'Not good news': 2 snowstorms coming to Red River Valley, worsening flood risk

The flood outlook is about to get a lot worse with two snowstorms slamming into the Red River Valley, including one that will leave southern Manitobans knee-deep in heavy, wet stuff.

Just as it feels like spring is arriving, with temperatures climbing into the plus range by next week, winter will take another swing at the Red River Valley, which is already inundated with an above-average snowpack in many places. 

One storm is due this weekend, Saturday into Sunday, and the other is expected around the middle of next week.

Both are developing out of Colorado and are expected to drop a combined 10 centimetres in the Grand Forks, N.D., area, according to the U.S. National Weather Service.

CBC meteorologist John Sauder doesn't expect this weekend's storm to hit southern Manitoba too hard.

The snow will likely begin Saturday afternoon or early evening and wrap up midday on a blustery Sunday.

"I'm not expecting a whole lot, and some of it is going to melt on contact," he said.

The second one, though, that's going to be a doozy. It's expected to pack a punch that will hit southern Manitoba from the U.S. border right up into the Interlake Region.

"This one is tracking further north, which means more snow and it is significant. The indications are 20-plus centimetres for southern Manitoba," Sauder said. "It's a big system, it has wind with it."

The snow is expected to start Tuesday evening and be most intense, with strong winds, on Thursday morning. It will eventually move out by Thursday night.

"This is a 48-hour event," said Sauder. "There are going to be schools closed, buses cancelled."

Eventually, that snow and much of what melts in North Dakota, will have to go somewhere. Unfortunately, extremely cold temperatures this winter have allowed frost to penetrate deep into the ground, limiting the ability of soil to absorb runoff.

That means overland flooding and more water running into the Red River, which flows north to Lake Winnipeg.

"What it will do to the flood forecast [in Manitoba] is not good news," Sauder said.

On Thursday, the U.S. National Weather Service said the threat for major spring flooding is increasing with a 50 per cent chance the Red River will reach 11 metres in the Fargo-Moorhead area.

That's up nearly 1.5 metres from the last flood outlook in February and is considered major flood stage.

"Some locations in this area did experience record snowfall for the month of February, and it just keeps coming," said Amanda Lee, a senior hydrologist with the weather service.

The frost level in Grand Forks is about a metre deep while further north, toward the border with Manitoba, the depth is pushing 1.5 metres, she said, adding that cooler-than-normal weather is expected to continue there until close to the end of March and into early April.

That means the shift to normal temperatures could be sudden, resulting in an unwanted fast melt.

"A nice, slow gradual melt would be the ideal situation [because] that's a pretty big area underneath the ground that needs to thaw out before before it can start sucking in any of that moisture," Lee said.

On the positive side, the moisture levels are still below that of the last major flood years in 1997, 2009 and 2011, she noted.

"So we do have that on our side. That's a good thing," Lee said. "But that all depends on this next system and the potential for next week's system, and when we happen to warm up.

"This will definitely be a more active year than we've seen for quite a while."

The province of Manitoba had its flood forecast last week, predicting flooding along the levels of 2011 but potentially as bad as in 2009.

That was before any of the current storm systems were on their radar, however.

The next flood outlook is scheduled to come out in March, but a provincial spokesperson said in an email that timeline could be moved up earlier "if indications indicate the need to do so."