Seg. Previsão do Tempo e Modelos - Novembro 2011

Tópico em 'Seguimento Meteorológico' iniciado por Duarte Sousa 1 Nov 2011 às 00:25.

  1. meteo.ptlousada

    meteo.ptlousada
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    Cirrus

    Registo:
    2 Set 2011
    Mensagens:
    83
    Local:
    Porto
    pode ser que sim, vi agora as previsões do IM e o que diz é que quinta sexta e sabado está prevista queda de neve nas terras altas , vamos ver .
    Obrigado ;)
     
  2. PedroAfonso

    PedroAfonso
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    Nimbostratus

    Registo:
    18 Fev 2008
    Mensagens:
    1,180
    Local:
    Covilhã (700 m) / Almada
    OFF Topic: Com as cotações de hoje, umas 45 descargas em todo o país. O mercado tem estado volátil até dizer chega...
     
  3. B84

    B84
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    Cirrus

    Registo:
    23 Out 2011
    Mensagens:
    26
    Local:
    Lisboa
    ESTOFEX:

    ... Western Iberia ...

    The arrival of the significant trough, cyclonically curved jet-stream along with the surface front should provide strong forcing for the development of convection. Current satellite images show that the front indeed does involve some clearly cellular forms of DMC. NWP simulates low end latent instability in both the warm sector, especially close to the front under the LLJ and also in the cooler airmass behind the front. It is probable that the most significant activity will be tied to the front, with development of large stratiform rain shield with embedded banded convection. Degree of the wind shear will be conducive to well organised convection, but in this scenario, strong isolated supecellular storms remain very unlikely. Nevertheless, strong low level shear induced by 25 m/s flow at 850 hPa and moderate SREH ahead of the front might support some rotation in few of the cells.

    It is likely that the most significant threat will be an excessive precipitation, due to the strong LLJ carrying very moist airmass and possibility of the passage of several bands of convection passing over one place. Threat will be diminished by relatively quick passage of the frontal system towards southeast, limiting chances for very long duration of consecutive cell passage. With the arrival of the jet-max during the night hours and its exit region over Southern Iberia, along with the front movement slowing down and the highest dew points, it is likely that the highest rainfall amounts will be observed here. Another threats might include marginally severe wind gusts and tornadoes, especially if some stronger cell can develop rotation in their lower levels.
     
  4. boneli

    boneli
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    Nimbostratus

    Registo:
    12 Jan 2008
    Mensagens:
    843
    Local:
    Braga. Lomar
    Parece que esta frente vai nos afetar até Sexta-feira mais coisa menos coisa, começando já hoje a diminuir intensidade.

    [​IMG]

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    Ainda é cedo mas parece que os modelos já estão a mostra a entrada de outra frente para a próxima semana a partir de Quarta-feira.

    [​IMG]

    Uploaded with ImageShack.us
     
  5. Jorge_scp

    Jorge_scp
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    Nimbostratus

    Registo:
    17 Fev 2009
    Mensagens:
    875
    Local:
    Sesimbra/Amadora
    Só uma correcção: A frente em si já passou, foi a que atravessou o país durante o dia de hoje. A partir de agora, e toda a precipitação que dão até Sexta/Sábado é resultado do pós-frontal, com aguaceiros que podem ser fortes, possibilidade de trovoadas e queda da temperatura, pois geralmente por detrás da frente vem uma massa de ar mais frio. :thumbsup:
     
  6. Zapiao

    Zapiao
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    Nimbostratus

    Registo:
    20 Set 2006
    Mensagens:
    882
    Local:
    Coimbra - 135m alt.
    É impressao minha ou este evento agora da parte da tarde amainou um pouco? Nem vento há:huh:
     
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  7. ricardop120

    ricardop120
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    Cumulonimbus

    Registo:
    20 Jul 2009
    Mensagens:
    3,235
    Local:
    Santa Comba Dão
    boas

    e pronto a frente ja passou e deixou uma bela rega, mas teremos a sua instabilidade do pós frontal, que pelas imagens de satelite parecem ser pequenas celulas, que poderao provocar aguaceiros pontualmente fortes e acompanhados de trovoadas dispersas principalmente no norte e centro... vamos aguardar as proximas horas...
     
