FIRST ALERT: Strong to severe storms expected

CEDAR RAPIDS, Iowa (KCRG) – It will be a very active two days across eastern Iowa.

First Alert Days

Today is the first of two First Alert Days in a row. Strong to severe storms are again likely, with a bit of a focus toward the afternoon and evening hours.

Damaging winds, large hail, and tornadoes will all be possible with storms. The tornado risk would be highest in individual storms, with damaging wind threats higher in lines of storms.

Timing Today’s Threats

It appears there are two time frames to watch for storm activity. The first will be in the morning, from about 10:00 a.m. to 1:00 p.m. Storms could develop in a scattered fashion, with some organization taking place within a few hours of development. Strong to severe storms will be possible if this occurs, with a large hail and damaging wind threat.

Another time frame to watch will be later in the afternoon and evening as a frontal boundary moves into the area. Storm development is likely ahead of it, especially near and after 3:00 to 4:00 p.m. With the ingredients we’re going to have in place, storms should fairly quickly turn severe.

The potential for the morning round ahead of it is putting a little extra uncertainty into this round, but I wouldn’t let your guard down even if morning storms occur.

Storms will be a part of the evening, with activity beginning to push out by late evening. Quieter conditions are likely for a good portion of this evening into the overnight.

Another Threat for Thursday

However, we’re not done with storms after this round. Another disturbance will be on the way, with more energy and wind shear (change of wind speeds and/or direction as you go up in the atmosphere) to fuel another severe storm threat. Thursday is a First Alert Day to cover this, and the Storm Prediction Center’s outlook puts most of us in the enhanced risk (in orange) again. Outside of that, a slight risk (in yellow) is in place.

Again, we face two time frames to watch on Thursday.

Timing Thursday’s Threats

The first is in the morning, with many indications in the data that we use to help make our forecasts that a cluster or line of storms will be on the way. These will develop at night in Nebraska and western Iowa. It looks like they should have energy to work with after this evening’s storms, and so that’s why organized thunderstorms will be possible. Damaging winds would be the main threat, with hail also possible. An isolated tornado could occur, too.

Then, things get a bit more complicated. The timing of the morning round and how much energy it uses up will determine what happens in the afternoon. If the atmosphere has a chance to recover, then more storm development is likely. These would form in an atmosphere rather conducive to severe weather, with all of the severe storm hazards possible. The timing on that would be late morning into the evening.

Heavy rainfall could add up to some significant totals in the next few days, too. 1 to 2 inches of new rainfall is quite possible, with isolated higher totals. This could result in some isolated flash flooding. At this time, river flooding looks unlikely with river levels generally running low in the area.

Stay weather-aware Today

The bottom line is that there’s a lot to pay attention to today and tomorrow. We strongly encourage you to stay weather aware, and stay with us for updates through Thursday. You can get those updates here on KCRG.com , KCRG-TV9, and the KCRG First Alert Weather app. We’ll keep you informed on all of the latest details on these threats.