2011 Atlantic Hurricane Season: AAA

Above Average Activity Predicted for This Year’s Atlantic Hurricane  Season

An “active to extremely active hurricane season” for the Atlantic Basin this year, says  NOAA’s Climate Prediction Center.

The six-month Atlantic Hurricane Season, which officially begins June 1 through November 30, and covers the entire Atlantic Basin, is predicted to see above average activity this year, according to NOAA.

• 12 to 18 named storms (winds of 39 mph or higher)
• 6 to 10 of those could become hurricanes (winds of 74 mph or higher) including
• 3 to 6 major hurricanes (Category 3, 4 or 5; winds of 111 mph or higher)

The probability of occurrence for each of the above is 70 percent, NOAA says, indicating that activity tops the seasonal averages of 11 named storms, six hurricanes and two major hurricanes.

Hurricanes Karl, Igor and Julia seen  left to right in this satellite image taken on on September 16, 2010. Source: NOAA 

Eastern Pacific Hurricane Season

NOAA predicts “below normal” hurricane season in the Eastern Pacific for 2011 with probability of 70 percent.

• 9 to 15 named storms, including
• 5 to 8 hurricanes, of which
• 1 to 3 could become major hurricanes (Category 3 or above on the Saffir-Simpson Hurricane Wind Scale).

East Pacific hurricane season began May 15th.

Central Pacific Hurricane Season

For the Central Pacific Region, NOAA predicts:

• Below normal season with a probability of 70 percent
• Near normal season,  a probability of 25 percent
• Above normal season, a probability of 25 percent

NOAA predicts 2-3 tropical cyclones to affect the central Pacific in 2011, with the average season experiencing 4-5 tropical cyclones (tropical depressions, tropical storms and hurricanes).

2010 season

2010 Atlantic Hurricane Season Track Map. Click image to enlarge.

The 2010 season (the third most active season on record jointly with 1887 and 1995) experienced 19 named storms, 12 of which developed into hurricanes (second most active hurricane season jointly with 1969.

There was NO hurricane landfall in the U.S. last year. In fact, there hasn’t been a hurricane landfall in the US since 2008 when 4 hurricanes (Dolly, Gustav, Ike and Kyle) struck.

2008 Atlantic Hurricane Season Track Map. Click image to enlarge.

FIRE-EARTH Forecast

Based on the blog models, recent trends set by the impact of weather extremes on population centers, especially since late 2009, and other geophysical and planetary factors, FIRE-EARTH believes 2011 could  prove less lucky than the last two years. We forecast a particularly costly hurricane season for the Atlantic Basin in 2011.  

About 40 million people in the coastal regions of the US, from  North Carolina to Texas, are most at risk of hurricanes.

The contiguous United States Population Concentration Map. Prepared by FIRE-EARTH based on a template provided by NOAA.

Atlantic Names 2011 (with pronunciations included for the audially challenged)

• Arlene ar-LEEN
• Bret bret
• Cindy SIN-dee
• Don dahn
• Emily EH-mih-lee   (!)
• Franklin FRANK-lin
• Gert gert
• Harvey HAR-vee
• Irene eye-REEN
• Jose ho-ZAY
• Katia ka-TEE-ah
• Lee lee
• Maria muh-REE-uh   (!!)
• Nate nait
• Ophelia o-FEEL-ya  (!!!)
• Philippe fee-LEEP
• Rina REE-nuh
• Sean shawn
• Tammy TAM-ee
• Vince vinss
• Whitney WHIT-nee

• NOAA updates
• 2011 Changes to the Valid Types of Tropical Cyclones 

Earlier Forecasts

• When Weather Went Really Crazy

Based on various climatic indicators and recent weather trends, FIRE-EARTH forecasts an increase of about 24% in the severity of extreme weather events during the next 20 months, compared with the previous period.

• Epic Flooding Could Inundate Large Parts of the U-S
• U-S Attacked by Continued Severe Weather

Climatic  Extremes, Primeval Geophysical Activities and WILD Weather to Wreak Mega Havoc in 2011/2012 and Beyond …
NOW IS THE PERFECT TIME TO POWER DOWN AND START THINKING HARD.  Encourage your folks, friends and neighbors to join in!! BECAUSE  for most of us the GAME would be OVER soon.

• Mega Tornadoes to Bombard U-S Tornado Alley

Start of Meteorological Spring Signals Hyper Tornado Season:Based on several climatic indicators and recent weather trends, FIRE-EARTH forecasts a deadly peak tornado season in 2011.

• 2011 – 2012: A Time for Mega Disasters

• Megadisasters Loom

2011-2012:  A TIME FOR MEGA-DISASTERS – Emerging Calamities You CAN’T Prepare for, or Insure against

Climate Change, Global Broiling, Volatility and Extremes of Weather, Mega Swings of Temperature, Megadeluges and Megadroughts, Giant Dust Storms, Megaquakes, Super Volcanic Eruptions, Extreme Wildfires, Food and Water Scarcity, Deadly Diseases, Megadeaths (Forests, Plants, Animal Species…) Looming Megadisasters Could Impact 1/3 to 1/2 of  Human Population

Related Links

• Global Climate Extremes INTENSIFYING
• Earth: Wounded and Feverish
• FEWW DISASTER FORECAST 2011
• Mega Tornadoes to Bombard U-S Tornado Alley

Your Worst Fears About El Niño

Worst fears about El Niño may come true

The El Niño, formally known as the El Niño-Southern Oscillation, or “ENSO” for short, is the most significant cause of large-scale climate variability in the tropics. El Niño episodes bring warmer than normal waters to the central and eastern Pacific Ocean from Indonesia in the western end to South America in the eastern end of the  ocean, helping to maintain the above-normal sea surface temperatures.

Figure below shows one of these Kelvin Waves progressing across the Pacific in February 2010.

Kelvin Wave Renews El Niño

The globes show sea surface height anomalies, which means places where the water surface is higher (red) or lower (blue) than average. A higher-than-average sea surface height at a given location indicates that there is a deeper-than-normal layer of warm water. Lower-than-average sea surface height indicates a shallower layer of warm water. The globes are based on 10 days of data centered on January 15, January 30, and February 15.

In January (left-hand globe), sea surface heights across the central and eastern equatorial Pacific were elevated (red), but not extremely so, potentially a sign that El Niño was weakening. But in early February, a strong sea level anomaly appeared northeast of Australia (center globe). This swell of deep, warm water is the start of the Kelvin wave, and by late February, it had spread eastward into the central Pacific (right-hand globe) and re-invigorated the current El Niño.

Where do Kelvin waves come from? Under normal conditions, the tropics’ prevailing easterly winds push Sun-warmed surface waters across the Pacific from the Americas toward Indonesia, creating a deep pool of warm water in the western Pacific. During an El Niño, the trade winds falter, and sometimes even reverse, for months. When the winds that maintain the warm pool falter, a large pulse of warm water from the western Pacific slides back toward the east. NASA Earth Observatory images by Jesse Allen, Kevin Ward, and Robert Simmon. Caption by Rebecca Lindsey, based on interpretation provided by Josh Willis and Bill Patzert, NASA JPL.

Related Links

• Climate Locked into ‘Unending’ El Niño?
• Imminent Flood Threat in the U.S. Midwest
• Unraveling El Niño Mysteries
• El Niño Update [15 March 2010]

• El Niño [Main Page, Links to Weekly Updates Archive]

El Niño Weekly Update [25 Jan 2010]

ENSO Cycle: Recent Evolution, Current Status and Predictions

El Niño Weekly UPDATE prepared by Climate Prediction Center / NCEP –  25 January 2010

The latest weekly SST departures are:

• Niño 4   ~  1.4ºC
• Niño 3.4  ~  1.4ºC
• Niño 3 ~ 0.8ºC
• Niño 1+2 ~ 0.1ºC

El Niño Map. [SOURCE: NOAA/ Climate Prediction Center / NCEP]

Weekly SST Departures (ºC) for the Last Four Weeks

• During the last four weeks, positive SST anomalies have weakened across the eastern half of the equatorial Pacific Ocean.
• During the last 30 days, equatorial SST anomalies have decreased across the east-central and eastern Pacific.

