NROW XVII & CSTAR VI Collaboration Project High Wind EVENTS IN Western New York: AN EXPANDED STUDY AND DEVELOPMENT OF POTENTIAL IMPACT TABLES Hurricane Force Wind Gust to 80 mph Homes and vehicles damaged by falling trees Two tractor trailers blown over on the NYS Thruway 100,000 lost power Est 2.1M in damages Temp dropped to -8C / 18F! NROW XVII & CSTAR VI Collaboration Project Shawn Smith General Forecaster NWS Buffalo, NY

High Wind Events in the Great Lakes Result from deepening cyclones tracking across the Great Lakes “Great Lakes Cutters” Common occurrence from late Fall through early Spring (Angel and Isard 1998) Frequently cause widespread infrastructure and property damage NWS BUF experiences highest frequency of all Great Lakes offices based on tally of warnings/advisories

Previous Buffalo High Wind Study Niziol and Paone (2000) A Climatology of Non-convective High Wind Events in Western New York 52 Events (50+ kts KBUF) from 1977-1997 Identified: Seasonality Prevailing Wind Direction Storm Track Composites of MSLP, 850mb Height and Temp and 500mb Heights Findings set the foundation for understanding high winds impacting WNY and are still widely used by forecasters today

What’s new with this expanded study? 27 updated cases from cold seasons of Nov 2004-Apr 2014 with expanded coverage area (Entire CWA) Breakdown of high wind events 11 Widespread (12+ zones) 16 Limited events (<12 zones) Addition of 35 Advisory-only events to set low threshold New storm track chart New NARR composite charts – 500 hPa Heights, MSLP and 850 hPa winds New Potential Impact Tables CSTAR Collaboration Project with goal of expanding this study to other ER Offices

Cyclone Tracks 2004-2014 500 miles

Comparison of Impact Area for Widespread vs Limited Event Widespread Event (12+ of 17 zones) Limited Event (Less than 12 zones) *Reports from NWS Storm Data with estimated gusts based on damage reports

500 hPa Composites for Pattern Recognition Weak signal here. Widespread Events composite matches very close to Niziol composites. Amplifying and negatively tilting 500hPa trough during and after event. Limited Events and Advisory composites a bit weaker. 12h Before At Onset 12h After Widespread Events Limited Events Advisory Events Amplifying and negatively tilting 500mb trough during and after event. Limited Events and Advisory composites a bit weaker. Niziol/Paone Events

MSLP Composites for Pattern Recognition Clear signal from MSLP composites. Widespread event composites much deeper than Niziol composites at onset time. (closer to Limited composites) Widespread event composites show deepening through the entire event, where others show weakening from onset to h+12. Highlights the need for a continually deepening surface low tracking northwest of Buffalo 12h Before At Onset 12h After Widespread Events Limited Events Widespread event composites much deeper than Niziol composites at onset time. (closer to Limited composites) Widespread event composites show deepening through the entire event, where Niziol composites, Limited and Advisory Events show weakening from onset to h+12. Advisory composites the weakest, showing a deeper MSLP scale from Widespread events to Advisory events. All composites show track of the cyclone is northwest of BUF CWA. Advisory Events Niziol/Paone Events

850 hPa Composites for Pattern Recognition A strong signal shows up when comparing 850 hPa wind composites. Widespread Events show maintenance of strong jet thru event, where others show weakening from onset to h+12. Advisory composites weakest, showing a 850hPa jet scale down from Widespread - Advisory Highlights the need for a strong and persistent 850 hPa jet tracking across WNY as key requirement for widespread high wind event. 12h Before At Onset 12h After Widespread Events 20 - 40 m/s (39 – 78 kts) VS Limited Events Advisory Events Widespread Event composites much stronger than Niziol composites (which again fit closer to Limited composites) Widespread Event composites show maintenance of strong jet throughout the event, where Niziol composites, Limited and Advisory Events show weakening from onset to h+12. Advisory composites the weakest, showing a 850mb jet scale down from Widespread Events to Advisory events. Niziol/Paone Events

Key requirements for High Wind Based on results of new composites we know that: Need a deepening low tracking northwest of Buffalo Need a strong an persistent jet tracking over WNY This led to the creation of…

High Wind Potential Impact Tables MSLP and 850hPa wind speed tables can detect an impact level of an expected wind event Quick way of assessing impact potential of any wind event *after determining high winds are expected Designed to help increase forecaster confidence for Watch/Warning/Advisory decision making

How were tables created? Statistical summaries were compiled from study cases

Box and Whisker Charts for Study Max +1SD Mean -1SD Min The deeper the Low, The stronger the 850 hPa jet! Note some overlap in the mid range

Development of tables from event cases (850 hPa winds example) *Note some overlap

Tables available on local intranet page and in AWIPS *Mixed categories based on overlap

So how do we know these tables work? Test them against post-events 7 Limited Events and 11 Advisory Events No Widespread Events occurred 2014-2016 cold seasons

Results of Testing Tables on 2014-2016 Events

Future Work Further testing is planned for 2016-2017 Cold Season and potentially pre-study events Interested in table performance results during Widespread Events. Feel the accuracy should improve with a larger dataset Expansion of the study beyond the Buffalo CWA as part of CSTAR IV

Questions?