likely to occur with just a marginal hail/strong wind gust threat. Isolated large hail is possible over SE-Italy and the S-Adriatic Sea, where DLS is somewhat stronger.

SE-Italy and the central/southern Adriatic Sea are also the regions, where waterspout development could be favored by quite steep LL lapse rates/some LL CAPE release and more than 500 J/kg MLCAPE, so rapid vortex stretching would be possible. A marginal level-1 was issued to reflect the combined hail/spout risk in this area.

... W/extreme NW-Turkey, eastern Greece, S-Greece and Bulgaria (until 21Z) ...

A sharp surface trough swings northwards from Malta (06Z) to the N-Ionian Sea (~12Z ) and is responsible for the temporarily speed up of the eastward moving cold front. This front will affect S/W-Greece at roughly 12Z and the west coast of Turkey at 18-21Z. Along and ahead of the cold front, storm relative helicity is augmented at both 1km and 3km. Due to the combination of a robust moisture surge NNE-wards and ongoing mid-level CAA, a broad sector becomes quite unstable with readings of 400-800 J/kg MLCAPE. Obviously the main risk is a severe wind gust risk during the passage of the active cold front with winds of 20-30m/s at 850hPa and well mixed lower levels. Steep mid-level lapse rates, strong veering at mid-levels, 30-40m/s DLS and a lowering WBZ all point to a quite widespread large hail risk with each more persistent thunderstorm, especially over NW-Turkey, extreme S-Bulgaria and E-Greece. The main limiting factor is the missing forcing, which arrives quite late / during the evening hours /, when instability is on a rapid decrease. Initiation is possible as atmosphere remains just weakly capped, but how widespread this will be is still quite uncertain, especially over NW-Turkey.

Regarding the tornado risk an isolated event can't be ruled out over S-Greece as LL directional shear is augmented along and just ahead of the front. However a more robust tornado risk arises at 12Z onwards over NE-Greece and W/NW-Turkey, as 20m/s LL shear, 200-400 J/kg SRH1 and 500J/kg MLCAPE overlap. The LCL rises from roughly 600-800m over NE-Greece to more than 1500m over NW Turkey. Even a strong tornado event is possible with those values. Thunderstorms over the extreme NE Aegean Sea will keep going through the night although it is questionable if thunderstorms can persist in an environment with constantly decreasing instability and extreme shear of 50-55m/s DLS.

A level-2 was issued for the area, where confidence in more widespread initiation is the highest and where all kind of severe weather modi are possible.

... NE Greece, Bulgaria and Romania at 21Z onwards ...

A constantly intensifying surface depression over W-Bulgaria and SW-Romania will be the main feature of interest during the following 9h. A warm front will be situated around the border Bulgaria/Romania at 21Z. At the same time aforementioned cold front finally enters SW-Bulgaria from the SW and moves rapidly northwards. The cold front will reach S-Romania around midnight and will finally catch up the warm front, so an occlusion process is forecast somewhere over S-central Romania around midnight. The quality of the warm sector airmass looks good with forecast dewpoints at the surface running just below 10°C and this looks reasonable, given latest readings of 6°C over S-Romania and 8-9°C over Bulgaria (18Z). This is not yet enough for surface based convection in respect to latest GFS forecast soundings, but we have to monitor that possibility. Nevertheless MUCAPE values of up to 400J/kg indicate that elevated thunderstorms are possible under the left exit of an extreme 55m/s mid-level jet. Strong to severe wind gusts and isolated large hail are likely over central/E-Bulgaria, S/E-Romania and the tornado threat has to be monitored in upcoming model runs.
Just west of the jet axis (W-Bulgaria and SW-Romania), very cold mid-levels and still appreciable surface moisture generate a swath of some modest instability release in a weakly shared environment and thunderstorms are possible, too. Weaker shear should limit the severe weather risk.

Altogether the main concern right now arises along the occlusion point, which will be around Bucharest at 00Z-03Z, where strongest shear/forcing/instability overlap. However, some run-to-run inconsistency in latest model outputs is still present, so we will stick with a broad level-1. Parts of Moldova and NE-Romania may need to see a level-1 for 00Z onwards but right now I fear that the ongoing occlusion process over central Romania could weaken the moisture surge northwards and hence limit instability release.


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 Subiectul mesajului: Re: Prognoza ESTOFEX
MesajScris: Vin Mar 06, 2009 1:31 am 
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Supercelula
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Misto de tot. Activitate electrica oricum prindem, ramane de vazut doar cat de tari vor fi furtunile si...ce tip de furtuni vor fi :twisted:


Sus
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 Subiectul mesajului: Re: Prognoza ESTOFEX
MesajScris: Vin Mar 06, 2009 1:52 am 
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CaTaLyN scrie:
[b][color=#FF8000]Strong to severe wind gusts and isolated large hail are likely over central/E-Bulgaria, S/E-Romania and the tornado threat has to be monitored in upcoming model runs.


Hopaa. :P Sincer, nu cred. Parca vad maine dimineata cum se flosteste GFS-ul si nici macar nu mai ploua, nu mai zic de tornade.


Sus
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 Subiectul mesajului: Re: Prognoza ESTOFEX
MesajScris: Vin Mar 06, 2009 1:55 am 
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gogulica scrie:
CaTaLyN scrie:
[b][color=#FF8000]Strong to severe wind gusts and isolated large hail are likely over central/E-Bulgaria, S/E-Romania and the tornado threat has to be monitored in upcoming model runs.


Hopaa. :P Sincer, nu cred. Parca vad maine dimineata cum se flosteste GFS-ul si nici macar nu mai ploua, nu mai zic de tornade.

LOL sectiunea asta n-am observat-o numai acum :lol:


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 Subiectul mesajului: Re: Prognoza ESTOFEX
MesajScris: Vin Mar 06, 2009 2:00 am 
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Daca viscol n-am avut, macar tornade sa vedem. :mrgreen:


Sus
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 Subiectul mesajului: Re: Prognoza ESTOFEX
MesajScris: Vin Mar 06, 2009 2:06 am 
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Tornade ...... hmm cam greu de spus suntem doar in martie :mrgreen:
Estofexul cam are obiceiul de a supraestima fenomenele severe . Am observat ca uneori daca este pericol intr-o zona restransa ei "codeaza" o arie mult mai larga jur imprejur ...... Alteori , le iese de minune prognoza .
Totusi daca vedem la vara COD 3 pe Romania , ar fi cazul sa iesim la un chase :lol:


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 Subiectul mesajului:
MesajScris: Vin Mar 06, 2009 2:10 am 
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Aia cu severe wind gusts o cam nimerira: pe la 12,25 acum noaptea asta fura nene niste rafale bestiale, cum nu prea am auzit pe aicea.
COD 3 Romania- nu cred ca o sa se dea asa ceva. Cu mare indulgenta COD 2. :lol:


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 Subiectul mesajului: Re:
MesajScris: Vin Mar 06, 2009 2:14 am 
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Neaceasca85 scrie:
COD 3 Romania- nu cred ca o sa se dea asa ceva.

Eu as vrea sa se dea COD 4 ! :lol:


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