In my last post I mentioned the uncertainty of the models for the first full week of June
…”There is even great disagreement within the GFS ensembles as to how long the trough will remain in the Great Lakes. Ensemble solutions range from soaking rains for the mid-south to a strong ridge with 90+ temperatures.”
Well, it appears the 90+ temperatures is the solution that will verify.
After another chance of scattered showers and thunderstorms Monday and to a lesser extent Tuesday, a ridge will begin to rebuild over the mid-south on Wednesday. Air from the desert southwest (which has been scorchingly hot recently with highs 105-110) will advect into Kentucky Thursday and Friday ahead of a cold front extending roughly along I-80 from the Plains into the Great Lakes. I foresee highs in south-central Kentucky and the Nashville metro area as high as 92-96 for Thursday and 94-98 for Friday with lows in the lower 70s; take a couple of degrees off those highs each day for the Bluegrass. The limiting factor in reaching those highs (especially Friday) will be the interaction of a cut-off low progged to be located off the mid-atlantic coast with the cold front. There is good ensemble consensus for the existence of this cut-off low but not for its location. According to the 12z operational GFS, the cut-off low will lower heights along the northern fringe of the SE ridge which would destabilize the atmosphere in the Ohio Valley as the I-80 front moves in. This could lead to scattered showers and thunderstorms over Kentucky which would likely act to keep highs Friday in the 88-92 range as opposed to middle to upper 90s. The cut-off could also lead to the front stalling over the mid-south next weekend, which could lead to more precipitation chances.
NOTE: Prior to June 10th, there has not been a maximum temperature >95 in Bowling Green since 1995 and it has only happened eight times since 1950 (although it did happen 15 times in the 1930s alone). It hasn’t happened in Louisville or Lexington since 1953.