Localizing and personalizing hurricane wind risks to inform decisions about hurricane preparations.

While the weather forecast enterprise has dramatically increased its capabilities to provide accurate forecasts of weather hazards at greater lead times and finer scales, a growing body of research demonstrates that people have a difficult time understanding what the impacts of those hazards will be. Even worse, people find it difficult to impossible to conceive of what the impact means for their unique situation. Very few people have the technical background to assess their vulnerability and interpret probabilistic forecasts of hazards to calculate the risks of specific consequences. The HurricaneRiskCalculator® web app is being created to fill these gaps.

The HurricaneRiskCalculator® web app is a public-facing decision support tool based on a probabilistic risk framework that intersects real-time tropical cyclone wind hazard predictions with information from a structural vulnerability assessment. Through this intersection of hazard, vulnerability, and exposure, the tool calculates the risks of various consequences, such as different degrees of structural damage and whether the structure will be habitable following the tropical cyclone.

Learn more about the project: wxrisk.ucar.edu

NCAR & UCAR News: NCAR scientists recruiting the public to help ground-truth hurricane risk app

Since it is a forecast product, the GTG is most useful for route planning, i.e., strategic avoidance of turbulence. However, given the rapidly evolving character of turbulence, for tactical avoidance it is more useful to have a rapidly updated nowcast system. This system, called GTGN™ (N for nowcast), has been developed at RAL and is primarily driven by the most recent available turbulence observations (in situ EDR measurements, turbulence pilot reports, NTDA output, and satellite–based turbulence inferences) merged together with a GTG short–term forecast. The product updates every 15 min.

VDRAS relies on data assimilation, a technique for combining real-world observations and computer model output to create a more accurate forecast.

VDRAS has a very fast update cycle, providing new data from real-time radar and other sources for assimilation every 6–12 minutes. The mathematical technique it relies on, called 4DVar (Four-Dimensional Variational), is the gold standard for the field of data assimilation. The system uses freely available observations from the National Weather Service's Doppler radar network, so it can be run anywhere in the country without requiring new and costly instrumentation.

VDRAS works with these two other NCAR-based tools: the advanced research version of the Weather Research and Forecasting model, which generates very detailed predictions of areas as small as 3 kilometers (1.8 miles) square; and the Dynamic Integrated ForeCast system, which fine-tunes and optimizes the ongoing forecast.