The flood threat forecast for Allen is about where rain goes after it lands as well as how much falls.
The National Weather Service has extended the watch covering Collin County through 7 a.m. Friday, Oct. 2. It begins at 4 p.m. Wednesday, Sept. 30, with slow-moving storms expected to bring 2 to 4 inches across the watch area and localized totals of 4 to 6 inches. All times are Central Daylight Time. The latest update was issued at 2:15 p.m. Sept. 29.
Allen is specifically listed in the alert. Forecasters say runoff could flood creeks, streams, low-lying locations and low-water crossings.
The county's 2022 hazard-mitigation plan identifies Rowlett, Cottonwood, Watters and Russell as Allen's four main creek systems. That geography helps explain why regional flood guidance is locally relevant, but the plan is background information: it does not establish current water levels or predict which crossing will flood this week.
Residents should monitor current forecasts and any later warnings, particularly before driving. A watch means flooding is possible; it does not confirm that every neighborhood is affected. The rainfall estimates cover the full watch area and may differ from the amount that falls at an individual home.
