The Role of the Mesoanalyst in the NWS WFO During High Impact Events

CIRA Director's Conference Room
Tuesday, September 30, 2014 - 10:00
NOAA/NWS WFO Omaha Nebraska
Daniel Nietfeld
Hosted By: 
Dan Lindsey

High impact meteorological and hydrological events, such as severe thunderstorms and flash floods, typically consist of phenomenon that occur on temporal and spatial scales that fall into the meso α, meso β, or meso γ range.   The associated atmospheric processes involve ageostrophic motions and are often nonhydrostatic, so Numerical Weather Prediction (NWP) models generally show poor predictive skill simulating the phenomenon, specifically the details.  Therefore, predicting the beginning, ending, areal distribution, and magnitude of high impact events remains a significant forecast challenge to operational meteorologists. 

The mission of the National Weather Service (NWS) is to, “Provide weather, water, and climate data, forecasts and warnings for the protection of life and property...”   The highest priority of the NWS Weather Forecast Office (WFO) is to predict any meteorological or hydrological event that could threaten the lives or property of the population of those within its forecast area, and to communicate that information to the populations at risk. 

To achieve the prediction component of this goal, the WFO in Omaha, Nebraska (OAX) has defined an operational position to serve in the role of a “mesoanalyst” during severe thunderstorm and flash flood events.  This position is dedicated to focusing on utilizing numerous tools, NWP output, and remotely sensed data to identify atmospheric processes that may lead to high impact events, or to assess atmospheric and/or hydrologic conditions that could influence trends in on-going high impact events.  One of the WFO meteorologists serves in this role on an as-needed basis leading up to and during severe thunderstorm and flash flood events. 

The layout of the WFO operations floor is designed to foster communication between the mesoanalyst and the meteorologists who are responsible for issuing the warning products (e.g., tornado warnings, severe thunderstorm warnings, and flash flood warnings).  Meteorological information that could influence the warning meteorologists’ decisions is provided by the mesoanalyst.  This teamwork allows those who are making warning decisions to focus on the evolution of the specific storms and generate the warning products, and to do so with enhanced knowledge about what phenomenon, processes, and impacts the mesoscale environment is conducive to.   This should, in theory, result in a higher probability of detection, a lower false alarm rate, and a longer lead time. 

This presentation will describe the duties of the mesoanalyst position, and examine the tools and datasets that are utilized.  WFO OAX operations will be illustrated, with emphasis on work flow and intra-office communications.  A case study will be examined to show the benefit of mesoanalysis during a recent event that included a tornado, severe thunderstorms, and flash flooding.   Extending the mesoanalyst position into other high impact events such as winter storms, high winds, and dense fog will be discussed.