Flash flood warnings blanketed 14 states Wednesday morning, with the National Weather Service tracking 41 active alerts — up from 25 a day earlier — as the flooding threat widened from Arizona’s burn-scarred watersheds into the Appalachian Mountains.
The sharpest impacts remain in northern Arizona. In Coconino County, the Weather Service extended its Flash Flood Warning for the Moenkopi Wash after a river gauge near Moenkopi recorded an 11-foot rise since 12:30 a.m. MST, pushing the waterway to major flood stage. Forecasters said flooding will continue through the morning from Moenkopi down to the confluence with the Little Colorado River, with roads and driveways at risk of washing out. The warning now runs until 9 a.m. MST (10 a.m. MDT).
To the south in Yavapai County, a newly issued warning covers the Agua Fria River, where a gauge just east of Cordes Lakes measured a rapid 4.5-foot rise tied to heavy rain that fell upstream Tuesday evening. The Weather Service said flash flooding was already occurring and urged drivers to avoid the Squaw Valley Road low-water crossing near Black Canyon City.
The overnight jump in alerts also reflects a new cluster of flooding across the central Appalachians. Warnings are active in Ritchie, Barbour, Randolph, Upshur and Wetzel counties in West Virginia, where the Weather Service says Doppler radar has detected heavy rain from thunderstorms, with flooding of rivers, creeks and low-lying, flood-prone areas imminent or already underway. Additional warnings extend into Piute County, Utah, and reach across Colorado, Idaho, Montana, New Mexico, North Carolina, Pennsylvania, Tennessee, Texas, Virginia, Wyoming and Alaska.
Unlike Monday, when the flooding threat centered on Arizona burn scars along with mountain terrain further west, Wednesday’s alert count shows the threat has expanded eastward into the Appalachians even as the Arizona rivers remain in active flood stage. With warnings now spanning river systems from the desert Southwest to the mid-Atlantic, the Weather Service is repeating its standard guidance for anyone who encounters a flooded roadway: “Turn around, don’t drown.” Officials note that water depth over a road is often impossible to judge from inside a vehicle, and that roads and driveways near warned waterways can wash out with little notice.
Most of Wednesday’s warnings are set to expire by mid-morning, but the Weather Service cautioned that additional flash flood warnings are likely later in the day as more thunderstorms move over ground already saturated from this week’s rainfall.