Chart of the day: Possible tropical cyclone in Gulf around October 13th. Discussion: GFS is on-and-off with a tropical storm risk in the Gulf of Mexico for later next week. Formation in the Bay of Campeche is becoming more certain. Where a system may track is not certain. Medium-range 6-10 Day Forecast Valid October 8-12, 2023 Discussion: The slightly cooler GFS (75% input) is favored over the ECM (25% input) in the East where an early autumn chill develops next week. Risk of <32F is apparent in Wisconsin and the eastern Ohio Valley early next week. Medium-range 11-15 Day Forecast Valid October 13-17, 2023 Discussion: The warm-up remains in the forecast biased toward the West (warmer change) while the East stays near normal. U.S. Medium-range Precipitation Forecast Discussion: Maintaining the 75% GFS/25% ECM combination, the medium-range percent of normal precipitation forecast yields a dry national climate in the 6-10-day period while the Mid-Atlantic States are wet in the 11-15-day period. Note the wet pattern across the Gulf of Mexico and Florida where late season tropical activity is possible. Days 16-20 Extended range Temperature Forecast valid October 18-22, 2023 Discussion: The U.S. is temperate in the extended range. Other previously warm models are also showing a cooler trend. California could see some late season hot weather. Wet weather is focused on the East and extends into the Southern U.S.