Saturday, May 21, 2011

Final Day of Hurricne Week, Baja time

(Click on images in this article to expand)

Hurricane Linda from space in the Eastern Pacific
The Eastern Pacific Hurricane Season begins May 15th, but residents of Baja will scoff about any threat so early in the season. I've heard tribal knowledge like, "Hurricanes never come up the Sea of Cortez before September 1st." Well, right off the bat, my first hurricane, Ignacio, proved that one wrong in 2003.
The earliest Tropical Cyclone (one of Tropical Storm intensity or greater) to make landfall in Baja was TS Calvine on July 8th, 1993. The earliest hurricane to make landfall in Baja was Category 1 Hurricane Doreen in 1977. The most powerful storm to hit Baja was Kiko in 1989, the only Category 3 storm to ever make landfall in Baja. The dealiest storm was Hurricane Lisa in 1976. Lisa was a Category 4 Hurricane that passed up the Sea of Cortez and indirectly resulted in the deaths of thousands in La Paz.
So, we did research and here's the scientific straight scoop. We went to the NHC's Historical Hurricane Plotter which has data on tropical weather compiled from 1948 to 2008. We looked at plots of tropical storms though Category 5 hurricanes that passed within 150 miles of Baja. To confirm our data, it was checked against the Unisys data complied independently.
There is a map for each month of the season, click on the map for an enlarged view of storms tracked during that month. Each table shows the year of the storm, the first date of it's highest wind speed and the highest Saffir-Simpson Scale Category rating the storm achieved. This is not necessarily the storm's rating when it made landfall in Baja California Sur. The storms are sorted by the day they achieved maximum strength, showing what part of the month is most prone to storms.
May Hurricanes
Hurricane Georges in the Caribbean 1997Let's Start with May, that's an easy one. Since 1951 not a single tropical storm or hurricane has passed within 250 miles of Baja.
In June the Eastern Pacific is starting to really warm up and the storm activity increases. By mid June hurricanes become a possibility in Baja, although still pretty remote. The last time a June hurricane hit Baja was in 1958. The early season storm packed winds of 85 mph as it passed within 25 miles of Cabo San Lucas, which wasn't much more than a few fishing huts at the time.
June Storms
YEAR DAY STORM NAME WIND SPEED (KTS) CAT
1958 15 Not Named 25 TD
1959 12 Not Named 45 TS
1960 25 BONNY 45 TS
1960 25 BONNY 45 TS
1974 21 CONNIE 25 TD
1990 23 DOUGLAS 30 TD

In July the water in the Sea of Cortez is warmer. But hurricanes in our hemisphere want to go to the west because of their rotation. The jet stream usually doesn't drop southward across Baja until late August. Historically speaking, July is a safe month too, as the storms move harmlessly out into the Pacific and dissipate. There has been one Category 2 hurricane brush past Magdalena Bay and make landfall north of San Ignacio back in July of 1954. Tropical storm Calvin hit East Cape in 1993 and another tropical storm Calvin hit Todos Santos in 1981. (yes, the same day twelve years apart!) Ok, we can make it though July without a hurricane.
July Storms
YEAR DAY STORM NAME WIND SPEED (KTS) CAT
1950 6 Not Named 75 H1
1952 19 Not Named 45 TS
1954 16 Not Named 75 H1
1954 16 Not Named 75 H1
1958 29 Not Named 45 TS
1964 7 NATALIE 45 TS
1970 18 HELGA 50 TS
1974 18 FRANCESCA 60 TS
1974 18 GRETCHEN 50 TS
1981 8 CALVIN 40 TS
1984 7 FAUSTO 90 H2
1984 11 GENEVIEVE 65 H1
1985 4 FEFA 60 TS
1989 27 FLOSSIE 25 TD
1993 8 CALVIN 50 TS
1998 18 CELIA 45 TS
2005 20 EUGENE 50 TS
2006 25 EMILIA 50 TS
2008 3 DOUGLAS 30 TD



