This analysis is made by the group of David Michael V. Padua, the famous meteorologist from Naga City.
Michael Padua is known all over the Philippines for his outstanding website "Typhoon2000". This website is extremely useful when a typhoon develops and approaches the Philippines.
The original data comes from NOAA, the US National Oceanic and Atmospheric Administration.
Click on the image to enlarge!
This map shows the isobars. Isobars are lines that link points of same atmospheric pressure.
If the isobars (the lines) are far from each other, then you may expect only weak or even no wind.
But when the isobars are very near, then it gets windy.
Storms have nearly concentric isobars around the center. In the center you find an L for "Low Pressure". Often the direction of the forward movement is indicated by arrows.
Severe storms are also marked with a cone out from the center. This cone shows the probability zone, where the center of the storm will pass.
It is not easy to find the Philippines in above Map of East-Asia. Although the country is in the centre, we have it extracted and enlarged.