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Developing a Climate Forecast for Iowa
Sandbags in Fargo, N.D., spring 2010. (Photo by Scott Rowe)
In 2010, Scott Rowe spent his spring break sandbagging in Fargo, N.D., to help protect the city from floodwaters. At the time, he was an undergraduate studying atmospheric sciences at the University of North Dakota. The sandbagging effort was successful, and Rowe says he was intrigued to see how the community came together to respond to the flood threat. “It was fun. We were overfed, almost,” Rowe says, remembering the outpouring of gratitude and food for the volunteers.
He also came away with a serious interest in hydrology, which brought him to IIHR and the Iowa Flood Center for graduate studies. But Rowe has been interested in weather for a long time. He spent the first 12 years of his life in Tornado Alley. Since Texas homes rarely have basements, Rowe took shelter in the bathtub when tornado warnings were issued, sometimes with his bike helmet on for extra protection.
From then on, Rowe was fascinated by weather. He is now working on a master’s degree at IIHR under the supervision of his advisor, Gabriele Villarini. Together, they are developing a statewide climate forecast for Iowa to offer a basic idea of what precipitation can be expected in the season ahead. Their forecasts will be basic by design, Rowe explains, and limited to predicting whether precipitation will be average, above average, or below average. “It’s difficult to even make an exact precipitation forecast for 24 hours for now,” he says. Compound that over an entire season, Rowe says, and that error can become “ginormous.” With that said, depending on the success of the new system, Rowe and Villarini may attempt more quantitative statements in the future.
Rowe is analyzing Iowa’s climate data to rank the average monthly temperature and precipitation back to 1950. By correlating the atmospheric anomalies associated with the wettest and driest months, Rowe says, they’re able to use a number of existing climate models to develop a long-lead climate forecast.
Once Rowe and Villarini have a few forecasts under their belt, they’ll evaluate the accuracy by comparing their prediction to what actually happened. That information will be vital to improving the predictions, Rowe explains. “A bad forecast model is of no use to us.”
Although Rowe has no interest in broadcasting, he enjoys weather forecasting and hopes to find a job with the National Weather Service or some other forecasting agency after graduation. He may even find his way back to North Dakota, where he first got his feet wet in weather forecasting.
NASA, IFC Event in Calmar CANCELLED
Updated, June 12, 11:30 AM
Due to severe weather forecasts, the NASA and Iowa Flood Center public outreach event scheduled for Wednesday, June 12 at 7 p.m. in Room 104, Wilder Business Center, on the Northeast Iowa Community College campus has been CANCELLED.
Representatives from NASA and the Iowa Flood Center will remain stationed at research sites to track the storm and monitor instrumentation.
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The public and media are invited to meet representatives from NASA and the Iowa Flood Center at an outreach event at 7 p.m. Wednesday, June 12, in Room 104 of the Wilder Business Center on the Northeast Iowa Community College campus in Calmar, Iowa.
This spring, NASA and Iowa Flood Center researchers have deployed state-of-the-art instruments across eastern Iowa to collect ground data on precipitation as part of the IFloodS (Iowa Flood Studies) campaign. A number of these instruments are currently located in the Turkey River watershed, including a weather radar on the southern edge of Calmar, another near Elkader, and numerous rain gauges and soil moisture probes throughout the watershed. The project is part of NASA’s Global Precipitation Measurement (GPM) mission, an international satellite mission that will set a new standard for global precipitation measurements from space.
Rain gauges (similar to those shown above) are deployed across the Turkey River watershed in northeast Iowa for the IFloodS campaign to calibrate NASA’s new satellite–based rainfall measurement system.
“We’re trying to figure out how well our satellites estimate rainfall,” says Walt Petersen, GPM ground validation scientist at NASA’s Wallops Flight Facility, Wallops Island, Va. “This study is unique in that it takes space-borne observations, it takes ground-based observations, and it brings those things into a modeling framework that should further our ability to predict flooding.”
Petersen will be one of the speakers at the outreach event, which is open to the public. He will be joined by Iowa Flood Center Director Witold Krajewski, based at the University of Iowa. Krajewski, who was instrumental in bringing the NASA team to Iowa, says the project will likely benefit the people of Iowa in a very real way.
“Our hope is that with all that information, we can really improve our flood forecasting models,” Krajewski explains.
Water Over the Bridge
Floods can happen unexpectedly, and often catch motorists off guard. The results can be fatal — in fact, as little as two feet of water can carry away even SUV-sized vehicles. According to the National Weather Service, more than half the deaths caused by flash floods happen when vehicles are swept away by floodwaters.
Timely, accurate information would give motorists a better chance of getting home safely, but given the vast number of road-stream intersections in Iowa, how is it possible to reliably predict when and where flash flooding will occur?
In cooperation with the Iowa Department of Transportation (DOT), researchers from the Iowa Flood Center (IFC) at the University of Iowa are working to do just that. They have initiated a two-year research project to design, implement, and evaluate an innovative flood forecasting system to help authorities better predict flooding potential in a watershed.
“Our vision is a paradigm shift in water-level observation and stream-flow modeling,” explains IIHR Research Engineer Ricardo Mantilla. With IFC Director Witold Krajewski, Mantilla has designed a hybrid flood forecasting system that combines real-time water level observations with an advanced mathematical hydrologic model. “This system gives us the best of both worlds,” Mantilla says.
Stream-stage sensors will be installed on bridges in the Squaw Creek watershed to help develop a flood forecast model for Iowa.
IFC researchers developed an affordable bridge-mounted electronic stream-stage sensor that uses sonar to measure the distance from the sensor to the water’s surface. Researchers deployed 20 of these sensors within the Squaw Creek basin in Central Iowa, upstream from its junction with the South Skunk River. The automated sensors measure stream water height and transmit the information automatically to the Iowa Flood Center, where it is available online through the Iowa Flood Information System.
The data these sensors collect are combined with a state-of-the-art mathematical model that uses detailed digital elevation models of the landscape, NEXRAD rainfall, and soils and land use data to accurately represent flow through the watershed. Sensor-collected data is used to continuously refine the hydrologic model’s reliability until it can provide dependable predictions at locations where no sensor is present.
“By the end of the two-year project, the system will provide accurate predictions of flooding potential for each and every road/stream intersection in the basin,” Mantilla says. “It will establish the basis for a customized real-time flood and flash-flood forecasting system for roads and bridges across the entire state — thus increasing public safety.”
The Iowa Flood Center is part of IIHR—Hydroscience & Engineering, a research institute based at the University of Iowa’s College of Engineering. The IFC was established in 2009 to provide accurate, state-of-the-science-based information to help Iowans better understand their flood risks. It is the nation’s first academic center devoted solely to the study of floods.
