NWS Blacksburg Working Hard to Serve You!

  by Dave Wert, Meteorologist-in-Charge

The National Weather Service (NWS) is a Federal Agency and is one of several agencies under the National Oceanic and Atmospheric Administration, which is under the Department of Commerce.  As a Federal Agency, we are directly indebted to you, the taxpayer, for our existence.  It is therefore of utmost importance that we serve you well.  We do this by striving to meet or exceed the Government Performance Results Act (GPRA) targets for operational performance.  In other words, we try to forecast the weather as accurately as possible - providing as much lead time as the science will allow to enable you to take whatever action is needed to prepare in advance of a weather threat.

Many of the GPRA targets that we try to exceed have to do with  forecasting low clouds and visibility (of primary interest to pilots and those who rely on pilots to get them safely from one point to another) and forecasting dangerous weather - such as the threat of tornadoes, flash floods and river floods, winter storms, and severe thunderstorms.  In this article, I would like to review the special emphasis that we have made this year to improve our severe thunderstorm forecasts.

The 2007 Severe Thunderstorm Season, which usually begins in March and winds down in September, was a record year for the Blacksburg NWS forecast office.  A total of 373 county-based Severe Thunderstorm Warnings were issued throughout the year.  This equates to an average of nearly 10 separate warnings for each of the 40 counties which fall in the Blacksburg area of jurisdiction!  The unprecedented number of county-based warnings exceeded the previous office record by almost 100 warnings!  One may therefore be tempted to ask "Why so Many Warnings - is the World About to End?".  The simple answer to this question is "no", but there are some valid reasons why we had such a distinctive season. 

One reason is that the Spring and Summer of 2007 were unusually warm, and despite the drought, the combination of increased warmth and residual moisture in the atmosphere allowed for the development of almost daily small thunderstorms over the area.  Because the thunderstorms were stationary or slow moving, only isolated areas received any rain on a daily basis, but those areas that did often experienced large hail, strong damaging winds, or a combination of the two. 

A second and just as important reason is that the Blacksburg office, in an attempt to serve you better, made a concerted effort this year to make even better use of existing technologies (e.g., Doppler Radar, high-resolution satellites, sophisticated computer models of the atmosphere, surface-based observational networks, upper-air balloon and aircraft soundings of the thermal profile of the atmosphere, etc.) as well as applying the latest scientific research into forecast operations.  Just as important, we spent a considerable amount of time during each severe weather event and immediately following the event to call folks immediately under the worst part of the storm to obtain the needed "ground-truth" to ascertain what was happening at ground level and to verify our warnings.

Despite a very hectic and record breaking year, our GPRA skill scores for Severe Thunderstorm Performance improved across the board, and were the best that the office has ever experienced.  All three of the GPRA targets that relate to Severe Thunderstorm Forecasting were exceeded.  Here are how the statistics fell out for the Blacksburg Office in 2007:

GPRA Probability of Detection Goal = 86%.  Actual Probability of Detection = 88%
GPRA False Alarm Rate Goal = 33%.  Actual False Alarm Rate = 25% (lower is better here)        
GPRA Lead Time Goal (time of actual severe weather experienced versus when warning issued) = 16.0 Minutes.  Actual Lead Time = 17.9 Minutes            

The NWS in Blacksburg intends to maintain or even exceed these stellar statistics in 2008 to continue to work as diligently as we can to serve you well and consistently.  Our effort this winter will be to maintain a very high Probability of Detection of impending Winter Storms, have very low False Alarm Rates, and provide plenty of Lead Time to enable you to take whatever action is necessary to safeguard your life and property well before the advent of the storm.
We appreciate each of you and consider it a joy, honor, and extreme privilege to serve you.  Please feel free to check out our web site at www.weather.gov/blacksburg or call us on our ring-through line at 540-552-0497 if you would like specific information for your particular area.