Avisos, Alertas e Previsões oficiais - Setembro 2014

Zapiao

Nimbostratus
Registo
20 Set 2006
Mensagens
882
Local
Coimbra - 135m alt.
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Aviso MeteoPT
As análises, previsões ou alertas neste fórum são apenas a opinião dos utilizadores que as proferem e são da sua inteira responsabilidade. Não são previsões ou alertas de entidades oficiais, salvo indicação em contrário, não devendo portanto ser usadas como tal.
Para previsões, avisos e alertas oficiais, consulte sempre os produtos do IPMA, Protecção Civil ou outras entidades com essa função.
 


supercell

Nimbostratus
Registo
3 Mai 2012
Mensagens
1,243
Local
Aveiro
showforecast.cgi
Storm Forecast
Valid: Fri 05 Sep 2014 06:00 to Sat 06 Sep 2014 06:00 UTC
Issued: Thu 04 Sep 2014 18:01
Forecaster: TUSCHY

A level 1 was issued for parts of the Balkan States, the Alps and SE Germany mainly for a few excessive rainfall events. An isolated tornado event is also possible.

The same for S/CNTRL Italy.

A level 1 was issued for NE Spain mainly for an isolated large hail and severe wind gust threat.

SYNOPSIS

Split flow / high-over-low pattern persists over Europe. An anticyclone is centered over Lithuania/Latvia and slides E/SE towards Belarus. A weakening cyclonic vortex hovers over the Adriatic Sea and another vortex can be found over NE France (although models differ if this one will be closed at all). A sharp trough north of Scotland chokes off the westerlies and drifts south as a closed cold-core low. A few non-severe thunderstorms fire within its vicinity.

DISCUSSION

Lowering thickness along the western and southern fringe of the high over Belarus atop a seasonable moist boundary layer with numerous weak mid-level disturbances cause a belt of enhanced shower and thunderstorm activity. This area runs from Benelux to Italy to the N-Aegean Sea. Weak steering flow supports slow moving storms with heavy rain and marginal hail. Effective PWs aoa 30 mm exist over the S Balkan States and that's where a rainfall level 1 was added. Mesoscale BL moisture pooling along convergence zones may increase chances for an isolated spout-type tornado event.

Same for SE-Germany and parts of the Alps, where another level 1 was issued.

Overnight convection is forecast west of Denmark over warm SSTs. Latest data keeps the main activity just offshore.

S/CNTRL Italy will be another area of concern. Slow moving storms could dump lots of rain in a short amount of time with local flash flood problems. Strong updrafts could also induce a few strong waterspout events along the coasts.

Overlap of moist marine air beneath steep mid-layer lapse rates is forecast over NE Spain as a thermal low over CNTRL Spain exhibits its diurnal intensification cycle. Easterly BL flow beneath 25-30 kt westerly flow at 500 hPa offer some directional shear, so an isolated better organized storm is possible. Large hail and localized downburst events are possible. We went a bit offshore with the level 1 to account for an evening cluster, which comes off the E-Pyrenees.
 

supercell

Nimbostratus
Registo
3 Mai 2012
Mensagens
1,243
Local
Aveiro
Atualização do estofex.

showforecast.cgi


Storm Forecast
Valid: Sat 06 Sep 2014 06:00 to Sun 07 Sep 2014 06:00 UTC
Issued: Fri 05 Sep 2014 22:18
Forecaster: PISTOTNIK

... Portugal into NW Spain and Alpine region into Germany and the Czech Republic ...

Rather rich low-level moisture allows the formation of a few hundred J/kg of CAPE in response to daytime heating. Scattered afternoon storms will form on the one hand over mountains and on the other hand along north-south oriented convergence zones in Germany and in western Iberia where the moisture is maximized. With weak winds and precipitable water above 30 mm, localized flash floods may occur. A small level 1 was introduced for north-central Germany, where the stationary convergence zone could foster thunderstorms over a prolonged period.
 

Duarte Sousa

Moderação
Registo
8 Mar 2011
Mensagens
6,701
Local
Loures
Actualização dos avisos do IPMA

Precipitação - "Aguaceiros por vezes fortes e acompanhados de trovoada."

r21jLTX.png


16:00 - 21:59 (06.09.2014)

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Precipitação - "Aguaceiros por vezes fortes e acompanhados de trovoada."

vu6cQGv.png


07:00 - 21:59 (07.09.2014)

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Trovoada - "Frequentes."

vu6cQGv.png


07:00 - 21:59 (07.09.2014)


Alguns destes avisos já foram anunciados pelo post do jonas_87.
 

rozzo

Moderação
Registo
11 Dez 2006
Mensagens
2,487
Local
Alcochete/Lisboa
Está bem compacta a massa de convecção.
Vamos ver como se comporta até lá, se se mantiver assim compacta, poderá realmente dar acumulados importantes - nas áreas montanhosas em particular. Está mesmo alinhada na posição ideal para a orografia acentuar a precipitação.

Alguns mesoscalas como o WRF da univ.Aveiro carregam bastante na precipitação com a ajuda da orografia. Outros como o Arome do IPMA nem tanto.


tbXS8l4.jpg
 

Snifa

Furacão
Registo
16 Abr 2008
Mensagens
11,916
Local
Porto-Marquês:145 m Mogadouro:749 m
De facto uma linha que parece bem organizada e cujo desenvolvimento pode ser aumentado pela orografia da Ilha:

mwxj0QT.jpg


Um aviso vermelho é uma situação potencialmente gravosa, por isso toda a prevenção nunca é demais, atenção à Madeira nas próximas horas :rain: :trovao: