Optimizing Local Thresholds for Flash Flood Prediction
A student led project, Zachary Flamig and his advisor Jonathan Gourley, submitted FLASH (Flooded Locations And Simulated Hydrographs) – a project that leverages existing technologies, resources, infrastructure and relationships to address critical data, knowledge and assessment gaps that will enhance the effectiveness of flood response and mitigation strategies
The Thriving Earth Exchange (TEX) and Amazon Web Services (AWS) are collaborating to use cloud-computing and Earth and space science to advance solutions to community challenges related to natural resources, climate change and natural hazards.
- $15,000 in grant funds to use AWS on-demand cloud services.
- Free registration to attend the annual 2015 AGU Fall Meeting, an Earth and space science conference attracting over 24,000 attendees. Assistance and direction in highlighting the project to enable adaptation by other communities and increase broader impact.
Graduate student and PhD candidate Race Clark (OU/CIMMS) won 3rd place at the 2015 OU GIS Day poster contest held November 17, 2015 in Norman, OK. His poster was titled “Processing Topographical Data for Hydrological Modeling”, which presented a new software tool for speeding up topographical preprocessing for hydrological models. This software tool is primarily designed for use during international capacity building workshops. His coauthor on the poster is fellow graduate student and PhD candidate Zac Flamig (OU/CIMMS). Both students are advised by Drs. J.J. Gourley (NOAA/NSSL) and Yang Hong (OU Civil and Environmental Engineering).
Continuing a strong 2015 conference showing by students in the FLASH group, Race Clark and Galateia Terti won 1st and 2nd place respectively in the graduate student poster contest at the 40th Annual Meeting of the National Weather Association. The annual meeting was held October 17th-22nd in Oklahoma City, Oklahoma. Race’s poster was titled “Towards Hazard Services Recommenders for Flash Flood Forecasting” while Galateia presented “Target the warnings: Probabilistic flash flood casualties prediction.”
Manabendra Saharia, Ph.D. student in CEES/ARRC, won 1st place in the graduate student poster contest at the Society of Environmental Journalism (SEJ) 25th Annual Conference. The conference was held in Norman, Oklahoma from October 7th-11th, 2015. Manab’s poster focused on his work to identify the basins in the US with the fastest rainfall-runoff response.
On the evening of May 23rd into the early morning of May 24th, 2015 the Blanco River in Texas experienced a significant flooding event resulting in the closure of I-35 north & southbound near the city of San Marcos, TX. There were also multiple high-water rescues in the area including helicopter rescues of victims trapped in houses. The Hays County jail in Texas was also evacuated due to threatening flood waters. The FLASH development system was running for this event producing products forecasting & monitoring the flooding in near real time.
Traditional rainfall based products including the rainfall accumulation and the ratio of rainfall to flash flood guidance highlight a large area northwest of San Marcos for flooding impacts. The storm system produced 6-8″ of rain over the region to the northwest resulting in exceedance of flash flood guidance by 160-180%.
The FLASH hydrologic model based products correctly show the heavy rainfall being concentrated into the rivers and the downstream flooding impacts in San Marcos resulting from the heavy rainfall to the northwest of the region.
- This was a very heavy rainfall event that was captured well by MRMS radar-only estimates
- The flash flood guidance product indicated significant exceedance over threshold values, but the areas of concern were limited to the headwaters of the Blancos river
- The distributed hydrologic model forecasts better refined the threat area to the Blancos river and provided several hours of lead time
- This event clearly highlights the need to account for overland flow and routing, displacing the impacts well downstream of the causative rainfall
The MRMS-FLASH system, running in a real-time demonstration mode for several years now, performed admirably for the recent flash flooding events in Oklahoma and Texas. The MRMS-FLASH system runs in a completely automated fashion ingesting quantitative precipitation estimates every 5-minutes from the MRMS mosaic of NEXRAD data. The FLASH hydrologic modeling system subsequently produces 6-hour forecast hydrographs for everywhere across the CONUS.
