Brief Relief this Weekend?

Thursday, July 28th 2011, 4:24 pm
By: News On 6

Thought perhaps a brief discussion on feedback might be of value. If you look at the first map on the right, it shows the 2" soil moisture across the state from the OK Mesonet. You can see clearly the effects of the spotty showers and storms that have occurred over the last few weeks as most of the soil across the state is extremely dry except in those locations. The second map shows the 2" soil temperatures across the state and you can clearly see the correlation between the two maps. Where there is more soil moisture, the soils are cooler whereas the drier soils are also hotter.

I mention this because this also has implications regarding air temperatures. Since the atmosphere is largely transparent to the sun's radiation, then the sun does not heat up the air directly. It is the re-radiation from the ground and other surface objects that primarily determines how hot we get during the day. As a result, the hotter the soil gets then it stands to reason the hotter the air temperature will be and hotter soils are also drier soils. Thus the drought is contributing to the heat that we have to deal with and the heat is also contributing to the drought by removing what little moisture is left in the soil. This feedback process is one of the reasons why droughts can be so difficult to break.

Speaking of which, is there any relief in sight? Well, there is a glimmer of hope that we will have at least more than one or two isolated showers or storms over the course of the weekend. Although TS Don is not expected to have a direct effect on our state as it should remain well south into Texas, we are expecting somewhat higher dew point temperatures over the next few days. A little more moisture aloft and a weak frontal boundary dropping to near the Ok/Ks state line will also help somewhat by dropping our daytime highs to near 100 for Fri-Sun. Some locations may even stay below triple digits, but not by much.

This extra moisture will also result in at least a slight chance of showers and storms, primarily during the daytime hours although a few may extend into the evenings as well. Overall, the chances will be on the order of 20-30% through the weekend with the most likely locations in the more favored terrain locations of E and SE OK. At least we have a chance.

After the weekend, all indications are that the ridge aloft will become even more dominant with temperatures well in excess of triple digits for much of the coming week along with little or no mention of rain. Thus, any localized relief that we may get this weekend will be short-lived.

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

Dick Faurot