Hurricanes and Tropical Storms National Hurricane Conference 2018 Bob Robichaud Warning Preparedness Meteorologist Canadian Hurricane Centre March 27 th , 2018
Contents • Introduction • Tropical Cyclones: Meteorological Overview of Tropical Storms and Hurricanes • Review of the 2017 Hurricane Season • Look ahead at the 2018 Hurricane Season
Why does Canada have a Hurricane Center?
Tropical Cyclones in Canada Clearly tropical cyclones are a threat in Canada as well
Operations at the Canadian Hurricane Centre NHC is the Regional Specialized CHC provides Canadians with Meteorological Center (RSMC) for the WMO meteorological information on hurricanes, RA-IV tropical storms and post-tropical storms
Operations at the Canadian Hurricane Center Canadian Hurricane Center Halifax, Nova Scotia Orlando Canadian Hurricane Center Atlantic Storm Prediction Center
Operations at the Canadian Hurricane Centre Canadian Hurricane Centre • Forecasters train at the National Hurricane Center in Miami • Monitor tropical activity throughout the Atlantic Ocean • Storm-specific bulletins only issued on storms that are expected to have an impact on Canada or coastal waters • Close interaction with emergency managers throughout the year • Heavy interaction with the media • Over the last few years the East Coast Hurricane Awareness Tour has kicked off in Canada
Tropical cyclones: Hurricanes and Tropical Storms
Tropical Cyclones Ingredients for formation • Very warm water (usually at least 80°F) • A pre-existing disturbance containing abundant convection • A moist and unstable air mass • Low vertical wind shear
What are Tropical Cyclones OUTFLOW OUTFLOW SINKING MOTION EYE EYE UPWARD UPWARD E E Y Y MOTION MOTION E E W W A A L L L L L INFLOW INFLOW
What are Tropical Cyclones
Tropical Cyclone Climatology Start of Hurricane Season End of Hurricane Season
Tropical Cyclone Hazards Storm Surge Wind Tornadoes Waves/Rip currents Heavy Rainfall and Inland Flooding
Review of the 2017 Hurricane Season Named Storms: 17 Hurricanes: 10 Major Hurricanes: 6
2017 Hurricane Season Outlook
Early start to hurricane season • First storm of the season was TS Arlene which formed on April 19 th • TS Bret and Cindy formed in June – no impact from Bret but Cindy resulted in 2 fatalities • TS Don and Emily formed in July – no impact from Don but Emily resulted in flooding in southern part of Florida • In early August, Franklin became the first hurricane of 2017 although was short- lived and impacts were minimal • Hurricane Gert formed in mid August but stayed offshore (Cat 2)
Hurricane Harvey • Harvey started as a typical weak August tropical storm that affected the Lesser Antilles • After some weakening Harvey began to re-intensify after crossing the Yucatan • Harvey rapidly intensified into a category 4 August 25 th making landfall along the middle Texas coast • Persistent heavy rains caused catastrophic flooding, and Harvey is the second-most costly hurricane in U.S. history, after accounting for inflation, behind only Katrina (2005)
Hurricane Harvey • Landfall along the Texas Gulf Coast late on August 25 th as a Cat 4 • First Major Hurricane to make landfall in the U.S. since 2005 • Peak recorded wind speed of 142 MPH • 57 reported tornadoes with Harvey • Significant storm surge was also reported (as high as 6-9 feet)
Hurricane Harvey • Very slow movement of the storm over the next few days resulted in extreme rainfall • Harvey was the most significant tropical cyclone rainfall event in United States history • The highest storm total rainfall report from Harvey was 60.58 inches • Radar estimates indicated that the peak rainfall could be in the 65 to 70 inch range • The rainfall was also extreme in areal coverage • This all resulted in catastrophic flooding
Hurricane Harvey • At least 68 people died from the direct effects of the storm in Texas • Over 300,00 structures were flooded • Up to 500,000 cars were flooded • 40,000 people evacuated or took refuge • About 30,000 water rescues were reported • 336,000 customers lost power • Preliminary estimates for damage costs are at $125 USB
