After minimal change in strength for several days, Nadine finally began to intensify on September 27, due to sea surface temperatures warmer than 79 °F (26 °C). At 1200 UTC on September 28, Nadine re-strengthened into a Category 1 hurricane on the Saffir–Simpson hurricane wind scale.[1] Around the time, satellite imagery indicated that the storm re-developed an eye feature.[27] After becoming disorganized, the National Hurricane Center erroneously downgraded Nadine to a tropical storm on September 29,[28] before upgrading it to a hurricane again six hours later.[29] Nadine had actually remained a hurricane and was intensifying further.[1] Winds increased to 85 mph (140 km/h) on September 30, after the eye became more distinct.[30] At 1200 UTC, the storm attained its peak intensity with maximum sustained winds of 90 mph (150 km/h) and a minimum barometric pressure of 978 mbar (28.9 inHg).[1]