Landfalling tropical cyclones on the coast of Mexico: A...
Transcript of Landfalling tropical cyclones on the coast of Mexico: A...
Landfalling tropical cyclones on the Pacific coast of Mexico: A review from
historical press reportsp p
G B Raga1 Beatriz Bracamontes‐Cevallos1 Luis M Farfán2 and G. B. Raga , Beatriz Bracamontes Cevallos , Luis M. Farfán and Rosario Romero‐Centeno1
1Centro de Ciencias de la Atmosfera, UNAMd d2CICESE, Unidad La Paz
Mexico
2011 Annual Conference, 12‐15 April, Seattle, Washington
Tropical cyclones: Current characteristics and potential changes under a warmer Tropical cyclones: Current characteristics and potential changes under a warmer Tropical cyclones: Current characteristics and potential changes under a warmer climate (IAI‐CRNII‐048 )
http://cabernet.atmosfcu.unam.mx/IAI
Tropical cyclones: Current characteristics and potential changes under a warmer climate (IAI‐CRNII‐048 )
http://cabernet.atmosfcu.unam.mx/IAI
EPAC climatology: satellite era
From official database at NHC (1949‐present)
• What has happened in the last 40 years?
20
1970‐1979 1980‐1989 1990‐1999 2000‐2009
16
18
12
14
8
10
4
6
0
2
average named storms average hurricanes average major hurricanes
Cat . 3
Variability of major hurricane trajectories as a function of
decade and intensity
1970‐1979
Cat . 4 Cat . 5
(Farfan, Romero‐Centeno & Raga, 2011)
Cat . 3
Variability of major hurricane trajectories as a function of
decade and intensity
1980‐1989
Cat . 5Cat . 4 54
(Farfan, Romero‐Centeno & Raga, 2011)
Cat . 3
Variability of major hurricane trajectories as a function of
decade and intensity
1990‐1999
Cat . 5Cat . 4
(Farfan, Romero‐Centeno & Raga, 2011)
Cat . 3
Variability of major hurricane trajectories as a function of
decade and intensity
2000‐2009
Cat . 5Cat . 4 54
(Farfan, Romero‐Centeno & Raga, 2011)
Landfalling TCs where they start, when they start, where they
land, how much rain they produce?On average about 15% of the total named cyclones make landfall
Genesis location of landfalling TC Genesis location of non‐landfalling TC
(Romero‐Centeno et al, 2011)(14N, ‐97.5W)(13.5N, ‐103W)
L df lli TC i M i ( )
SINALOA
Landfalling TCs in Mexico (1951‐2000)
BAJA CALIFORNIA
SINALOA HUR= 18TT= 8
BAJA CALIFORNIASUR HUR= 19TT 30TT = 30
(Jauregui, 2003)OAXACAHUR = 2TT = 11
Clear intraseasonal variability of land‐falling cyclonesMany trajectories are not simple: how to predict tem?Many trajectories are not simple: how to predict tem?Heavy precipitation associated with land‐fall
(flooding, landslides, human casualties, large economic
Land‐fall variability associated with large‐scale patterns (e g geopotential @500 hPa up to 72hrs prior patterns (e.g. geopotential @500 hPa, up to 72hrs prior to land‐fall)
6 81969‐2008
(Farfan, et al, 2011)
L df lli d t EPAC : 1969 2008Landfalling dates EPAC : 1969‐2008
Formation dates of landfalling TC
10‐30 MayBefore rains 10‐30 Septemberstart in most of MexicoDRY SOIL
3 pWhen rains are present in most of Mexico
WET SOIL
(Romero‐Centeno et al, 2011)
High impact over landover land
Accumulated i it ti f precipitation for 3
selected cyclones that d l df llmade landfall in 2006
Low impact pover land
(Farfan et al, 2011)
Metodología: Archivos históricos en oficinas g fregionales de gobierno, periódicos y boletines oficialesoficiales
Source: Archivo Historico Municipal de Mazatlan
Historical records of landfalling TCs in 4 M i SMexican States
Baja California Sur (BCS), Sinaloa (Sin), Jalisco (Jal),Guerrero (Guerrero (GueGue))Guerrero (Guerrero (GueGue))
No recordsfound
(B. Bracamontes)
Historical records of landfalling TCs in 4 g 4Mexican States:
Baja California Sur (BCS), Sinaloa (Sin), Jalisco (Jal),Guerrero (Guerrero (GueGue))
time Inactive(B. Bracamontes)
Record of landfalling TCs in EPAC:Record of landfalling TCs in EPAC:Guerrero, Jalisco, Sinaloa and BCS
(1850 2009)(1850-2009)Entrada a Tierra: Guerrero, Jalisco, Sinaloa y BCS
25
30
15
20
5
10
0
Prensa HURDAT
HURDATReconstructed period
Reconstructed landfalling timeseriesReconstructed landfalling timeseriesparameter value 95% CI
N: 155N: 155mean: 1.8 ± 0.2 1.6 ... 2.1
d ( ) 6 s.d.(n): 1.6 ± 0.2 1.4... 1.7
skew: 0.7 ± 0.3 0.4 ... 0.9
A liAnomalias
Correlation coefficientPeriodogram (1850:2010) Correlation coefficient
period Index Pearson Spearman1850‐2010 NAO 0,01 0,221866‐2009 SOI ‐0,02 0,131900‐2010 PDO 0,09 0,311856‐2010 Niño3 0,01 0,22
Wavelet (1850:2010)Black curve: cone of influence
Autocorrelation (1850:2010)
I fl f MJO i l df lli ??Influence of MJO in landfalling??
During the convective phase:
M i• More convection
• Increased low‐level cyclonic
vorticity
• Incread eddy kinetic energy and • Incread eddy kinetic energy and
barotropic energy conversion
Only 1998 l d
• Increased wind shear
• Genesis N of IZTC closer to coast
Aiyyer and Molinari, 2008
analyzed Genesis N of IZTC, closer to coast
SummaryFrom NHC database total number in EPAC
SummaryFrom NHC database, total number in EPAC hasn’t changed much but hurricanes and major hurricanes have decreased in last major hurricanes have decreased in last decade
Large intraseasonal variability of land‐falling cyclones
Many trajectories are not simple and their prediction is not easyprediction is not easy
Relationship between total and landfalling cyclones not understoodcyclones not understood
Summary
df ll d
Summary
Landfalling timeseries were reconstructed from historical records and newspapers p pback to 1850, for 4 Mexican States in the PacificPacific
Variability comparable to that observed in NHC d bNHC database
Average of 1.8 ± 1.6 landfalls per yearg p yLargest correlation with PDO index
bl fl f d bPossible influence of MJO needs to be explored systematically