Why It's So Hot, When It Might End and Why We Should Count Our Blessings
Polite elevator conversation usually includes something like, "How about that weather, huh?" Lately, that conversation might be more along the lines of, "Holy shit, I went outside and thought I was going to die!" Normally, summers in Houston turn the average resident into either a hermit, scurrying from one air conditioning source to another as quickly as possible, or a grumpy bastard who does nothing but complain about the heat to anyone who will listen, as if no one else has been outside since April, or some combination of the two. Unfortunately, this year, those responses are not just normal, they are justified.
High pressure is like the Heat Miser but not claymation.
Houston is currently suffering through what will turn out to be the hottest summer on record. We already broke July records and the average August temperature is three degrees higher than the hottest month in Houston history. It was 103 degrees on Wednesday -- part of a 17-days-and-counting streak of over 100-degree days breaking the previous record of 14 -- and there is even a chance we could see temperatures near 105 next week (the record highest temperature ever recorded in Houston, if you're curious, is 109). Normally, our hottest week of the summer is the last week in July with average temperatures in the upper 90s, so, yeah, this heat is sucking our will to live, but why has this year been so bad and when will it end?
Our unreasonably warm temperatures are the result of a dome of high pressure sitting over Texas that is so persistent, it has been given the nickname "bulldog" by some members of the meteorological community. This large mass of high pressure is also responsible for our record-setting drought. It generally prevents storm clouds from forming within the area and holds in heat like a pressure cooker, making us the chili (no beans, thank you very much).
High pressure, as a general rule, is not a bad thing. In the fall, it produces beautiful, sunny afternoons and often ushers out rain from cold fronts passing through. Remember cold fronts? But, when a high pressure system like this one builds over us during the summer months, it toasts our lawns and makes us all want to punch our neighbor in the face when he makes a crack about it.
Changes in the current high pressure system is what has been causing us to have the rare, occasional day of rain. When the high moves slightly west and weakens just a bit, we get our normal burst of summer afternoon showers, the result of warm, moist air moving in off the Gulf of Mexico. The pattern this summer is that the high then slides back east and rebuilds over our area with a vengeance. Forecasters believe this pattern will persist for at least a few more weeks, at least through the end of this month and perhaps as long as the first week or two of September.
As we get deeper into September, upper level patterns in the atmosphere begin to change radically as cool fronts start working their way further and further southward, eventually giving us a relief from the summer pain -- normally, we get our first real shot of cool air in mid-October. As that happens, the current mass of high pressure will dissipate and give way to the emerging cooler weather.
So, figure at least another two weeks of this hell on earth before we start to see changes, albeit very moderate ones (think 95 for an afternoon high instead of 105). But, in every puffy, summer cloud, there is a silver lining. In this case, the high pressure that makes us all want to move to the mountains with a tiny sherpa guide is also acting like a giant weather force field, preventing low pressure systems from moving into our area. "Why should I care about that?" you may ask. Well, my friend, the reason is that hurricanes are intense areas of low pressure and they do NOT move into areas of high pressure, particularly ones as large as the one sitting over us.
In fact, at this moment an area of disturbed weather moving across the Caribbean that will likely become a tropical depression in the next day or so is being guided west toward Central America by upper-level atmospheric steering currents that, in part, have resulted from our old friend high pressure.
Unfortunately, about the time that high starts to recede, we will be at the peak of our hurricane season -- the second week of September. If we can make it until the last week of September, however, hurricane season is essentially over -- for Texas, anyway, which has never seen a major hurricane strike after the last week in September -- and we can look forward to temperatures starting to trend downward. We just have to survive one of the most brutal summers Texas has ever seen and a couple weeks of tropical terror. No biggie.