Severe Thunderstorm Chances

7:15 PM Update: Severe Thunderstorm Watch #668 is in effect for portions of extreme western Iowa until 2 AM. Expect other watches to be issued tonight for other portions of the state as the threat moves off to the east. Currently thunderstorms over NE and KS have become severe with a cluster of thunderstorms also over northwest Iowa. The cells over northwest Iowa have intensified and a severe thunderstorm warning was just issued for Plymouth county, possible large hail. Expect watches and warnings over the western third of the state through 10 PM when the next update will likely be issued...

4:45 PM Update: Thunderstorm chances still likely over the entire state this evening and throughout the night as a cold front sweeps across the state. The severe risk however has fallen with warm temperatures aloft and weaker instability than what was expected. Thunderstorms may still become severe this evening over areas of NE/KS and move into western Iowa by sunset with a risk of mainly damaging winds and isolated large hail. These thunderstorms will continue across the state reaching I35 after midnight and being in extreme eastern Iowa by sunrise. The severe weather risk will diminish after midnight with only an isolated severe storm or two east of I35.

11:40 AM Update: Another update from the SPC has spread the slight risk over the remainder of the state, essentially putting the entire state under the risk for severe weather during the night. Thunderstorms expected to increase in coverage during the evening hours over eastern parts of SD/NE/KS; spreading east into MN/IA and MO during the nighttime hours. By the time the thunderstorms reach the state tonight, mainly a linear or line of storms is expected. The severe threat will most likely be damaging winds with isolated large hail, the severe threat should however begin to diminish after midnight as storms move past central Iowa.

7:20 AM Update: With a strong cold front coming into the plains this afternoon and sweeping through during the overnight hours, expect the possibility of severe weather over the western half of the state. Current Storm Prediction Center outlook has much of the state under a slight risk, only extreme eastern Iowa is not included. This outlook indicates that thunderstorms developing over eastern NE/SD will begin this evening and spread into western Iowa by early nighttime hours if not sooner. Initial threats will include large hail, damaging winds and isolated tornadoes for the extreme western quarter of the state. As the storms continue into the nighttime, expect the chance for mainly large hail and damaging wind gusts for the remainder of the state. By morning expect these thunderstorms to mainly be confined to the eastern third of the state and even they should have moved out of the area by mid-afternoon.

Highs today before the front will be warm and humid, 80s throughout the state; lowest in the east due to cloud cover and possible showers. Lows tonight will range from the upper 60s in the east to lower 60s in the west as the cold front continue to move through. Highs to end the work week will be quite nice, mid 70s to near 80 from north to south; Lows in the 50s.

More Updates possible on the severe weather threat as it becomes more defined during the afternoon hours...