Notice the dew point temperature map from the OK Mesonet on the right. This shows a very pronounced gradient over the state with some dry air in NW OK and much more humid conditions elsewhere. The gradient is where a weak boundary managed to move into the state and will be moving back northward as a warm front by morning. More importantly is the lower 70 dew point temperatures that are evident east of I-35.
Anytime the dew point temperature is above 70, that creates a number of issues. First, unless it mixes out with somewhat drier air aloft, these high dew point temperatures also keep us from cooling off much at night and our nights will be much warmer than normal and quite muggy for this time of year. Secondly, dew point temperatures greater than 70 during the day will combine with the daytime heating to create very uncomfortable heat index values. Granted, this is not at all unusual for the state, but it typically does not get like this till later in the summer after we have had a chance to acclimate. This early start to heat index values approaching 100 or perhaps a little more is unusual and you need to be prepared for it. That means taking it easy with the outdoor activities, lots of rest breaks, utilizing the shade as much as possible, and lots of fluids, water in particular.
This combination of heat and humidity also means a few of those popcorn showers or storms could develop on just about any given day. The chances will be on the slim side, but they are also non-zero. So, a few cooling showers or storms are not out of the question and some of them could cause some small hail, gusty winds, and brief, but locally heavy rainfall.
Fortunately, our winds will not be as strong as was the case over the last several days. But, they will be basically from a S to SE direction which will maintain the warm and humid conditions that are much higher than normal for this time of year. Look for our overnight lows to be generally in the low-mid 70s and our daytime highs to range from the upper 80s to near 90 on Wednesday to the low-mid 90s for the latter part of the week.
This early start to summer also means we may see an early start to tropical activity and as Alan mentioned in his excellent morning discussion, some of those disturbances moving along the underside of the ridging aloft may enhance our chances for showers and storms later in the weekend or early next week.
As always, stay cool, stay tuned and check back for updates.