Title: Reasons for the Unusually Destructive 2004 Atlantic Basin Hurricane Season
1Reasons for the Unusually Destructive 2004
Atlantic Basin Hurricane Season Phil Klotzbach
and William Gray Department of Atmospheric
Science Colorado State University Climate
Diagnostics Workshop October 25, 2005
2Outline
- 2004 Atlantic Hurricane Summary
- Activity-Enhancing Features
- Westward Track-Enhancing Features
- Conclusions
3Outline
- 2004 Atlantic Hurricane Summary
- Activity-Enhancing Features
- Westward Track-Enhancing Features
- Conclusions
42004 ATLANTIC BASIN TROPICAL CYCLONE ACTIVITY
52005 Season
62004 Storm Tracks
Figure taken from http//www.nhc.noaa.gov/tracks/2
004atl.gif
72005 Storm Tracks
Figure taken from http//www.wunderground.com/hurr
icane/at2005.asp
8 9 Landfalls
92004 United States Hurricane Landfalls
10Outline
- 2004 Atlantic Basin Statistics
- Activity-Enhancing Features
- Westward Track-Enhancing Features
- Conclusions
11August-September 2004 SST Anomalies
12?
1860 1900
1940 1980
2020
Adapted from Goldenberg et al. 2001
13August-September 2004 850 MB U Anomaly
14August-September 2004 V Anomalies
Anomalous Northerlies
200 mb
Anomalous Southerlies
850 mb
15August-September 2004 OLR Anomaly
16(No Transcript)
17Genesis Parameter (GP) Definition
GP ?V U850mb SSTA
Where ?V 850 mb 200 mb average
August-September V wind component from (7.5N
7.5S, 20-45W) U850mb 850 mb average
August-September U wind component from (5-15N,
20-60W) SSTA Average August-September sea
surface temperature anomaly from (5-15N,
20-60W)
18Genesis Parameter (GP) Component Locations
SSTA U
1.5 km
V
1.5 km
12 km
19Genesis Parameter Values (in Standard Deviations)
20Atlantic Basin Genesis Parameter Ratios
21August-September SST (1995-2004) (1950-1969)
22August-September 200 mb U (1995-2004)
(1950-1969)
23Upper-Level Wind Parameter (UP) Definition
UP -ZWA
Where ZWA 200 mb average August-September U
wind component from (5-15N, 20-60W)
24Upper-Level Wind Parameter (UP) Location
- ZWA
12 km
25Upper-Level Wind Parameter Values (in Standard
Deviations)
26Outline
- 2004 Atlantic Basin Statistics
- Activity-Enhancing Features
- Westward Track-Enhancing Features
- Conclusions
27FRAN
OPAL
BRET
1995-2003 Intense Hurricane Tracks (32 tracks)
28August-September 500 mb Ht. (2004) (1995-2003)
29August-September 500 mb Ht. (2004) (1995-2003)
30Westward Track Parameter (WP) Definition
WP Zone 1 Zone 2 Zone 3
Where Zone 1 500 mb average August-September
500 mb height from (40-50N, 65-75W) Zone 2
500 mb average August-September 500 mb height
from (50-60N, 20-30W) Zone 3 500 mb average
August-September 500 mb height from (40-50N,
100-110W)
31L
L
H
32United States Tropical Cyclone Landfall Parameter
(LP) Definition
LP GP UP WP
Where GP Genesis Parameter UP Upper-Level
Wind Parameter WP Westward Track Parameter
33United States Landfall Parameter (LP) Values (in
Standard Deviations)
34United States Landfall Parameter Ratios
35Outline
- 2004 Atlantic Basin Statistics
- Activity-Enhancing Features
- Westward Track-Enhancing Features
- Conclusions
36Conclusions
- The 2004 hurricane season was very active both in
terms of overall tropical cyclone activity and in
terms of United States landfalls - A strong Intertropical Convergence Zone, weaker
trade winds, and warm Atlantic sea surface
temperatures contributed to the very active
season - A mid-level ridge predominated over the East
Coast of the United States with mid-level troughs
to the west and east which helped push storms
westward into the longitudes of the United States