Hurricanes and Tropical Storms - National Hurricane Conference 2018 Bob Robichaud - National ...
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Hurricanes and Tropical Storms
National Hurricane Conference 2018
Bob Robichaud
Warning Preparedness Meteorologist
Canadian Hurricane Centre
March 27th, 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
UPWARD E E UPWARD
MOTION Y Y MOTION
E E
W W
A A
L L
L L
INFLOW L INFLOWWhat are Tropical Cyclones
Start of Hurricane Season
Tropical Cyclone Climatology
End of Hurricane SeasonTropical Cyclone Hazards
Storm Surge Wind
Tornadoes
Heavy Rainfall and Inland Flooding Waves/Rip currentsReview of the 2017 Hurricane Season
Named Storms: 17
Hurricanes: 10
Major Hurricanes: 62017 Hurricane Season Outlook
Early start to hurricane season
• First storm of the season
was TS Arlene which formed
on April 19th
• 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 25th
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
25th 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 floodingHurricane 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
USBHurricane Irma • Developed off the coast of Africa in late August and became a hurricane early on August 31st • 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 6th landfall in the Lower Florida Keys on September 10th 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
JoseHurricane 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
month2017 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
SeasonEl Niño and Atlantic Hurricanes
Increase in high-level westerly Higher vertical wind shear
winds during El Niño yearsSea 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
Neutral Hurricanes
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 conditionsProbabilistic El Niño Prediction
About 30% chance of El Niño during the peak of hurricane
season while 70% chance of no El Niño2018 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 5th April 5th April 5th
University
TBD TBD TBD
NOAA May 24th May 24th May 24th
30-year average 12 6.5 2Thank you!
Bob Robichaud
VE1MBR
Warning Preparedness Meteorologist
Canadian Hurricane Centre
Halifax, NSYou can also read