SST Departures (°C) in the Tropical Pacific During the Last 4 Weeks

During the last 4-weeks, equatorial SSTs were more than 2.0°C above average between 170°W and 145°W.
Click image to enlarge.

Global SST Departures (°C)

During the last four weeks, equatorial SSTs were above-average across the Pacific, Indian, and eastern Atlantic Oceans. Also, above-average SSTs covered large areas of the Northern Hemisphere subtropics.

Click image to enlarge.

Atmospheric Circulation over the North Pacific & North America During the Last 60 Days

From late November to early January, strong mid-latitude westerlies(East Asian and Atlantic jets) were accompanied by troughs over the North Pacific and North America. The troughs contributed to below-average temperatures across the U.S. and southern Canada. At higher latitudes, strong ridging led to above-average temperatures across Alaska and northern Canada. Since early January, the East Asian jet has extended farther east and a trough has strengthened over the eastern Pacific. Over much of N. America, strong ridging has contributed to above-average temperatures across Canada and the northern and western U.S. Troughs and below-average temperatures have prevailed over the southeastern U.S. This recent pattern is typical of ElNiño.

Unless otherwise stated, information and images on this page are sourced from Climate Prediction Center/NCEP/NOAA. Edited by FEWW

For additional information, previous entries and diagrams see links below:

Summary:

• El Niño is present across the equatorial Pacific Ocean.
• Sea surface temperatures (SST) are 1.0ºC-3.0ºC above-average across much of the central and east-central equatorial Pacific.
• Based on current observations and dynamical model forecasts, El Niño is expected to continue at least into the Northern Hemisphere spring 2010.

Related Links:

• Climate Locked into ‘Unending’ El Niño?
• What Florida Might Look Like in 2014
• SE Australia Toasted Brown
• UK Flooding
• Speaking of El Niño, OLR Anomalies in Australia
• El Niño Update [16 Nov 2009]
• Recognizing El Niño
• El Niño and La Niña: Tracing the Dance of Ocean and Atmosphere
• TAO Diagrams
• El Niño Forecasts

El Niño Updates:

• El Niño Weekly Update [18 Jan 2010]
• El Niño Weekly Update [11 Jan 2010]

• El Niño Weekly Update [4 Jan 2010]
• El Niño Weekly Update [28 Dec 2009]
• El Niño Weekly Update [21 Dec 2009]
• El Niño Weekly Update [7 Dec 2009]
• El Niño Update [30 Nov 2009]
• El Niño [Main Page and Links Archive]

Fewest named hurricanes since 1997

El Niño helped ensure fewest named storms and hurricanes in 13 years

The 2009 Atlantic hurricane season officially ended on November 30 with Nine named storms,  three hurricanes including 2 major hurricanes at Category 3 strength or higher.

2009 Atlantic Storm Tracks – Preliminary. Credit: NOAA

On average, the Atlantic hurricane season clocks up 11 named storms and 6 hurricanes including 2 major hurricanes, NOAA said

“The reduced activity was expected and reflects the development of El Niño during the summer,” said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center, a division of the National Weather Service. “El Niño produced strong wind shear across the Caribbean Sea and western tropical Atlantic, which resulted in fewer and shorter-lived storms compared to some recent very active seasons.”

Although Claudette and Ida, struck the U.S. mainland with tropical storm force winds,  no hurricanes hit the U.S. in 2009, the first time in three years. Only 38 hurricane hunter aircraft reconnaissance missions were flown  over the Atlantic Basin this year compared to 169 in 2008, signifying a less active season, NOAA said.

“El Niño is expected to reach peak strength this winter, and will likely continue into the spring. It is far too early to say whether El Niño will be present next summer,” added Bell.

