Weather Forecast 09/01/2015
Doldrums are at their maximum southerly position after the recent surge in the NE trade winds over the last few days. Now, the trades are starting to relax allowing the doldrums will begin moving slowly north and gradually widen as the fleet approaches from the north.
*** SYNOPSIS ***
00Z FRIDAY (09-JAN-2015):
1) Strong high pressure (1044mb) is centered near 40N/17W. The high pressure is continuing to support moderate to strong NEíly trade winds
from about 35 north to about 10N. Nearly all areas south of 35N are 20+ knots, with some areas of 25-30 knots between the Canary and Cape Verde Islands.
2) The trade winds start to gradually decelerate with distance south of the Cape Verde Islands, and especially south of about 10N.
3) Wake regions downwind of the Cape Verde Islands will be active, with lulls extending considerable distance downwind of the islands. There
will be zones of accelerated breeze in between the islands.
4) The trade winds will begin to very slowly decrease all areas today.
5) The strong trades have allowed for the doldrums to be well south. Winds generally ease south of about 8N approaching Doldrums, where winds become variable or light Eíly.
6) The northern boundary of the doldrums extends from 7N/20W to 3N/25W to 2N/30W to 2N/35W.
00Z SATURDAY (10-JAN-2015):
1) The NE trade winds will ease very gradual, but remain moderate to fresh over most of the trade wind region between the Canary Islands and 10N.
2) The high pressure (1040mb) near 40N/17W will be gradually weakening. As this northern anchor to the trade winds weakens, so will the winds.
3) A general right trend is expected north of 25N toward the ENE, while south of there winds remain NE. Winds in the veering zone will be easing more quickly out to about 30W as an area of lighter, right shifted breeze expands westward off the African coast.
4) As noted above, wake regions of lighter and more variable wind will extend 100nm downing of Cape Verde Islands. Accelerated trade wind flow will persist between the islands.
5) Winds will be easing from fresh to moderate and possibly light-moderate south of the Cape Verde Islands today. Easing conditions south of 15N will extend to about 29W.
6) The northern boundary of the doldrums begin to start lifting north very slowly. The northern edge the doldrums will extend from 8N/20W to 5N/25W to 4N/30W to 4N/35W.
00Z SUNDAY (11-JAN-2015):
1) The trade winds will continue to slowly ease from east to west, especially south of about 20N.
2) The easing trend will be most pronounced east of about 21W and south of 25N as an area of lighter breeze over western Africa starts to expand westward.
3) Note that winds will tend to back from NE to NNE/N where it is easing most abruptly, this due to a coastal trough develop just off Africa.
4) Firmer (stronger) breeze will hold west of the Cape Verde Islands, especially west of about 27W.
5) The northern boundary of the doldrums will extend from 7N/20W to 5N/25W to 5N/30W to 4N/35W. The southern boundary of the of the doldrums marking the start of SEíly trades out of the Southern Hemisphere will be around 1N.
6) The doldrums region of light air separating it from the SE trades will increase to about 4-5 deg latitude width at 20W to 2-3 degs latitude at 25W. The zone will of course be narrower in the west, closer to 30W.
7) Within the doldrums, there is expected to be some breeze, more or less Eíly. A complete calm zone is not forecast, though some very light patches are still possible.
8) South of the doldrums, winds will be ESE 10-15.
9) Showers and squalls are very limited around the doldrums at the moment.
00Z MONDAY (12-JAN-2015):
1) The wind field within the trades will be very similar to Sunday.
2) Stronger winds between the Canary Islands and Cape Verde, easing south and west of the Cape Verdes out to 30W.
3) NE trade winds will extend to the northern Doldrums boundary, which will be very close to the same position it is expected to be on Sunday.
4) As noted above, some Eíly flow is expected within the doldrums and a complete glass-off doesnít appear to be in the cards.
5) South of the Doldrums, winds shift ESE and build light moderate winds, Moderate ESE tending SE winds are expected by 2S.
General Forecast along race route
*** FRIDAY (09-JAN-2015) ***
>>> CANARY ISLANDS (African coast to 20W and 25N to 30N): NE 22-27 gusting 30-35 south of the islands. Locally 40+ knots in accelerated areas downwind of the islands. Wake zones of lighter breeze extending 30-50nm directly downwind of islands. All areas veering ENE and easing 17-22 through the day, except from the Canary Islands north, esing 14-18.
>>> OPEN ATLANTIC (20W to 25W and 25N to 30N): NE 20-25, tending ENE.
>>> TRADE WIND ZONE EAST (African coast to 20W and 15N to 20N): NE 20-25 gusting 25-30, except lighter 15-20 near the African coast, specially overnight to late morning.