Well, dream on if you think the luck will hold though August. I heard it said just days before Hurricane Ignacio in 2003  "...it was no concern, storms never come up the Sea until after September 1st." That is nothing but an old wives tale. By the end of August we can start to get into some serious hurricane weather.
Anyone who has spent the summer in Baja knows, about August 15th the days become still and humid, and this is in addition to near 100 degree heat every day. Thunderstorms appear regularly over the mountains between Cabo San Lucas and La Paz. The earliest hurricane to make landfall in Baja Sur was August 15th and the latest was October 17th, thus defining Baja's hurricane season. However, a Category 1storm passed just 30 miles south of Cabo in 1958, certainly close enough to deliver some punch to the peninsula.
Hurricane Fran from space - off the coast of FloridaThe warm water of the Sea can be in the upper 80°'s by late August and this becomes a very strong hurricane magnet. Storms that generate NW of Acapulco can sometimes get stuck  'inside' and travel up the Sea. Hurricane Ignacio did exactly that on August 26, 2003.
The good news is August tropical cyclones in Baja are still rare. The upper atmosphere steering winds are still moving eastward far north of the hurricane track and a majority of the storms move off into the colder waters of the Pacific and spin apart.
August Storms
Hurricane and tropical storm tracks affecting Baja California
However, August can spawn monster storms too, like Kiko in 1989. Kiko made it to Category 3 has it churned up the Sea of Cortez and  made landfall on the East Cape with winds in excess of 120 MPH. Kiko was the ONLY category 3 storm to ever make landfall in Baja.



to ever make landfall in Baja.
YEAR DAY STORM NAME WIND SPEED (KTS) CAT
1960 19 DIANA 75 H1
1960 19 DIANA 75 H1
1965 31 EMILY 45 TS
1967 31 KATRINA 75 H1
1968 18 HYACINTH 45 TS
1969 23 EMILY 50 TS
1971 11 KATRINA 50 TS
1977 15 DOREEN 65 H1
1981 29 IRWIN 35 TS
1981 30 IRWIN 30 TD
1988 18 JOHN 30 TD
1989 26 KIKO 45 H3
1993 24 HILARY 40 TS
1995 11 FLOSSIE 70 H1
2000 15 ILEANA 60 TS
2003 23 IGNACIO 55 TS
2003 24 IGNACIO 60 TS
2008 24 JULIO 40 TS
September is the month to be a storm watcher in Baja. More than 150 tropical storms have passed within 250 miles of Cabo San Lucas since 1950. Many of them were just tropical storms, but September is the peak of the storm season.
By mid September the jet stream has dropped well down into Baja Sur before it makes a dramatic turn to the east. While I was plotting hurricane Marty the computer models forecast a continued NW progress harmlessly into the Pacific. Friday afternoon I noticed a drop to the south in the jet stream on the US Navy plots. These high speed upper air currents came almost as far as Magdalena Bay, then turn 90° east. That Friday night the BajaInsider predicted that Marty would not continue into the Pacific, but would turn and cross the peninsula south of Magdalena Bay. Marty hit the eastward winds south of the jet stream and banked against it's spin, progressively to the east. Marty arrived in La Paz on Monday morning. (thanks to my amateur weather tutor, Jim from Sea Witch!)
The jet stream can make a hurricane turn and it can tear it apart. The central column of convection is the engine that drives a hurricane. Hard turns or strong high altitude winds can disrupt the column and spin the storm apart. As the northern hemisphere cools these upper atmosphere steering winds drop further down Baja before turning east. The combination of these winds and energy still built up in the tropical regions are what make the period from September 15th to October 15th the peak of our storm season.

September Storms
YEAR DAY STORM NAME WIND SPEED (KTS) CAT
1949 10 Not Named 75 H1
1953 16 Not Named 75 H1
1957 21 Not Named 45 TS
1958 11 Not Named 45 TS
1958 11 Not Named 45 TS
1959 9 Not Named 75 H1
1962 21 CLAUDIA 45 TS
1964 7 TILLIE 45 TS
1965 25 HAZEL 45 TS
1966 28 KIRSTEN 45 TS
1969 5 FLORENCE 45 TS
1969 10 GLENDA 55 TS
1971 7 NANETTE 70 H1
1973 25 IRAH 90 H2
1976 30 LIZA 120 H4
1978 25 PAUL 40 TS
1986 23 NEWTON 70 H1
1988 7 DEBBY 25 TD
1993 12 LIDIA 85 H2
1995 4 HENRIETTE 80 H1
1995 14 ISMAEL 70 H1
1995 15 ISMAEL 70 H1
1996 13 FAUSTO 85 H2
1998 2 ISIS 60 TS
1998 2 ISIS 65 H1
1999 7 GREG 65 H1
2000 17 MIRIAM 30 TD
2001 27 JULIETTE 80 H1
2003 22 MARTY 75 H1
2006 1 JOHN 100 H3
2007 4 HENRIETTE 75 H1
2007 24 IVO 25 L
2008 11 LOWELL 30 TD

