Hydro-Meteorology

Many of the most beautiful places on the planet can also be the most vulnerable to weather related impacts. Floods, droughts and hurricanes are among many severe weather events that can alter the landscape and cause lasting damage to a community. The experts in HDR meteorological services use hydro-climate-based forecasts to produce detailed and accurate weather predictions, taking into account long- and short-term weather impacts.

Some of our specialized services include drought mitigation plans that factor in the cause-effect of extreme meteorological and hydrological drought in a region or upon a community. By evaluating the relationship among precipitation, climatic and physical factors during peak and non-peak cycles, we create innovative prediction tools to forecast low yield/drought runoff years, linking climatic indicators and actual seasonal stream flows. We use GIS-based Doppler radar and our own radar rainfall algorithms to estimate rainfall depth and duration and can provide rainfall reconstruction scenarios to bolster the accuracy of our estimates. Hurricane storm surges, wind and hail damage and weather impacts on accidents are routinely evaluated.

HDR can produce scientifically defensible design storm scenarios with radar-defined spatial and temporal characteristics to help communities understand potential weather-related hazards and develop appropriate mitigation plans. We work with communities and stakeholders to ensure comprehensive understanding of our services and prediction forecasts to bring the greatest value.

Radar - Rainfall Reconstruction:

Castlewood Canyon / West Creek – Pair of flooding events in Douglas County, CO only days apart. The Castlewood Canyon flood was in excess of the 500-year event in one area and the West Creek event caused significant road and dwelling damage.
New York - Motthaven Rail Yard – Early morning summer thunderstorm resulted in flooding over an important rail-yard in The Bronx. HDR ASG helped to define the intensity and duration of the event to assist local HDR engineering staff define the event for yard owners.

Precipitation Fields for Basin Calibration:

Southwest Washington Watershed District October 4-5, 2005 – Extreme flooding event occurred across an eastern suburban area of Minneapolis/St.Paul. Conventional radar and precipitation data could not explain the observed flooding when modeled. HDR ASG was able to reconstruct the storm on a finer scale that helped close the gap between the modeled and observed results.
South Boulder Creek / Model Calibration – A pair of radar-derived storm events were carefully reconstructed in South Boulder Creek, Colorado. One storm was used in the hydrology and hydraulics model calibration with the other storm event used to validate the model.

Design Storm:

South Boulder Creek - Detailed analysis of both general (multi-day) and thunderstorm (few hour) events in topographically diverse area of Colorado foothills. Results of analysis led to the acceptance of a scientifically defensible basin-specific design storm used in FEMA floodplain delineation study.
El Paso / Beaver Creek – Radar-based analysis of thunderstorms in and near project area helped better defined observed storm characteristics. Results indicate that temporal and areal coverages of storms differ notably from current criteria.

Site Specific Probable Maximum Precipitation (SSPMP) Studies:

Extreme Precipitation Analysis Tool (EPAT) – GIS-based automated analysis software that determines the characteristics of site-specific storms for basins defined by the user. Results are derived through use of a comprehensive historical storm archive and accepted storm transposition techniques. Program is used to determine PMF for dam sites above 5500’ in State of Colorado as of Jan. 2008.
Jerry Creek SSPMP – Site-specific PMP performed for dam owner north of Grand Junction, Colorado. Analysis resulted in 30-35 % reduction in the PMF as compared to standard analysis techniques.
Safford SSPMP - (Coming Soon)