The recorded version of the January 2017 Warning Decision Storm of the Month webinar is now available on-line for viewing.
Presenter: Kevin Laws, SOO Birmginham, AL
Abstract: There are multiple layers to the process of improving warning performance, and these layers differ across the country. This session will present a process used at the Birmingham, AL, office. The layers that will be discussed include:
Presenter: John Ferree, NWS Severe Storms Services
Abstract: The capability to deliver Impact-Based Tornado and Severe Thunderstorm warnings has been demonstrated at 46 of the 122 WFOs (38 in Central Region, 5 in Southern Region, 2 in Western Region, and 1 in Eastern Region) that includes both AWIPS 1 and 2 offices. The presentation will review two events (November 17, 2013 tornado outbreak in Central Region, and at the Jackson, MS office on April 28, 2014). Some recent research that addresses the ability of forecasters to discriminate storms with the greatest impact will be presented. The initial results of social science studies of emergency managers, and a preview of a longer term study of public response to impact-based warnings will be included. Finally, Michael Hudson, Central Region Chief Operations Officer, will join us for a question and answer period.
Presenter: David Stark, WFO Upton
Abstract: On 8-9 February 2013, a historic winter storm impacted the New York City metropolitan area into New England. Heavy snowfall, with blizzard conditions, and accumulations in excess of two feet in many locations paralyzed the region’s transportation systems. Two distinct mid-level shortwaves acted in tandem with a dual jet stream structure to create a classic deepening coastal low pressure system. Measurements from the dual-polarized WSR-88D KOKX (Upton, NY) provided unique insight into the microphysical processes of this storm, which produced dramatic hydrometeor diversity. With an abundance of high quality in-situ reports, the location of the radar yields a truly unique dataset. This presentation reviews this historic storm event as a valuable and unique look into the rapid evolution of a winter storm from the synoptic to the microphysical scale.
Presenter: Josh Weiss, WFO Wilmington, NC
Abstract: An ice storm of any scale or duration is rare in the Carolinas. From February 11 through February 13, 2014, a winter storm produced icing of 0.5” or more over the majority of the WFO Wilmington CWA, with some areas reporting up to 1.5”. The storm peaked late morning through the afternoon of February 12, with icing rates of 0.10-0.15 in/hr, prompting Josh to contact the SPC for a consultation, resulting in a Mesoscale Discussion highlighting the threat. Societal impacts were on the scale of a hurricane: extensive forestry damage, power losses, and economic losses due to businesses closed. This webinar will present “life in the nowcasting seat” for this event, the benefits of WFO and SPC collaboration, and the overall challenges of working an historic event.
Presenters: Hayden Frank and Joe DelliCarpini, WFO Boston, MA
Abstract: Early on Sunday morning, December 1, 2013, spotty light freezing rain and freezing drizzle produced icing on roadways throughout central Massachusetts. Traffic was heavier than usual for a Sunday since it was the end of the Thanksgiving weekend. Though icing was forecast over the previous two days, many accidents occurred throughout the region, most notably a 70-car pileup on elevated Interstate 290 which runs through Worcester, MA. This type of event has happened in many places across the U.S. It is especially challenging in terms of messaging and is tough for WFO staff given the time of day. This webinar will review the synoptic and mesoscale features that can produce light freezing rain/drizzle and present lessons learned to improve anticipation and messaging for future icing events.
Presenters: Chad Entremont and Daniel Lamb, WFO Jackson, MS
Abstract: One of the most notable benefits that has emerged from the recent upgrade to dual-polarization technology is the ability to detect tornadic debris. A study of over 180 tornadic debris signature (TDS) cases has found there is a significant correlation between maximum TDS height and tornado intensity. The primary goal of this research is to increase the confidence of the warning forecaster in the likelihood of a damaging/significant tornado occurring based on dual pol data. This knowledge will be particularly useful as the National Weather Service continues to move into the impact based warning era. To demonstrate this, we will take a look back at NWS Jackson's use of dual pol data during the April 28, 2014 tornado outbreak.
Presenter: Whitney R. Smith, WFO Columbia, SC
Abstract: Multiple supercell thunderstorms moved across the Midlands and Pee Dee regions of South Carolina during the afternoon and evening of 23 May 2014. The strongest storms produced up to 3 inch diameter hail in two of the warned areas, in addition to damaging winds of 50 to 65 mph. Based on the Probability of Detection and False Alarm Rate, the severe thunderstorm warnings issued by the NWS Office in Columbia, South Carolina (CAE) verified well for large hail and damaging winds. This study focuses on the radar data (including dual polarization) that went into the NWS forecasters’ decision making process in real time as well as lessons learned from post storm analysis. We will also examine how the nature of these storms affected the warning polygons, which complicated the messaging to those affected.
