All of Iowa, Severe Weather

Severe Weather Possible Wednesday

Note: Yes I know the date is supposed to be May 11th not the 12th on the image.

The Storm Prediction Center has a slight risk on severe weather for the southern and southeastern counties of the state on Friday. Surrounding this is a marginal risk that includes southwestern through central into eastern and northeastern Iowa. The main threats look to be from large hail and damaging straight line winds. A tornado is possible as well but is not considered a main threat at this time.

A system (separate from the one that came through last night into today) will move into the state from the west. Some sunshine during the afternoon will help to destabilize the atmosphere and may lead to some thunderstorm development which in turn could turn severe. There are some limiting factors that could preclude severe weather chances. First off, there will be some thunderstorms possibly ongoing during the morning hours over the state. This will be left over nocturnal activity from Kansas and Nebraska. If it were to stick around too long, this would keep clouds around longer, temperatures lower and storms at bay. Another factor could be storms forming to our south over Missouri. This could cut off the moisture flow into any activity that may try to develop over our area. We don’t think this will be a big factor, but it’s something to watch nevertheless. Another factor could be a capping inversion setting up across the state. SPC has mentioned this in the outlook and if we get too strong a cap, thunderstorms may not fire (we don’t think the cap will be too strong however nor too weak either)

What we are likely to see is a warm front situated over the southern counties of the state. Storms are likely to fire along and south of the warm front and could become cellular. This would likely happen during the mid-afternoon into early to mid evening on Wednesday. These storms will move to the east and northeast, although the further north they get from the front, the more elevated they will likely become.

The severe weather threat looks to move out of the state by 10pm Wednesday night with only a few showers possible the rest of the night into early Thursday morning. Heavy rainfall is not a major problem, although with the amount of rain some areas have seen over the last 24-36 hours, some localized flooding is possible and precautions should be taken if Flash Flood Warnings are issued.

Stay tuned for any changes to this possible severe weather episode.