Post on 06-Jan-2016
description
“Working Together To Save Lives”
Tropical Storm Tornadoes – WFO PerspectiveBart Hagemeyer
NOAA/NWS Melbourne, Florida
“Working Together To Save Lives”
10 DEADLIEST FLORIDA TORNADO OUTBREAKS
FEBRUARY 1998 42 DEADMARCH 1962 17 DEADAPRIL 1966 11 DEADJUNE 1972 7 DEAD HURRICANE AGNESJANUARY 1936 7 DEADSEPTEMBER 1882 6 DEAD HURRICANESEPTEMBER 2004 6 DEAD HURRICANE IVAN*APRIL 1925 5 DEADMARCH 1939 4 DEADOCTOBER 1992 4 DEAD Un-Named HybridAPRIL 1988 4 DEAD
(* Compare total of 7 direct wind-related deaths from Charley)
“Working Together To Save Lives”
Increasing Population - Increasing Tropical CycloneActivity - Greater Documentation - Greater Risk
18801890
19001910
19201930
19401950
19601970
19801990
20002010
0
20
40
60
80
100
120
140
0
5
10
15
20
25
Tornado Events (85) (Y1)
Tornadoes (437) (Y1)
Population (Y2)
Through 2004 Season
Tropical and Hybrid Events by Decade
85 Cases (1882-2004)
“Working Together To Save Lives”
Bonnie – Charley – Frances – Ivan - JeanneRecord Season with 74 Florida Tornadoes
54 F0, 17 F1, 3 F2
2004 Tornado Producing Tropical Cyclones
“Working Together To Save Lives”
Types of Tornado-Producing Systems (1882-2004)
Hurricane 42
Tropical Storm 22
Tropical Depression 8
Sub-Tropical/Hybrid 8
Tropical Disturbance 5
Virtually all Tropical Systems produce tornadoes
“Working Together To Save Lives”
694
1 2
RightFront
Location of Tornadoes Relative to Cyclone CenterWith Respect to Cyclone Motion (1882-2004)
9*
85 Cases
“Working Together To Save Lives”
Tropical Cyclone Destructive Wind Forecast and Preparedness Challenges are:
-Tornadoes Associated With Dominant Outer Rainbands in the Right Front Quadrant.
-Extreme Winds of the Eyewall and Innermost Rainbands at Landfall.
“Working Together To Save Lives”
FOCUS ON SIGNIFICANT TROPICAL/HYBRIDCYCLONE TORNADO EVENTS!
Any Tornado-Related Death
Five or More Tornadoes in 24-Hour Period With atLeast One Tornado of F2 or Greater Intensity
Any F3 Tornado
20 Significant Cases in Recorded History:
10 Huricanes, 6 Tropical Storms, and 4 Hybrid Cyclones
Most TC Tornadoes are Weak and Short-Lived
“Working Together To Save Lives”
Track Segments of Significant Tropical/Hybrid CasesDuring Florida Tornado Production Phase 1882-2004
Charley
Ivan
All Significant Tornado Cases Began Well Before Landfall
“Working Together To Save Lives”
Ivan Pre-Landfall Jeanne Pre-Landfall
Differences in Gulf and Atlantic Pre-Storm Environment
“Working Together To Save Lives”
Significant Tornadoes - Focus on Outer Rainbands
Very Different Storms - Same Tornado
Result
OPAL
GORDON
“Working Together To Save Lives”
Hurricane Opal 10/4/95F2 Tornado 1 Dead
“Working Together To Save Lives”
Tropical Storm Gordon 11/15/94F2 Tornado 1 Dead
“Working Together To Save Lives”
The Central Characteristic of a Tropical Cyclone is not a Reliable Indicator of
Tornado Potential – It is the Mesoscale Environment of the Dominant Outer Rainbands, Often 100 or More Miles
Away That Determines Tornado Potential.
Tornadoes are Typically the First Threat to Arrive
“Working Together To Save Lives”
Hurricane Agnes June 1972 (Category 1) Tropical Cyclone Tornado Archetype
“Working Together To Save Lives”
Hurricane Agnes June 1972
Deadliest Tropical Cyclone Tornado Outbreak in Florida History...28 Tornadoes in 26 hours... (2 F3, 9F2, 11 F1, 6 F0). 10 killer/injury tornadoes.
“Working Together To Save Lives”
Experiences From 2004 Hurricane Season
Ivan Images – Irv Watson, SOO, WFO TLH
“Working Together To Save Lives”
Ivan – Agnes Clone – Missed Peninsula!3 Killer Tornadoes - 2 F2 and 1 F1 – 6 Dead
“Working Together To Save Lives”
0704 UTC 9/15/04
“Working Together To Save Lives”
Blountstown Killer F2
0208 UTC 9/16/04
“Working Together To Save Lives”
Irv Watson WFO TLH
“Working Together To Save Lives”
20 Hours of Severe Weather Signatures
“Working Together To Save Lives”
Note: Ivan also produced a tornado outbreak in VA and MD a day later!
