Prévisions météo 29-DEC-2014

Situation générale : la masse d'air froid qui se développe sur le sud et sud-ouest de l'Europe devrait persister encore plusieurs jours. Des vents violents pourront souffler au large  à mesure que cette goutte se développe et que l'air froid s'installe. Le pic d'air froid est attendu pour le milieu de semaine , mais les vents devraient commencer à mollir dans la journée de lundi et devenir de plus en plus faibles d'ici mercredi, jour du départ.

Meteo DÉC. 29, 2014 08:03

 *** SYNOPSIS ***

00Z TODAY (29-DEC-2014):

1)      Strong low pressure (996mb) is over Greece with a trough extending west across southern Italy, southern Sardinia, Palma to eastern Spain near Valencia.

2)      Strong high pressure (1040mb) is located over southwest England.

3)      The pressure gradient between the Greek low and English high pressure is supporting  Mistral out of the Gulf of Lyon and into the western Med. Some of the Mistral is flowing down the Catalonian coast toward the waters of Barcelona.

4)      This flow has peaked, but will remain fresh to strong today before easing.

 

00Z TUESDAY (30-DEC-2014):

1)      The Greek low will weaken (1010mb) and move to the waters between Greece and Crete.

2)      Lee-side low pressure (1023mb) will be embedded with a trough downwind of the French Alps.

3)      The English high will strengthen (1043mb) and move to Britany with a ridge extending south to central Spain.

4)      Strong Northely Mistral winds will remain over the Gulf of Lyon, but a slight backing trend will reduce the flow down the Catalonian coast toward Barcelona.

 

00Z WEDNESDAY (31-DEC-2014):

1)      The pattern will start to change favoring much lighter winds off Barcelona and even down the coast into the Gulf of Valencia.

2)      Low pressure will intensify near Crete (1002mb) and there will be still be a lee-side trough/low (1026mb) just west of Corsica.

3)      High pressure will be moving toward central France, weakening slowly (1039mb) while a second high (1035mb) will be over central Spain.

4)      NΓÇÖly Mistral will continue out of the Gulf of Lyon, however the angle of flow will keep lighter, NW/W winds present off the Spanish mainland coast between Barcelona and the Gulf of Valencia.

 

00Z THURSDAY (01-JAN-2014):

1)      Low pressure deepens (1007mb) and retrogrades to south of Italy.

2)      High pressure (1037mb) holds over central France, but the Spanish extension of the high moves west to be off Vigo. A ridge will extend east from primary high across southern Germany to eastern Europe.

3)      The gradient will veer sufficiently to end the Mistral, but fresh NE winds will remain over waters south of France in the gradient between the low and cold high pressure.

4)      Moderate to fresh NE flow may work its way into the waters offshore eastern Spain and into the Gulf of Valencia.

5)      This build is expected to be short-lived as new high pressure build off the coast and the Gulf of Valencia with time.

 

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General Forecast for Barcelona Waters:

 

*** MONDAY (29-DEC-2014) ***

In the morning, NW drainage winds will be in on the shore, varying from 5- 15 knots in the morning. The will extend anywhere from 3-10nm offshore, before converging with Strong N/NNE winds which will build up to 20-25 kts at 15-20nm offshore and perhaps gusting 20 kts.

The NW drainage flow will ease at the coast through the morning, and N/NNE winds will shift closer to shore.

During the afternoon, becoming N/NNE 10-15 close to shore, and 20-25 kts offshore. Winds will tend to increase with distance northeast along the coast away from Barcelona. Lighter winds will be found down the coast south/southwest of Barcelona.

 

Weather: Mainly sunny. Some cumulus may develop just offshore this morning through early afternoon marking the transition/convergence between lighter

breeze inshore and stronger breezes just offshore. Any convergence clouds will clear and/or shift south as the expected N/NNE wind fills into the coast.

Temperatures: 3C to 11C

Seas: NE swell around 1m inshore building 2m offshore. Rough.

 

*** TUESDAY (30-DEC-2010) ***

In the morning, NW winds 10-15 kts will become more prevalent along the coast off Barcelona, with strong 20-25 kts NW winds out of the Rio Erbo delta to the south. This NW wind will tend to be strongest in the morning as a combined gradient and drainage flow.

Conditions will moderate to light and variable in the afternoon within 10nm of shore. Beyond 10nm, winds increasing to NNE 10-15kts and up to 20 kts beyond 20nm.

 

Weather: Cold. Mainly clear inshore in the morning, but convergence cloud offshore. Convergence cloud will hold offshore during the day, possibly shifting a little closer to shore and marking the transition between lighter winds in shore and stronger NNE winds offshore.

Temperatures: -1C to 10C

Seas: NW swell 0.7-1m inshore increasing to 1.5 to 2m offshore.

 

*** Preliminary Outlook for the Start on WEDNESDAY (31-DEC-2014) ***

It will be a light start in some lumpy seas, but a new NE gradient is expected to develop and spread in from offshore in the afternoon, bringing new breeze from behind to the departing fleet.

 

NW drainage winds in the morning becoming light and variable late morning to mid-day in the starting area.

New breeze tending NNE/NE early afternoon 5-10 knots initially, but building 10-15 kts and possibly more well offshore through the afternoon. This new breeze will build southwest toward the waters between Palma and the mainland coast with time. Here it will tend NE to E.

Wind will tend to be stronger all the time further offshore, and lighter closer into the coast.