The National Weather Service has lowered its projected flood crest range for the Red River in Fargo by a foot.
The weather service says the river could crest as early as Sunday between 39 and 40 feet. Previous estimates put the river as high as 41 feet.
But a possible weekend storm is still cause for concern. The NWS says the storm brings the potential for up to three-quarters of an inch of rain, with heavier amounts possible if thunderstorms develop.
NWS forecaster Mark Ewens said where the rain falls will be critical, and it's too early to predict the exact storm track.
"This system is just now moving in to the west coast of the United States, and it's a fairly large powerful storm," Ewens said. "So we have to wait and see exactly how that plays out once it moves into the plains. The Rocky Mountains do really weird things to weather systems. So once they start to form out in the plains we'll have a really good idea where it's headed."
Ewens said rain upstream from Fargo-Moorhead would likely prolong the crest or bring a second crest next week.
Forecasters hope to have a better picture of the developing storm by Friday.
Fargo Deputy Mayor Tim Mahoney said he's pleased at how much volunteers have already accomplished along the Red River.
"We're very pleased about the volunteers yesterday. [We] anticipated sandbag dikes would take three days and got 80 percent done yesterday," Mahoney said.
He said they anticipated getting all of the sandbagging done early Thursday afternoon. The city has suspended its ongoing request for volunteers from the community.
Fargo Mayor Dennis Walaker said once those protections are set, then monitoring the dikes and levees 24 hours a day becomes essential. The city is using a wide number of different equipment and devices to hold back the water.
"When you think about the process of having 58 miles of a variety of devices out there, thanks to our engineering department, with the different tools coming forward there are always opportunities for failure," Walaker said.
Across the river in Moorhead, the sandbag work is about 60 to 65 percent complete. Students from the school district have received a state waiver to be released from class Thursday and Friday to help with the sandbag efforts in that city.
Tributaries that flow into the Red River will have a big impact on the flood crest in addition to the weather. Right now the Sheyenne River in North Dakota has backed up in rural areas because it can't flow into the swollen Red River.
(The Associated Press contributed to this report.)