Oklahoma continues to be one of the hottest locations in North America – hotter than Death Valley in fact. Yesterday, it was possible that Oklahoma was the hottest location on the planet for a time. This extreme heat, which is breaking records left and right, is also contributing to a "flash drought," which is adding insult to injury. Drought begets extreme temperatures and also enhances the fire danger across the region.
First, I'll address these ridiculously high temperatures. It was unlikely this summer would challenge the previous one in the intensity of heat, but it is certainly doing so this week. In fact, one year ago today, the high was 112º. On August 3, 2011, the high was a scorching 113º. We had 3 days in a row of 110º+ readings then and it looks like that will be the case here in 2012 as well. Growing up in Tulsa, I only recall ONE day that topped 110º. To say this is because of global warming would be presumptuous. In the 1950s and, of course, the Dust Bowl era of the 1930s, we had similar, remarkable heat waves. Our all-time record high of 115º was set back in the Dust Bowl (August 10, 1936). Even without the extremity or longevity of that drought though, we are closing in on the number today. There are many words to describe our current heat wave: oppressive, miserable, extreme, mind-melting. In a more scientific description, we'd call it highly anomalous. That basically means, this kind of heat is not quite unprecedented, but a major divergence from the norm.
We may see 4 days in a row of 110º+ readings before the streak is over. Given the urban heat island of Tulsa, the inability to cool off much at night with concrete storing that heat and releasing after dark, we have also reached another all-time record: the hottest average daily temperature. On both this date last year and July 31st of this year, we averaged 100º during the day. On top of that, yesterday featured 12 hours of 100º temperatures in Tulsa. I'm not sure if that breaks a record, but it has to be close!
It's no surprise the hottest temperatures in the country are having an adverse effect on our drought. The "flash drought" I mentioned earlier is a term used to describe the acceleration of drought development due to extreme heat. Within a week, extreme drought went from covering 50% of Oklahoma to 71% of the state. That's the second worst drought category as you can see above. Topsoil has been all but entirely depleted of moisture and vegetation has shriveled, wilted, and yellowed in a big hurry. That's why fires are so dangerous and Burn Bans encompass the entire region. There's a lot of dry fuel for fires and the heat makes fighting them a nightmare.
OK, enough doom and gloom. There IS relief in the forecast, albeit brief. A wave in the jet stream to our north will be strong enough to send a cold front into Oklahoma this weekend. Saturday still may be a scorcher, but that night into Sunday, scattered showers and storms are possible. Even if you don't see the rain, clouds and a northerly wind should contribute to cooler, sub-100º weather. The high pressure ridge, the culprit of this heat, builds back next week, but not to the extreme we are seeing now.
Finally, the Tropics are active once again after a hiatus this past month. What will soon be Tropical Ernesto will slowly intensify as it moves through the Caribbean, possibly into the Gulf of Mexico next week. It's a definite long-shot, but that storm could actually be a nice, rain-maker for the region. If it happened to move ashore in Texas and move north, we could be in for exactly the kind of steady, substantial rain we need. We'll cross our fingers that some relief from the drought/heat combo comes our way soon. If not, we'll just have to stick it out till September.