Dangerous heat and humidity this afternoon followed by the potential for organized severe weather this evening highlights the forecast this morning.
Models remain quite consistent in dew points rising into the upper 70s and lower 80s across a large portion of the area by this afternoon, as we have seen on several occasions this summer.
The pooling of highest dew points across northern sections and near the Arkansas River Valley supports heat indices of 110-113 in these areas and the heat warning/advisory will be left in its present configuration. At this point, it appears most of northwest Arkansas will remain just below advisory levels.
By later this afternoon and especially this evening, an advancing cold front will encounter a very unstable airmass over northeast Oklahoma. Strong to severe storms will likely develop along the front across Missouri then quickly build back into northeast Oklahoma primarily just after midnight.
Storm mode should become linear rather quickly with damaging downburst winds being the main hazard. Progressive nature of storms should preclude a significant flash flood threat, however, given forecast values near two inches in pre-frontal airmass, excessive rainfall rates are likely for at least a brief duration. Storms will weaken in intensity overnight as they gradually push south.
A frontal boundary will remain in the vicinity of the Red River Tuesday into Wednesday with shower and thunderstorm chances persisting south of I-40.
Severe weather threat during this time frame appears considerably lower, but the threat of heavy rainfall will continue.