Related Links:

• El Niño
• Hurricanes 2009
• CSU Lowers Hurricane Forecast
• FEWW FORECAST: 2009 Likely Wettest Year on Record
• 2009 Hurricane Season: Storms in Teacup, or Nasty Surprises?
• Vanishing Fred & Atlantic Hurricane Season 2009

El Niño Update [2 Nov 2009]

ENSO Cycle: Recent Evolution, Current Status and Predictions

The following UPDATE is prepared by

Climate Prediction Center / NCEP –  2 November 2009

The latest weekly SST departures are:

• Niño 4   ~  1.6ºC
• Niño 3.4  ~  1.5ºC
• Niño 3 ~ 1.2ºC
• Niño 1+2 ~ 0.4ºC

El Niño Map. [SOURCE: NOAA/ Climate Prediction Center / NCEP]

SST Departures (°C) in the Tropical Pacific During the Last 4 Weeks
During the last 4-weeks, equatorial SSTs were at least 1.0°C above average between 165°E and 140°W and in small areas in the eastern Pacific.

Global SST Departures (°C)
During the last four weeks, equatorial SSTs were above-average in the Pacific and Indian Oceans. Also, above-average SSTs covered large areas of the Northern Hemisphere subtropics.

Weekly SST Departures (°C) for the Last Four Weeks

• During the last four weeks, equatorial SST anomalies strengthened across the central and eastern Pacific Ocean.

• During the last 30 days, equatorial SST anomalies increased in much of the central and eastern Pacific.

Tropical OLR and Wind Anomalies During the Last 30 Days

• Positive OLR anomalies (suppressed convection and precipitation, red shading) were present over Indonesia, Malaysia, and Australia. Negative OLR anomalies (enhanced convection and precipitation) were located across the northern Philippines, Papua New Guinea, and over the western tropical Pacific Ocean.

• Low-level (850-hPa) westerly anomalies were observed over parts of the western and central equatorial Pacific.

• Upper-level (200-hPa) easterly anomalies were observed across most of the equatorial Pacific.

Pacific Niño 3.4 SST Outlook

• Most ENSO models indicate El Niño will continue through the Northern Hemisphere winter 2009-10.
• The models disagree on the eventual strength of El Niño (SST anomalies ranging from +0.5°C to greater than +2.0°C), but a majority indicate at least a moderate strength El Niño (greater than +1.0°C) during November-December-January 2009-10.

SST Outlook: NCEP CFS Forecast Issued 1 November  2009
The CFS ensemble mean predicts El Niño will last at least through Northern Hemisphere spring 2010.

Summary

• El Niño is present across the equatorial Pacific Ocean.
• Sea surface temperatures (SST) were at least 1.0ºC above-average across much of the central and east-central equatorial Pacific.
• Based on current observations and dynamical model forecasts, El Niño is expected to strengthen and last at least through Northern Hemisphere spring 2010.

Information and images on this page are sourced from Climate Prediction Center/NCEP/NOAA. Edited by FEWW

Related Links:

• Recognizing El Niño
• El Niño and La Niña: Tracing the Dance of Ocean and Atmosphere
• TAO Diagrams
• El Niño Forecasts

El Niño Updates:

• El Niño [Main Page and Archive]

El Niño Update [28 Oct 2009]

ENSO Cycle: Recent Evolution, Current Status and Predictions

The following UPDATE is prepared by

Climate Prediction Center / NCEP –  26  October 2009

The latest weekly SST departures are:

• Niño 4   ~  1.4ºC
• Niño 3.4  ~  1.1ºC
• Niño 3 ~ 0.8ºC
• Niño 1+2 ~ 0.1ºC

El Niño Map. [SOURCE: NOAA/ Climate Prediction Center / NCEP]

SST Departures (°C) in the Tropical Pacific During the Last 4 Weeks
During the last 4-weeks, equatorial SSTs were at least 1.0°C above average between 165°E and 140°W and in small areas in the eastern Pacific.

Global SST Departures (°C)
During the last four weeks, equatorial SSTs were above-average in the Pacific and Indian Oceans. Also, above-average SSTs covered large areas of the Northern Hemisphere subtropics.