>>> TRADE WIND ZONE WEST (20W to 30W and 15N to 20N): NE 20-25 gusting 30. Generally strongest 25W to 30W.
>>> CAPE VERDE ISLANDS EAST (African Coast to 20W and 10N to 15N): NE/NNE 20W 20-25 except easing N/NNE 14-18 east of 19W and lighter on the immediate African coast.
>>> CAPE VERDE ISLANDS WEST (20W to 30W and 10N to 15N): NE 22-27 gusting 30-35. Acceleration 35+ between the islands, and downwind wakes of much lighter wind extending downwind by >100nm. Generally easing 20-25 or less through the day.
>>> Tropical Atlantic (20W to 30W and 05N to 10N): NE 15-20, except lighter 10-15 south of about 7N. Tending lighter through the day, especially east of 29W and south of 10N.
>>> DOLDRUMS (20W to 30W and Equator to 05N): North of 3N, NNE/NE 10-15, easing close to 3N. Generally light east of 25W and tending NNE. South of 3N, veering ENE/E and 5-10. Much lighter east of 25W. South of 1N, winds becoming ESE 10-15.
SEAS: 2-4m in the trade winds north of 10N. Decreasing 1-2m close to 5N and 1m in the doldrums.
WEATHER: Mainly fine weather except for island showers ending around Canary Island. Showers continue near Cape Verde Islands. Cloud buildups increasing south of 10N in decelerating winds toward Doldrums. A few showers around doldrums, but widespread development not expected.
*** SATURDAY (10-JAN-2015) ***
>>> CANARY ISLANDS (African coast to 20W and 25N to 30N): ENE 15-20 backing NE 17-22 through the day.
>>> OPEN ATLANTIC (20W to 25W and 25N to 30N): ENE 20-25, tending NE 18-23.
>>> TRADE WIND ZONE EAST (African coast to 20W and 15N to 20N): NE 15-20 increasing 18-23. Lighter near the African coast.
>>> TRADE WIND ZONE WEST (20W to 30W and 15N to 20N): NE 20-25 gusting 30.
>>> CAPE VERDE ISLAND EAST (African Coast to 20W and 10N to 15N): Easing NNE 10-15. East of 18W, Tending ENE/E 10-15 decreasing to 5-10 near the African coast.
>>> CAPE VERDE ISLANDS WEST (20W to 30W and 10N to 15N): Starting NE 22-27 easing 20-25. Acceleration 35+ between the islands, and downwind wakes of much lighter wind extending downwind by >100nm.
>>> Tropical Atlantic (20W to 30W and 5N to 10N): NE 15-20, except lighter 10-15 south of about 8N. Tending lighter through the day.
>>> DOLDRUMS (20W to 30W and Equator to 05N: North of 4N, NE 10-15 easing 5-10. South of 04N, becoming ENE/E 5-10 or less, veering E/ESE with distance south toward 2N. South of 2N, becoming ESE 8-13.
SEAS: 2-4m north of Cape Verdes. Decreasing 1-2m south of 11N and 1m south of 7N.
WEATHER: Showers continue near Cape Verde Islands. Cloud buildup south of 10N in decelerating winds toward Doldrums. A few showers and squalls possible around doldrums, but widespread development not expected.
*** SUNDAY (11-JAN-2015) ***
>>> TRADE WIND ZONE EAST (African coast to 20W and 15N to 20N): NE veering NNE/N 10-15. Much lighter and variable at the African coast.
>>> TRADE WIND ZONE WEST (20W to 30W and 15N to 20N): NE/NNE 15 at 20W, increasing to NE 20-25 west of 25W.
>>> CAPE VERDE ISLANDS WEST (20W to 30W and 10N to 15N): NNE 10-15 at 20W, increasing NE 18-23 gusting 25 near 30W. Generally easing with time.
>>> Tropical Atlantic (20W to 30W and 5N to 10N): NNE/NE 10-15.
>>> DOLDRUMS (20W to 30W and Equator to 05N): South of 5N, becoming ENE/E 5-10. South of 1N, becoming ESE 5-10, increasing to 8-13 at the Equator.
>>> SE trades (20W to 20W and Equator to 05S): ESE 8-13 at the equator, becoming ESE/SE 11-16 at 5S.
SEAS: 2-3m north of Cape Verde Island. 1-2. South of Cape Verde Islands and near 1m at the doldrums.
WEATHER: Mainly fine conditions. Scattered showers and a few squalls south of 8N. Frequent showers likely in the doldrums.