Billion Dollar U.S. Flood Disasters in PDF Free Download

Billion Dollar U.S. Flood Disasters in 2016 ArkLaMiss, Mar. 16 Houston, Apr. 16 WV, June 16 LA, Aug. 16 Matthew, Oct. 16 Greg Carbin Chief, Forecast Operations Branch NCEP/Weather Prediction Center College Park, Maryland

Billion Dollar U.S. Flood Disasters in 2016 ArkLaMiss, Mar. 16 Houston, Apr. 16 WV, June 16 LA, Aug. 16 Matthew, Oct. 16 5 Fatalities 8 Fatalities 23 Fatalities 13 Fatalities 49 Fatalities $25 Billion in Losses * 98 Fatalities * * Source: NCEI www.ncdc.noaa.gov/billions/events.pdf

WPC Mission: Provide precipitation and medium range forecasts to enable national readiness for hazardous weather events. National Weather Situational Awareness Heavy Rainfall Winter Weather Medium Range Hazards Actionable information that is scientific, probabilistic, & impact-based

ArkLaMiss Flooding Rains, March 8-10, 2016 Highly anomalous PW ~50mm (1.97 inches) 12-24 inch rainfall amounts in 48-hours Five fatalities and extreme flash flooding 500-1000 year recurrence interval event

2016 Daily Coverage of 1-inch Isohyet (% of CONUS) % of CONUS covered by 1-inch (or more) 24h precipitation 2016

% of CONUS covered by 1-inch (or more) 24h precipitation 2016 Daily Coverage of 1-inch Isohyet (% of CONUS) Example mean: 1.6% coverage 18-year mean:1.6% 2016

% of CONUS covered by 1-inch (or more) 24h precipitation 2016 Daily Coverage of 1-inch Isohyet (% of CONUS) 20160310: 8.6% coverage 18-year 99th percentile: 7.7% 18-year mean:1.6% 2016

Houston Flooding Rains, April 15-18, 2016 16.22 inches at Monaville, TX (northwest of Houston) Bulk of rainfall in 6- to 8-hour time span Eight fatalities and extreme flash flooding Particularly vulnerable metropolitan area

% of CONUS covered by 1-inch (or more) 24h precipitation 2016 Daily Coverage of 1-inch Isohyet (% of CONUS) 20160418: 5.8% coverage 19-year 99th percentile: 7.7% 19-year mean:1.6% 2016

West Virginia Flooding Rains, June 22-23, 2016 24h Maximum Rainfall ~ 7 + Accumulating Rainfall (inches) at Lewisburg, WV (LWB) 24-hour Flash Flood Guidance FFG ~3 inches at LWB --- 8 pm EDT 6/22 through Midnight EDT 6/24 --- Extreme rainfall in vulnerable basin (terrain) 23 fatalities from flash flooding

West Virginia Flooding Rains, June 22-23, 2016 24h Maximum Rainfall ~ 7 + Extreme rainfall in vulnerable basin (terrain) 23 fatalities from flash flooding

% of CONUS covered by 1-inch (or more) 24h precipitation 2016 Daily Coverage of 1-inch Isohyet (% of CONUS) 20160624: 3.6% coverage 18-year 99th percentile: 7.7% 18-year mean:1.6% 2016

Historic Louisiana Flooding Rains, August 11-13, 2016 L L L L L L L 8/13/16 8/12/16 8/11/16 8/10/16 8/9/16 8/8/16 8/7/16

Historic Louisiana Flooding Rains, August 11-13, 2016 22-24 inches in 48-hours near BTR and Abbeville, LA (max 31.39!) Widespread flood of historic proportions, 13 fatalities

% of CONUS covered by 1-inch (or more) 24h precipitation 2016 Daily Coverage of 1-inch Isohyet (% of CONUS) 20160813: 5% coverage 18-year 99th percentile: 7.7% 18-year mean:1.6% 2016

Hurricane Matthew s Flooding Rains, October 6-10, 2016 4 Day Precipitation Totals (valid 00Z 10/06/2016-00Z 10/10/2016) WPC Surface Analysis (valid 12Z 10/08/2016) overlaid with track of Matthew Catastrophic flooding after 15-20 inches of rain 49 fatalities, millions of dollars in property losses

Hurricane Matthew s Flooding Rains, October 6-10, 2016 Catastrophic flooding after 15-20 inches of rain 49 fatalities, millions of dollars in property losses

% of CONUS covered by 1-inch (or more) 24h precipitation 2016 Daily Coverage of 1-inch Isohyet (% of CONUS) 20161009: 3.3% coverage 18-year 99th percentile: 7.7% 18-year mean:1.6% 2016

% of CONUS covered by 1-inch (or more) 24h precipitation 2016 Daily Coverage of 1-inch Isohyet (% of CONUS) 20160216: 10.3% coverage 20161129: 9.5% coverage?? 18-year 99th percentile: 7.7% 18-year mean:1.6% 2016

18 Years of Daily Coverage of 1-inch Isohyet (% of CONUS) 18-year 99th percentile: 7.7% 18-year mean:1.6%

18 Years of Daily Coverage of 1-inch Isohyet (% of CONUS) How has the annual daily mean changed over time? 18-year 99th percentile: 7.7% 18-year mean:1.6%

18 Years of Annual Avg. Daily Coverage of 1-inch Isohyet % of CONUS covered by 1-inch (or more) 24h precipitation Example mean: 1.6% coverage 2016 18-year mean:1.6%

18 Years of Summed Daily Coverage of 1-inch Isohyet

18 Years of Daily Coverage of 1-inch Isohyet (% of CONUS) How many of these days per year? 18-year 99th percentile: 7.7% 18-year mean:1.6%

Days per Year in Top 1% of 1-inch CONUS Coverage (7.7%)

Important Caveats on WPC Precip Reanalysis! Short time-series analysis (under 20-years) Greater coverage does not correlate to more flooding Subjective analysis with change in data resolution and obs Only one-inch analyzed, what about higher amounts? More research needed but much has already been done www.climate.gov/news-features/blogs/beyond-data/2016-historicyear-billion-dollar-weather-and-climate-disasters-us

Historic Louisiana Flooding, August 2016 The Great Louisiana Flood of August 2016 is the only non-hurricane event to place in the top 5 greatest National Flood Insurance Program (NFIP) payouts since 1978. The extreme rainfall during this event was forecast in the first-ever Day 2 High Risk in WPC s Excessive Rainfall Outlook.

QUESTION TIME Thank you! Greg Carbin @GCarbin Chief, Forecast Operations Gregory.Carbin@noaa.gov Facebook.com/NWSWPC/ @NWSWPC wpc.ncep.noaa.gov