Hurricane Preparedness Week 2020 - 1-5 June 2020 In collaboration with the Government of Bermuda Disaster Risk Reduction Mitigation Team - Bermuda ...
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Hurricane Preparedness Week 2020
1-5 June 2020
In collaboration with the Government of Bermuda
Disaster Risk Reduction Mitigation Team
Hurricane Season 2020
Agenda
Take-home points
Hurricane Basics
Science and Predictions
• 2019 Season - Review
• 2020 season - Precursor conditions
and seasonal predictions
Operations:
• BWS and NHC Products
• Communications with local
stakeholders
27/05/2020 2:34 PM Bermuda Airport Authority 2
Seasonal Outlook
Take Home Points • An active 2020 Atlantic Hurricane Season is
expected.
• While the most active part of the season is usually
August through October, a tropical storm or
hurricane is possible at any time - June-November is
officially Hurricane Season, but Arthur proves
tropical systems can occur beyond these times.
• It only takes one storm to make it an ‘active season’
for Bermuda
COVID-19 Impacts and Response
• Operations at the Bermuda Weather Service have
remained 24/7 through the shelter-in-place period,
and are expected to continue on that basis.
• Predictability may be decreased due to reduced
Source: Cooperative Institute for Meteorological Satellite aircraft data availability.
Studies / University of Wisconsin-Madison
27/05/2020 2:34 PM Bermuda Airport Authority 3
Take Home Points
BWS Operational Products
• Tropical Update Bulletins (TUBs) are issued on active systems
every 6 hours - Intermediate TUBs possible for imminent
systems
• Potential Threat – storm centre to track within 400 nm in
next 72 hours
• Threat – storm centre to track within 100 nm in next 72
hours
• TS/Hurr Watch – TS/Hurricane conditions possible within 48
hours
• TS/Hurr Warning – TS/Hurricane conditions expected within
36 hours
27/05/2020 2:34 PM Bermuda Airport Authority 4
Tropical Cyclone Terminology
Tropical Depression Arthur
• Tropical Depression* - A tropical cyclone in which the
maximum sustained surface wind speed is
Areas of Responsibility NHC: analysis and forecasting of tropical BWS: Observations, forecasts, analyses, watches & cyclones in the North Atlantic, Caribbean Sea warnings for Bermuda and Marine Area out to 25nm and Gulf of Mexico
Climatology of Atlantic
Tropical Cyclones - Early
Arthur
MAY
27/05/2020 2:34 PM Bermuda Airport Authority 7
Climatology of Atlantic
Tropical Cyclones - Peak
18 September 2019
Major Hurricane
Humberto
12-13 October 2016
Major Hurricane
Nicole
17 October 2014
Major Hurricane
Gonzalo
5 September 2003
Major Hurricane
Fabian
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Climatology of Atlantic
Tropical Cyclones - Late
Preferred storm track pathways
Source: FSU and BIOS
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Historical Tropical Cyclone Record For Bermuda Storms within 100nm (i.e. meeting BWS Threat criterion) Sources: NOAA, BWS, BIOS, University of Reading
Hiroyuki Murakami et al. PNAS
doi:10.1073/pnas.1922500117
©2020 by National Academy of Sciences
27/05/2020 2:34 PM Bermuda Airport Authority 112019 Atlantic Hurricane Season Review
Summary
• 18 Named Storms
• 6 Hurricanes
• 3 Major Hurricanes
• 3 named storms that
achieved threat criteria.
• 1 Major hurricane impact
27/05/2020 2:34 PM Bermuda Airport Authority 12Hurricane Humberto – September 2019 Track and Wind Swath Satellite Imagery & Rainfall 27/05/2020 2:34 PM Bermuda Airport Authority 13
Hurricane Humberto – September 2019 Wind field expansion Doppler Radar Imagery 27/05/2020 2:34 PM Bermuda Airport Authority 14
Hurricane Humberto – September 2019 Highest recorded wind speeds & gusts Resulting Damage 27/05/2020 2:34 PM Bermuda Airport Authority 15
Hurricane Humberto – September 2019 Storm surge Resulting Damage Maximum surge at NOAA’s Esso Pier Tide Gauge: 18/09/2019 20:54 (local time) 3.143 feet above the predicted tide 27/05/2020 2:34 PM Bermuda Airport Authority 16
2020 Atlantic Hurricane Season
Source: Cooperative Institute for Meteorological Satellite
Studies / University of Wisconsin-Madison
27/05/2020 2:34 PM Bermuda Airport Authority 17Ocean Surface Temperature Anomalies
• Ocean Temperatures – influence over
seasonal hurricane activity
• Warm Atlantic Main Development
Region
• Cool Equatorial Pacific
Source: tropicaltidbits.com
More locally:
Source: NOAA
• Currently cooler than average
• Warming to the south
Source: tropicaltidbits.com
27/05/2020 2:34 PM Bermuda Airport Authority 18Decreased aircraft and surface observations could degrade
weather forecast model reliability.
• Aircraft produce over 700 000 high-
quality daily observations of air
temperature, winds, humidity and
turbulence. (Source: World
Meteorological Organization).
• “Recent figures show a decrease of 80%
of such observations in Europe and 60%
globally.” (Source: European Centre for
Medium-range Weather Forecasts).
March 2020 European AMDAR observations. Source: DWD
(German Met. Service).