Weekly SST Departures (°C) for the Last Four Weeks

• During the last four weeks, equatorial SST anomalies strengthened across the central Pacific Ocean.

• During the last 30 days, equatorial SST anomalies increased over the central Pacific.

Tropical OLR and Wind Anomalies During the Last 30 Days

• Positive OLR anomalies (suppressed convection and precipitation, red shading) were present over Indonesia, Malaysia, and Australia. Negative OLR anomalies (enhanced convection and precipitation, blue shading) were located across the Philippines, Papua New Guinea, and in the western tropical Pacific Ocean.
• Low-level (850-hPa) equatorial winds were near-average over the central and eastern Pacific. Westerly anomalies were observed in the western Pacific.
• Upper-level (200-hPa) easterly anomalies were observed across most of the equatorial Pacific.

Pacific Niño 3.4 SST Outlook

• Most ENSO models indicate El Niño will continue through the Northern Hemisphere winter 2009-10.

• The models disagree on the eventual strength of El Niño (SST anomalies ranging from +0.5°C to greater than +2.0°C), but a majority indicate at least a moderate strength El Niño (greater than +1.0°C) during during November-December-January 2009-10. Figure provided by the International Research Institute (IRI) for Climate and Society (updated 15 Oct 2009).

SST Outlook: NCEP CFS Forecast Issued 18 October 2009
The CFS ensemble mean predicts El Niño will last through Northern Hemisphere winter 2009-10.

Summary

• El Niño is present across the equatorial Pacific Ocean.
• Sea surface temperatures (SST) were at least 1.0ºC above-average across much of the central and east-central equatorial Pacific.
• Based on current observations and dynamical model forecasts, El Niño is expected to strengthen and last through Northern Hemisphere winter 2009-10.

Information and images on this page are sourced from Climate Prediction Center/NCEP/NOAA.

Related Links:

• Recognizing El Niño
• El Niño and La Niña: Tracing the Dance of Ocean and Atmosphere
• TAO Diagrams
• El Niño Forecasts

El Niño Updates:

• El Niño [Main Page and Archive]

El Niño Update [13 Oct 2009]

ENSO Cycle: Recent Evolution, Current Status and Predictions

The following UPDATE is prepared by

Climate Prediction Center / NCEP – 13 October 2009

The latest weekly SST departures are:

• Niño 4   ~ 1.0ºC
• Niño 3.4  ~ 0.7ºC
• Niño 3 ~ 0.7ºC
• Niño 1+2 ~ (-0.7)ºC

El Niño Map. [SOURCE: NOAA/ Climate Prediction Center / NCEP]

SST Departures (°C) in the Tropical Pacific During the Last 4 Weeks
WeeksDuring the last 4-weeks, equatorial SSTs were at least1.0°C above average across parts of the central and eastern Pacific.

Global SST Departures (°C)
During the last four weeks, equatorial SSTs were above-average in the Pacific and Indian Oceans. Also, above-average SSTs covered large areas of the Northern Hemisphere subtropics.

Weekly SST Departures (°C) for the Last Four Weeks
During the last four weeks, SST anomalies remained positive across the equatorial Pacific Ocean, except in the far eastern Pacific, which have become negative. •During the last month, equatorial SST anomalies decreased over much of the eastern Pacific and increased over the central Pacific.

Sub-Surface Temperature Departures (°C) in the Equatorial Pacific

Atmospheric Circulation over the North Pacific & North America During the Last 60 Days
During mid August through September, an anomalous trough was prevalent in the North Pacific Ocean/Gulf of Alaska. During September, an anomalous ridge was present downstream, focused over Canada and the northern United States. The pattern also featured a weak trough over the central U.S., which contributed to below-average temperatures in the region, while the northern U.S. and Canada remained warmer-than-average. Recently, an anomalous ridge has dominated the Gulf of Alaska, and a downstream trough has led tobelow-average temperatures across much of the western and northern U.S.

Pacific Niño 3.4 SST Outlook

Most ENSO models indicate El Niño will continue through the Northern Hemisphere winter 2009-10.

