Michael was preceded by a so-called Predecessor Event (PRE) which brought moderate to heavy rainfall across several counties through early on the 11th of October. A deep moisture plume surged north on the periphery of the subtropical ridge with very precipitable water producing high rain rates. The heaviest rainfall from the PRE was concentrated in the Watauga and upper of the New River basin where the rainfall ranged from 2 to 6 inches with isolated higher amounts in the 24 hours ending at 700 AM local time on the 11th of October.

Heavy Rain in WATAUGA, NORTH CAROLINA
From 10-OCT-18 06:00:00 to 11-OCT-18 06:00:00 (EST-5)
Location: BOONE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP site at Boone 1 SE (BOON7) measured 5.24 inches in 24-hours ending at 700 AM local time on the 11th. This was the 2nd highest 24-hour rainfall total in October (after the 5.95 inches October 24, 2017) and 8th highest for any day since records began in 1980.

Heavy Rain in ALLEGHANY, NORTH CAROLINA
From 10-OCT-18 06:00:00 to 11-OCT-18 06:00:00 (EST-5)
Location: SPARTA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP site at Sparta 3.5 SSW (SPRN7) measured 4.45 inches in 24-hours ending at 700 AM local time. This was the 5th highest 24-hour rainfall total for any October day, with data from 1942-2009 and starting again in 2018.

Heavy Rain in WILKES, NORTH CAROLINA
From 10-OCT-18 06:00:00 to 11-OCT-18 06:00:00 (EST-5)
Location: NORTH WILKESBORO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP site at North Wilkesboro (WKSN7) measured 5.17 inches in 24-hours ending at 700 AM local time on the 11th. This was the 2nd highest 24-hour rainfall during the month of October and 6th highest for any day, with records dating back to 1921. This value also falls into the 90 percent confidence interval (4.88-5.82 inches) for a 10-year recurrence interval event (.10 annual exceedance probability) per NOAA Atlas 2.

Flash Flood in ALLEGHANY, NORTH CAROLINA
From 10-OCT-18 16:15:00 to 10-OCT-18 22:15:00 (EST-5)
Location: ENNICE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Brush Creek was reported out of its banks and observed flowing  over Scenic Valley Road which was also shown in a social media post. Other social media posts also showed flash flooding with water over six inches deep flowing across several roads including the intersection of the Blue Ridge Parkway and Highway 18 and Saddle Mountain Church Road near the Blue Ridge Parkway.

Flash Flood in WILKES, NORTH CAROLINA
From 10-OCT-18 16:00:00 to 10-OCT-18 18:00:00 (EST-5)
Location: WILKES CO ARPT
Flood cause: Heavy Rain
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Emergency Manager

There were numerous reports of flash flooding in the Wilkesboro and North Wilkesboro areas as 2 to 4 inches fell in a just a few hours.  News reports called it some of the worst street flooding in 'years'. A mud slide temporarily blocked River Road near the Colonial Drive intersection and North Wilkesboro police helped a woman and a young child exit their car and get to safety when the car stalled in high waters on East Main Street. Flooded locations in Wilkesboro included College and East Main streets. Cub Creek left its banks and flooded portions of Cub Creek Park.

Heavy Rain in WILKES, NORTH CAROLINA
From 10-OCT-18 15:15:00 to 10-OCT-18 16:15:00 (EST-5)
Location: NORTH WILKESBORO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A local mesonet site in downtown North Wilkesboro measured 2.00 inches of rain between about 415 and 515 PM local time. Numerous flash flood reports were received in the area.

Heavy Rain in ALLEGHANY, NORTH CAROLINA
From 10-OCT-18 07:00:00 to 11-OCT-18 07:00:00 (EST-5)
Location: GLADE VLY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

The CoCoRaHS site at Glade Valley 3.0 ENE (NC-AG-3) reported 7.49 inches for the 24 hours ending at 800 AM local time. Streets and fields were flooded and water draining off the hills. According to NOAA Atlas 2, this 24-hour amount falls into the 90 percent confidence interval (6.49-7.85 inches) for a 50-year rain event (.02 annual chance).  The observer also reported 4.21 inches in 8 hours from 800 AM to 400 PM local time.

Heavy Rain in WATAUGA, NORTH CAROLINA
From 10-OCT-18 06:30:00 to 11-OCT-18 06:30:00 (EST-5)
Location: BOONE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

The CoCoRaHS site at Boone 4.5 E (NC-WT-37) reported 6.73 inches for the 24 hours ending at 730 AM local time.  According to NOAA Atlas 2, this 24-hour amount falls into the 90 percent confidence interval (6.51-7.91 inches) for a 25-year rain event (.04 annual chance).