While Omaha didn’t get a "real” thunderstorm, per se, we still had a severe thunderstorm warning for the metro early Monday morning as strong winds moved into the area and caused quite a bit of real damage.
Just before nine o’clock Monday morning, the National Weather Service in Valley issued a severe thunderstorm warning that included Omaha as the gust front associated with storms to our north arrived. The wind came through quickly with gusts generally between 60-75 mph. Other than a few raindrops, we didn’t get much, if any, rain with this wind. However, it did do quite a bit of damage to trees, either uprooting them or breaking off branches, sent trampolines into neighbor’s yards, and knocked out power to nearly 55,000 OPPD customers around the Omaha area.
These storms started to form in south-central South Dakota around two o’clock Monday morning thanks to a cold front moving through South Dakota and Nebraska. These storms moved eastward into an unstable environment with a lot of energy and moisture to use and quickly intensified over just a few hours. The strongest part of the storm complex stayed northeast of Omaha and reached the Des Moines area around 11 o’clock Monday morning.
The image above shows showers and storms starting to form in south-central South Dakota around two o'clock Monday morning. The image below shows those storms already much stronger, just three hours later.
Winds gusted between 60-75 mph as they moved through parts of eastern Nebraska and western Iowa.
The image above shows the thin green line which is the gust front moving into northwest Omaha just before nine o'clock Monday morning. The image below shows the gust front based on velocity data as the brighter red line showing the gust front moving away from the radar site in Valley and about halfway through the Omaha metro at that point in time.
The image above shows the complex of storms moving into and through the Des Moines, IA area around 11 o'clock Monday morning. The image below shows the radar near Des Moines measuring wind speeds moving towards the radar site at almost 110 mph. Keep in mind, this is measuring wind speeds above the ground, but gusts at the ground translated to about 70-80 mph.
The storms had traveled about 400 miles already by the time they passed through Des Moines with wind damage reports along almost 260 miles.
This type of storm complex is called a derecho. It is a storm with very strong straight-line winds causing a damage path more than 240 miles long with wind gusts over 58 miles per hour. The storm has intensified even more than when it was moving through parts of eastern Nebraska and western Iowa In fact, the severe thunderstorm watch issued for areas ahead of this derecho on Monday morning warned of wind gusts possibly up to 100 mph and is considered a “Particularly Dangerous Situation” as these strong winds can cause tornado-like damage and sometimes quick tornadoes can spin up along the leading edge of these types of storms or even be embedded within. This storm will continue racing eastward through Iowa and into Illinois (its forward speed is about 70 mph!) and is expected to impact the Chicago area this afternoon.
While we are used to “generic” severe thunderstorm warnings in the Midwest and need to heed those warnings, severe thunderstorm warnings for these kinds of storms need to be taken especially seriously. If you find yourself in the path of a storm like this, seek shelter in a sturdy building and head to the basement.
For more info from 3 News Now about the damage in Omaha, click here.
If you have tree limbs that you need to get rid of, Omaha and Bellevue have provided information
about drop-off sites for storm debris:
OMAHA
The City will open three locations for debris dropoff for residents only.
156th and F Football field
Tranquility Park 120th & Maple
11th and Locust
Hours: Tuesday-Thursday 8:00am - 6:30pm
BELLEVUE
In response to this morning's wind storm, the City of Bellevue Public Works Department has opened the City's Tree Dump effective immediately for citizens to drop off tree and brush debris only. The Tree Dump will remain open during daylight hours through 3:30pm on Friday, August 14, 2020.
You can find more information about the dump sites at the following link:
