The Heat and Humidity Return.


Monday, August 15th 2011, 8:55 pm
By: News On 6


Previous blogs have detailed the amount of rain that was received last week which was certainly a blessing. But, considering how dry we were to start with, the question is how deep into the ground did that moisture go which has obvious implications regarding the response of the vegetation and how quickly we may dry out again.

The first map on the right details a measure of soil moisture called the fractional water index at 2 inches and the second map the same thing at 10 inches courtesy of the OK Mesonet. Notice that much of the state has received at least some relief at the 2 inch level, but the lack of deeper moisture in the more western counties suggests that shallow moisture will quickly evaporate if additional rains are not forthcoming. For the most part, the more eastern counties are in pretty good shape down through 10 inches, even though we are still well behind our annual normal rainfall. Bottom line: the drought has not been completely broken, particularly for our more western neighbors and it could quickly return for us if we do not receive adequate moisture going into the fall. In fact, the current drought actually started during the last half of the summer last year, so we will see.

So, can we expect much in the way of additional rainfall anytime soon? Well, the chances are non-zero on any given day, but the chances are not all that great either. The flow pattern aloft is not particularly favorable for much in the way of widespread showers or storms such as we enjoyed last week, but there will be at least a slight chance of a shower or storm during the afternoon and early evening hours and again during the late night and early morning hours on just about any given day. The NW flow pattern aloft is weaker than we had last week and the main focus for storms will likely be further north with some of those storms brushing our more northern counties.

Since we have more moisture around that also means that as we heat back up, the humidity will be more of a factor and the combination of heat and humidity will be more uncomfortable each day. Our daytime highs will be largely dependent on the amount of cloud cover left over from any showers as they decay in KS, but we are expecting enough sunshine for triple digits at most locations once again. In fact, it now appears that triple digits or close to it will be the general rule right on through the coming weekend. And, with dew point temperatures remaining in the mid-upper 60s here in E OK, then the heat index will likely be another 4-8 degrees higher. In other words, not only will it be hot again, but the humidity will be worse. However, we do not see the extremes of heat that we experienced the first week of August in our future.

So, stay cool, stay tuned, and check back for updates.

Dick Faurot