Is the climate changing in the United States? With the extreme heat we’re experiencing in some parts of the county right now, it would be natural to assume that, by golly, yes! It’s hotter than ever at an earlier date than ever before. Houston, Texas, for example, has already seen records fall on at least two days in June when the temperature reached a whopping 105 degrees Fahrenheit. 105! That had people shaking their heads and wondering about the extreme weather. “So hot and so early in the year.” “It isn’t even summer yet!” I’m sure you’ve heard all the remarks if you live in these parts. And the extreme heat seems to have spread northward, with cities such as Chicago and Washington, D.C. sweltering too. But I digress. This is June. Let’s go back a month.
In May, when things were already drying out and heating up in Texas, some rather sizable parts of the country were actually cooler and wetter than normal, and NOAA has the data to prove it. Take a look at the NOAA maps below for May, 2011.
Interesting, isn’t it? A broad swath of the country experienced below normal temperatures, with five states reporting “much below normal” temperatures. I’ve done a little bit of research into the reason for this, and it seems that it has to do with all that snowfall last winter. The snowpack is extremely deep and extremely broad, and it’s hung around this spring. I’ve heard reports of some ski resorts in Utah still being open, and that people would be skiing on the Fourth of July, though that may have been in jest. If any of you are familiar with ski resorts out west, please let me know what the current situation is.
At any rate, this huge snowpack presumably had a cooling effect on the local weather, which is perfectly understandable. Vast snowpacks supposedly have a cooling effect not only because they cool the surrounding air, but snowpacks also increase the Earth’s albedo, or reflectivity, reflecting light from the sun out into space. Makes you wonder, doesn’t it? More and more snow might make for cooler and cooler temperatures – at least in some places. The earth’s surface never heats or cools uniformly.
One more thing about that big snowpack and all the cool air blowing southward. Unfortunately for us, a lot of that cool air ran into warm, moist air from the “hot” Gulf of Mexico, blowing in over “hot” states, and the result was a record, and deadly, tornado season. That was bad news for us.
Now let’s take a look at precipitation during May:
The areas of drought really stand out, don’t they? I’m sort of surprised that parts of Texas didn’t show up as “Record Driest,” but this is a trustworthy map, so I’ll go along with it. As you can see, most of the country is wetter than normal, with eleven states reporting “Much Above Normal” precipitation. All of this extra rain contributed in a big way to the historic flooding we’ve had this spring, no doubt.
So is the climate in the United States changing? Is it getting hotter and dryer? It really depends on where you are, doesn’t it? I’m eager to see what the maps look like at the end of June. The deep south dearly needs a few very gentle tropical systems to scatter some rain our way. No high winds or floods, please, just some gentle, soaking rains. Those would be very welcome.