The models disagree on the eventual strength of El Niño (SST anomalies ranging from +0.5ºC to +2.0ºC), but a majority indicate at least a moderate strength El Niño (greater than +1.0°C) during November-December-January 2009-10.

Summary

• El Niño is present across the equatorial Pacific Ocean.
• Sea surface temperatures (SST) were at least 1.0ºC above-average across much of the central and east-central equatorial Pacific.
• Based on current observations and dynamical model forecasts, El Niño is expected to strengthen and last through Northern Hemisphere winter 2009-10.

Information and images on this page are sourced from Climate Prediction Center/NCEP/NOAA.

Related Links:

• Recognizing El Niño
• El Niño and La Niña: Tracing the Dance of Ocean and Atmosphere
• TAO Diagrams
• El Niño Forecasts

El Niño Updates:

• El Niño [Main Page and Archive]

El Niño Update [28 Sept 2009]

ENSO Cycle: Recent Evolution, Current Status and Predictions

The following UPDATE is prepared by

Climate Prediction Center / NCEP – 28 Sept 2009

The latest weekly SST departures are:

• Niño 4   ~ 0.8ºC
• Niño 3.4  ~ 0.8ºC
• Niño 3 ~ 0.7ºC
• Niño 1+2 ~ -0.1ºC

El Niño Map. [SOURCE: NOAA/ Climate Prediction Center / NCEP]

Niño Region SST Departures (ºC) –  Recent Evolution

Highlights

SST Departures (°C) in the Tropical Pacific During the Last 4 Weeks
During the last 4-weeks, equatorial SSTs were at least1.0°C above average across much of the central and eastern Pacific.

Global SST Departures  (ºC)
During the last four weeks, equatorial SSTs were above-average in the Pacific and Indian Oceans. Also, above-average SSTs covered large areas of the Northern Hemisphere mid-to-high latitudes.

Weekly SST Departures (ºC) for the Last Four Weeks

• During the last four weeks, SST anomalies remained positive across the equatorial Pacific Ocean.
• During the last month, there was little change in the equatorial SST anomalies.

Sub-Surface Temperature Departures (ºC) in the Equatorial Pacific

• In the first half of September 2009, temperature anomalies increased in the eastern Pacific due to the downwelling phase of a Kelvin wave.
• The most recent period shows a continuation of positive anomalies across the equatorial Pacific, with the largest values between 50-150m depth.

Atmospheric Circulation over the North Pacific & North America During the Last 60 Days
During late July through September, an anomalous trough was prevalent in the central North Pacific Ocean. During September, an anomalous ridge was present downstream, focused over Canada and the northern United States. The pattern also featured a trough over the southern U.S., which contributed to cooling in the region, while the northern U.S. and Canada remained warmer-than-average.

Pacific Niño 3.4 SST Outlook

• Most ENSO models indicate El Niño will continue through the Northern Hemisphere winter 2009-10.
• The models disagree on the eventual strength of El Niño (SST anomalies ranging from +0.5°C to +2.0°C), but a majority indicate at least a moderate strength El Niño (greater than +1.0°C) during November-December-January 2009-10.

Figure provided by the International Research Institute (IRI) for Climate and Society (updated 14 Sept 2009).

ONI Evolution
The most recent ONI value (June –August 2009) is +0.7oC.

Summary:

• El Niño is present across the equatorial Pacific Ocean.
• Sea surface temperatures (SST) were at least 1.0ºC above-average across much of the central and east-central equatorial Pacific.
• Based on current observations and dynamical model forecasts, El Niño is expected to strengthen and last through Northern Hemisphere winter 2009-10.

Information and images on this page are sourced from Climate Prediction Center/NCEP/NOAA.

