The November 2009 nor'easter (also referred to as "Nor'Ida") was a powerful autumn nor'easter that caused widespread damage throughout the east coast of the United States. This extratropical cyclone formed in relation to Hurricane Ida's remnant mid-level circulation across southeastern Georgia and moved east-northeast offshore North Carolina, before slowly dropping south and southeast over the succeeding several days. The system eventually dissipated on November 17.

The origins of the nor'easter originated from with the remnants of Hurricane Ida, a storm that formed on November 4 over the southern Caribbean Sea.^[1] After tracking through Nicaragua as a Category 1 hurricane, the system attained Category 2 status over the Yucatán Channel. Once in the Gulf of Mexico, the combination of increasing wind shear and cooler waters caused Ida to weaken. The system eventually moved over the southeastern United States on November 10 before transitioning into an extratropical cyclone. Ida's remnant low later dissipated over the Florida Panhandle on November 11.^[1] However, Ida's mid-level circulation led to the formation of a new low over southeastern Georgia, which eventually moved off the coast of North Carolina.^[2] This new low quickly intensified and became a powerful nor'easter that caused substantial damage throughout the Mid-Atlantic States.^[1] Due to the rapid succession of these systems, United States media referred to the nor'easter as "Nor'Ida".^[3] By November 12, the system attained a minimum pressure of 992 mbar (hPa; 29.29 inHg) along with winds of 65 mph (105 km/h).^[4] In combination with a large area of high pressure, a long stretch of easterly, onshore winds impacted areas from Virginia to southern New England.^[5] Tracking parallel to the North Carolina coastline, the system eventually moved onshore near Cape Hatteras by November 13. Due to the high-pressure system situated over Vermont, the low turned southeastward, bringing its center back over water. Gradual weakening took place during this period, though heavy rains continued to fall across much of the Chesapeake Bay area. On November 14, a brief secondary low developed within the system, off the coast of Delaware.^[2] Continuing to weaken, the cyclone resumed a northward track after the high weakened and persisted through November 17, by which time it had moved over Atlantic Canada.^[6]

As the remnants of Ida began to weaken within the developing nor'easter on November 11, flood warnings were already in force from Alabama to Georgia and watches extended northward into the Mid-Atlantic states. Coastal flood watches and high wind warnings were also in effect from North Carolina to Delaware.^[7] Flood warnings were later expanded into South Carolina and coastal advisories were extended to New Jersey and Long Island.^[8][9] Gale warnings continued to grow in coverage, encompassing areas from North Carolina to New Jersey by the afternoon of November 12.^[10] By November 13, the watches and warnings gradually began to be discontinued as the low moved offshore.^[11] Although the Hydrometeorological Prediction Center issued their final advisory on the system later on November 13, flood advisories remained in effect due to residual impacts from the cyclone.^[12]

Following the widespread flooding caused by the storm, a major disaster declaration was signed by President Barack Obama on December 9 to provide residents in Virginia with federal assistance. According to the Federal Emergency Management Agency (FEMA), the cost of federal public assistance in the state would reach $11,227,376.^[24]

• October 2009 North American storm complex: Formed from the remnant circulation associated with Typhoon Melor, in a similar manner
• Winter storms of 2009–2010
• November 2006 nor'easter
• 2009 Atlantic hurricane season