27/05/2020 2:34 PM Bermuda Airport Authority 19Degradation of Surface Observations
BWS’ team of Meteorological Technicians
have continued a 24/7 service of making
weather observations and maintaining
Bermuda’s climate record through the
shelter-in-place period.
There is a decrease in the number of surface and
aircraft meteorological measurements due to
COVID-19. These issues highlight the importance
of ongoing surface & upper-air observations
through weather balloon launches.
27/05/2020 2:34 PM Bermuda Airport Authority 20Spring Seasonal Hurricane Predictions
To Date:
0
Average Prediction:
High activity
8
Note: Hurricane predictions
only (does not include
tropical / subtropical storms)
https://seasonalhurricanepredictions.bsc.es/
5/27/2020 2:34 PM BERMUDA AIRPORT AUTHORITY 21Review of Operational Products
60-h Forecast
Information on
Cone Graphic
NOAA
Also reflected in BWS products
27/05/2020 2:34 PM Bermuda Airport Authority 22Forecast Products at the US National Hurricane Center 27/05/2020 2:34 PM Bermuda Airport Authority 23
Forecast Products at the US National Hurricane Center 27/05/2020 2:34 PM Bermuda Airport Authority 24
The ‘Cone of Uncertainty’
Track forecast accuracy
improvements lead to
smaller cone of
uncertainty.
27/05/2020 2:34 PM Bermuda Airport Authority 25Forecast Products at the
Bermuda Weather Service
Tropical Update Bulletin
• Based on NHC Advisory # and time
• Current position relative to Bermuda
and intensity details
• Timing and location of forecast closest
point of approach (‘CPA’), within the next
72 hours
• Any additional detail (e.g.
Watch/Warning valid)
• Whether the system is a ‘Threat’ or
‘Potential Threat’ (see next slide)
27/05/2020 2:34 PM Bermuda Airport Authority 26Threat Criteria, Watches and Warnings
40N 400nm
100nm
T+72 hrs
30N
T+0 hrs
20N
70W 60W 50WThreat Criteria, Watches and Warnings
40N 400nm
100nm
30N
The centre of a tropical system is forecast
to come within 400 nautical miles of
Bermuda within 72 hours. 20N
70W 60W 50WThreat Criteria, Watches and Warnings
40N 400nm Threat:
The centre is forecast to come
within 100 nautical miles of
Bermuda OR the effects of the
100nm
tropical system (including tropical
storm force winds) are possible
within 72 hours.
30N
20N
70W 60W 50WThreat Criteria, Watches and Warnings • Tropical Storm Watch: 48 hours or less prior to possible onset of tropical storm force winds (34-63kt). Includes similar conditions in subtropical storms and outer fringes of hurricanes. • Tropical Storm Warning: tropical storm force winds expected within 36 hours. • Hurricane Watch: 48 hours or less prior to possible onset of hurricane force winds (64 knots or more) or other damaging hurricane conditions. • Hurricane Warning: Hurricane force winds &/or damaging hurricane conditions expected within 36 hours.
Timeline for Threats, Watches and Warnings
Issuance of Cessation of
Cessation of TS force
POTENTIAL
THREAT
Issuance Potential for hurcn force winds. TS
of Onset of strongest winds. HURCN WARNING
(400nm) or Issuance of
THREAT TS/HURCN
TS/HURCN TS/Hurcn winds/swells/ WARNING downgraded
Creation
(100nm) WATCH
WARNING force surge and eye downgraded to to Small Craft
of TUBs winds passage TS WARNING warning
Time=>
>T-72hrs T-72hrs T-48hrs T-36hrs T-0hrs CPAReminder of BWS/NHC Policy Changes • BWS, in consultation with NHC, is able to issue watches & warnings on tropical disturbances that are not yet a tropical cyclone, but which pose the threat of bringing TS or Hurricane conditions to the Island within 48hrs. • These will be labelled ‘Potential Tropical Cyclones’ • An example of when this might have been useful was Hurricane Karen in 2001 which formed on Bermuda’s doorstep – BWS was able to issue gale and storm warnings but not ‘more impactful’ tropical warnings
BWS Communications www.weather.bm Automated BTC telephone recordings 977, 9771, 9772, 9773 Radio interviews (including 100.1FM) Marine VHF Channel 2 (Bermuda Radio) OneComm Channel 4 & WOW Channel 100 BWS Weather Channels Social Media – BWS Facebook page: www.facebook.com/BermudaWeatherService News media announcements Communications with EMO, Aviation & Marine operations via email, fax, phone, satellite phone Full redundancy for BWS equipment, electricity & comms
Messages for the Public ◦ Tropical systems do not behave like winter weather – they can change very rapidly. At the watch stage, please monitor the progress carefully at the warning stage please respond to preparations ◦ Keep updated on the official sources of information: ◦ www.weather.bm ◦ EMO website for preparation information ◦ Emergency Broadcast Facility (100.1FM) during event ◦ Bermuda Tree Frog app ◦ Press release to be issued; various links/videos on www.weather.bm ◦ Please do not become complacent. ◦ Review/create a Hurricane Preparedness Plan for your family and business incorporating lessons from previous years.
Hurricane Preparedness Week 2020
1-5 June 2020
In collaboration with the Government of Bermuda
Disaster Risk Reduction Mitigation TeamYou can also read
