Recap: Twin Cities Severe Weather Event on June 21, 2013

Why was there so much damage throughout the Twin Cities?

While many environmental factors go into a thunderstorm a few characteristics contributed to the intense rainfall and strong winds as a result of the June 21, 2013 event.

1. An Unstable Atmosphere: The atmosphere was unstable which enhanced stronger winds along the surface rather than higher up in the atmosphere resulting in the widespread damaging wind seen throughout the Twin Cities.

2. Saturated Soil & Heavy Rains: Previous heavy rainfall over the last few months in the area had soil throughout the Twin Cities saturated which allowed for trees to be uprooted more easily as well as urban flooding to occur as there were not many places for the water to go as it fell leaving low lying and/or poorly drained roads vulnerable during the downpour. Some area reported two inches of rainfall and had many reports of flash flooding nearby.

3. Radar Loop: The conditions together converged over the Twin Cities (Note: Click the image to see the radar loop in action).

Loop image of radar showing wind direction from the radar (located in eastern Carver County). Green colors indicate motion towards the radar and red colors indicate motion away from the radar. As the winds move into the Twin Cities you can see how the winds are green coming from the west and red coming from the south converging over the Twin Cities. (Source: NWS, Twin Cities)

Why Didn’t the Sirens Sound?

In Hennepin County sirens sound for winds in excess of 70 mph. While winds were close to the barrier in Hennepin County they did not exceed 70 mph and the sirens did not sound accordingly. I am curious to see if the policy changes based upon the damage and the widespread downed power lines throughout the Twin Cities metro area on June 21st.

Wind speeds recorded on June 21, 2013 (Source: NWS, Twin Cities)

Just how much damage was there?

In the National Weather Service-Twin Cities report there were so many reports provided that not all of the reports could be shown. A similar storm came into the area the following evening and caused similar damage throughout the Twin Cities area for a second evening.

Across the Twin Cities over 97,000 residents did not have power as a result of the severe weather event. Xcel Energy had the power grid completely restored by 10:00pm the following Wednesday, five days after the storm rolled through the area. Xcel Energy said they had to replace over 100 poles and 37 miles of utility wire throughout the restoration process.

Tree branch along a utility line in the middle of CR-101 in Plymouth, MN (Source: Kitty Hurley)
Flash flooding along a road in New Hope MN (Source: Fox 9 News)
Uprooted trees in the Longfellow neighborhood in Minneapolis, MN (Source: Minnesota Public Radio)

What is in store for future events?

I foresee many changes in the warning program, coordination efforts as well as the public and private relationships in future events from the severe weather event last month. The Twin Cities haven’t seen such a widespread event since the derecho events in 1998 effecting much of the state. While events like the one seen on June 21st are devastating and costly they prove to be beneficial for future events that may have even more costs or disastrous effects.


1. National Weather Service-Twin Cities Office Recap:

2. Pioneer Press News Release:

3. Minnesota Public Radio News Release:



Meteorology has always intrigued me; living in a metropolitan area covering 6,365 square miles and 3,615,902 residents (Census 2010) making it the 13th most populous metropolitan area in the United States makes weather prediction very difficult across the viewing area. It wasn’t until a few years ago I realized how difficult such a prediction could be. There are many days throughout the year where the northwestern Twin Cities metro region will receive large amounts of precipitation and the southern cities wouldn’t see a cloud in the sky. Meteorology, in particular severe weather, has always fascinated me and I have always been interested in the formation of severe weather and tornadoes.

Development of the Minneapolis/St. Paul metropolitan area from 1966-2006. Map published by Metropolitan Council.

I recently read meteorologist, Mike Smith’s books titled, Warnings: The True Story of How Science Time the Weather (2010) and When the Sirens Were Silent: How the Warning System Failed a Community (2012). Both of Smith’s books discuss the evolution in warning the public of weather warnings in the last fifty years to today. If you haven’t already, read both of Smith’s books – you will not be disappointed.


One of the reoccurring themes in both of Smith’s books is the Forecaster’s Lament from an anonymous writer (113):

“And now among the fading embers;
These in the main are my regrets,
When I am right no one remembers;
When I am wrong no one forgets.”

It is very much true in Minnesota where weather is dynamic and can change in the matter of hours. Minnesotans have coined the phrase, “if you don’t like the weather just wait five minutes and it will change.”  Often time’s meteorologists take the blame for the dynamic weather seen across the Midwest. There are times when I see the variations across the metropolitan region where I wish I could send a direct response to the local meteorologists to show my support of them because they are accurate more than the public gives them credit for and they have saved many lives throughout their careers.

