Surprising Iowa Tornado This Past Friday

Large tornado near Hospers, Iowa Friday.  

Here's proof that despite all the good forecasting systems now in place, you can still get an unexpected tornado outbreak.

At least five tornadoes spun up in western Iowa, north of Sioux City on Friday. They hit mostly rural areas, but there was damage. This included at least one house that lost its roof.

The weird thing about these tornadoes is they weren't highly anticipated at all. And they took advantage of just the briefest window of conditions that were conducive to twisters.

Almost always, hours or even a day or so before a cluster of tornadoes, NOAA's Storm Prediction Center will release maps showing at least a marginal risk of severe storms in an area where twisters eventually hit.

This time, the Storm Prediction Center only said there might be thunderstorms in the area, but they wouldn't be severe.

All this goes to prove the Storm Prediction Center is great at forecasting severe weather, but sometimes - not often - conditions break out unexpectedly to prompt bad storms at the last minute.

Even when the tornadoes were ongoing, the prediction center Friday evening put out one of their forecast discussions, saying they would not issue a tornado watch for the area, since the conditions that helped create the tornadoes would rapidly come to an end.

Sure enough, shortly after that statement was released, the thunderstorms producing the tornadoes rapidly weakened Friday evening.

The takeaway for all of us: If there are predictions of possible severe weather hours or days in advance, yes definitely pay attention.

But also keep an eye to the skies, and take any last minute, unexpected warnings seriously.  Things can and do develop in a moment's notice.

Here's a video of one of the Iowa tornadoes: