Weather Forecast 10/01/2015
The doldrums are looming in the near future for the fleet leaders. In fact, almost in anticipation of the fleet’s approach, the doldrums are starting to move slowly north to meet them. While trade winds will remain good for the next 24 hours, some noticeable easing of the wind and an increase in shower/squall activity is expected.
*** SYNOPSIS ***00Z SATURDAY (10-JAN-2015):1) The NE trade winds will ease very gradually, but remain moderate to fresh over most of the trade wind region between the Canary Islands and 10N.2) A general right trend is expected north of 25N from NNE/NE to NE/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, left-shifted breeze expands westward off the African coast.3) 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 30W.4) Winds will decrease from 10N approaching the northern Doldrums boundary. There will also likely be an increase in vertically developed cumulus cloud, as well as some showers and perhaps a squall – mainly close to the doldrums boundary.5) The northern boundary of the doldrums has started lifting north very slowly. The northern edge the doldrums extends along a line from 6N/20W to 4N/25W to 3N/30W to 3N/35W.6) The southern boundary of the doldrums is right around 1N. The doldrums region of light and variable7) One big change in the pattern is an increase in shower and squall activity associated with the doldrums, especially along the northern edge. The coverage is still pretty scattered, but increased wind variability is expected with the increased cloud and shower coverage. Activity is most widespread east of about 21W and west of about 29W.8) ESE tending SE trade winds are light to light-moderate south of the Equator. Winds tending back left south to ESE south of about 5S. There is also a building trend south of this boundary.00Z SUNDAY (11-JAN-2015):1) The pattern will not change significantly, except we do continue to get some northward movement of the doldrums.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. Very light winds are expected within about 60nm of the African coast north of the Cape Verde Islands.3) Note that winds will tend to back from NE to NNE/N where it is easing most abruptly as a coastal trough moves west off African shore.4) Stronger breeze will hold west of the Cape Verde Islands, especially west of about 26W.5) The northern boundary of the doldrums will extend from 7N/20W to 5N/25W to 5N/30W to 4N/35W. 6) The southern boundary of the doldrums marking the start of ESE/SE trades out of the Southern Hemisphere will hold around 1N.7) The doldrums region of light air separating it from the SE trades will increase to about 3-4 deg latitude width at 20W to 2-3 degs latitude at 25W. The zone will of course be narrower further west, closer to 30W.8) Shower and squall activity is expected to slowly increase in and just north of the doldrums region. Most widespread activity will be mainly east of 25W.9) Within the doldrums, there is expected to be some breeze, more or less E’ly. A complete calm zone is not forecast, though some very light patches are still possible.10) South of the doldrums, winds will be light-moderate ESE/SE to about 5S. South of there, winds will back ESE and increase to moderate strength. 00Z MONDAY (12-JAN-2015):1) The wind field within the trades will be very similar to Sunday.2) Continued slow backing trend NE to NNE north of about 15N, and winds will become moderate at 30W and light-moderate east of 25W.3) NE trade winds will extend to the northern Doldrums boundary, which will move to about 5N or 6N between 20W and 30W.4) As noted above, some E’ly flow is expected within the doldrums and a complete glass-off doesn’t appear to be in the cards. Whoever, the winds will be lighter east of 25W.5) The southern Doldrums boundary will move north to around 2N to 3N.6) South of the Doldrums, winds shift ESE and build light-moderate winds, Moderate ESE tending SE winds are expected by 1S, becoming Moderate around 4S. 7) Winds moderate SE tending ESE south of about 5S.00Z TUESDAY (13-JAN-2015):1) Again, no huge change from Monday. Light-moderate NE trades south of 15N and east of 29W.2) Northern doldrums boundary it still around 5N-6N, though wider and further north east toward 20W.3) The southern boundary moves north to about 3N.4) Winds are expected to hold light-moderate E’ly in the Doldrums, with less easing than expected on the previous days. In fact, winds may hold best west of about 28W.5) South of the doldrums, a modest building trend if ESE wind to light moderate, especially west of 25W. Moderate ESE winds will be south of 5S.**************************************General Forecast along race route*** SATURDAY (10-JAN-2015) ***>>> CANARY ISLANDS (African coast to 20W and 25N to 30N): ENE 15-20 gusting 25 backing NE easing 14-18 through the day.>>> TRADE WIND ZONE EAST (African coast to 20W and 15N to 20N): NE 15-20. Easing NNE 10-15 near the African coast.>>> TRADE WIND ZONE WEST (20W to 30W and 15N to 20N): NE 18-23 locally gusting 25.>>> CAPE VERDE ISLAND EAST (African Coast to 20W and 10N to 15N): Easing NNE 10-15. East of 19W, Tending N/NNE 10-15 decreasing to variable 5-10 near the African coast.>>> CAPE VERDE ISLANDS WEST (20W to 30W and 10N to 15N): Starting NE 22-27 easing 18-23, especially north of the islands. >>> Tropical Atlantic (20W to 30W and 5N to 10N): NE 15-20, except lighter 10-15 south of about 8N. Tending lighter all areas through the day.>>> DOLDRUMS (20W to 30W and Equator to 05N: North of 4N, NE 10-15 easing 5-10. South of 3N/4N, becoming ENE/E 5-10 or less, veering E/ESE with distance south toward 2N. South of 2N, becoming ESE 8-13.SEAS: 2-3m north of Cape Verdes. Decreasing 1-2m south of 12N 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 the northern doldrums boundary.*** 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 east of 19w to the African coast.>>> TRADE WIND ZONE WEST (20W to 30W and 15N to 20N): NE/NNE 15 at 20W, increasing to NE 15-20 west of 25W.>>> CAPE VERDE ISLANDS WEST (20W to 30W and 10N to 15N): NNE 10-15 at 20W, increasing NE 18-23 near 30W. Generally easing with time.>>> Tropical Atlantic (20W to 30W and 5N to 10N): NNE/NE 10-15. Much lighter near 5N east of 25W.>>> DOLDRUMS (20W to 30W and Equator to 05N): South of 5N, becoming ENE/E 5-10. South of 1N/2N, becoming ESE 5-10, increasing to 8-13 at the Equator.>>> SE trades (20W to 30W 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. 1-2m south of Cape Verde Islands and near 1m at the doldrums.WEATHER: Scattered showers and a few squalls south of 8N. Frequent showers likely near the doldrums northern boundary at 5N. Scattered showers within the doldrums. Some clearing/showers ending south of 1N/2N out of the doldrums zone.*** MONDAY (12-JAN-2015) ***>>> CAPE VERDE ISLANDS WEST (20W to 30W and 10N to 15N): N/NNE 10-15 east of 25W. NNE/NE 15-20 west of 25W.>>> Tropical Atlantic (20W to 30W and 05N to 10N): Generally NE 10-15 at 10N decreasing to NE/ENE 5-10 at 05N. Much lighter toward 20W. >>> DOLDRUMS (20W to 30W and Equator to 05N): North of 02N, E 5-10. Much lighter and variable east of 21W. South of 02N, ESE 7-12 increasing to 10-15 at the equator.>>> SE Trades (20W to 30W and Equator to 05S): ESE 10-15 at the equator, tending SE 12-16 at 05S.>>> SE Trades (20W to 30W and 05S to 10S): SE 12-15 backing ESE with distance south.SEAS: 1-2m in NE trade wind zone, decreasing to around 1m or less in doldrums and 1m south of the doldrums. WEATHER: Frequent showers and squalls north of the doldrums. Scattered showers in the doldrums. Clearing south of about 02N