Powerful storm forecast to sideswipe Corridor

Another powerful storm is expected to bring heavy rains and strong winds this week to the Corridor, but spare the region from the snow it's forecast to dump in neighboring states.

Like its predecessor, the March 'bomb cyclone,” this sequel is expected to generate blizzard conditions in some Midwest areas and heavy rain, thunderstorms and flooding in others.

Iowa already is recovering from severe flooding that struck the western part of the state the worst - and now also cope with Mississippi River flooding on the eastern border.

Depending on how this new batch of water enters waterways, flooding may get worse in the days ahead, and is expected to continue to be an issue this spring.

According to the Quad Cities office of the National Weather Service, which makes forecasts for the Corridor region, the main threat in this area from the intense system will be bouts of rain accumulating Wednesday and Thursday.

'Early indications suggest areas along and north of the Interstate 80 corridor will have the best chance of receiving significant rainfall amounts during this period,” the weather service said. 'It is too early to determine exact impacts to area rivers, but potential rises on tributary rivers in these areas, as well as localized runoff affecting the main stem Mississippi River will have to be kept in mind.”

Forecasters said increasing winds raised concerns starting today and Tuesday about wildfires.

'There will be a risk for grass fires spreading out of control in dried vegetation across portions of Eastern Iowa into far northwest Illinois,” the weather service said.

The storm system was expected to rapidly take shape Tuesday as a frigid river of air 30,000 feet off the ground moves through the Rockies. Then Wednesday, it spills over the open Plains, uncorking the cap on the already volatile situation.

Pressure at the storm's center is expected to drop to 980 millibars or lower. The lower the pressure, the stronger the storm.

Compared with a low pressure of 968 millibars associated with the bomb cyclone a few weeks ago, this latest storm may be slightly less intense. But it's still about as low as pressure gets in the region this time of year.

A large zone from Wyoming to southern Minnesota was already under a winter storm watch, including almost all of South Dakota into northern Nebraska. Much of that area is expecting at least 8 to 12 inches of snow, and some places could see more.

But not the Corridor, where temperatures will be cooler but not down to the freezing point.

The chances of rain Wednesday in the Corridor grow from 60 to 70 percent. Temperatures over those two days are expected to range from a high of 49 degrees to a low of 36.

The Washington Post contributed.