Once we get to October you would think that the season is winding down. Well, not exactly. The threat of tropical weather extends through the entire month of October. It is said the British Privateer Cromwell and Spanish explorer Cabrillo were taken by surprise in a late season storms.
Hurricane Nora off the coast of BajaBy October the Sea of Cortez has reached it's high temperature, acting as a magnet to the warm water hungry storms. In addition the high altitude steering winds now have enough strength to overpower the storms desire to head west. One look at the storm plot for October and you can see what I mean.  There are fewer storms than in September, but the path moves them right over Baja.
October Storms
YEAR DAY STORM NAME WIND SPEED (KTS) CAT
1955 2 NOTNAMED 45 TS
1958 3 NOTNAMED 75 H1
1958 4 NOTNAMED 75 H1
1962 4 DOREEN 75 H1
1962 4 DOREEN 75 H1
1963 18 MONA 75 H1
1967 13 OLIVIA 75 H1
1968 2 PAULINE 75 H1
1976 1 LIZA 120 H4
1976 28 NAOMI 40 TS
1978 5 ROSA 60 TS
1981 7 LIDIA 45 TS
1984 3 POLO 40 TS
1985 8 WALDO 75 H1
1986 1 PAINE 80 H1
1986 2 PAINE 80 H1
1987 1 PILAR 30 TD
1990 2 RACHEL 55 TS
1998 19 MADELINE 35 TS
2005 5 OTIS 20 L
2006 25 PAUL 40 TS
2008 11 NORBERT 95 H2
The good news is that by November 1st, like a line in the sand, the threat is over. Since 1950 only three tropical storms have even made it to within 250 miles of Cabo, none of them making land or achieving hurricane strength.
Monster hurricane Bonnie in the Atlantic


November Storms
YEAR DAY STORM NAME WIND SPEED (KTS) CAT
1951 29 NOTNAMED 45 TS
1970 4 SELMA 50 TS
1991 12 NORA 30 TD




Friday, May 20, 2011

What is it like to go through a hurricane?

