Major Climate Anomalies during 2005

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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
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Outline

1. Global Precipitation and Temperatures
2. Weak El Niño August 2004 April 2005
3. 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

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October 2004 September 2005
Surface Temperature Rankings Since 1950

• Warm
• Atlantic Ocean
• Africa
• Australia
• Amazon Basin

Red is the warmest. Purple is the coldest
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October 2004 September 2005 Precipitation
Departures (mm)
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Major Regional Anomalies during 2005
Strong MJO Activity
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Major Precipitation Anomalies during 2005
Dry
Dry Summer
Dry
Dry
Dry
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Monsoon Rains During 2005
Dry
Wet
Avg toWet
Wet
Dry
Dry
Dry
Avg
Avg
2005 Monsoons CPC Monsoon Working Group Poster
2.5
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Hurricanes/ Cyclones/ Typhoons during 2005
10 Landfalling Typhoons
Active Atlantic Hurricanes
Inactive East Pac. hurricanes
7 U.S. landfalling TCs
5 Cyclones
7 Cyclones
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Weak El Niño August 2004 - April 2005
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Niño Region Indices show Weak El Nino
Largest positive SST anomalies (1.2C) in Niño
4 region.
Niño 3.4 Anomalies only reach 0.8C
Niño 3 Anomalies only reach 0.65C. Oceanic
Kelvin Wave
No ENSO Signal in Niño 12 region
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Outgoing Longwave Radiation (OLR) Anomalies
5N-5S
NOV
Suppressed convection east of date line
indicating weak El Niño. Strong intra-seasonal
variability evident.
DEC
JAN
Time
FEB
MAR
APR
0 60E 120E 180 120W 60W 0
Longitude
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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. 330 Today
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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.
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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.
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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
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NOAAs 2005 Atlantic Hurricane Outlooks
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August 16 May
2005 2005
2005
Outlook Outlook Totals
Chance Above Normal 95-100 70

Tropical Storms 18-21
12-15 22 Hurricanes
9-11 7-9
12 Major Hurricanes
5-7 3-5 6
ACE of Median 180-270
120-190 gt200
Higher prediction made in August reflects record
July activity.
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NOAAs 2005 Eastern Pacific Hurricane Outlook
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May
2005 2005
Outlook Totals to date
70 Chance of Below Normal Season
Tropical Storms
11-15 15
Hurricanes 6-8
7 Major Hurricanes
2-4 2 ACE of
Median 45-95 65
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2005
Since 1995, 9 of 11 Atlantic hurricane seasons
have been above normal. Seven years have been
hyperactive (ACE gt 175 of median) We are 10
years into an active hurricane era that can last
20 years.
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Anomalous Conditions During 15 June-31 July
Vertical Wind Shear Anomalies (Shaded) 200-hPa
Height Anomalies (Contours)
Extremely low vertical wind shear linked to
positive height anomalies over western Atlantic.

Main Development Region
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15 August-30 September
Vertical Wind Shear Anomalies (Shaded) 200-hPa
Heights (Contours)
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.
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Western Pacific 20 Named Storms 14 Typhoons 7
Super Typhoons (gt 125 knots) 10 landfalling
Typhoons
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Very Stormy in Western U.S. ends
Drought (December-May) Exceptionally Warm and
Wet in Midwest and East (December-January) See
Complete CPC Analysis http//www.cpc.ncep.noaa.gov
/products/expert_assessment/california_assessment_
2005.pdf
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Mid-December Through Mid-January
Total Precipitation
of Normal Precipitation
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Conditions Typify Major West Coast Precipitation
Events
Key Circulation Features1. Blocking Ridge2.
Deep Trough3. Flow Undercutting Block
(Pineapple Express) shows links to MJO
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Western Europe Drought (October 2004 - Present)
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(No Transcript)
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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.
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Summary

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

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Extras 1. New England Flooding during mid-October
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Northeastern U.S. Heavy Rains/ Flooding (mid-Octob
er)
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New England Rainfall Totals 9-17 October 2005
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Circulation 9-12 October 2005
200-hPa Heights and Anomalies
850-hPa Heights and Anomalies
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Circulation 9-12 October 2005
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Palmer Drought Index
Ending 21 May 2004
Drought throughout Western United States in 2004.
Moderate/ Severe Drought
Ending 21 May 2005
Extremely Moist
Drought ends in Southwest and Inter-mountain
regions. Drought confined to Montana
and Wyoming by late May.
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Standardized, Area-Averaged 500-hPa Height
Anomalies