a proposition on seasonal prediction of tc activity over western north pacific

A proposition on Seasonal Prediction of A proposition on Seasonal Prediction of

TC Activity over western North PacificTC Activity over western North Pacific

H. Joe KwonKongju National University, KOREAKongju National University, KOREA

KKongju ongju NNational ational UUniversityniversity


TC activity Prediction for 2005

Prediction Climatology Observation

May - Dec19 – 32(22.7) 25.1 20

Sep - Nov9 – 11(9.7) 11.5 9

KMA’s seasonal forecast (2/3)KMA’s seasonal forecast (2/3)


TC activity Prediction for Sep-Nov 2004

Prediction Climatology Observation

WNP (Sep-Nov)9 - 12(10.1) 11.5 9

Korea (Sep-Nov)1 - 2(1.4) 0.9 1

KMA’s seasonal forecast (3/3)KMA’s seasonal forecast (3/3)


KMA/CPD issues seasonal(JJA, SON) outlook for temp/precip and TC activity. Number of TCs over western North Pacific, affecting Korea.

Joint Meeting for seasonal forecast (CN-JP-KR)

University contribution - Hongkong (Prof. Chan): Statistical model - Kongju (Prof. Kwon): Statistical model & Dynamic model ensemble

APCC(APEC Climate Center) Seasonal prediction of TC may be one of the important components.

IRI Seasonal forecast for WNP and ATL

ECMWF TC genesis over the whole basin (coupled global model)

Activities over western North Pacific for Seasonal forecast of TCActivities over western North Pacific for Seasonal forecast of TC


Hurricane outlook of NHC, USAHurricane outlook of NHC, USA

Probability forecastProbability forecast

Number of Number of TC genesis &TC genesis &ACEACE

Category forecastCategory forecast


N

n

nV1

2max )(ACE (Accumulated Cyclone Energy)

=

ACEACE


Definition of hurricane season of NHC Definition of hurricane season of NHC


Typhoon genesis over the western N. PacificTyphoon genesis over the western N. Pacific

16163939


23.7 28.7

Accumulated distribution of AN,NN,BN Accumulated distribution of AN,NN,BN based on 1951-2004 tropical cyclone activitiesbased on 1951-2004 tropical cyclone activities

Classification by annual total of tropical cyclones(1/2)Classification by annual total of tropical cyclones(1/2)


0

1

2

3

4

5

6

7

8

16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39Annual Total of Tropical Cyclones

Num

ber

of

Year

Below Normal Near Normal

Above Normal

23.7 28.7

Classification of AN, NN, BN Classification of AN, NN, BN based on 1951-2004 tropical cyclone activitiesbased on 1951-2004 tropical cyclone activities

Classification by annual total of tropical cyclones(2/2)Classification by annual total of tropical cyclones(2/2)


Example of 2 different tropical cyclonesExample of 2 different tropical cyclones


2

1max )/)((

4

1TY

N

n

VnV

)(max nV

• NTA (Normalized Typhoon Activity) Index

=

= 6-hourly maximum sustained wind speed

VTY = 64 kt

NTA = 1 means that a tropical cyclone of TY strength exists for 1 day

▶▶

▶▶

Classification by NTA, annual total of tropical cyclones and TY genesis numberClassification by NTA, annual total of tropical cyclones and TY genesis number

Comprehensive Typhoon Activity Index based uponComprehensive Typhoon Activity Index based upon frequency, duration and intensityfrequency, duration and intensity


NTA = 0.3NTA = 0.3 NTA = 17,4NTA = 17,4


AN

NN

BN


NTANTA

128.1128.1


ClassificationClassification NTANTAAnnual Total of Annual Total of Tropical CycloneTropical Cyclone

