The persistent warmer than normal North Atlantic SSTA contributes to wet weather/increased flood risk in the East-central U.S. for spring and the Mid-Atlantic region to Appalachian Spine for meteorological summer.

The Nino34 SSTA has shifted to neutral phase as the conventional index for monitoring ENSO phase indicates oceanic La Nina has ended. However, the multivariate ENSO index (MEI) which accounts for the atmospheric reaction to the equatorial Pacific SSTA regime remains in La Nina phase.

Interaction of today’s Northeast U.S. storm with the deep tropics due to the presence of a transient Madden Julian oscillation (MJO) which causes unusually low pressure (975-980 MB) will cause a high wind event later today as the storm backs westward toward the coast while peaking in strength.

The most important part of this week’s ENSO diagnostic report is an eastward shift of an aggressive Kelvin Wave to just east of the Dateline. The next MJO event to move through the equatorial East Pacific could push this warmth to the South America coast and trigger an El Nino onset. The latest NCEP CFS V2 Nino34 SSTA forecast indicates chance of a strong El Nino later this year.