North East West passage Forecast: 27 Aug - day 45
Posted in North East West passage | By Marc |
This map show the synoptic situation valid for Saturday 1200utc. The main development during this period is the building of the Russian continental high pressure system. This feature is going to expand over the East Siberian and Chukchi Sea (red arrow). As a result the wind gradient, which is the pressure difference over a certain distance, becomes very small, hence wind will become weak. Click image to see the full display.
Weather Forecast North East West passage -27 Aug- day 45
General situation
Along the Southerly flank of the synoptic scale depression, that is positioned over the Northern parts of the Laptev and East Siberian Sea, a favourably Westerly wind is blowing for the greatest parts of today. But during the night the conditions are expected to change. From tomorrow onwards and during the next three or four days the wind and weather conditions will be dominated by the powerful, continental Russian high. This pressure system wants to expand over the East Siberian Sea and later over the Chuckchi Sea as well. This results in decreasing pressure gradient, hence decreasing wind speed. This means from tomorrow onwards wind are likely to be weak and variable (see details below).
On longer term (beyond the 29th of AUgust) this means that for the 30th and 31st of August (across the Chuckchi Sea) will be rather weak as well. Than the wind is expected to pick up again on the 1st/2nd of September: 10-15kt from SOuth. As you may noticce this is considerably different than expected yesterday, which is not unusual in this region for outlooks beyond 72 hours.
(All forecasted winds are average values).
Day 1: 27 Aug
Expected track: 71/160 to 71/168
Weather: sunny, scattered cloudiness-no precipitation.
Wind: 270-290°12-17kt after 18utc becoming 290-310°8-13kt.
Day 2: 28 Aug
Expected track: 71/168 to 70.2/173
Weather: sunny spells, broken clouds-no precipitation
Wind: 310-330°4-8kt after 15utc becoming less than 5kt
Day 3: 29 Aug
Expected track: 70.2/173 to 69.8/178
Weather: sunny spells, scattered clouds, no precipitation.
Wind: 100-120°4-8kt, after 12utc becoming 200-220°3-7kt, later dropping away.
30-31 August, towards 68.9/-178
S-SSE 4-8kt, becoming less than 5kt from variable directions
01-02 September: on the first of September the wind turns to Southerly sector, slowly increasing.