Lessons Learned During the 2017-2018 Wind Hurricane Seasons That’s What Most Think About

Daniel Brown National Hurricane Center

Water U.S. Atlantic Tropical Cyclone Deaths What Most Do Not Consider 1963-2012 Water accounts for about 90% of the direct deaths

Rain 27% Storm Surge 49%

Surf 6%

Offshore 6%

Wind 8% Tornado 3% Other 1%

Rappaport 2014

2017-18 Hurricane Seasons 2017 Records & Other Highlights 12 Tropical Storms and Hurricanes Affected the U.S. • Five category 5 landfalls – 4 by Irma in the Caribbean – 1 by Maria in the Caribbean

• Costliest year on record for the US with $265 Billion in damage – 2nd (Harvey), 3rd (Maria) and 5th (Irma) costliest U.S. individual storms

• Several hundred direct and indirect deaths in the US, but NONE known from storm surge

1 Harvey - $125 Billion Irma - $50 Billion 2018 Records & Other Highlights

• TS Alberto struck the U.S. before the official start of the season

• Gordon made landfall along the northern Gulf coast as a strong tropical storm Maria - $90 Billion United States Facts & Figures • Slow-moving Florence produced • More than $265 billion in damage record setting rainfall in the • Several hundred direct and Carolinas indirect deaths • Maria was the strongest hurricane • Michael (category 4) was the most- to make landfall in Puerto Rico intense Florida Panhandle landfall since 1928 on record • Historic rains from Harvey

Florence - $24 Billion Michael - $25 Billion New GOES-16 Satellite Provided High-Resolution Images of Hurricane Harvey

United States Facts & Figures • Florence produced more than 30 inches of rainfall in North Carolina breaking a state record set during Floyd (1999) • Michael had the 3rd lowest minimum pressure at landfall in the continental United States • Michael is the 4th strongest by maximum winds on record in the U.S. • Michael is the strongest U.S. landfalling hurricane since Andrew (1992)

Hurricane Harvey First Issuance of a Storm Surge $125 billion in damage – 68 fatalities Warning in the United States • Deadliest hurricane in Texas since 1919

• Storm surge maximum of 8-10 feet near Rockport

• Meandering track after landfall led to historic rainfall – Over 60 inches!

• 57 total tornadoes from Texas to Tennessee

2 Quick Transition from Wind/Surge Storm Surge Warning to Inland Flooding Threat

Hurricane Harvey Focus on Impacts and Hazards Record Setting Rainfall Rainfall & Flooding

60.58 inches of rain at Nederland, TX broke the U.S. tropical cyclone rainfall record of 52 inches set in Hawaii in 1950.

• Potential for extreme rainfall well forecast • NHC began mentioning potential for heavy rainfall a day before Harvey regenerated in the Gulf (3 days prior to landfall)

Hurricane Irma Hurricane Irma

5 days before landfall

Actual

• Category 4 landfall in the Florida Keys • Category 3 landfall in SW Florida • Significant surge damage in Florida Keys, and wind impacts across much of the state

3 Storm Surge Highly Sensitive to Track! Significant Storm Surge Impacts Irma 2017 Far from the Center

Observed Track Ft. Myers Beach & Simulated Forecast Track & Storm Surge Sanibel Is. Simulated Miami Storm Surge a Day Before Landfall

~30 nm

Miami ~50,000 people ~200,000 people with 3+ foot surge with 3+ foot surge Jacksonville, FL Credit: CBS News

Potential Storm Surge Flooding Map Hurricane Irma Over Eighty Indirect Deaths in Florida

Shows height above ground that the water could reach

• Available when a hurricane watch or warning is in effect for the Atlantic and Gulf coasts of the United states (about 48 hours Most frequent factors: cardiovascular, loss of electricity, before winds begin on the coast) vehicle accident, and evacuation

Hurricane Maria Hurricane Maria Consistent NHC Forecasts

Every NHC forecast predicted landfall in Puerto Rico.

All but the first predicted major hurricane intensity • Category 4 landfall in Puerto Rico, but at landfall. category 5 winds likely occurred at some elevated locations • Significant storm surge and devastating rain-induced flooding occurred • Death toll remains highly uncertain

4 Hurricane Florence Hurricane Florence Unexpected Strengthening

• Category 4 over the Atlantic • Category 1 landfall in North Carolina • Significant surge damage in portions of eastern North Carolina • Storm slowed producing more than 30 inches of rains in parts of North Carolina Category 1 to 4 in 36 hours – no model suggested this would occur

Hurricane Florence Hurricane Florence Intensity Forecast Difficulty In-house 6- and 7-day Forecasts

NHC Intensity Forecasts – Florence (2018) NHC Experimental 6- and 7-day forecasts

Some long-range forecasts suggested Florence NHC missed period of rapid strengthening and would re-curve over the central Atlantic then over-forecast intensity near landfall

Track Forecast Success During Florence’s Approach to the U.S. Record Setting Rainfall Predicted Forecast vs. Observed Rainfall

Some long-range forecasts suggested Florence 5-day Rainfall Forecast Observed 5-day Total would re-curve over the central Atlantic

5 Weather Prediction Center Hurricane Michael Excessive Rainfall Graphic Highlights Risk of Flash Flooding

More from Greg Carbin later today

Comparing Michael and Tracking Hurricane Michael Andrew (1992) Tree Damage

Hurricane Andrew

Photo courtesy of Getty Images Hurricane Michael Pine Tree Damage in Andrew

Photo courtesy of Georgia National Guard Hurricane Andrew

Intensity Forecasting Struggles Storm Surge Products Provide NHC Forecasts Major Hurricane but Too Low “Reasonable Worse-Case” Scenario

NHC forecast above guidance but not high enough

6 “Officials Warn it Could be Track Forecasts Very Consistent in Storm of the Century” Showing Threat to the Florida Panhandle

“Life-threatening wind, surge closing in”

Improvements in Track Forecasting Improvements in Track Forecasting 3-day Forecasts in 1990 3-day Forecasts Today

1992 1992

Shrinking Forecast Cone Challenge Communicating Risk Means More Impacts Outside Cone • “This is just a CAT 1 hurricane” • “It has never flooded here before” • “I’ve been through a CAT 3, nothing happened here” • “I saw the new forecast, that GFS thing says it won’t come here, phew!” • “This is the same surge forecast as the last one and I didn’t flood then” • “We are going to evacuate for all CAT1 hurricanes from now on” • “Ah great, I have a GIS map. Finally something accurate” • “We just had our 100 year storm last year”

7 Focus on Hazards & Impacts Key Messages and Social Media Not Track or Category

Use of Twitter, Facebook, and Facebook Live to provide live storm updates

Focus on Hazards & Impacts Hurricane Preparedness Week Not Track or Category Actionable Daily Themes • Sunday – Determine Your Risk • Every storm is different • Monday – Develop an Evacuation Plan • Must remain focused on • Tuesday – Assemble Disaster Supplies water & wind hazards • Wednesday – Get an Insurance Checkup • Thursday – Strengthen Your Home • NHC probabilistic products • Friday –Help Your Neighbor help decision makers • Saturday – Complete your written hurricane plan • Significant impacts occur far from the center – outside the cone • Share only reliable sources of information

Weather Ready Nation Address the “last mile” - connects forecasts to critical emergency management decisions & individual preparedness

The Past Accurate, consistent forecast with decision support

8 Weather Ready Nation Questions? Help Us!

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