Presenter: Taylor Trogdon, WFO Memphis, TN
Abstract: In an operational environment, it is sometimes difficult to determine whether or not damaging wind gusts within a convective line are reaching the surface. Dual-polarization radar allows users to make inferences about the internal structure of these storms both horizontally and vertically which can aid in decision-making behind the warning desk. This presentation examines the 30 June 2014 bow-echo across eastern IA where a feature was observed, most notably in Differential Reflectivity, which may help to determine when damaging wind potential is increasing or decreasing during the life cycle of a bow-echo. This feature has been termed a “ZDR Arch.”
Presenters: Marc Austin and Jonathan Kurtz, Forecasters, WFO Norman, OK
Abstract: The flash flooding that occurred in the Oklahoma City metro during the evening of May 31st and early morning of June 1st killed a total of 13 people, making this event the deadliest ever for the city. Yet, what is remembered most about that night is the enormous El Reno tornado and the excessive number of people choosing to flee in their vehicles. The challenges of communicating multiple hazards that night will be presented, as well as lessons learned for improving messaging for future multiple hazard events. The talk then moves to May 6, 2015, which brought another tornado and flash flooding event to the metro, and an opportunity to better address the messaging challenge.
Presenter: Mike Evans, SOO WFO Binghamton, NY
Abstract: A potent storm system raked across the northeast U.S. on July 8, 2014, bringing numerous severe storms to the Binghamton (BGM) forecast area. Among the storms was the first deadly tornado to strike the BGM county warning area since the late 90s. This event was well-anticipated by forecasters through the use of new tools such as the SPC storm-scale ensemble of opportunity and a locally-developed severe weather analog tool. However, the deadliest tornado was the most challenging to detect on radar, occurring within a Quasi-Linear Convective System structure. Additional challenges of discriminating between tornadic and non-tornadic supercells will be discussed, along with challenges associated with detecting the deadly tornado, and how Dual-Pol products aided in this event.
Presenters: Scott Overpeck and Lance Wood, WFO Houston, TX
Abstract: After record rainfall in May, a slow moving line of thunderstorms moved into Harris County during the evening of May 25th resulting in widespread, historic flooding. Excessive rainfall rates, including 4.8? in one hour and 10.1? in six hours, were measured. Despite hundreds of water rescues, the flooding resulted in 8 fatalities and thousands of flooded homes. Throughout the event NWS meteorologists were in constant communication with decision makers, broadcast meteorologists and storm spotters through NWSChat. The office?s first ever FFW emergency was issued and it expanded to include 3.2 million people!
Presenters: Jon Zeitler, Aaron Treadway, and Jason Runyen , WFO Austin-San Antonio, TX; Greg Waller, West Gulf River Forecast Center
Abstract: After nearly continuous rainfall throughout May 2015, a slow-moving longwave trough, strong upper level divergence, high precipitable water air from the Gulf of Mexico, and the topography of the Balcones Escarpment combined to produce heavy rainfall of 6-13 inches on the upper reaches of the Blanco River overnight on May 23-24. The resulting flooding at Wimberley, TX, shattered the previous record by almost 12 feet and resulted in 12 fatalities and nearly 3000 flooded homes/businesses. Interstate 35 was closed for three hours, and not fully-re-opened for six hours. Our focus will be on: challenging predictability of intense rain, resulting river flows and stages in headwater/flashy terrain, and promising research and operational tools coming in 2016. The need for action-based messaging and preparedness at the watch stage for these events will also be discussed.
Presenter: Joe Dellicarpini, WFO Boston, MA
Abstract: Although the winter of 2014-2015 in southern New England started slowly, with many believing it would be a lean winter, a record-setting snow blitz began in late January and lasted for six weeks. Boston and eastern Massachusetts were buried under feet of snow, after what seemed to be an endless series of coastal storms brought blizzard conditions, high winds, and coastal flooding. This active period of snow and prolonged cold led to nearly continuous IDSS activities at WFO Boston which included over 180 briefings to Emergency Managers, more than 600 media interviews, and an explosion of social media posts. Rather than discuss the meteorology, this presentation will focus on some of the human factors involved at WFO Boston during this historic stretch of winter weather. Many had to balance life at home and at work under stressful conditions, either being at work for days at a time or having to travel under varying road and weather conditions. IDSS activities focused on the “before, during, and after” each storm - as well as the “next one” which forced other office activities to be put on hold. Takeaways will be discussed in order to share best practices for other WFOs to utilize for similar significant weather events.