On evening of May 25th, 2015 the city of Houston, Texas experienced a serious flash flooding event. MRMS precipitation estimates indicate that the western portions of the city experienced 6-8″ of rainfall.
The ratio of precipitation to flash flood guidance shows exceedance values of 100-140% over this area, however some of the USGS stream gauges reporting flash flooding (blue triangles) and the flash flood local storm reports (brown circles) fall outside of this region. This product is important because it is equivalent to the main tool operational NWS forecasters have available for flash flood monitoring and prediction.
The Coupled Routing and Excess Storage (CREST) distributed hydrologic model, a part of the MRMS-FLASH hydrologic modeling suite, generates maps of streamflow and unit streamflow (cubic meters per second per square kilometer) every 15 minutes. Comparisons between the observations of flash flooding and the maps of unit streamflow show a good correspondence between areas of high unit streamflows and flash flooding.
The MRMS-FLASH suite of hydrologic models are able to correctly identify areas of flash flooding thanks to the incorporation of
- Stream & overland routing
- Modeling of impervious surfaces
Elizabeth Mintmire Argyle received the Student Presentation Award from the 10th Symposium on Societal Applications, held as a part of the 2015 AMS Annual Meeting in Phoenix, AZ in January 2015, for her oral presentation “Forecaster ‘Best Practices’ During Operations in the Hazardous Weather Testbed Hydrology Experiment 2014.” As part of the recognition, Ms. Argyle received a $200 cash award and a certificate from the American Meteorological Society. Ms. Argyle works as a Graduate Research Assistant for the Cooperative Institute for Mesoscale Meteorological Studies at NOAA’s National Severe Storms Laboratory, in Norman, OK. She is also a PhD candidate in Industrial and Systems Engineering at the University of Oklahoma. Her PhD advisors are Dr. JJ Gourley (NOAA/NSSL), Dr. Ziho Kang (OU), and Dr. Randa Shehab (OU). Funding for Ms. Argyle’s research was provided by NOAA/OAR/Office of Weather and Air Quality (OWAQ) under the NOAA cooperative agreement, NA11OAR4320072.
Zac Flamig and Race Clark received awards at the 95th Annual Meeting of the American Meteorological Society in Phoenix, AZ in January 2015. The awards were selected by the 31st Environmental Information Processing Technologies (EIPT) & the 5th Transition of Research to Operations (R2O) Conference Committees.
Mr. Flamig’s poster, entitled “HWT-Hydro: Evaluation of Experimental Forecast and Nowcast Tools” was selected as a 3rd Place Winner – Poster Presentation Category in the Joint EIPT-R2O Conferences Student Competition. Mr. Clark’s oral presentation, entitled “The Inaugural Hazardous Weather Testbed – Hydrology (HWT-Hydro) Experiment” was the 3rd Place Winner – Oral Presentation Category of the Joint EIPT-R2O Conferences Student Competition. Each will receive a $100 award and a Certificate of Appreciation. Both Mr. Flamig and Mr. Clark are currently PhD candidates at the University of Oklahoma’s School of Meteorology. Each works as a Graduate Research Assistant for the Cooperative Institute for Mesoscale Meteorological Studies at NOAA’s National Severe Storms Laboratory. Their PhD advisors are Dr. JJ Gourley (NOAA/NSSL) and Dr. Yang Hong (OU).
The FLASH project was heavily represented at the various conferences of the 95th Annual AMS Meeting. In addition to Mr. Flamig and Mr. Clark, Dr. JJ Gourley presented an evaluation of flash flood products from the FLASH project, Ms. Elizabeth Argyle presented on forecaster “best practices” during the HWT-Hydro Experiment, and Mr. Brandon Smith presented on observations collected in support of the HWT-Hydro Experiment. Funding for the research presented at the AMS meeting was provided by NOAA/OAR/Office of Weather and Air Quality (OWAQ) under the NOAA cooperative agreement, NA11OAR4320072.