The LaNina pattern the last few months has been getting weaker and weaker. This could signal the slow end to La Nina and maybe a start to El Nino by the end of the year. The El Nino start is a long shot so I would want to focus more on the LaNina fading pattern for hurricane outlook.
The Hurricane season officially starts June 1 but with this type of pattern I do think this will not get going until August. We could see a stray system before than but due to climatology factors and the fading La Nina I think the %'s are that this is a August-October season.
The ocean temps in the Atlantic Ocean are up this year but it's not all over the Atlantic Ocean. The Central and Eastern tropical Atlantic were a little off the pace but should start to increase by early June. The target this year could be the US coast on the Atlantic side. My call is that Hatteras to Miami have an increased chance of a hurricane this year in August and September. The La Nina issue and the warmer waters WILL INCREASE the chances in the normally active Carolina Zone.
FROM THE W.M.O. (World Meteorology Organization)
WMO had predicted last October that the phenomenon would last until March.
But it said Monday that it now appeared likely that it would persist until June or July and could last longer. It said it was still difficult at this stage to predict how long.
"During the last three months La Niña conditions have become slightly stronger," a WMO statement said. "Sea surface temperatures are now about 1.5 to 2 degrees Celsius (2.7-3.6 Fahrenheit) colder than average over large parts of the central an eastern Equatorial Pacific."
This La Niña had been in the average range of such events, but the recent cooling will likely put it in the stronger-than-average category, WMO said.
La Niña normally lasts nine to 12 months. The current event started in the July-September quarter of last year, WMO said.
"It is rare for a La Niña event to persist for two years or more, such as occurred from early 1998 to early 2000," WMO said. "The likelihood of the current La Niña continuing for such a period will remain unclear for some months."
La Niña is the flip side of the El Niño phenomenon, where Pacific surface temperatures rise and are blamed for other changes in weather patterns around the world.
| EL NIÑO/SOUTHERN OSCILLATION (ENSO) |
| DIAGNOSTIC DISCUSSION |
issued by
CLIMATE PREDICTION CENTER/NCEP |
| 8 May 2008 |
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Spanish Version
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Synopsis: A transition from La Niña to ENSO-neutral conditions is possible during June- July 2008.
La Niña continued to weaken during April 2008, as reflected by changes in sea surface temperatures (SSTs) across the equatorial Pacific Ocean. Negative SST anomalies in the central and east-central equatorial Pacific have weakened, while positive SST anomalies are confined to parts of the eastern equatorial Pacific (Fig. 1). The latest weekly SSTs in the westernmost Niño-4 and Niño-3.4 regions are between 0.6°C and 0.8°C below average, while departures in the easternmost Niño-3 and Niño-1+2 regions are 0°C and -0.3°C respectively (Fig. 2).
Positive subsurface ocean temperatures at thermocline depth have continued to increase in central and east-central equatorial Pacific (Fig. 3). While this increase has resulted in positive heat content anomalies (average temperatures in the upper 300m of the ocean; Fig 4), a shallow layer of negative anomalies in the central Pacific continues to persist between the surface and 100m. Despite these changes, SSTs remain sufficiently cool to maintain the persistent atmospheric anomalies associated with La Niña. Enhanced low-level easterly winds and upper-level westerly winds continued across the central equatorial Pacific, convection remained suppressed throughout the central equatorial Pacific, and enhanced convection covered the far western Pacific. Collectively, these atmospheric and oceanic conditions indicate an ongoing La Niña.
A majority of the recent dynamical and statistical SST forecasts for the Niño 3.4 region indicate La Niña will persist through May-June-July 2008 (Fig. 5). Thereafter, there is considerable spread in the forecasts, with the majority reflecting ENSO-neutral conditions (-0.5 to 0.5 in the Niño-3.4 region) during the second half of the year. However, the spread of the models spans the possibility of a return to La Niña or even an El Niño by the end of 2008. Based on current atmospheric and oceanic conditions and recent trends, a transition from La Niña to ENSO-neutral conditions is possible during June- July 2008.
Atmospheric conditions related to La Niña often persist for a couple months after SSTs return to ENSO-neutral conditions. Expected La Niña impacts during May-July 2008 include a continuation of above-average precipitation over Indonesia and below-average precipitation over the central equatorial Pacific.
This discussion is a consolidated effort of the National Atmospheric and Oceanic Administration (NOAA), NOAA’s National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions).
THIS CHANGE IN THE LA NINA AS OF MAY 8TH COULD INDICATE THE END OF LA NINA BY MID OR LATE JUNE. THIS WOULD GO ALONG WITH MY THEORY OF NO LA NINA BY JULY OR AUGUST, BRINGING ON AN ACTIVE HURRICANE SEASON.
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