Weather Forecast 17/01/2015

The lead boats are now working their way through the transition from trade winds to westerlies, with some complex patterns to navigate over the next couple days. Mid-fleet, the E’ly trades hold, though some areas of showers embedded within flow will create areas of unstable wind. Spirit of Hungary continues to transition out of the Doldrums and into the South
Atlantic trade winds.

Meteo JAN 17, 2015 07:09

*** SYNOPSIS ***
00Z SATURDAY (17-JAN-2015):
1)    Little change in the SE/ESE trade winds from the Doldrums, south to
about 15S. There will be lighter E’ly winds now over the waters south
of the doldrums to about 3S.
2)    A persistent area of stronger, more consistent ESE wind will be in a
zone around 7S to 12S/32W to 27W.
3)    From about 15S to 23S, the wind field will become more contaminated
with embedded clouds and showers.
4)    South of 20S, winds will be backing NE to N between 30W and the
Brazilian coast.
5)    High pressure (1022mb) is centered near 29S/22W. A ridge will extend
west/northwest of the high to near 25S/36W. This ridge axis marks the
shift from E/NE trades to the north, to N/NW pre-frontal winds to the
south around the southwest quadrant of high pressure.
6)    A zone of accelerated NNE/NE flow persists south and east of Cabo Frio.
7)    A stationary front lies west to east along 31S. A second high (1022mb)
moves to 35S/20W. Over the course of the day, the front between the
two high pressures washes out, and the high merge and move southeast.
West of 25W, the front shifts south to about 33S while weakening.
00Z SUNDAY (18-JAN-2015):
1)    Steady, moderate E/ESE winds north of 16S.
2)    Lighter  and more patchy trade winds south of 16S and east of 34W
where the South Atlantic high becomes a ridge extending from 22S/32W
to 30S/18W to the new, merged high center (1027mb) near 37S/4W.
3)    A cold front will move north of 39S at 30W and near 35S at 40W. Strong
N winds off Cabo Frio back to strong NW’lies ahead of the front and
south of the high pressure ridge.
4)    A zone of lighter winds will persist around the area where the old
stationary front was between 33S and 24 S west of 25W, all the way to
the coast.
5)    New high pressure will be ridging east off the Argentinian coast near
BA and behind the cold front.
00Z MONDAY (19-JAN-2015):
1)    Moderate E’ly trade winds will extend from about 10S to 20S. The
trades will be a bit patchy and easing with distance south from about
17S.
2)    Trades weaken and back E/ENE north of a ridge axis from 30S/20W to
27S/30W to 25S/35W. Between the ridge and Cabo Frio, winds accelerate
NE/NNE, then back NW south of the ridge axis.
3)    A cold front stalls around 32S at 30W.
4)    A high pressure (1019mb) will be moving quickly east along 37S at 34W.
5)    The westerlies will be active south of this high along 39S at 30W.
6)    Over the course of the day, a strong cold front will be moving
northeast off the Argentinian coast and east, marking a new, northward
surge in the westerlies.
00Z TUESDAY (20-JAN-2015):
1)    E’ly trades exten south to a ridge axis lying west to east off Cabo
Frio along about 24S.
2)    This ridge marks the transition between E’ly trades and developing NW
pre-frontal flow around the southern side of the high pressure ridge.
3)    A significant low (980mb) near 46S/37W will have a cold front wrapping
from the low center to just northeast of the Rio de la plate.
4)    Strong NW winds will extend to 18W at 35S ahead of the front. Behind
the front, winds shift strong SW’ly, and will be pushing northeast to
36S at 35W through the day.
**************************************
General Forecast along race route
*** SATURDAY (17-JAN-2015) ***
* Equator to 10S *
WIND: SE/ESE 9-14, increasing 14-18 near 10S.
SEAS: 1-2m
WEATHER: Partly cloudy. Scattered showers.
* 10S to 18S *
WIND: ESE 12-16 at 10S backing E at 18S.
SEAS: 1-2m
WEATHER: A mix of clouds and sun. Some showers, especially close to coast
and south of 17S.
* 18S to 25S and 25W to 40W *
WIND: East of 30W, backing NE to N with distance south 14-18. Near 20 of
Cabo Frio. East of 30W, ENE/E 10-15.
SEAS: 1-2m at 30W increasing to 2-3m off Brazilian coast.
WEATHER: Mix of clouds and sun. Showers likely north of 22S.
* 25S to 30S and 25W to 40W *
WIND: East of 30W, backing N to NNW with distance south 14-18. Tending NW
near 30W, lighter east of 30W.
SEAS: 1-2m at 30W increasing to 2-3m off Brazilian coast.
WEATHER: Mix of clouds and sun. Scattered showers.
* 30S to 35S and 25W to 35W *
WIND: NW 15-20, except west of 30W, a zone of light wind 33S to 34S.
SEAS: 1-2m increasing 2-3m with distance south.
WEATHER: Cloudy with frequent showers and squalls, especially 30S to 32S.
*** SUNDAY (18-JAN-2015) ***
* 05S to 10S *
WIND: SE/ESE 13-17.
SEAS: 1-2m
WEATHER: Partly cloudy. Showers possible.
* 10S to 20S *
WIND: ESE/E 12-16 at 10S backing E/NE 10-15 south of 17S. Stronger NE/NNE
15-19 close to Brazilian coast south of 18S.
SEAS: 1-2m
WEATHER: A mix of clouds and sun. Some showers, especially close to coast a
nd between 10S and 15S.
* 20S to 30S and 25W to 40W *
WIND: NE/N 10-15 increasing to 18-23 west of 36W. Becoming N/NW south of
28S.
SEAS: 1-3m off Brazilian coast.
WEATHER: Mix of clouds and sun. Scattered showers.
* 30S to 35S and 20W to 35W *
WIND: NW 18-23 easing NW 15-20. Tending lighter from west to east and
especially west of 30W. South of 33S, shifting S/SW west of 30W through the
day.
SEAS: 2-3m.
WEATHER: Cloudy with frequent showers and a few squalls, especially north
of 33S.
*** MONDAY (19-JAN-2015) ***
* 05S to 10S *
WIND: SE/ESE 10-15.
SEAS: 1-2m
WEATHER: Partly cloudy. Scattered showers.
* 10S to 25S *
WIND: ESE/E 12-16 at 10S backing E/NE 10-15 south of 20S. Strong NE/NNE
closer to Brazilian coast south of 20S.
SEAS: 1-2m
WEATHER: A mix of clouds and sun. Scattered showers.
* 25S to 30S and 30W to 40W *
WIND: NE/N 10-15 near 30W increasing to 15-19 west of 35W. Becoming N/NW
south of 28S.
SEAS: 1m at 30W increasing to 1-3m west of 35W.
WEATHER: Mix of clouds and sun. Scattered showers.
* 30S to 35S and 20W to 35W *
WIND: NW 14-18 gusting 20-25 north of 32S. Shifting E/SE and lighter 7-12
from west to east and especially west of 30W and south of 32S.
SEAS: 1-3m, subsiding west to east.
WEATHER: Cloud with frequent squalls 30S to 32S.