With increased rainfall seen during the beginning of August, area weather expert Jim Andrus discussed what the rest of the monsoon season could look like in the Four Corners.
Andrus told The Journal that there are five significant climate zones in the Northern Hemisphere from the equator to the poles. The tropical zone, which is the first, is close to the equator, while the subtropical zone extends farther north. The temperate zone is next, and is categorized by weather that is neither too hot nor too cold.
The subarctic and arctic zones round out the climate zones. With weather in the Northern Hemisphere, where the United States is located, the zones will move north or south depending on the season.
Because the Four Corners area is in its hot summer season at this point, the tropical and subtropical zones will expand further north, as will the temperate zone. The arctic regions will shift further south and get colder, causing the subtropical and tropical zones to shrink.
The main climate zones that affect Cortez are the subtropical zone and the temperate zone, according to Andrus. When the subtropical zone shifts further north, it sets up the climate for the monsoon seasons.
Two climate patterns along the equator, El Nino and La Nina, also affect the climate patterns in the Northern Hemisphere. In an El Nino episode, the ocean temperatures are warmer than normal. In the La Nina episode, the ocean temperatures are cooler than normal.
Although the Four Corners had been in a neutral position, Andrus said the area’s now entering a La Nina episode.
A high pressure area commonly found over the southeastern United States and Texas draws up moisture from the Gulf of Mexico in a clockwise circulation that turns the moisture north toward the Four Corners, creating a monsoon.
“That is what a monsoon flow is,” Andrus said. “The high pressure area, it can get stronger, it can get weaker, it can help the entire area shift further east or further west. That’s why the monsoon flow behaves like a river.”
At the beginning of August, the high pressure area was “perfectly situated” to draw moist air into the Four Corners. Now, it has shifted further east.
The monsoon flow has now moved further east over New Mexico, and Andrus said that the area “might just be on the very edge of the monsoon flow.”
While the weather does fluctuate year to year, Andrus said the monsoon season and rain patterns have been similar for the past 20 years or so, noting that the area’s now in a “mega drought.”
“The drought started in the late 90s, and it’s over 20 years old,” Andrus said. “We’ve had below normal precipitation.”
Before the mega drought, the region received approximately 13.2 inches of precipitation. Now, it’s about 11.79 inches.
Andrus also said that former Montezuma County Commissioner Steve Chappell, before his death, told him the change in precipitation is why he no longer planted winter wheat.
“Farmers and ranchers had to make some long term decisions,” Andrus said.
Because the monsoon season isn’t a steady pattern, it’s hard to predict what the rest of the monsoon season could look like. In the first 12 days of the month, the Four Corners saw above-average precipitation for the entire month thanks to the rainfall the area received, Andrus said.
Following Saturday thunderstorms, the National Weather Service is predicting cloudy and partly sunny days in the coming days ahead of another thunderstorm slated to take place on Sept. 1.
