Thursday, November 15, 2007

Tail end of a cold front

Manila, Philippines - Busy areas of the city went underwater because of a steady rain due to a cold front. One of the worst hit are roads leading to the airport. I wonder how people who need to catch a flight managed. In Meteorology 101 we define a cold front as " the transition zone where a cold air mass is replacing a warmer air mass." Cooler air that wedges below the warm air mass causes that air to rise. This causes precipitation as the front passes.

The precipitation is usually not as bad as a monsoon (which is guaranteed to sink Manila) but it seems that even a light steady rain is now able to sink the city under water! This should give our city authorities some pause for thought.

In temperate climes the passage of a front is dramatic. The rains come and after a few hours when the front has passed the temperature can drop as much as 10 degrees celsius and bright sunny weather follows. Cold fronts are major rainmakers in these climates. Their effects can be dramatic in autumn or winter.

Since PAGASA does not have Doppler Radar it can't advise the public about how much rain is expected with these weather features. Until it can acquire one we will have to second guess by looking at the sky.

No comments: