national oceanic and atmospheric administration...

WEATHER PREDICTION CENTERNATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION

ArkLaMiss, Mar. ‘16 Houston, Apr. ‘16 WV, June ‘16 LA, Aug. ‘16 Matthew, Oct. ‘16

Billion Dollar U.S. Flood Disasters in 2016

Climate Matters Workshop, April 21, 2017 NASA/Goddard

Greg Carbin

Chief, Forecast Operations Branch

NCEP/Weather Prediction Center

College Park, Maryland


ArkLaMiss, Mar. ‘16 Houston, Apr. ‘16 WV, June ‘16 LA, Aug. ‘16 Matthew, Oct. ‘16

Billion Dollar U.S. Flood Disasters in 2016


$25 Billion in Losses *

* Source: NCEI www.ncdc.noaa.gov/billions/events.pdf

98 Fatalities *

5 Fatalities 8 Fatalities 23 Fatalities 13 Fatalities 49 Fatalities



National Weather Situational Awareness

WPC Mission: Provide precipitation and medium range forecasts to enable national

readiness for hazardous weather events.

Heavy Rainfall

Actionable information that is scientific, probabilistic, & impact-based

Winter Weather

Medium Range

Hazards



“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



● 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

“ArkLaMiss” Flooding Rains, March 8-10, 2016



2016 Daily Coverage of 1-inch Isohyet (% of CONUS)

% o

f CO

NU

S c

over

ed b

y 1-

inch

(or m

ore)

24h

pre

cipi

tatio

n

2016




% o

f CO

NU

S c

over

ed b

y 1-

inch

(or m

ore)

24h

pre

cipi

tatio

n Example mean: 1.6% coverage

18-year mean:1.6%

2016




% o

f CO

NU

S c

over

ed b

y 1-

inch

(or m

ore)

24h

pre

cipi

tatio

n

18-year mean:1.6%

2016

18-year 99th percentile: 7.7%

20160310: 8.6% coverage



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




% o

f CO

NU

S c

over

ed b

y 1-

inch

(or m

ore)

24h

pre

cipi

tatio

n

19-year mean:1.6%

2016


20160418: 5.8% coverage


|--- 8 pm EDT 6/22 through Midnight EDT 6/24 ---|

Accumulating Rainfall (inches) at Lewisburg, WV (LWB)

24-hour Flash Flood GuidanceFFG ~3 inches at LWB

24h Maximum Rainfall ~ 7”+

West Virginia Flooding Rains, June 22-23, 2016


● Extreme rainfall in vulnerable basin (terrain)

● 23 fatalities from flash flooding


24h Maximum Rainfall ~ 7”+

West Virginia Flooding Rains, June 22-23, 2016


● Extreme rainfall in vulnerable basin (terrain)

● 23 fatalities from flash flooding




% o

f CO

NU

S c

over

ed b

y 1-

inch

(or m

ore)

24h

pre

cipi

tatio

n

18-year mean:1.6%

2016


20160624: 3.6% coverage



Historic Louisiana Flooding Rains, August 11-13, 2016

8/7/168/8/168/9/168/10/168/11/168/12/16

LLL

LLL

L

8/13/16



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




% o

f CO

NU

S c

over

ed b

y 1-

inch

(or m

ore)

24h

pre

cipi

tatio

n

18-year mean:1.6%

2016


20160813: 5% coverage



Hurricane Matthew’s Flooding Rains, October 6-10, 20164 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




% o

f CO

NU

S c

over

ed b

y 1-

inch

(or m

ore)

24h

pre

cipi

tatio

n

18-year mean:1.6%

2016


20161009: 3.3% coverage




% o

f CO

NU

S c

over

ed b

y 1-

inch

(or m

ore)

24h

pre

cipi

tatio

n

18-year mean:1.6%

2016


? ?

20160216: 10.3% coverage 20161129: 9.5% coverage



18 Years of Daily Coverage of 1-inch Isohyet (% of CONUS)

18-year mean:1.6%





18-year mean:1.6%


How has the annual daily mean changed over time?



% o

f CO

NU

S c

over

ed b

y 1-

inch

(or m

ore)

24h

pre

cipi

tatio

n

18 Years of Annual Avg. Daily Coverage of 1-inch Isohyet

18-year mean:1.6%

Example mean: 1.6% coverage 2016



18 Years of Summed Daily Coverage of 1-inch Isohyet




18-year mean:1.6%


How many of these days per year?



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-historic-year-billion-dollar-weather-and-climate-disasters-us

https://www.climate.gov/news-features/blogs/beyond-data/2016-historic-year-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.




National Weather Situational Awareness

WPC Mission: Provide precipitation and medium range forecasts to enable national

readiness for hazardous weather events.

Heavy Rainfall

Actionable information that is scientific, probabilistic, & impact-based

Winter Weather

Medium Range

Hazards



QUESTION TIME

Thank you!

Greg Carbin @GCarbinChief, Forecast [email protected]

• Facebook.com/NWSWPC/• @NWSWPC

wpc.ncep.noaa.gov

national oceanic and atmospheric administration...

Documents