The top three things I took away from Smith’s books were:

1. Time;
2. Communication; and
3. Innovation.


Smith mentions the time it took to perfect the warning system in the United States. “It was only nine years after President Kennedy had committed America to putting a man on the moon that Neil Armstrong took his first lunar steps. It took double that amount of time to get a network of Doppler radars running in the United States” (187).

We cannot expect overnight results, no matter the urgency. Some things take time despite their needs today.


Things have certainly changed in the last 100 years. Tornadoes continue to strike as they always have destroying homes and towns along the way but deaths and injuries are on the decline. Why? The National Weather Service technologies, including NOAA weather radios, as well as broadcast meteorologists have been able to warn residents of danger hours and in some cases prepare days in advance.

For instance, as Smith writes, “The Greensburg (May 4, 2007) and Udall (May 25, 1955) tornadoes were as identical as two tornadoes could possibly be. Both occurred in the same state – Kansas – so there is similarity in the building codes governing the two towns. Both occurred well after dark. The two tornadoes approached from the south, rather than the much more common southwest. And because of the southern approach, the tornadoes themselves were obscured by rain and hail…In both cases, 95 percent of the buildings were destroyed, and the other 5 percent were damaged. Both tornadoes were F5 intensity…The two supercells [from radar] are virtually identical. In the Udall (1955) tornado, eighty-two people were killed and 260 were injured. The casualty rate in the town was 68 percent. In Greensburg (2007), with triple the population, nine people were killed and fifty-nine were injured. The casualty rate in Greensburg was less than one-fourteenth that of Udall’s” (275-6). “Two hundred thirty-two lives saved in a single evening. Meteorology has come a long way since my dad came running into the house shouting ‘Here it comes!’” (279).

There is, unfortunately, the Joplin tragedy. Due to many factors, warnings were not provided in either a timely or accurate fashion to the city of Joplin. There were “too many tornado warnings with no tornado. Too many siren activations. People learn from experience. Sometimes they learn the wrong thing. The citizens of Joplin were unwittingly being trained not to act when the sirens sounded” (14). “[The National Weather Service] were behind the curve. But May 22, 2011, was an extraordinarily busy day. For example, a fatal tornado, EF-2 in intensity, struck Minneapolis two and a half hours before the Joplin tornado…Forecasters were behind events and confused about the location of the threat. Their warnings included incorrect locations of the tornado; incorrect directions of movement, focusing on Galena when the threat had shifted to Joplin; and incorrect threat emphasis, with discussions of golf-ball and then baseball-size hail as the tornado was about to move into and through Joplin. These issues only served to confuse what should have been an urgent and straightforward message: Take cover Joplin” (42-3).

AccuWeather Enterprise Solutions (AES) predicted tornado path at 5:16pm compared to the National Weather Service (NWS) predicted tornado path as the tornado entered Joplin. Image source: Mike Smith Enterprise Blog (

This is why, to this day, even as technologies have altered the way we can predict the weather – we still need to remember to deliver clear, concise reports to residents. One message delivered a minute earlier could save a life.


Both time and communication are key but one of the most important takeaways from Smith’s books is innovation. As Smith writes, “Good  science does not have to take billions of dollars. It requires dedication, outside-the-box thinking, and a willingness to go where the data and experimental results might take you” (284).

I believe this is not only true for science but in everything we do every day. We should never go “through the motions” but rather learn something new every day and apply our knowledge elsewhere in our lives.

I-35W Bridge Collapse Anniversary

Today marks the fifth anniversary of the devastating I-35W bridge collapse in Minneapolis, Minnesota that took 13 lives and injured 145 others. It was 6:05pm on Wednesday August 1, 2007 during the peak of rush hour when the bridge gave way and took nearly 100 vehicles stopped in traffic with it into the Mississippi River.

The incident was one of the worst man-made Minnesota has ever seen and while we reflect on those effected by the collapse we can certainly say we are more prepared than we were in 2007. Bridges are examined much closer than they were prior to the collapse and given more funding to repair and even replace the most critical of structures.

State and county engineers say the I-35W disaster raised awareness of bridge safety, tightened inspection and reporting requirements and made it easier to get state and federal money to repair or replace aging bridges.

I-35W Bridge Collapse in Minneapolis, Minnesota on August 1, 2007