That urban heat island effect was evident again this morning as Tulsa ‘officially' only dropped to 79 but the surrounding, more rural locations were in the upper 60s and lower 70s. As the day wears on, look for sunny skies with just a few clouds and afternoon temperatures to top out around the 100 degree mark. A few locations did not quite make triple digits yesterday and that should be the case again today with upper 90s and a few triple digit afternoon temperatures. We will also have a brisk southerly breeze at 10-20 mph which does provide some ventilation and the relative humidity will be dropping into the 20% range during the heat of the day. That means the heat index will contribute very little to the discomfort level.
Unfortunately, the flip side of that is the low humidity, hot temperatures, and brisk winds also result in high evaporation rates which are running more than ½ inch per day under these conditions. At that rate, our soils are rapidly drying out which places additional stress on the vegetation and as the vegetation dries out we have an enhanced fire danger situation. Notice the soil moisture map on the right courtesy of the OK Mesonet. There are only a few pockets of adequate soil moisture and that is rapidly being depleted. As the soil and vegetation dries out, that makes it easier for the sun to heat up the air even more and we have a vicious cycle in place.
At least there is a bit of hope over the next few days. The dominant ridge aloft responsible for the heat and dryness is splitting into two parts with a weakness developing right over us. What that means is that temperatures aloft will be dropping by a few degrees which does translate into somewhat lower surface temperatures as well. Not only that, but the weakness aloft will also allow for a little moisture to work its way northward into E OK. So, look for a few clouds this afternoon, a few more on Sunday and will even go so far as to call it partly cloudy on Monday. A few showers/storms are also expected on Monday, with the emphasis on few. If you happen to catch one, count your blessings as the ridge aloft looks to be rebuilding over the state for the rest of the coming week.
So, after a brief break in the triple digit heat and even a very slight chance of a shower/storm, things will likely be heating back up by the middle to latter part of the coming week.
In the meantime, stay cool, stay tuned, and check back for updates.