  • 96 hours before landfall
    At first there aren't any apparent signs of a storm. The barometer is steady, winds are light and variable, and fair weather cumulus clouds dot the sky. But the perceptive observer will note a swell on the ocean surface of about a meter (3 feet) in height with a wave coming ashore every ten seconds. These waves race out far ahead of a storm at sea, but could easily be masked by locally wind driven waves.
  • 72 hours before landfall
    Little has changed, except that the swell has increase to about 2 meters (6 feet) in height and the waves now come in every nine seconds. This means that the storm, still far over the horizon, is approaching.
  • 48 hours before landfall
    If anything, conditions have improved. The sky is now clear of clouds, the barometer is steady, and the wind is almost calm. The swell is now about 3 m (9 feet) and coming in every 8 seconds. A hurricane watch is issued, and areas with long evacuation times are given the order to begin.
  • 36 hours before landfall
    The first signs of the storm appear. The barometer is falling slightly, the wind is around 5 m/s (10 kts, 11 mph), and the ocean swell is about 4m (13 feet) in height and coming in 7 seconds apart. On the horizon a large mass of white cirrus clouds appear. As the veil of clouds approaches it covers more of the horizon. A hurricane warning is issued and low lying areas and people living in mobile homes are ordered to evacuate.
  • 30 hours before landfall
    The sky is now covered by a high overcast. The barometer is falling at .1 millibar per hour (.003 inches of Hg/hr), and the winds pick up to about 10 m/s (20 kts, 23 mph). The ocean swell, coming in only 5 seconds apart, is beginning to be obscured by wind driven waves, and small whitecaps begin to appear on the ocean surface.
  • 24 hours before landfall
    In addition to the overcast, small low clouds streak by overhead. The barometer is falling by .2 mb/hr (.006"Hg/hr), the wind picks up to 15 m/s (30 kts, 34 mph). The wind driven waves are covered in whitecaps and streaks of foam begin to ride over the surface. Evacuations should be completed and final preparations made by this time.
  • 18 hours before landfall
    The low clouds are thicker and bring driving rain squalls with gusty winds. The barometer is steadily falling at half a millibar per hour (.015 "Hg/hr), and the winds are whistling by at 20 m/s (40 kts, 46 mph). It is hard to stand against the wind.
  • 12 hours before landfall
    The rain squalls are more frequent and the winds don't diminish after they depart. The cloud ceiling is getting lower, and the barometer is falling at 1 mb/hr (.029 "Hg/hr). The wind is howling at hurricane force at 32 m/s (64 kts, 74 mph), and small, loose objects are flying through the air and branches are stripped from trees. The sea advances with every storm wave that crashes ashore and the surface is covered with white streaks and foam patches.
  • 6 hours before landfall
    The rain is constant now and the 40 m/s wind (80 kts, 92 mph) drives it horizontally. The barometer is falling 1.5 mb/hr (.044 "Hg/hr), and the storm surge has advanced above the high tide mark. It is impossible to stand upright outside without bracing yourself, and heavy objects like coconuts and plywood sheets become airborne missiles. The wave tops are cut off and make the sea surface a whitish mass of spray.
  • 1 hour before landfall
    It didn't seem possible, but the rain has become heavier, a torrential downpour. Low areas inland become flooded from the rain. The winds are roaring at 45 m/s (90 kts, 104 mph), and the barometer is free-falling at 2 mb/hr (.058 "Hg/hr). The sea is white with foam and streaks. The storm surge has covered coastal roads and 5 meter (16 foot) waves crash into buildings near the shore.
  • The eye
    Just as the storm reaches its peak, the winds begin to slacken, and the sky starts to brighten. The rain ends abruptly and the clouds break and blue sky is seen. However the barometer continues falling at 3 mb/hr (.09 "Hg/hr) and the storm surge reaches the furthest inland. Wild waves crash into anything in the grasp of the surge. Soon the winds fall to near calm, but the air is uncomfortably warm and humid. Looking up you can see huge walls of cloud on every side, brilliant white in the sunlight.
    At this point, the barometer stops falling and in a moment begins to rise, soon as fast as it fell. The winds begin to pick up slightly and the clouds on the far side of the eyewall loom overhead.
  • 1 hour after landfall
    The sky darkens and the winds and rain return just a heavy as they were before the eye. The storm surge begins a slow retreat, but the monstrous waves continue to crash ashore. The barometer is now rising at 2 mb/hr (.058 "Hg/hr). The winds top out at 45 m/s (90 kts, 104 mph), and heavy items torn loose by the front side of the storm are thrown about and into sides of buildings that had been in the lee before the eye passed.
  • 6 hours after landfall
    The flooding rains continue, but the winds have diminished to a 'mere' 40 m/s (80 kts, 92 mph). The storm surge is retreating and pulling debris out to sea or stranding sea borne objects well inland. It is still impossible to go outside.
  • 12 hours after landfall
    The rain now comes in squalls and the winds begin to diminish after each squall passes. The cloud ceiling is rising, as is the barometer at 1 mb/hr (.029 "Hg/hr). The wind is still howling at near hurricane force at 30 m/s (60 kts, 69 mph), and the ocean is covered with streaks and foam patches. The sea level returns to the high tide mark.
  • 24 hours after landfall
    The low clouds break into smaller fragments and the high overcast is seen again. The barometer is rising by .2 mb/hr (.006"Hg/hr), the wind falls to 15 m/s (30 kts, 34 mph). The surge has fully retreated from land, but the ocean surface is still covered by small whitecaps and large waves.
  • 36 hours after landfall
    The overcast has broken and the large mass of white cirrus clouds disappears over the horizon. The sky is clear and the sun seems brilliant. The barometer is rising slightly, the wind are a steady 5 m/s (10 kts, 11 mph). All around are torn trees and battered buildings. The air stinks of dead vegetation and muck that was dredged by the storm from the bottom of the sea to cover the shore. The all clear is given.

Thursday, May 19, 2011

Quote for CPC Outlook

The 2011 eastern Pacific hurricane season outlook is an official product of the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center (CPC), and is produced in collaboration with scientists from the NOAA National Hurricane Center (NHC). The eastern Pacific hurricane region covers the eastern North Pacific Ocean east of 140oW north of the equator.
Interpretation of NOAA’s eastern Pacific hurricane season outlook
This outlook is general guide to the expected overall activity during the upcoming hurricane season. It is not a seasonal hurricane landfall forecast, and it does not imply levels of activity for any particular region.
Preparedness
Hurricane disasters can occur whether the season is active or relatively quiet. It only takes one hurricane (or even a tropical storm) to cause a disaster. Therefore, residents, businesses, and government agencies of coastal and near-coastal regions are urged to prepare for every hurricane season regardless of this, or any other, seasonal outlook. NOAA, the Federal Emergency Management Agency (FEMA), the NHC, the Small Business Administration, and the American Red Cross all provide important hurricane preparedness information on their web sites.

