2013 North Atlantic hurricane seasonal forecast Ray Bell with thanks to Joanne Camp (met office)

2013 North Atlantic hurricane seasonal forecast

Ray Bell with thanks to Joanne Camp (met office)

TS has surface wind speeds > 17 m/s (39 mph)H > 33 m/s (74 mph)

• 3 consecutive years of 19 TS.• Active hurricane period that began in 1995 averaged 15 TS, 8 H and 4 MH

© Crown copyright Met Office

Met Office public forecast

http://www.metoffice.gov.uk/weather/tropicalcyclone/seasonal/northatlantic2013

Slightly more active than normal

0.41

0.42

0.42

Jo Camp

Method

• GloSEA5 (42 members)• ECMWF System 4 (41 members)

• A Simple tracking algorithm (mean sea level pressure based).

• TS, H and ACE calibrated with previous years (hindcasts)

© Crown copyright Met Office

2013 North Atlantic Hurricane Season

• Statistical forecasts: CSU and TSR predict an active hurricane season

• Dynamical forecasts: ECMWF predict near-normal hurricane season.

Summary Table

S

S

D

D

Jo Camp

9

NOAAD

13-20 7-11 3-6

NOAA Hurricane seasonal outlook

© Crown copyright Met Office

ENSO forecast

ECMWF GloSea5

Neutral conditions during ASOJo Camp

• CSU predict 72 % chance of MH landfallStatistical relation between seasons activity and landfalling in previous years.

• Land major hurricane landfall Hurricane Wilma 2005 (longest since 1900)

• NOAA – realtime doppler radar on Hurricane hunters which will be used in upgraded HWRF

Intensity forecast

EPAC forecast

• below-normal hurricane season(11 - 16 TS) 15(5 – 8 H) 8(1 – 4 MH) 4

CPAC forecast

• below-normal hurricane season(1 - 3 TS) 4-5

© Crown copyright Met Office

Tropical Storms: Eastern and Western North Pacific June-November 2013

• Near-average numbers of tropical storms predicted in the Western and Eastern North Pacific

• Forecast skill low

Western Pacific Eastern Pacific