The Great Southern Route : 2008 - 2009
WEATHER ROUTING 030 | GSR likely to occur. Winter season travel (November through April) offers a greater possibility of delays and/or stoppages due to adverse weather, particularly in NW-NE-E wind surges further south (south of the Mexican Riviera), and NW-N wind surges further north (Sea of Cortez and the Baja Peninsula). Routing options during the winter season become more limited as well. The best routing would be to maintain coastal routes.....taking these routes reduces the likelihood of encountering large seas associated with wind surges, especially further south and in NW-NE-E'lys, and affords more readily available stoppage ports. EASTERN AND CENTRAL NORTH PACIFIC, EAST OF THE INTERNATIONAL DATELINE TO 110W. Two weather features are prevalent throughout the year across more northern waters (north of 10N): high pressure to the west and a thermal trough (low pressure) further east. The thermal trough is normally found covering the Sea of Cortez, Gulf of California, and the Baja Peninsula. The trough will tend to be weaker and cover a smaller area during the mid to late autumn months (November/December), the winter and the early spring, as figure 3 shows. This is due to the presence of cold fronts moving southeastward into and across much of the western U.S. and (during the winter) into the northern Baja Peninsula, occuring about every three to four days. Later in the spring and during the summer/early autumn (May through October), the thermal trough tends to be stronger, as figure 4 indicates, with troughing extending as far north as interior/ coastal California and Oregon. Weakening and a southward suppression of the trough will occur as smaller, weaker areas of high pressure "break away" from the nearly stationary high pressure ridge in the tropical/subtropical Pacific and into the northwest U.S. Weakening will also occur, as weakening cold fronts move southeastward into the western U.S., more likely to occur later in the period (in October), as cold fronts become somewhat stronger upon arrival along the U.S. West Coast. Further west, a semi-stationary high pressure dominates across the tropical and subtropical Pacific, found mainly across waters between 40N and 10N and west of 110W. Slight flutuations in coverage and strength are likely to occur over a given time period. The ridge will tend to be weakest during the winter season (December through February), as larger, more intense gales and storms track slightly further south from their summertime positions, but still well north of the region. However, transitory high pressure ridges moving into the Western Pacific will eventually merge with and "reinforce" the semi-stationary ridge, inducing surges of higher N-NE-E winds and larger N-NE-E swells across this region as well. The ridge will tend strongest during the summer months, as gales/storms in the North Pacific track further north. Looking south of 10N, the aforementioned ridge will interact with a broad east to west oriented trough of low pressure (equatorial trough), on average covering the Pacific between 10S and 10N.During the late spring and summer months (May through August), the northern extent of Figure 3 -- Typical winter patterns in the Eastern Pacific Figure 4 -- Typical summer patterns in the Eastern Pacific Trades, trades, and oh yes, more trades. That 's the dominant wind regime in place across this "neck of the woods"
2010 - 2011