Butlletí del 06/01/2015
Els alisis del NE han tornat i s'estenen ara des del golf de Cadis fins a la zona habitual al sud i sudoest de les illes Canàries. Algunes condicions d'inestabilitat es continuaran donant prop de la costa marroquina, al nord de Casablanca, però a la resta hi haurà un general increment dels alisis en velocitat i consistència.
*** SYNOPSIS ***
00Z TUESDAY (06-JAN-2015):
1) High pressure remains north of Madeira (1030mb) near 34N/17W. A ridge
extends west and southwest to 31N/26W, while another extends northeast
to near Lisbon.
2) East of the high center, moderate N/NNE winds are found from about 15W
to 9W. East of 9W and into the Moroccan coast, much lighter and
variable conditions are present, except for land breezes on the
3) ENE trades across the Canary Islands are tending to back more NE, with
well defined connection now in place with the N/NNE winds north of 30N.
Accelerated flow is developing in and downwind of the channels between
the Canary Islands.
4) South of the Canary Islands (and especially south of 27N), NE trade
winds are strengthening, becoming quite fresh extending out of the
African coast and well west toward the Central Atlantic. Note that
winds will be lighter closer to Africa, but fresh to strong west of
5) As the acceleration zones south of the Canary Islands develop, they
will extend into the zone of stronger trades south of 27N.
6) A North Atlantic cold front extending from Ireland southwest to about
halfway between the Azores and Madeira will be slowing in progress
east and south. The high pressure north of Madeira will shift west
through the day and weaken/elongate the front more west to east along
00Z WEDNESDAY (07-JAN-2015):
1) The northern trade wind zone (north of about 33N) will be shrink to
mainly east of 12W as the cold front shift east to off the northwest
Iberian coast and south to just north of Madeira.
2) The high will weaken to a ridge extending from Madeira, just ahead of
the front to Lisbon. This will push lighter winds south to 33N west of
3) A high pressure (1033mb) will be north of the front, centered just
east of the Azores and becoming nearly stationary.
4) South and southeast of Madeira, the trade winds will be holding at
first, but may ease through the day as the ridge breaks down and the
remains of the cold front move southeast. However, stronger NE trade
winds will hold east of 13W and south of 32N over to the African coast.
5) South of the Canary Island, strong 20-25 knot ENE/NE trades will
extend from the African coast well west into the Atlantic.
6) The acceleration zones will be active between the Canary Islands, with
significant lulls in the lee of the islands extending up to 120nm
00Z THURSDAY (08-JAN-2015):
1) The high pressure ridge around Madeira dissipates, as the cold front.
High pressure (1036mb) near 39N/18W elongates toward the Iberian coast.
Moderate to fresh NE trade winds will be present over waters southwest
of Madeira east east to the African coast.
2) From the Canary Island south, the trade wind zone looks like it will
be wide and relatively strong, extending from the Canary Island
south/southwest beyond the Cape Verde Islands and well west to 35W.
3) Note that the acceleration zones will be active between the Canary
Islands, with significant lulls in the lee of the islands extending up
to 120nm downwind.
00Z FRIDAY (09-JAN-2015):
1) Strong high pressure (1043mb) off the northwest coast of Iberia will
support an unusually wide zone of fresh to strong NE/ENE trade winds.
All areas south of 35N are expected to have winds 20+ knots, and some
areas with 25-30 knots.
2) The trade winds will extend all the way south to the doldrums south of
3) There will be exception very close to the African coast, where lighter,
more right-shifted E/SE winds are possible.
General Forecast along race route
*** TUESDAY (06-JAN-2015) ***
>>> GULF OF CADIZ (North of 35N and East of 10W): West of 7W N 5-10
building 10-15 late in the day. East of 7W, light and variable except SE
land breeze along the Moroccan coast morning to mid-day. Sea breeze on the
coast in the afternoon will pull NW/N winds from offshore into the coast.
>>> MOROCCAN COAST (30N to 35N and East of 10W): Light and variable except
SE land breeze along the Moroccan coast morning to mid-day. Sea breeze on
the coast in the afternoon will pull NW/N winds from offshore into the
>>> OPEN ATLANTIC (10W to 15W and north of 30N): N/NNE 10-15 tending 15-20,
except lighter waters northeast of Madeira.
>>> CANARY ISLANDS (African coast to 20W and 25N to 30N): ENE 15 tending
ENE/NE 15-20. More left-shifted between Lanzarote and Africa and becoming
stronger west to 19W. Generally building over the waters south of Canary
Islands where 20-25 develops (except where leeside wakes are present
downwind of the islands).
>>> OPEN ATLANTIC (20W to 25W and 25N to 30N): ENE/NE 12-16 increasing 14-
SEAS: Generally 1m Gulf of Cadiz and Moroccan coast. Elsewhere, 1-2m,
except building 2-3m near 25N.
WEATHER: Fine conditions with no significant areas of showers or rain.
There may be some showers approaching from the northwest over waters north
of Madeira. Also, some showers possible windward of the Canary Islands.
*** WEDNESDAY (07-JAN-2015) ***
>>> MOROCCAN COAST (30N to 35N and East of 10W): Some lighter land breezes
on the immediate coast at first. Otherwise, NNE/NE 10-15, increasing with
distance south and west.
>>> OPEN ATLANTIC (10W to 15W and north of 30N): North of 34N, variable
conditions. South of 34N, NNE/NE increasing 10-15 in the north, increasing
to 15-20 in the south. Wind generally increasing and veering with distance
south toward 30N
>>> CANARY ISLANDS (African coast to 20W and 25N to 30N): Generally NE from
15-20 north of the islands, increasing to 20-25 south of the islands.
Accelerated flow with locally 30-40 between the islands. Wakes of lighter
wind will extend 70-100nm downwind of the island, with accelerated flow
holding downwind if the channels.
>>> OPEN ATLANTIC (20W to 25W and 25N to 30N): NE/ENE 14-18 increasing 16-
>>> TRADE WIND ZONE EAST (African coast to 20W and 15N to 20N): Increasing,
>>> TRADE WIND ZONE WEST (20W to 30W and 15N to 20N): Increasing, NE 20-25.
SEAS: 1m north of 32N. 1-2m 32N to Canary Islands. 2-3m south and southwest
of Canary Islands.
WEATHER: Some showers possible around Madeira and the Canary Islands.
Otherwise fine weather with no organized areas of showers or rain.
*** THURSDAY (08-JAN-2015) ***
>>> OPEN ATLANTIC (10W to 15W and north of 30N): NE 13-18 except 16-20 near
30N. Building 15-20 gusting 25 all areas through the day.
>>> CANARY ISLANDS (African coast to 20W and 25N to 30N): NE 15-20 gusting
25 north of the islands, increasing to NE 20-25 gusting 30 south of the
islands. Locally up to 40 knots in accelerated areas downwind of the
>>> OPEN ATLANTIC (20W to 25W and 25N to 30N): NE 14-18 increasing NE/ENE
>>> TRADE WIND ZONE EAST (African coast to 20W and 15N to 20N): NE 20-25.
>>> TRADE WIND ZONE WEST (20W to 30W and 15N to 20N): NE 20-25.
SEAS: 1-2m north of 30N, building. Elsewhere 2-3m.
WEATHER: Variable cloud cover north of 28N and east of 24W with a few
localized showers. Some isolated squalls north of 32N possible. Showers
near the Canary Islands.