Noaa May update of ENSO=Neutral thru August

[cycloneye]

EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP
May 5, 2005




Synopsis: ENSO-neutral conditions are expected to prevail during the northern summer (June-August), in spite of recent increases in SST anomalies associated with strong Madden-Julian Oscillation (MJO) activity.

Surface and subsurface water temperatures increased substantially in the eastern equatorial Pacific during April, associated with the arrival of the downwelling phase of a strong oceanic Kelvin wave. Sea surface temperature (SST) anomalies increased by more than 2°C in the extreme eastern equatorial Pacific during April (Fig. 1, bottom), and by the end of the month, positive equatorial SST anomalies greater than +0.5°C (~0.9°F) were observed in most areas from Indonesia eastward to the South American coast (Fig. 1, top). The increase in SST anomalies in the eastern equatorial Pacific during April was reflected by an increase in the SST anomalies in the Niño 3 and Niño 1+2 regions(Fig. 2) and by an increase in the upper-ocean heat content in the eastern half of the equatorial Pacific (Fig. 3). Subsurface cooling and a decrease in upper-ocean heat content have been evident in the central equatorial Pacific, associated with the upwelling phase of the Kelvin wave (Fig. 3). This cooling is expected to propagate eastward, reaching the eastern equatorial Pacific during May. Thus, the effects of the warming along the west coast of South America should be brief.

Cloudiness, precipitation and low-level winds displayed considerable week-to-week variability during the month, associated with strong MJO activity (Fig. 4 and Fig. 5). During the first ten days of April enhanced precipitation (negative OLR anomalies) was observed over Indonesia (Fig. 4 top left panel), while stronger-than-average easterlies prevailed over the central equatorial Pacific (Fig. 4, top right panel). The enhanced precipitation moved eastward into the western tropical Pacific during mid-April, (Fig. 4, middle left panel) accompanied by anomalous westerly low-level winds over the extreme western equatorial Pacific (Fig. 4, middle right panel). However, during the last ten days of April the OLR anomalies and low-level wind anomalies weakened over the central equatorial Pacific and drier-than-average conditions developed over Indonesia (Fig. 4 bottom panels). Continued strong week-to-week variability in the patterns of tropical atmospheric circulation and precipitation is likely during May.

A majority of the statistical and coupled model forecasts indicate that ENSO-neutral conditions will prevail during the northern summer (June-August). The spread in the forecasts indicates increasing uncertainty during the last half of 2005.




http://www.cpc.ncep.noaa.gov/products/a ... _advisory/

However uncertainty grows by the last months of 2005 as they say at the last paragrafh.But I agree with this latest forecast as well what the aussies said about cooler waters moving eastward behind the recent Kelvin Wave.

[x-y-no]

Yes ... here's the point I've been making:

Subsurface cooling and a decrease in upper-ocean heat content have been evident in the central equatorial Pacific, associated with the upwelling phase of the Kelvin wave (Fig. 3). This cooling is expected to propagate eastward, reaching the eastern equatorial Pacific during May. Thus, the effects of the warming along the west coast of South America should be brief.

I can't say what will happen at the end of the season, but I'm now pretty confident we'll have essentially neutral (nominally a little warm maybe, but not enough to have significant impact) conditions through the heart of the season.

With that in mind, I'm ready to lock in my preliminary prediction for the season - I'll post in the prediction thread today.

Jan

[cycloneye]

Yes ... here's the point I've been making:

Subsurface cooling and a decrease in upper-ocean heat content have been evident in the central equatorial Pacific, associated with the upwelling phase of the Kelvin wave (Fig. 3). This cooling is expected to propagate eastward, reaching the eastern equatorial Pacific during May. Thus, the effects of the warming along the west coast of South America should be brief.

I can't say what will happen at the end of the season, but I'm now pretty confident we'll have essentially neutral (nominally a little warm maybe, but not enough to have significant impact) conditions through the heart of the season.

With that in mind, I'm ready to lock in my preliminary prediction for the season - I'll post in the prediction thread today.

Jan

Ok Jan I will be ready to add your numbers to the list of forecasts.

[donsutherland1]

I'm in strong agreement with the latest ENSO diagnostic discussion concerning June-August.

[HURRICANELONNY]

That's not the updated one.

[x-y-no]

That's not the updated one.

It's not? Are you sure? It's dated May 5.

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/

[hcane]

Graphs showing average landfalls for tropical cyclones along streches of the East and Gulf coast. Interesting, especially for "neutral" years in certian areas.

[Anonymous]

Hmmm...Texas and the East Coast maybe?

[x-y-no]

Can that really be right? The Carribean has nearly double the number of landfalls in el Nino years as La Nina years?

That's more than a little counterintuitive.

[hcane]

You were correct ... the chart labels were backwards .....


[img]

will have new ones shortly

[hcane]

sorry for the mistake

[x-y-no]

You were correct ... the chart labels were backwards .....


[img]

will have new ones shortly

OK ... that makes a lot more sense.

[cycloneye]

That's not the updated one.

Why you say the update is not the latest one? It says the date of May 5 and it all looks like I haved seen things evolve with the recent Kelvin Wave and what is behind and those are less warm waters.

[BayouVenteux]

Can't find the numbers on the hurricanealley.net website (maybe they are in the subscriber only area), but if I read the charts correctly, the numbers would be something like this...

1950-2004
Neutral ENSO Years
Location / Avg. Landfalls per season
__________________________
Atlantic
Florida / .63
Georgia to Virginia / .77
Virginia to Maine / .38

Gulf of Mexico
Eastern / .75
Central / .72
Western / .87

Wish there was, say, 4 or 5 centuries worth of data to establish a more definitive set of averages, but one must work with the data one has available.

[cycloneye]

Can't find the numbers on the hurricanealley.net website (maybe they are in the subscriber only area), but if I read the charts correctly, the numbers would be something like this...

1950-2004
Neutral ENSO Years
Location / Avg. Landfalls per season
__________________________
Atlantic
Florida / .63
Georgia to Virginia / .77
Virginia to Maine / .38

Gulf of Mexico
Eastern / .75
Central / .72
Western / .87

Wish there was, say, 4 or 5 centuries worth of data to establish a more definitive set of averages, but one must work with the data one has available.

Interesting data there.Thanks for posting it.

[weatherwindow]

just a general observation on the graphics.....most regions are experiencing at least a modest increase in landfall in the enso neutral phase vs el nino...and the central gulf jumps dramatically. does anyone have an explanation

[hcane]

East coast average landfalls by enso type