NOAA does NOT make seasonal hurricane landfall predictions
NOAA does not make seasonal hurricane landfall predictions. Hurricane landfalls are largely determined by the weather patterns in place as the hurricane approaches, which are only predictable when the storm is within several days of making landfall.

Nature of this Outlook and the “likely” ranges of activity
This outlook is probabilistic, meaning the stated “likely” ranges of activity have a certain likelihood of occurring. The seasonal activity is expected to fall within these ranges in 7 out of 10 seasons with similar climate conditions and uncertainties to those expected this year. They do not represent the total possible ranges of activity seen in past similar years.

This outlook is based on 1) predictions of large-scale climate factors and conditions known to be strong indicators of seasonal eastern Pacific hurricane activity. The outlook also takes into account uncertainties inherent in such climate outlooks.

Sources of uncertainty in the seasonal outlooks
  1. Predicting El Niño and La Niña (also called ENSO) impacts is an ongoing scientific challenge facing climate scientists today. Such forecasts made during the spring generally have limited skill.
  2. Many combinations of named storms and hurricanes can occur for the same general set of climate conditions. For example, one cannot know with certainty whether a given climate signal will be associated with several short-lived storms or fewer longer-lived storms with greater intensity.
  3. Weather patterns that are unpredictable on seasonal time scales can sometimes develop and last for weeks or months, possibly affecting seasonal hurricane activity.
2011 Eastern Pacific Hurricane Outlook Summary
NOAA’s 2011 Eastern Pacific Hurricane Season Outlook indicates a 70% chance of a below-normal season, a 25% chance of a near-normal season, and only a 5% chance of an above normal season. See NOAA definitions of above, near-, and below-normal seasons. The eastern Pacific hurricane region covers the eastern North Pacific Ocean east of 140oW north of the equator.
This outlook is based on the analysis and prediction of two main climate signals:
Climate patterns similar to those expected this year have historically produced a wide range of activity. Allowing for uncertainties, we estimate a 70% chance of occurrence for each of the following ranges of activity this season:
  • 9-15 named storms,
  • 5-8 hurricanes,
  • 1-3 major hurricanes,
  • An ACE range 45%-105% of the median.
The seasonal activity is expected to fall within these ranges in 7 out of 10 seasons with similar climate conditions and uncertainties to those expected this year. They do not represent the total possible ranges of activity seen in past similar years.
The 1981-2010 averages for the eastern Pacific hurricane season are 15-16 named storms, 8-9 hurricanes, and 4 major hurricanes.
There will be no further updates to this outlook.
DISCUSSION
1. Expected 2011 Activity
This Outlook is a general guide to the expected overall activity for the 2011 eastern Pacific hurricane season. It is not a seasonal hurricane landfall forecast, and it does not imply levels of activity for any particular area.
The climate factors expected to guide the 2011 eastern Pacific hurricane season are 1) a continuation of conditions that have been suppressing activity since 1995, and 2) A high likelihood of ENSO-neutral conditions (no El Niño or La Niña) during the peak months (July-September) of the season, but with lingering La Niña impacts perhaps into the summer.
This outlook considers the historical distribution of activity for these climate factors, uncertainties in ENSO, and the possibility of other unpredictable factors also influencing the season.
Historically, seasons with climate patterns similar to those expected this year have typically produced below normal activity, with some producing near-normal activity. Therefore, we estimate a 70% chance of a below-normal season, a 25% chance of a near-normal season, and only a 5% chance of an above normal season.
An important measure of total seasonal activity is NOAA’s Accumulated Cyclone Energy (ACE) index , which accounts for the combined strength and duration of tropical storms and hurricanes during the season. Based on the expected climate factors above, we estimate a 70% chance that the 2011 seasonal ACE range will be 45%-105% of the median. According to NOAA’s definitions of season strength, an ACE value below 94% of the 1981-2010 median indicates a below normal season, and a value of 94%-141% of the median indicates a near-normal season.
Consistent with the expected ACE range, other likely (70% chance) ranges of activity for 2011 are: 9-15 named storms, 5-8 hurricanes, and 1-3 major hurricanes.
