A powerful Arizona storm that produced destructive hail and damaging winds Wednesday is carrying a broad flood threat into Thursday, with National Weather Service offices warning that additional severe thunderstorms remain possible. The risk spans several regions rather than one isolated city, and conditions are changing quickly as the system shifts east.
In central Arizona, the National Weather Service in Phoenix said a flood watch covers the Phoenix metro area through Thursday afternoon and higher terrain through Thursday evening. Forecasters placed Phoenix and areas to the north and east under a slight risk of excessive rainfall, with the flash-flood threat expected to peak Wednesday night into Thursday morning. Thursday storms may again bring large hail, damaging winds and an isolated tornado.
Hail and wind already caused damage
The storm’s first phase was unusually intense for October. The Associated Press reported 2- to 3-inch hail that damaged roofs, windows and vehicles, along with downed trees in Flagstaff and Mesa. AP also reported that tornado watches issued Wednesday were Arizona’s first since October 2010, citing the National Weather Service.
Those damage reports describe Wednesday’s conditions; they should not be treated as a count of statewide losses. No consolidated state damage estimate was available in the cited records Wednesday night. The continuing concern is that repeated rain can create new hazards even where the most severe hail has ended.
Northern and southeastern areas remain exposed
The Flagstaff forecast office said the Pacific system could produce widespread showers and thunderstorms with 1 to 3 inches of rain and locally higher totals. Its Wednesday afternoon forecast discussion called flooding and flash flooding the primary concerns through Thursday, while also noting the potential for severe winds, large hail and isolated tornadoes as the threat shifts toward eastern Arizona.
Official warning products also showed the geographic breadth of the event. The Weather Service’s Arizona alert summary included a flash-flood warning for Moenkopi Wash in Coconino County, a severe-thunderstorm watch for Coconino, Navajo and Yavapai counties, and flood watches extending into Pinal, Graham and Greenlee counties. Warning boundaries and expiration times can change, so residents should use the live NWS map rather than rely on a static list.
Flood watches indicate that flooding is possible, while flash-flood and severe-thunderstorm warnings call for immediate action in the named area. That distinction matters during a fast-moving event: a watch is preparation time, and a warning means a hazard is occurring or imminent.
The practical guidance is straightforward: avoid flooded roadways, move indoors and away from windows during severe warnings, and keep more than one way to receive alerts overnight. Hail, wind and flash flooding can vary sharply over short distances. This article summarizes conditions reported Wednesday night and does not imply that every community in a watch area will experience severe weather.
