When the ITCZ meets the Tropical Wave

One of the things I miss living in the second and third of my worlds is the Weather Channel. Of course weather around here is pretty predicatable, at least temperatures stay within a narrow range and precipitation is of one kind only. After all this time I was excited to have found a scientific explanation for what local weather we do have. Sort of. Weather here seems to be driven by two main things: the Intertropical convergence zone and Tropical waves.

The Intertropical convergence zone (ITCZ) is basically a band of clouds and thunderstorms that circles the globe near the equator. It is where the trade winds of the Northern and Southern hemispheres meet. It moves north and south with the seasons. (Red represents July, blue January, though obviously not this year!)

Tropical waves are the bottom edges of elongated high pressure ridges that move across the oceans from east to west. The bottom edges get kind of ragged and unstable and tend to produce a lot of rain and it is thought that they can also be instrumental in producing hurricanes and typhoons.

So what happens when a Tropical Wave meets up with the ITCZ? Well, I think we are finding out! We had a lot of rain last week and I once again realized the disadvantages of small umbrellas. The heavy rain continues this week. The other night it poured all night long after having poured all evening. There was flooding in many parts of the city, which isn't unusual but this time they even cancelled school in some areas! Our new neighbor found out what we meant by the flooding garage under his place. Thankfully his little sedan still started this morning.