OTTUMWA — Severe weather is possible for the area on Saturday, but that’s not forecasters’ main concern.
Heavy rains are expected to make much of the weekend a washout and could cause flooding. Daytime rain Saturday could be in the half-inch to three-quarter inch range. That’s enough for a wet day. But Saturday night’s total is forecast at a whopping 1-2 inches, with another inch possible Sunday.
“We’re going to get into a pretty wet pattern,” said Cory Martin, a meteorologist with the National Weather Service in Des Moines.
The rain arriving this weekend is the remnant of what was Tropical Storm Imelda. The system weakened before making landfall in Texas but still brought very heavy rains to the Houston area.
If rains like this arrived in the spring, when the ground was already saturated, Martin said it would have raised serious concerns about flooding. But large portions of southeast Iowa are currently in the early stages of drought after a very dry late summer. That means the ground should be able to hold much of the rainfall.
There’s a cautionary note, though. The ability of the ground to absorb rain also depends on how fast the rain falls. A 1-inch rainfall over the course of eight hours is a very different situation than that same inch in an hour or less. That means forecasters cannot rule out flooding.
“There is a potential there for flash flooding,” Martin said. And, with the heaviest rain during the night, people will need to be very cautious.
Drivers should slow down, since it becomes difficult to tell the difference between wet pavement and water over a roadway at night. And drivers should never drive into a flooded area.
The rain should come to an end late Sunday. Next week’s forecast is much cooler, with seasonal temperatures in the 70s expected.