(EXTRACTED FROM FXUS63 KLOT 142014) For the 18Z TAFs... Under a ridge of high pressure, the main concern for the terminals for the remainder of the afternoon and into the evening will be winds. Latest radar imagery indicates that a lake breeze boundary has formed, but is making little inland progress. some of the high res model guidance is suggesting that the lake breeze could push inland through ORD by 21-23z, but with a speed of less than 10kt. Other guidance would suggest that the boundary could stall before reaching ORD/MDW but pushing through GYY. Have included the wind shift to ely at 7kt at 23z. Diurnal cu development across the region should remain sct through the afternoon and then dissipate with sunset while winds go lgt/vrbl as well. The next concern will be pcpn trends for the late night hours and into tomorrow. Latest guidance remains consistent on pcpn spreading from southwest to northeast, with some potential for at least some sct shra toward daybreak and then increasing in coverage and intensity as a low pressure system tracks newd through the Middle Mississippi Valley. High levels of deep layer moisture are expected to be in place, so local pcpn rates should be relatively high at times. With at least some modest instability with the system, expect that tsra would be more embedded within a larger shield of shra, so, have maintained the prob30 group for tsra, but with higher confidence in pcpn chances, have gone with prevailing shra by late morning. Cigs/vis will likely drop to mvfr with the heavier shra/tsra and there is a chance for short periods of ifr conditions.