STORM2K

Good afternoon everyone. A very dangerous situation is beginning to take shape in north central Iowa just north of Des Moines this afternoon as a warm front is over central Iowa at this time. Warm moist air continue to spread north out of the Gulf of Mexico. At the same time, colder drier air is advecting south out of Canada. Where those airmasses meet, we're seeing explosive severe thunderstorm development across north central Iowa today. Numerous counties north of Des Moines are under a severe thunderstorm warning. Main threat remains very large and destructive hail. Doppler radar indicates hail up to 2-2.5 inches in diameter with these storms. Golfball to baseball sized hail can be expected with these storms across north central Iowa. The entire Des Moines area as well as Omaha remain under a severe thunderstorm watch until 9 pm CDT. This means severe thunderstorms are possible in and close to the watch area. I suspect more severe wx watches will be issued further east into the Quad Cities and the Chicago area later this evening. Main threats over there is hail up to golfball sized or larger.

Some of these storms in north central Iowa have also shown some rotation, mainly in mid levels, which is only enhancing the large hail threat.

Jim