Major Climate Anomalies during 2005 Gerry Bell Presented by Vernon Kousky Climate Prediction Center/ NOAA/ NWS National Centers for Environmental Prediction (NCEP) Camp Springs, MD

Outline 1.Global Precipitation and Temperatures 2.Weak El Niño: August 2004 –April Strong MJO Activity 4.Active Atlantic Hurricane Season 5.Suppressed East Pacific Hurricane Season 6.Wet Winter and Spring ends western U.S. drought 7.Dry in Western Europe since October 2004

October 2004 – September 2005 Surface Temperature Rankings Since 1950 Red is the warmest. Purple is the coldest Red is the warmest. Purple is the coldest Warm: Atlantic OceanAtlantic Ocean AfricaAfrica AustraliaAustralia Amazon BasinAmazon Basin

October 2004 – September 2005 Precipitation Departures (mm) Dry: IndonesiaIndonesia East-Central Eq. PacificEast-Central Eq. Pacific Amazon Basin (since 1995)Amazon Basin (since 1995) Gulf of Guinea RegionGulf of Guinea Region Wet: Western/ Central Equatorial PacificWestern/ Central Equatorial Pacific Indian Monsoon RegionIndian Monsoon Region Southwestern U.S.Southwestern U.S. Tropical Atlantic (Since 1995)Tropical Atlantic (Since 1995) Sahel Monsoon Region (Since 1995)Sahel Monsoon Region (Since 1995)

Major Regional Anomalies during 2005 Strong MJO Activity Weak El Nino Warm

Drought Ends Wet Major Precipitation Anomalies during 2005 Dry Summer Dry

Monsoon Rains During Monsoons: CPC Monsoon Working Group: Poster 2.5 Dry Wet Dry Avg Dry Avg Avg to Wet

Hurricanes/ Cyclones/ Typhoons during U.S. landfalling TC’s Inactive East Pac. hurricanes Active Atlantic Hurricanes 10 Landfalling Typhoons 7 Cyclones 5 Cyclones

Weak El Niño: August April 2005

Niño Region Indices show Weak El Nino JUL OCT JAN APR JUL OCT JAN APR Niño 3.4 Anomalies only reach +0.8C Niño 3 Anomalies only reach +0.65C. Oceanic Kelvin Wave No ENSO Signal in Niño 1+2 region Largest positive SST anomalies (+1.2C) in Niño 4 region.

Outgoing Longwave Radiation (OLR) Anomalies: 5N-5S Longitude Time Suppressed convection east of date line indicating weak El Niño. Strong intra-seasonal variability evident. 0 60E 120E W 60W 0 NOV JAN FEB DEC APR MAR

MJO Activity during January-September Strongest since 1997 Smears ENSO signal Influences Western U.S. Precipitation Intraseasonal fluctuations in Atlantic, Eastern Pacific Indian Ocean Hurricanes See talk by Jon Gottschalck et al. 3:30 Today

Madden / Julian Oscillation (MJO) 200-hPa Velocity Potential Anomalies (5N-5S) MJO activity during December 2004-May 2005 and July- September 2005 dominated tropical divergence anomalies.

Oceanic Heat Content in Equatorial Pacific (ºC) Shows El Niño warming and Kelvin Waves Kelvin Waves triggered by fluctuations in the strength of the low-level zonal winds associated with MJO activity.

Another Very Active Atlantic Hurricane Season and Another Below-Normal East Pacific Season See talk by Chelliah and Bell (This Session) See poster by Bell and Chelliah: Session 2, P 2.1

NOAA’s 2005 Atlantic Hurricane Outlooks 2 August 16 May 2 August 16 May Outlook Outlook Totals Outlook Outlook Totals Chance Above Normal % 70% Tropical Storms Hurricanes Major Hurricanes ACE % of Median % % >200% Higher prediction made in August reflects record July activity.

NOAA’s 2005 Eastern Pacific Hurricane Outlook 16 May 16 May Outlook Totals to date Outlook Totals to date 70% Chance of Below Normal 70% Chance of Below Normal Season Tropical Storms Hurricanes Major Hurricanes ACE % of Median 45-95% 65%

Since 1995, 9 of 11 Atlantic hurricane seasons have been above normal. Seven years have been “hyperactive” (ACE > 175% of median) We are 10 years into an active hurricane era that can last 20+ years. 2005

Extremely low vertical wind shear linked to positive height anomalies over western Atlantic. Anomalous Conditions During 15 June-31 July Vertical Wind Shear Anomalies (Shaded) 200-hPa Height Anomalies (Contours) Main Development Region 200-hPa Streamfunction Anomalies Inter-hemispheric symmetry of circulation anomalies--- linked to suppressed convection near date line

Extremely low vertical wind shear persists. Ridge persists over SE U.S. Major hurricanes form in Gulf of Mexico where vertical wind shear is almost zero. 15 August-30 September Vertical Wind Shear Anomalies (Shaded) 200-hPa Heights (Contours)

Western Pacific: 20 Named Storms 14 Typhoons 7 Super Typhoons (> 125 knots) 10 landfalling Typhoons

Very Stormy in Western U.S. ends Drought (December-May) Exceptionally Warm and Wet in Midwest and East (December-January) See Complete CPC Analysis

Mid-December Through Mid-January % of Normal Precipitation Total Precipitation

Conditions Typify Major West Coast Precipitation Events Key Circulation Features: 1. Blocking Ridge 2. Deep Trough 3. Flow Undercutting Block (Pineapple Express) shows links to MJO

Western Europe Drought (October Present)

Percentage of Days with Positive and Negative 500-hPa Heights Anomalies Persistent pattern of above-average heights is major cause of the drought in western Europe. Positive height anomalies consistent with extreme warmth in North Atlantic.

Summary 1.Weak El Niño: 2.Strong MJO Activity 3.Monsoons: Enhanced in Western Africa, portions of IndiaEnhanced in Western Africa, portions of India Suppressed in Amazon Basin, Indonesia, southwestern U.S.Suppressed in Amazon Basin, Indonesia, southwestern U.S. 4.Active Atlantic Hurricanes, Below-normal eastern Pacific Hurricanes Both Well forecastBoth Well forecast Ongoing multi-decadal signal since 1995Ongoing multi-decadal signal since Wet Winter and Spring ends western U.S. drought 6.Dry in western Europe since October 2004

Extra’s 1. New England Flooding during mid-October

Northeastern U.S. Heavy Rains/ Flooding (mid-October)

New England Rainfall Totals: 9-17 October 2005

Circulation: 9-12 October hPa Heights and Anomalies 850-hPa Heights and Anomalies

Circulation: 9-12 October 2005

Palmer Drought Index Extremely Moist Moderate/ Severe Drought Drought ends in Southwest and Inter-mountain regions. Drought confined to Montana and Wyoming by late May. Ending 21 May 2005 Ending 21 May 2004 Drought throughout Western United States in 2004.

Standardized, Area-Averaged 500-hPa Height Anomalies