On the following day, the storm began moving northeastward and threatened the Azores but late on September 19, Nadine veered east-southeastward before reaching the islands.

Nadine transitioned into an extratropical cyclone on October 3, and merged with an approaching cold front northeast of the Azores soon after.

[3] Based on satellite intensity estimates, the National Hurricane Center declared the disturbance as Tropical Depression Fourteen at 1200 UTC on September 10, while the storm was about 885 miles (1,424 km) west of Cape Verde.

[4] Late on September 10, convection began to increase slightly near the center, but because Dvorak intensity T-numbers were between 2.0 and 2.5, the depression was not upgraded to a tropical storm.

Geostationary satellite imagery and scatterometer data indicated that the depression strengthened into Tropical Storm Nadine at 0000 UTC on September 12.

[1] By September 12, a central dense overcast developed and due to favorable conditions, the National Hurricane Center noted the possibility of rapid deepening.

[7][8] By early on September 13, convective banding wrapped almost completely around the center and cloud tops reached temperatures as low as −112 °F (−80 °C).

However, because microwave satellite data could not determine if an eye had developed, Nadine's intensity was held at 70 mph (110 km/h)—–just below the threshold of hurricane status.

[9] The National Hurricane Center noted that "the window for Nadine to strengthen may be closing", citing computer model consensus of an increase in wind shear and little change in structure.

[13] Due to an increase in satellite intensity estimates and re-organization, Nadine was upgraded to a hurricane at 1800 UTC on September 14.

[15] Late on September 16, the eye became tilted and disappeared, convective bands began disorganizing, and the overall shower and thunderstorm activity waned since early that day.

[1] Early on September 22, the National Hurricane Center noted that regeneration into a tropical cyclone was a distinct possibility.

[24] The remnant low pressure area soon moved over warmer seas and a low-shear environment, causing deep convection to re-develop.

Another blocking ridge over the Azores forced Nadine to move west-northwestward on September 24, causing it to execute a small cyclonic loop.

[26] By September 26, Nadine curved south-southwestward to southwestward around the southeastern portion of a mid- to upper-level ridge over the western Atlantic.

[1] 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).

[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).

[32] Due to strong wind shear and cold sea surface temperatures, showers and thunderstorms rapidly diminished, and by late on October 3, Nadine became devoid of any deep convection.

[33] At 0000 UTC on October 4, Nadine transitioned into an extratropical low-pressure area, while about 195 miles (314 km) southwest of the central Azores.

After re-generating, Nadine posed a threat to the Azores again, which resulted in a tropical storm watch for the entire archipelago at 1500 UTC on October 1.

[46] The remnants of Nadine produced a plume of moisture that dropped heavy rainfall over the United Kingdom, particularly in England and Wales, reaching 5.12 in (130 mm) at Ravensworth in the former.