Hurricanes, Harvey and the 2018 Hurricane Season Outlook

Dan Reilly NWS /Galveston

Hurricane Harvey, Photo Credit NASA Outline

 Hurricane hazards (basics)  How to stay informed  Hurricane season outlook Hurricane/Tropical Storm Potential Hazards Every storm will have a different set of hazards

Storm Surge Flooding Tornadoes

Ike (2008), Carla (1961) Buelah (1967) Harvey (2017)

Flooding Rains Damaging Winds TS Allison (2001) Alicia (1983) Harvey (2017) Andrew (1992) Camille (1969) Carla (1961) Which Hazards are the Most Deadly? Indirect Hazards

Rappaport and Blanchard, BAMS 2016 View from Radar

Heavy Rain Wall

Mdt Rain

Light Rain

Spiral Bands Saffir-Simpson Hurricane Wind Scale Category 1-min. Sustained Winds Storm Examples Wind Impacts (mph) Tropical Less than 39 mph Relatively minor Depression Tropical Between 39 and 73 Allison Can be significant Storm 1 74 - 95 Jerry 1989 Very dangerous; will produce Claudette 2003 some damage Humberto 2007 2 96 - 110 Georges 1998 Extremely dangerous; will Ike 2008 produce extensive damage 3 111 - 130 Alicia 1983 Devastating damage Katrina 2005 Rita 2005 4 131 - 155 1900 - Galveston Catastrophic damage Carla 1961 5 > 156 Andrew 1992 Catastrophic damage Camille 1969 Not the Saffir Simpson Hurricane Wind Scale Hurricane Wind Damage Category 1 Damage in Houston

Typical damage with Ike around Houston: downed or snapped Trees, some roof damage GOES-16 Satellite Infrared Loop August 25-28; Note development of eye and rapid intensification, then weakening after ; Intense bands of thunderstorms on eastern side shown by red and black colors

Category 4

Surge is Highest to Right of Center Track

Hurricane Ike Depth of Water Above Ground

Harris County Flood Control District Early rise trapped many on Bolivar, Don’t wait too long to evacuate surge zones, especially barrier islands; Need to account for the forerunner; water covering roads 24 hours ahead of landfall

Water on Roads Landfall Hurricane Ike: SE TX Coast Surge/Coastal Flooding

AP Photo/David J. Phillip 5-12 ft surge Port Aransas, TX Impacts

8 ft storm surge Flooding Due to Rainfall From Hurricanes/Tropical Storms • A concern especially of storm is large and/or slow moving!

TS Allison Greens Bayou, Home Owned Estates – June 10, 2001 Harvey’s Slow Looping Track Harvey made landfall near Rockport, TX as a cat 4 major hurricane where winds and storm surge caused tremendous damage; it then slowed down and “weakened” to a tropical storm; slow looping storms are notorious for producing tremendous amounts of rainfall (Allison, Claudette) Radar Animation from 10 AM Friday Aug. 25th to 7 PM Thursday Aug. 31st Note eye of hurricane and spiral bands to east

Red = Heavy Rain, Yellow = Moderate, Green = Light Record Rainfall; This analysis a combination of gauges and radar estimates; extremely large area of 30 to 60 inches of rain! 60.58 inches near Nederland, TX Businesses are surrounded by floodwaters in Humble, . David J. Phillip/ AP Harvey Tornadoes

Roger Edwards Be Prepared • Stay informed: Be aware of forecast and what is going on in tropics; hurricane can form in the Gulf and make landfall with little notice (Alicia) only a few days notice; listen to local officials for evacuation instructions/recommendations • Make a plan: If you or tenants in your facility need to evacuate have a plan on how you will do it, where you/they will go • Build a kit: Make sure you or your tenants have adequate supplies whether evacuating or sheltering in place

National Hurricane Center Web Page http://hurricanes.gov

Top panel Tropical Weather Outlook: 2-day shown up front, click for satellite version

Gaston Maps, Advisories for Active Storms including new products Hermine Where might tropical depression or storm develop within next 48 hours?

Would become Tropical Cindy 2 days later; gives you additional lead time! Would become TS Bret 5 days later; gives you additional lead time! Where might tropical depression or storm develop within next 120 hours?

Would become TS Cindy 4 days later; gives you additional lead time! 50% Would become TS Bret 5 days later; gives you additional lead time! 20%

Average Hurricane Season: Running Totals

On average, 11-12 named storms, 6 hurricanes, 2-3 major hurricanes

We are here Very active 2017!: 17 named storms, 10 hurricanes, 6 major SEASONAL HURRICANE FORECAST FOR 2018 Colorado State (Dr. Klotzbach)

1981-2010 Median (in parentheses) Issue Date: April 5th 2018 (Above Normal Activity)

Named Storms: (12.0) 14 Hurricanes: (6.5) 7 Major Hurricanes (2.0) 3 Accumulated Cyclone Energy (ACE) (92) 130

2017 Seasonal Forecast: April 6th, June 1st, July 5th, Aug. 4th, Observed

Named Storms 11 14 15 16 17 Hurricanes 4 6 8 8 10 Major Hurricanes 2 2 3 3 6 Accumulated Cyclone Energy 75 100 135 135 226

NOAA will issue their outlook in late May. Seasonal forecasts tend to improve later on. Last years April forecast for season was for below normal, turned out to be much above. No matter what the seasonal forecast it only takes one; need to prepare the same every year! 1983 very “quiet” for Atlantic overall but SE Texas had a direct hit from Hurricane Alicia

Least active season 1983 (4 named storms!)

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