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  8. boneli

    boneli
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    Nimbostratus

    Registo:
    12 Jan 2008
    Mensagens:
    843
    Local:
    Braga. Lomar
    Obrigado :thumbsup:
     
  9. Duarte Sousa

    Duarte Sousa
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    Staff

    Registo:
    8 Mar 2011
    Mensagens:
    4,941
    Local:
    Loures
    Sim. Como dizia o Jorge_scp, à hora do seu post a frente já tinha passado. Na minha opinião, a frente passou entre as 07h e as 11h. Depois disso é tudo o pós-frontal, que como dizia o Jorge_scp: "A partir de agora, e toda a precipitação que dão até Sexta/Sábado é resultado do pós-frontal, com aguaceiros que podem ser fortes, possibilidade de trovoadas e queda da temperatura, pois geralmente por detrás da frente vem uma massa de ar mais frio. " e o boneli "mas teremos a sua instabilidade do pós frontal, que pelas imagens de satelite parecem ser pequenas celulas, que poderao provocar aguaceiros pontualmente fortes e acompanhados de trovoadas dispersas principalmente no norte e centro... vamos aguardar as proximas horas... ".
     
  10. Nuno_1010

    Nuno_1010
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    Cumulus

    Registo:
    22 Dez 2009
    Mensagens:
    194
    Local:
    Atouguia da baleia-Peniche
    http://www.estofex.org/cgi-bin/polygon/showforecast.cgi?lightningmap=yes&fcstfile=2011110406_201111022108_1_stormforecast.xml

    Storm Forecast
    Valid: Thu 03 Nov 2011 06:00 to Fri 04 Nov 2011 06:00 UTC
    Issued: Wed 02 Nov 2011 21:08
    Forecaster: GATZEN
    A level 1 was issued for the British Isles and northern France mainly for large hail, severe wind gusts, and tornadoes.

    A level 1 was issued for southern France and the west Mediterranean mainly for excessive rain.

    A level 1 was issued for western and southern Iberia and surroundings mainly for severe wind gusts and tornadoes.

    SYNOPSIS

    The deep Atlantic long-wave trough will slowly enter Iberia during the period. A strong south to south-westerly flow will affect the British Isles, France, the western Mediterranean, and Iberia. The cold front will become mostly parallel to the jet and will be present from the western North Sea to France and the west Mediterranean at Friday morning. Rich low-level moisture is already present along the cold front and will even increase over the west Mediterranean given a moist south-easterly flow and strong low-level convergence. QG lift is likely from the British Isles to the west Mediterranean ahead of the eastward moving trough. This lift is expected to lead to increasing lapse rates that will overlap with the moisture.

    DISCUSSION

    British Isles, northern France

    A tongue of very moist low-level air mass has spread into the British Isles and France and latest observations indicate surface dew points of 14°C. While the cold front crosses the Iberian Peninsula during the day, a frontal wave will be associated with backing surface winds from northern France to the British Isles in the afternoon and evening hours, associated with continuous moisture advection. Lift can be expected through-out the period given the approaching trough and mid-level jet streak as well as the frontal wave associated with warm air masses at low levels spreading northward. As a consequence, steepening lapse rates are forecast and CAPE becomes likely.

    The overlap of the rich low-level moisture with strong low-level vertical wind shear (12 m/s 0-1km bulk shear) is clearly indicated by latest models. Main uncertainty will be the lapse rates and the chance of surfaced-based instability as well as the lift that may be rather weak. Current thinking is that showers and thunderstorms will develop rather isolated and will rapidly move northward. Some of these storms are expected to develop into supercells capable of producing large hail, tornadoes, and severe wind gusts. The convective activity will likely last until the night hours.

