We continue to keep a close eye on the forecast for your Sunday. Over the past few days, we have been alerting you to the possibility of severe weather across the western 2/3rds of the state. This evening, the threat of severe weather remains.
A cold front will be advancing to the southeast late tomorrow afternoon, into the early evening. This will be the main focus for storm development. Storms will be developing ahead of this front along a line extending from Minnesota, northwest Iowa, eastern Nebraska, and back on into Kansas. Ahead of this cold front, dew point temperatures will be in the mid 60s. This will help prime the atmosphere and make it unstable.
The greatest risk of severe weather will occur from eastern Nebraska to northwest Iowa (light blue outlined area in the image above). This is where large hail (greater than 2 inches in diameter), damaging winds, and a few tornadoes will be possible. Storms will hold off until afternoon due to the cap. This cap will weaken by the afternoon and this will allow storms to form. Storm development looks to be around or shortly after 4pm Sunday. Initially these storms will be isolated. This is when the best chance for tornadoes will occur. Storm motion Sunday will be very slow, so a flooding threat will also be likely as these storms will produce very heavy rainfall totals. These storms will begin to line out as the evening sets in, and this is when the tornado threat will transition to a damaging wind event.
If you have outdoor plans tomorrow afternoon, you will want to keep a very close eye to the weather as it is a holiday weekend and many people will be out enjoying the wonderful weather. Our chase team is keeping a close eye on this system, and will have our chase plans in the morning. Continue to look for all the very latest updates on our Facebook and Twitter pages, and right here at www.iowachase.com.