“Working Together To Save Lives”
*includes Georgia and Alabama Tornadoes
TLH CWAPOD 0.913FAR 0.846CSI 0.152AVG Lead Time 11.2 MinutesWarnings in Effect for Killers
Ivan Tornado Stats Summary
(MLB also had high FAR for Charley and Frances)
“Working Together To Save Lives”
Hurricane Charley 8/13/04 – Late Morning
Classic Situation
“Working Together To Save Lives”
MLB Graphical Hurricane Hazards 8/13/04
1130 AM
“Working Together To Save Lives”
PrimaryOuter Rainband
EyeWall
2+ Million People
Friday Evening 8/13/04
“Working Together To Save Lives”
BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING
*AT 642 PM EDT...THE NATIONAL WEATHER SERVICE HAS ISSUEDA TORNADO WARNING FOR DESTRUCTIVE WINDS OVER 100 MPH AND TORNADOES IN THE EYE WALL AND INNER RAIN BANDS OFHURRICANE CHARLEY.
* THE LEADING EDGE OF HURRICANE CHARLEYS DESTRUCTIVE WINDS IS EXPECTED TO MOVE INTO THE KISSIMMEE AND GREATER ORLANDO AREA BY 715 PM.
“Working Together To Save Lives”
“Working Together To Save Lives”
Costliest Severe Storm in Orlando area history!
No Direct Lives Lost!
Customers Responded And requested we issue “eyewall” warning again for Frances and Jeanne.
LP1 station liked EAS
“Working Together To Save Lives”
The Eyewall and innermost rainbands of landfalling hurricanes are extremely dangerous mesoscale phenomena that produce very localized devastation!
Charley – Metro Orlando
“Working Together To Save Lives”
Hurricane Jeanne 25 SEP 2004
“Working Together To Save Lives”
Conceptual Model of Hurricane Eyewall “Mini-Swirls”
“Working Together To Save Lives”
Jeanne
“Working Together To Save Lives”
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
858 PM EDT SAT SEP 25 2004
THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A
* TORNADO WARNING FOR...
MARTIN COUNTY
ST. LUCIE COUNTY
IN EAST CENTRAL FLORIDA
* UNTIL 1000 PM EDT
* AT 855 PM EDT...THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING FOR MARTIN AND ST LUCIE COUNTIES MAINLY FOR THE ONSET OF EXTREME HURRICANE WINDS AND EMBEDDED TORNADOES ASSOCIATED WITH THE INNER CORE OF HURRICANE JEANNE AS THE CENTER NEARS THE COAST. WINDS TO 100 MPH WITH GUSTS TO 120 MPH ARE EXPECTED...ALONG WITH TORNADOES.
“Working Together To Save Lives”
• We are not attempting to warn for the individual enhanced convective features within the eyewall – They are ephemeral and moving at 100 mph.
• We are warning prior to the impact of the eyewall and/or innermost rainbands
“Working Together To Save Lives”
“Working Together To Save Lives”
“Working Together To Save Lives”
Survey results -Jeanne
One Lucky Row of Manufactured Homes – Barefoot Bay
“Working Together To Save Lives”
Eyewall “Mini-swirls”
And Some Not so Fortunate
“Working Together To Save Lives”
• Eyewalls and innermost rainbands are dangerous mesoscale phenomena.
• Damage gradient extreme, destruction localized – county scale and lower.
• Historic severe weather events where they occur.
• Hurricane Warnings may have been out for 24 hours or more.
Extreme Hurricane Winds
“Working Together To Save Lives”
• Power may be out and information lacking just before the worst hits (NWR, TV Re-broadcast).
• Citizens need final warning – last chance to save lives ~ 1-2 Hours. Need EAS.
• Not talking about track – but impact!
• WFO mission is suited for this role.
“Working Together To Save Lives”
There is no reason to believe that in the future, a TC tornado outbreak could not kill more people than the February 1998 Extratropical Outbreak (42).
Remembering Agnes, and now Ivan, is useful as a planning metric – The outer rainband tornado archetypes – to realize what is really possible.
Concluding Thoughts – TC Tornadoes
We Now Know a Lot About Tornadoes and Tropical Cyclones...but Major Issues Remain.
“Working Together To Save Lives”
The ability to separate the typical TC tornado from the truly dangerous outbreaks is improving.High resolution models and continued research provideour best chance for improvement.
Extended threat period with lengthy periods of inactivity followed by brief periods of strong tornadoes – hard to keep guard up that long - desensitizing risk is high.
Forecast ability has improved significantly: TornadoWatches are put up for most tropical cyclones. TornadoWarnings must be taken seriously, but potential for false alarms can be high in some cases. In other cases tornadoes can spin up rapidly with little warning.
“Working Together To Save Lives”
Significant Tornado Parameter
CAPE, 0-6 km Shear, 0-1 km SRH, LCL hgt
(From SPC: Thompson et al., 2004)
Hurricane Charley
Local Analysis and Diagnostics
“Working Together To Save Lives”
T.S. Gabrielle September 2001
ARPS Radar Reflectivity Simulation
“Working Together To Save Lives”
Evacuation and Sheltering - Evacuate mobile -manufactured homes in threat area? - This could be 200 miles from landfall and 24 to 36 hours before landfall?
Safe Rooms in homes built for hurricanes will perform well for about 99% of Florida Tornadoes. Shelters in manufactured home parks would be beneficial.
Shelters don’t exist in most cases. But there are recent success stories: Gulfstream Harbor Manufactured Home Park – Orange Co. Florida Warning & Information Network Grant
700 Weather Radios for all residentsHardened Community Club HouseComprehensive Plan
Concluding Thoughts – Preparedness
“Working Together To Save Lives”
Thank You!
Bart Hagemeyerbart.hagemeyer@noaa.gov