With the official start of summer just around the corner, today gave us a taste of what is to come. The map on the right, courtesy of the OK Mesonet, shows the maximum heat index values this afternoon and you can see some locations topped out right at 100. That is not likely to change much anytime soon. The only real limitation on our daytime heating right now is how much cloud cover we have on any given day and evapotranspiration from the vegetation and the relatively damp soils.
Since temperatures will remain above normal all week long and since we will have gusty southerly winds each of the next several days, then evaporation rates will be quite high and together with the moisture removed by the vegetation, it will not take long for the soils to dry out. Bottom line is we have a hot, humid week ahead with only a very slight chance of relief from what few showers/storms can crank up on any given day.
Our rain chances are non-zero, but not by much despite the presence of dew point temperatures in the 60s to around 70. Problem is that there is also a layer of warm, dry air just above the surface and that makes it difficult for showers/storms to develop. However, any late afternoon storms that can pop up will be capable of dumping locally very heavy rains in a short time, causing locally damaging winds, and possibly even some small hail. But, the chances of any one location receiving measurable rainfall are less than 20% for at least the next few days.
Those southerly winds will be decreasing to 10 or 12 mph during the overnight hours, then back up into the 20+ range during the daytime hours. This will provide some pretty good ventilation which will help given those high heat index values. Later in the week, a boundary looks like it will make it into KS and stall out well to our north. However, the pressure gradient should also relax by then and our winds should have more of an easterly component. That may be just enough to knock a few degrees off our daytime highs as we should have a little more cloud cover under those conditions. Hopefully, we will also have a few more showers/storms developing during that time frame, but don't get your hopes up too high.
There is not a lot of consistency regarding how that following week will play out. One set of guidance suggests we may be looking at our first triple digit temperatures while another set of guidance paints a very different picture. It will take several more model runs before the guidance begins to converge on a more consistent solution. In the meantime, above normal temperatures and little or no mention of rain will be the general rule for the coming week.
So, stay tuned and check back for updates.