TYTY

AN 152 or higher 30 or higher 17 or higher

NN 118 ~ 152 25 ~ 29 14 ~ 16

BN 118 or lower 24 or lower 13 or lower




NTANTA

nTCnTC

nTYnTY

2424 2929

ANAN

NNNN

BNBN

118118 152152

1313 1717

NTANTA

nTCnTC

nTYnTY

2424 2929

118118 152152

1313 1717

NTANTA

nTCnTC

nTYnTY

2424 2929

118118 152152

1313 1717

2424 2929

118118 152152

1313 1717

2424 2929

118118 152152

1313 1717

2424 2929

118118 152152

1313 1717

2424 2929

118118 152152

1313 1717

2424 2929

118118 152152

1313 1717

2424 2929

118118 152152

1313 1717

• nTC means annual total number of tropical cyclonenTC means annual total number of tropical cyclone• nTY means number above TY gradenTY means number above TY grade


YEARYEAR NTANTA TS(12)TS(12) TY(15)TY(15) SUMSUM ClassificationClassification

1968 222 4 23 27 AN

1997 198 11 17 28 AN

2004 194 10 19 29 AN

1967 192 21 18 39 AN

1994 191 17 19 36 AN

1991 190 12 17 29 AN

1992 188 15 16 31 AN

1972 185 12 19 31 AN

1971 181 16 20 36 AN

1982 181 7 18 25 AN

1987 174 6 17 23 AN

1986 171 11 18 29 AN

1958 168 15 16 31 AN

1962 166 12 18 30 AN

1976 162 11 14 25 AN

1990 162 10 19 29 AN

2002 156 11 15 26 AN

1957 153 7 15 22 NN

1989 150 12 20 32 AN

1953 144 9 14 23 NN

1963 143 10 14 24 NN

1979 142 11 13 24 NN

1965 140 18 14 32 NN

1978 137 15 15 30 NN

1954 135 7 14 21 NN

1959 134 7 16 23 NN

1996 133 11 15 26 NN

1970 133 13 13 26 NN

1960 129 13 14 27 NN

1984 129 11 16 27 NN

1966 128 18 17 35 AN

1980 125 9 15 24 NN

2003 125 7 14 21 NN

1951 120 11 10 21 BN

1981 119 16 13 29 NN

1952 118 13 14 27 NN

1961 118 16 13 29 NN

1969 117 5 14 19 BN

2001 116 10 16 26 BN

1985 115 11 16 27 BN

1993 115 13 15 28 BN

1974 113 17 15 32 BN

1964 112 20 14 34 NN

1983 106 13 10 23 BN

1988 104 20 11 31 BN

2000 99 10 13 23 BN

1956 97 11 12 23 BN

1955 96 17 11 28 BN

1977 95 10 11 21 BN

1975 86 8 13 21 BN

1995 81 14 9 23 BN

1973 72 10 11 21 BN

1998 55 8 8 16 BN

1999 45 17 5 22 BN


Y=1968, NTA=222, TC=27, Y=1968, NTA=222, TC=27, TY=23TY=23





NN AN⇒

A Few ExampleA Few Example

NN AN⇒


A Few ExampleA Few Example

AN NN⇒

BN AN⇒


SummarySummary

Definition for Normal, Above Normal, Below Normal range of tropical cyclone activity over the western North Pacific

Proposition # 1Proposition # 1


Things to be predicted - NTA index, No of Total TC, No of Typhoon


? - June

SST, MSLP, Z500, . . .

? - June

SST, MSLP, Z500, . . .

Selection of Predictors

1952

2002

2003

? - June

SST, MSLP, Z500, . . .

? - June

SST, MSLP, Z500, . . .

? - June

SST, MSLP, Z500, . . .

? - June

SST, MSLP, Z500, . . .

1952

2002

2003

Lag Correlation?


MSLP-120.421

160E 22.5N

SST+40.393

166W 16N

Example of lag correlation between SON TCs and synoptic variables

A priori assumption: (1) stronger correlation between NTA and synoptic variables (2) better prediction of NTA


International/Inter-organizational collaborations are highly recommended. - Joint meeting for seasonal forecast (CN-JP-KR) - APCC - IRI - Kongju University, Hongkong University


Any Contributions Welcome!Any Contributions Welcome!

Thank you!Thank you!

a proposition on seasonal prediction of tc activity over western north pacific

Documents

kmas seasonal forecast

seasonal forecast cnjp

statistical model kongju

western north pacific

atlecmwf tc genesis

global model activities

son outlook

accumulated distribution