Flood — Salem (c), Virginia

2013-07-03 to 2013-07-04 · near Salem (c), Salem (c), Virginia

Event narrative

Widespread flooding occurred across the City of Salem as several rounds of heavy rainfall occurred over several days. 48-hour rainfall amounts ending 12Z on the 4th ranged from 4 to 6 inches with isolated 8-inch totals. Two mobile home parks in Salem were evacuated due to high water along Mason Creek and the Salem swift water rescue team performed 12 boat rescues. The Roanoke River through Salem was above flood stage at the Salem Pump Station IFLOWS gage (SPSV2) from the late evening hours of the 3rd through much of July 4th. The gage crested at 9.9 feet (Flood Stage is 7.0 feet) on the afternoon of the 4th. Numerous smaller streams also flooded including Dry Creek and Mason Creek. A person was apparently swept or fell into Dry Creek in Salem during the late afternoon or evening of the 4th when creeks were near their peak stages.

Wider weather episode

The synoptic pattern during the most of the first week of July was favorable for heavy precipitation as the Blacksburg Hydrologic Service Area (HSA) remained within a mean upper trough between two very strong ridges over the western U.S. and over the western Atlantic. Deep southerly flow into the mountains persisted flow through most of this period combining with disturbances emanating from the Ohio Valley to produce scattered to widespread rainfall each day. The persistent synoptic setup was favorable for heavy rain. On the afternoon of the 2nd clusters of storms tracked from the Carolinas north into the portions of the Blue Ridge and parts of New and upper Roanoke river basins. Rainfall amounts were impressive over a large area with widespread 2 to 4 inch amounts across these basins by 12Z on the 3rd, with isolated totals in excess of 4 inches. Heavy rainfall continued moving from south to north on the 3rd with widespread minor flooding reported by the afternoon and evening. The concentration of rainfall across the upper Roanoke basin brought rapid rises both the North and South Forks of the Roanoke River and prompted a River Flood Warning for the Roanoke River forecast point (RONV2) issued at 1204 AM on the 4th, at which time the Roanoke gage had already reached flood stage of 10 feet. The river rose from a stage of 3.56' (1540 cfs) at around 00Z on the 4th (7 PM EDT) to 10.83' (10,600 cfs) in just a little over 6 hours, finally cresting at 14.38' the highest since September 2004 and 10th highest on record. This was also the first time since 1905 at Roanoke that the river reached flood stage in July, although that was measured on a different datum and may not be comparable. Additional rainfall through 12Z on the 4th ranged from 3 to 5 inches across parts of the upper Roanoke and James River basins and a few 24-hour totals were even more impressive including Mason Creek IFLOWS (MSCV2) at 6.30', New Castle IFLOWS (NECV2) 4.61', Mason Cove IFLOWS (MASV2) 4.30' and Craig Valley RAWS (CVGV2) 4.21'.

View location on OpenStreetMap → (37.2782, -80.1012)

Source: NOAA Storm Events Database, event_id 463537. Narrative written by the NWS forecast office that issued the report.