Related Links:

• Recognizing El Niño
• El Niño and La Niña: Tracing the Dance of Ocean and Atmosphere
• TAO Diagrams
• El Niño Forecasts

El Niño Updates:

• El Niño [Main Page]

• El Niño Update [21 Sept 2009]

• El Niño Update [14 Sept 2009]
• El Niño Update [8 Sept 2009]
• El Niño Update [31 Aug 2009]
• El Niño Update [17 Aug 2009]
• El Niño Update – 10 August 2009
• El Niño Update – 3 August 2009
• El Niño Update – 27 July 2009

• El Niño Update – 20 July 2009
• El Niño Update # 1
• El Niño conditions is in progress —NOAA
• El Niño event almost certain: BOM
• El Niño could develop June – August 2009
• World Now
• 2009 Hurricane Season

El Niño Update [21 Sept 2009]

ENSO Cycle: Recent Evolution, Current Status and Predictions

The following UPDATE is prepared by

Climate Prediction Center / NCEP – 21 Sept 2009

The latest weekly SST departures are:

• Niño 4   ~ 0.8ºC
• Niño 3.4  ~ 0.9ºC
• Niño 3 ~ 0.8ºC
• Niño 1+2 ~ 0.3ºC

El Niño Map. [SOURCE: NOAA/ Climate Prediction Center / NCEP]

Niño Region SST Departures (ºC) –  Recent Evolution

Highlights

During the last 4-weeks, equatorial SSTs were at least1.0°C above average across much of the central and eastern equatorial Pacific.

Global SST Departures  (ºC)
During the last four weeks, equatorial SSTs were above-average in the Pacific and Indian Oceans. Also, above-average SSTs covered large areas of the Northern Hemisphere mid-to-high latitudes.

Weekly SST Departures (ºC) for the Last Four Weeks
During the last four weeks, SST anomalies have remained positive across the equatorial Pacific Ocean. •During the last month, the change in equatorial SST anomalies was slightly positive in the east-central Pacific.

Atmospheric Circulation over the North Pacific & North America During the Last 60 Days
During late July through mid-September, an anomalous trough was prevalent in the central North Pacific Ocean. Downstream over the United States, the anomalous height pattern generally featured a trough over the eastern United States with ridging prevalent over the western U.S. This anomalous pattern led to below-average temperatures over the central and eastern U.S. and to above-average temperatures over portions of the western U.S.

ONI Evolution
The most recent ONI value (June –August 2009) is +0.7oC.

Pacific Niño 3.4 SST Outlook

• Most ENSO models indicate El Niño will continue through Northern Hemisphere winter 2009-10.
• The models disagree on the eventual strength of El Niño (SST anomalies ranging from +0.5°C to +2.0°C), but a majority indicate at least a moderate strength El Niño (greater than +1.0°C) during November-December-January 2009-10.

Figure provided by the International Research Institute (IRI) for Climate and Society (updated 14 Sept 2009).

SST Outlook: NCEP CFS Forecast Issued 20 September 2009
The CFS ensemble mean predicts El Niño will last through Northern Hemisphere winter 2009-10.

Summary

• El Niño is present across the equatorial Pacific Ocean.
• Sea surface temperatures (SST) remain +0.5 to +1.5ºC above-average across much of the equatorial Pacific Ocean.
• Based on current observations and dynamical model forecasts, El Niño is expected to strengthen and last through Northern Hemisphere winter 2009-10.

Information and images on this page are sourced from Climate Prediction Center/NCEP/NOAA.

Related Links:

• Recognizing El Niño
• El Niño and La Niña: Tracing the Dance of Ocean and Atmosphere
• TAO Diagrams
• El Niño Forecasts

El Niño Updates:

• El Niño [Main Page]

• El Niño Update [14 Sept 2009]
• El Niño Update [8 Sept 2009]
• El Niño Update [31 Aug 2009]
• El Niño Update [17 Aug 2009]
• El Niño Update – 10 August 2009
• El Niño Update – 3 August 2009
• El Niño Update – 27 July 2009

• El Niño Update – 20 July 2009
• El Niño Update # 1
• El Niño conditions is in progress —NOAA
• El Niño event almost certain: BOM
• El Niño could develop June – August 2009
• World Now
• 2009 Hurricane Season

Climate Prediction, El Niño weekly report, Global SST anomalies, Oceanic Kelvin waves, equatorial Pacific Ocean.