Presenters: Barry Goldsmith, WFO Brownsville and Robert Ricks, WFO Slidell
Abstract: It may be a blizzard, a hurricane, a tornado outbreak, flash flood, or other type of historic or high-impact weather event, but a career event may be right around the corner. How do you respond in these moments? What value can you add to the message and the framework that exists in the warning process? We will hear from one forecaster who answered these questions in a unique and impactful way before Hurricane Katrina reached the Gulf Coast back in 2005. And in the spirit of teamwork and understanding how no one can do it alone, we will also get a perspective from someone who helped put that framework into place well before the event, because response has a direct correlation to preparation in career-defining moments.
Presenters: Aaron Ward and Katie Pojorlie WFO Rapid City, SD
Abstract: On 3-5 October 2013, a potent low-pressure system produced a record-breaking blizzard that devastated northeastern Wyoming and western South Dakota. Prolonged damaging wind gusts of around 50 to 70 mph, combined with 2 to 5 feet of snow, created treacherous conditions across much of the region. Tens of thousands of livestock were killed, damage took months to clean up, and three indirect fatalities resulted from the blizzard. Four National Weather Service employees were stranded at the office for 42 to 54 hours. The meteorology of this system will be discussed briefly with a focus on the impacts of the storm and the challenges endured by these four employees (including the presence of a government shutdown).
Presenters: Rich Thompson and Joey Picca, Storm Prediction Center
Abstract: The Storm Prediction Center (SPC) is developing tornado damage rating conditional probabilities from datasets of tornadic and severe non-tornadic thunderstorms. Null storms have also been analyzed, and this study now includes their (unconditional) probabilities. Evidence from this research will show the skill of these probabilities in forecasting tornadic supercells and estimating real-time tornado intensities based on radar data and near-storm environments. These results will then be linked to the critical role of radar data quality for identification of low-level rotational velocity and assessing tornadic potential.
Presenter: Heather Stanley, Lincoln, Illinois WFO
Abstract: A powerful EF-4 tornado forever changed Washington, Illinois on November 17, 2013. In the days that followed, the NWS in Central Illinois conducted a detailed damage assessment, focusing on both the physical damage and the experiences of those impacted. Our speaker witnessed the devastation first hand, recounting both her experience and what was learned from those who suffered loss after this deadly storm. Their stories, their grief, and their triumphs provide a new perspective on the NWS mission and the service we provide.
Presenter:Vivek Mahale, Norman, Oklahoma WFO
Abstract: A tornado developed in southwest Oklahoma City as a supercell thunderstorm interacted with an effective frontal boundary. This tornado produced up to EF-2 damage in Moore, OK. An analysis of the event is conducted using the KTLX WSR-88D radar data and surface observations from the Oklahoma Mesonet. Precursors of tornadogenesis were found, including: 1) storm-scale cyclogenesis indicated by radar reflectivity observations of a developing ‘kink’ along the surface boundary coincident with localized surface pressure falls and backing winds; 2) a rapidly descending rear-flank downdraft (RFD) surge with maximum radial velocities of >75 knots); 3) a dual-RFD structure with two storm-scale wind maxima; and 4) highly divergent air aloft indicated by maximum storm-top divergence >190 knots
Presenter: Matt Elliott, Sterling, VA WFO
Abstract: CONUS-wide total lightning data has recently become available within AWIPS, allowing forecasters to utilize this rich dataset alongside traditional data sources (e.g., radar, satellite) during severe weather warning operations. This discussion will provide examples, best practices, strengths, and limitations for incorporating total lightning data into warning decisions. In addition, improved visualization techniques for total lightning data within AWIPS that enable forecasters to more easily establish trends in total flash rates will be presented.
Presenters: Justin Pullin, Chris Outler, & Stan Czyzyk: WFOs Tallahassee & Las Vegas
Abstract: October 2015 featured an abnormally wet and stormy pattern across the Las Vegas CWA, courtesy of one upper level low that impacted the region twice in a ten day stretch. This system yielded historic flash-flooding across Death Valley National Park as well as severe thunderstorms and several supercells across the region. A new way to conduct after action reviews at NWS Las Vegas was put to its first major test in between these systems, as the local after action team quickly took steps to gather feedback and present it to the staff, influencing much needed changes ahead of the second event. This talk will tell the story of these events, highlight how these after action items are conducted and show how they influence improvements for the second round of historic weather.
