Post by Admin on Nov 9, 2015 7:37:58 GMT 8
Northeast Monsoon (Amihan)
The Northeast Monsoon is a large-scale seasonal flow of winds from High to Low Pressure regions during the winter season in the Northern Hemisphere. Air mass in mid-latitude areas during this season is cold and heavy enough to cause an intense and large area of High Pressure to develop over Siberia or Mainland China.
Surface winds from the center of that strong High Pressure cell come out in a clockwise motion, and flow towards a series of Low Pressure Areas in the Southern Hemisphere across Northern Australia through the northern part of the South Indian Ocean.
As this happens, these surface winds pass across the Philippines from a Northeast direction, thereby establishing the Northeast Monsoon flow across the country.
Figure 1 – Siberian High, where Asian Northeast Monsoon originates.
In the Philippines, the Northeast Monsoon normally sets in during the month of November and lasts until the early part of March of the following year. However, due to the current strong El Niño event, this year’s Northeast Monsoon came in earlier.
Figure 2 – Large-scale seasonal wind flow (Northeast and Southwest Monsoon).
The Northeast Monsoon brings moderate to occasionally strong and relatively cold dry winds across the country, thus significantly reducing surface temperature.
Though it comes from a dry land mass, the Northeast Monsoon can produce light to moderate rains along the eastern sections of the Philippines, since it picks moisture when it passes over the country’s northern and eastern seas before reaching the coastlines. The rains could sometimes be heavy when the Northeast Monsoon is accompanied by a tail-end of a cold front or a tropical cyclone located over the southernmost part of the Philippine Sea-Northern Australia Area.
The Northeast Monsoon is a large-scale seasonal flow of winds from High to Low Pressure regions during the winter season in the Northern Hemisphere. Air mass in mid-latitude areas during this season is cold and heavy enough to cause an intense and large area of High Pressure to develop over Siberia or Mainland China.
Surface winds from the center of that strong High Pressure cell come out in a clockwise motion, and flow towards a series of Low Pressure Areas in the Southern Hemisphere across Northern Australia through the northern part of the South Indian Ocean.
As this happens, these surface winds pass across the Philippines from a Northeast direction, thereby establishing the Northeast Monsoon flow across the country.
Figure 1 – Siberian High, where Asian Northeast Monsoon originates.
In the Philippines, the Northeast Monsoon normally sets in during the month of November and lasts until the early part of March of the following year. However, due to the current strong El Niño event, this year’s Northeast Monsoon came in earlier.
Figure 2 – Large-scale seasonal wind flow (Northeast and Southwest Monsoon).
The Northeast Monsoon brings moderate to occasionally strong and relatively cold dry winds across the country, thus significantly reducing surface temperature.
Though it comes from a dry land mass, the Northeast Monsoon can produce light to moderate rains along the eastern sections of the Philippines, since it picks moisture when it passes over the country’s northern and eastern seas before reaching the coastlines. The rains could sometimes be heavy when the Northeast Monsoon is accompanied by a tail-end of a cold front or a tropical cyclone located over the southernmost part of the Philippine Sea-Northern Australia Area.