Our neighbourhood would be an ideal one for someone who wanted to study the way meteorology works. To the north of us are the mountains that surround Mexico City, and in passing through them, the bus goes past stretches of pine trees and alpine forest, with signs warning of ice that forms in bad weather. At 10,000 ft above sea-level, it’s not a hot part of Mexico.
On this side of that high crest, the mountains slope south and downward, breaking to form a kind of uneven shelf a mile wide and roughly five miles from east to west. Roughly, it’s about 5,000 ft, or one mile, above sea-level. That’s where I am. At the west end of this shelf is a volcanic ridge, with the town of Tepoztlan rising up it. Here at the east end, the high hills push south to end the shelf, and provide a barrier between us and the volcano, Popocatepetl, about 25 miles away. This village, Amatlan, is surrounded by the high cliffs these hills form, while to the south, the shelf drops quite steeply down about 800 ft to the valley where the towns of Oacalco and Yautepec sit. Beyond that, still further south, are more ranges of hills.
This reservoir for horses and cattle to drink is half full this August: a dark horizontal line on the left shows where the maximum water level would be. The reservoir is in sunshine, while the mountains to the north are crowned with rainclouds. Yet no rain came on this day.
From different vantage points, therefore, a person can see clear skies or looming storm-clouds, while immediately above there can be the opposite. A couple of nights ago, I watched a fierce lightning storm down in the Yautepec valley, while a light shower sprinkled this village.
Looking down to the Yautepec valley, which is covered in clouds, to the south of us.
A few mornings ago, skies here were clear, but the clouds had settled low in the valley, and I was looking down on their tops. I might wake to clear blue above, but then, in the rainy season, wraiths of mist form on the hilltops, and for a time in the early morning we’re overcast.
Early morning wraiths of mist on the hilltops around Amatlan.
The result is quite a complex series of wind and rain patterns in a relatively small area and, of course, it makes weather prediction no easy task. The forecast might say we’re getting a storm in the evening and we have a barely noticeable sprinkle of raindrops. Another day during the rainy summer, no storm is expected, but suddenly we’re engulfed in a downpour.
And so on.
This year rain has been sparse here, and there’s some fear the corn won’t be done growing before it stops. Everywhere’s green, but the water table has dropped from last year, and the streams are just trickles when they should be flowing steadily. Now, 2018 had a lengthy and intense rainy season, so we’re not in a crisis in 2019; but the overall sequence seems to be changing from how it was a decade ago.
Our rain comes in across the Pacific, and the typhoons and other storms there affect the quantities we receive, and also where the rain arrives. How it will change in years to come is anyone’s guess.