    Southern France, west Mediterranean

    Rich boundary-layer moisture is present over the west Mediterranean and southern France. As the mid-level trough approaches, lift will result in increasing lapse rates. Strongest low-level convergence is expected to the south of France ahead of the cold front and will spread eastward during the evening and night hours.

    The frontal rain band of the cold front will likely become more convective as is moves across the Mediterranean Sea. Embedded storms are forecast to lead to excessive precipitation especially over southern France. Additionally, strong vertical wind shear may lead to tornadoes. The main activity will spread into Italy at the end of the forecast period.

    Iberia

    The Iberian Peninsula will be affected by convectively mixed maritime air masses. As the base of the deep trough will move eastwards, increasing lift is expected over Iberia. Surface winds will likely back to south-east and low-level moisture is also expected to increase in the afternoon hours. Especially in the evening this will likely lead to CAPE that overlaps with strong low-level vertical wind shear over south-western Iberia. Supercells are forecast capable of producing severe wind gusts and tornadoes until the morning hours.
     
  11. Gerofil

    Gerofil
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    Super Célula

    Registo:
    21 Mar 2007
    Mensagens:
    9,643
    Local:
    Estremoz (401 metros)
    Previsão para 5ª feira, 3 de novembro de 2011

    Regiões Norte e Centro: Céu geralmente muito nublado. Aguaceiros, por vezes fortes e acompanhados de trovoada em especial até ao final da manhã e no litoral a norte do cabo Mondego.

    IM
     
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  12. Aurélio

    Aurélio
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    Cumulonimbus

    Registo:
    23 Nov 2006
    Mensagens:
    4,335
    Local:
    Faro
    Bom dia olhando aos modelos não se prespectiva grande alteração na situação que estamos vivendo sendo que atmosfera nos proximos 10 ou até mesmo 15 dias deverá ter alguma instabilidade, sem nada de especial previsto, sendo que apesar de tudo a situação mais interessante parece residir até amanhã.
    Assim sendo penso que no interior a maior parte que era para chover já choveu, sendo que agora os aguaceiros e as trovoadas são mais prováveis no litoral Oeste, sendo que pelo que mostram os modelos as células ao chegarem a terra a maior parte deverão dissipar-se e será sempre a região mais a norte (litoral) que será mais afectada.
    Do ponto de vista de circulação da atmosfera e apesar do forte anticiclone a leste e nordeste da Europa, as depressões talvez influenciada pelo AO+ e NAO+=, tendem sempre em rodopiar em torno da Islândia e assim não existem á vista uma alteração deste padrão, pelo que existindo precipitação serão sempre as regiões mais a norte as mais afectadas .... pela persistência de precipitação.

    Contudo não será de descartar uma pontual alteração do padrão neste mês !!
     
  13. Mário Barros

    Mário Barros
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    Furacão

    Registo:
    18 Nov 2006
    Mensagens:
    12,501
    Local:
    Cavaleira (Sintra)
  14. Aurélio

    Aurélio
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    Cumulonimbus

    Registo:
    23 Nov 2006
    Mensagens:
    4,335
    Local:
    Faro
    Um grande pacote de pipocas !!:lol::lol::lol:
     
  15. Meteo Trás-os-Montes

    Meteo Trás-os-Montes
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    Cumulonimbus

    Registo:
    28 Jan 2007
    Mensagens:
    4,393
    Local:
    Carcavelos /Chaves / Vilardevós - Galiza
    Onde andará a cota de neve? :rolleyes:

    MeteoGalicia:

    6ª Feira: 1300m Sábado: 1200m Domingo: 1000m

    AEMET:

    5ª Feira: 1500m (estará a nevar no alto do Larouco?)
    6ª Feira: 1300m Sábado: 1300m Domingo: 1200m

    IM:

    6ª Feira: 1400m Sábado: 1500m
     
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