Severe Weather (Aug. 20)

10:40 PM Update: Severe thunderstorm warnings stretch across much of central Iowa as a line of thunderstorms mainly capable of damaging winds has developed. I previously was just outside of Ames in attempt of some lightning photos, however a majority of the strikes were within the rain core and thus the attempt was futile. Expect these storms to continue off to the east/northeast with some severe warnings continuing into the nighttime hours. Wind damage will be the main threat, with heavy rains also being a problem for several areas. This may be the last update for the night; for now if you are west of a Spencer to Des Moines to Leon line you should be in the clear for severe weather.

8:15 PM Update: Warnings continue to spread over southwest Iowa; Audubon, Guthrie, Cass & Adair are the latest to go under severe warnings for the bow echo line of storms that is capable of gusts up to 80 mph. Reports have been received with winds of at least 80 mph in other counties previously warned and these storms are likely to at least maintain intensity for the time being. Severe Thunderstorm Watch #626 has been issued, covering much of western & central Iowa until 2 AM.

7:45 PM Update: Severe Thunderstorm Warning has been issued for Pottawattamie & Mills county for damaging winds between 60 and 70 mph; Harrison county now also included. Additional watches are likely to be issued in the next couple of hours, Mesoscale Discussion #1823 discusses the potential for areas north and east of the current tornado watch; MD #1824 discusses the increasing damaging wind threat to the east of the current watch.

7:30 PM Update: Severe & Tornadic thunderstorms are currently moving through southeastern Nebraska and will soon cross the border into Iowa. Harrison, Pottawattamie, Mills and Fremont will be the first tier of counties that will be under the gun from these storms. The storms are currently moving east, on an average speed of 45 mph and should work their way further into the state as the evening turns to night. Other scattered thunderstorms are also developing over northeastern Nebraska & southeastern SD and they may also have some potential of becoming severe. These will also work eastward and make it into the state during the early nighttime hours. Those in the path of storms be ready to take immediate action once warnings are issued, continued updates are possible throughout the night.

4:00 PM Update: The Tornado Watch has been issued for portions of southwest and west-central Iowa. Tornado Watch #623 is in effect until 10 PM; thunderstorms should continue to develop in eastern Nebraska and move into the state this evening. Expect that additional watches may be issued later tonight as storms congeal into line segments and pose more of a wind and hail threat.

3:30 PM Update: This morning saw round 1 of severe weather make its' way through western Iowa. This morning a line of thunderstorms entered the state from SD/NE moving southeastward and became severe soon after entering the state. 3 large hail reports and 4 damaging wind reports came in from those storms, the strongest wind being 70 mph from Storm Lake. Other damage included trees and even a house roof was partially blown off near Charter Oak. Hail reports were fairly minimal, all reports an inch or less from this mornings' storms.

Another round of severe weather is expected over the western half of the state this evening and overnight. The Storm Prediction Center has indicated the thunderstorms with the potential for large hail, damaging winds and isolated tornadoes are likely to develop this afternoon and a watch will be issued shortly. This watch will probably be a tornado watch that covers the western couple tiers of counties and last into the early nighttime hours. Continued Severe Weather Updates Likely this Afternoon...