Hurricane Irma • Developed off the coast of Africa in late August and became a hurricane early on August 31 st • Eventually reached Cat 5 with winds of 180 mph • Landfall in Barbuda and St Martin at peak intensity • Two more landfalls as Cat 5 – British Virgin Islands, Cuba and one as Cat 4 in Bahamas
Hurricane Irma • Irma made its 6 th landfall in the Lower Florida Keys on September 10 th as a Major Hurricane • Final landfall was near Marco Island before the storm crossed the spine of Florida • Peak wind was 160 mph (unofficial report of 199 mph) • Peak wind in the U.S. was 120 mph in the Florida Keys • Heavy rainfall caused flooding in many areas • 21 tornadoes were reported
Hurricane Irma • Positive storm surge was reported at several locations in the Caribbean and in the U.S. • Offshore winds on the northern side of Irma’s circulation initially caused a negative storm surge and receding water levels along Florida’s West Coast • Some normally submerged areas went virtually dry, allowing people to walk out onto the sea or bay floor • This is a very dangerous situation as the water will eventually rise and rise rapidly
Hurricane Season 2017 Continues • Jose formed in early September and intensified rapidly to Cat 4 then meandered off the coast of New England for a few days • Katia was a short-live Cat 2 hurricane that formed in the Gulf of Mexico • Lee formed in mid- September and reached Cat 3 but stayed offshore Katia Irma Jose
Hurricane Maria • Maria also formed in mid- September and eventually become a Cat 5 hurricane with winds of 175 mph • Direct hit on Puerto Rico with winds of 155 mph • 112 fatalities • Dominica sustained catastrophic damage • Electric grid was devastated • Total cost still being evaluated • Recovery still very much ongoing today
Hurricane Season 2017 Continues • Nate was a Cat 1 Hurricane that formed in early October and impacted the western Caribbean and the U.S. • Ophelia was a storm that formed in mid-October and became the final hurricane of 2017 • Ophelia reached Cat 3 and followed an odd track that brought it into Europe as a strong Post-Tropical Storm • Phillip was a late October TS – minimal impacts • Finally Rina formed in early November. With Rina, 2017 became the only season with a named storm in every month
2017 Hurricane Season Summary • 2017 was an historic season with several new records set during the season • 6 major hurricanes formed in 2017, the most since the hyperactive 2005 season • Harvey was the first major hurricane to make landfall in the continental U.S. since Wilma in 2005 ending a record-long period without a landfall major hurricane • Harvey set a new record for tropical cyclone-generated rainfall in the U.S. with 60.58” • First time the U.S. had two landfalling category 4 hurricanes the same year – Harvey and Irma • Ophelia was the farthest east that an Atlantic major hurricane had ever been observed
Outlook for the 2018 Atlantic Hurricane Season
El Niño and Atlantic Hurricanes Increase in high-level westerly Higher vertical wind shear winds during El Niño years
Sea Surface Temperature Anomaly Cooler water in the Main Cooler water in the Development Region equatorial Pacific (La Nina)
El Nino prediction for the next few months Hurricane Season 2018 El Niño Fewer Hurricanes Hurricanes Neutral La Niña More Storms About 1/3 of the models suggest El Niño conditions by the peak of hurricane season while 2/3 show either neutral or La Niña conditions
Probabilistic El Niño Prediction About 30% chance of El Niño during the peak of hurricane season while 70% chance of no El Niño
2018 Hurricane Season Outlook Major Named Hurricanes Hurricanes Storms Category 1 to 5 Category 3-5 Tropical Storm Risk 11-19 4-10 1-5 Colorado TBD TBD TBD State April 5 th April 5 th April 5 th University TBD TBD TBD NOAA May 24 th May 24 th May 24 th 30-year average 12 6.5 2
Thank you! Bob Robichaud VE1MBR Warning Preparedness Meteorologist Canadian Hurricane Centre Halifax, NS
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