Rain from a hurricane that made landfall in Mexico was threatening on Wednesday to inundate drought-stricken parts of Texas that haven’t seen heavy rain, or any rain, in months. Other pockets of the Central United States, including parts of Colorado, Kansas and Iowa, also faced the threat of heavy rain, which could lead to flash flooding. At a news conference this week, Gov. Greg Abbott of Texas said officials had positioned crews and equipment across the state ahead of moisture sent into the region from Hurricane Polo, which made landfall twice this week on Mexico’s western coast — about 500 miles from the parts of Texas expected to be hit by storms.

At Dallas Fort Worth International Airport, no rain fell from July 16 to Sept. 20, a 67-day stretch that tied for the second-longest period without measurable precipitation, according to the National Weather Service. More than 43 percent of Dallas County is experiencing an exceptional drought, the highest category of drought conditions. Over the next two days, the heaviest rainfall is expected in a band stretching across Central Texas from the Mexican border and into Oklahoma. Downpours could drop up to five inches of rain in a short period, creating a severe risk of flash flooding.

Emergency managers were also concerned about lingering rainfall over southeastern Colorado. In New Mexico, Tuesday's storms caused concerns that three dams could fail, leading to evacuation orders. The southern part of the state typically gets about eight inches of rain a year, but an area near Las Cruces, N.M. received about one to three inches of rain on Tuesday, prompting officials to worry that a dam could overrun and cause flooding.