Presenters: Dave Noble and Chris Gibson, WFO Missoula, MT
Abstract: The staff at the NWS WFO in Missoula, MT anticipated a busy but routine day supporting wildfire suppression on August 10, 2015. By the end of that evening, the events that transpired will not soon leave the minds and memories of the people that lived this experience. An intense line of thunderstorms with damaging winds inflicted a cascade of issues and impacts across Missoula and the surrounding area. This wall of wind affected multiple outdoor events, aggravated wildfire fighting efforts, and even compromised the WFO’s building equipment and power for a time. With their building and their city surrounded by blowing dust, grass fires, and power outages, the staff fought through the challenges in one of the most memorable weather events in the area's history.
Presenter: Kevin Skow, WFO Des Moines, IA
Abstract: In the days following the passage of a strong QLCS across central Iowa on August 31, 2014, the entire 350-km path of the storm was imaged at 1-m resolution through the USDA National Agricultural Imagery Program. This imagery offers an extraordinary glimpse into the quantity, evolution, and scale of surface vortices generated throughout the entire lifespan of this QLCS. A total of 111 such tracks were cataloged and 35 classified as tornadoes. This presentation will showcase notable tracks, a proposed reclassification of tornadic debris signatures that is better suited for QLCS tornadoes, possible tornadogenesis mechanisms, and NWS WFO warning/Storm Data implications using aerial datasets.
Presenter: John Stoppkotte NWS North Platte, NE
Abstract: Understanding of supercell tornadogenesis through peer-reviewed research and development of fine-scale models has grown, yet applying these findings to the NWS WFO warning decision making process has been limited. Using a radar-based case study approach, this discussion will look at several tornadic and non-tornadic events that can be related to this recent research. The goal is to develop a more detailed conceptual model of supercell tornadogenesis for forecasters through storm-scale interrogation of WSR-88D dual pol parameters. A more detailed and operationally relevant conceptual model can enhance both our warning strategies and messaging.
Presenter: Andy Haner NWS Seattle, WA
Abstract: On August 11, 2014, three firefighters on the Beaver Fire in California became entrapped and were left with no other choice but to use their last-resort fire shelters in order to save their own lives. This occurred about 25 minutes following the arrival of a thunderstorm outflow boundary. As the Beaver Fire's Incident Meteorologist (IMET), Forecaster Andy Haner of NWS Seattle will recount both the meteorological and human events of this incident-within-an-incident, with a special focus on the topic of Critical Incident Stress Management.
Presenters: Randy Bower and Todd Lindley, WFO Norman;
Aaron Johnson, WFO Dodge City;
Stephen Bieda and Robert (BJ) Johnson, WFO Amarillo
Abstract: This is the story of how SPC and WFO forecasters worked together to overcome their internal “Normalcy Bias” for a “this has never happened” tornado outbreak in November, after dark, with multiple, significant, tornadoes. Normalcy Bias is a term used within the EM community, and overcoming that bias, for both the NWS forecasters and the EMs, was a key element in the success of the event. An equally vital takeaway from this story was within two weeks, a multi-office, dual-region Hot Wash was conducted. The Hot Wash captured the important lessons of forecasting an anomalous event, when NWS performance matters most.
Presenters: Kevin Cadima and Joe Dellicarpini, WFO Boston
Abstract: The East Coast Blizzard of January 23-24, 2016 was the first threat of significant snowfall for southern New England since the winter of 2014-2015, when record-breaking snowfall occurred. The 2016 Blizzard presented very different challenges, as southern New England was expected to be on its northern edge, with considerable uncertainty about snowfall amounts. There were also concerns with precipitation type, damaging winds and coastal flooding. Conveying this uncertainty in the days, and even 12 to 24 hours, before the snow began, was a constant challenge with Decision Support Services provided by NWS Boston to core partners. “Most likely” scenarios along with reasonable “best” and “worst” cases were used, along with experimental probabilistic snowfall forecasts. This presentation will focus on the “Living on the Edge” messaging strategies used by NWS Boston.
Presenters: Jamie Morrow and Steve Keighton, WFO Blacksburg, VA
Abstract: The President's Day holiday weekend in February of 2016 brought a mixed precipitation and flooding event to the Blacksburg, VA, CWA. This combination brought significant forecasting challenges, especially in regards to p-type transitions, which will be discussed. Messaging and communications proved crucial, and stakeholders had to make tough decisions. Social media aided in this role, as well as having a plan in place to ensure adequate staffing.