We expect dominant features of the ongoing low activity era to prevail this season, including increased vertical wind shear, generally shorter-lived and weaker storms, and a reduced westward track to those storms. These conditions would likely be accentuated if the current La Niña-related circulation anomalies persist even after La Niña dissipates.
This outlook is generally consistent with newly emerging climate model forecasts. Predictions from the Climate Forecast System (CFS), the European Centre for Medium Range Weather Forecasting (ECMWF), and the EUROpean Seasonal to Inter-annual Prediction (EUROSIP) ensemble are all suggesting normal or below-normal tropical cyclone activity in the eastern Pacific this season, though their forecast skill for the region is quite limited at this lead time.
2. The ongoing low-activity hurricane era in the eastern Pacific
The eastern Pacific has experienced suppressed hurricane activity since 1995 (while the Atlantic Basin has experienced greatly enhanced activity). The expected continuation of this low-activity era, combined with ENSO-Neutral conditions and the possibility of lingering La Niña-related circulation anomalies, is the main reason we expect the 2011 hurricane season to be below-normal.
During 1995-2010, 63% of eastern Pacific hurricane seasons were below normal, 31% were near normal, only one (1997) was above normal due to an El Niño episode of near-record strength. Eastern Pacific seasons during this period averaged about 14 named storms, 7 hurricanes, and 3 major hurricanes, with an ACE value of 83% of the median. This value falls within NOAA’s definition for a below-normal season.
Several regional circulation patterns have been associated with this reduced activity. The Pacific ITCZ has shifted farther to the north, allowing for extensive southwesterly flow into the eastern tropical North Pacific. Also, the upper-level ridge over Mexico has been stronger than average, resulting in enhanced upper-level easterly winds. This combination of factors leads to increased vertical wind shear, which limits the number, intensity, and duration of the tropical storms and hurricanes. Also, these storms tend to form closer to Mexico and closer to cooler ocean temperatures, both of which limit their duration.
The levels of hurricane activity since 1995 in the eastern Pacific and the Atlantic basin contrast sharply with those of the preceding period 1982-1994. The eastern Pacific was much more active during this earlier period, while the Atlantic basin was more suppressed. This multi-decadal see-saw in hurricane season strength between the two regions is associated with the tropical multi-decadal signal (Chelliah and Bell 2004, Bell and Chelliah 2006). For the eastern Pacific, 62% of hurricane seasons during 1982-1994 were above normal, 31% were near normal, and only one season (1988) was below normal. Seasons during that period averaged about 18 named storms, 11 hurricanes, and 5-6 major hurricanes, with an ACE value of 162% of the median. This value falls within NOAA’s definition for an above-normal season.
3. The El Niño/ Southern Oscillation (ENSO)
ENSO is an important climate predictor for eastern Pacific hurricane activity. The three phases of ENSO are El Niño, La Niña, and Neutral. El Niño acts to reduce the vertical wind shear and is therefore more conducive to eastern Pacific hurricane activity, while Neutral and La Niña conditions increase the wind shear and suppresses the activity. These typical impacts can be strongly modulated by conditions associated with the tropical multi-decadal signal.
We expect ENSO-Neutral during the peak months of the 2011 eastern Pacific hurricane season, but with lingering La Niña impacts into the summer. Both ENSO-Neutral and La Niña conditions typically enhance the dominant features of the ongoing low-activity era. Currently, the 2010-11 La Niña episode is waning. Based on current observations and ENSO forecast models, NOAA’s CPC indicates that ENSO-Neutral conditions are likely during the peak months of the 2011 eastern Pacific hurricane season.
However, predicting the various phases of ENSO and their impacts is an ongoing scientific challenge facing climate scientists today. Such forecasts made during the spring generally have limited skill. The present uncertainty in the model forecasts is indicated by the large spread in predicted SST departures in the east-central equatorial Pacific during July-September 2011. Most models predict ENSO-Neutral conditions (defined by the CPC as SST departures between -0.5oC and +0.5oC) during this period. However, some models predict weak La Niña conditions (SST departures cooler than -0.5oC) while others predict weak El Niño conditions (SST departures above +0.5oC).