As is typical in El Ninos, precipitation is favored over the East Coast into the Gulf of Mexico coast, with little precipitation over the Ohio Valley and Midwest. The image above very well shows the pattern described, with a wet pattern holding out over the East Coast. But is the atmosphere showing an El Nino in other indices?
A look at the 30 day average of the SOI, used in the graph above, shows that the 30 day average has shot up to a value of positive 2. Positive values above 8 indicate a La Nina. This is fairly confusing for the atmosphere, because sea surface temperatures are positive, while the SOI is in fairly neutral territory. This will become interesting to monitor as we progress into the fall months to see if the atmosphere can sort itself out.
So while the precipitation appears to support an El Nino pattern, the SOI is in disagreement, and it will likely take a good month to see the SOI sort itself out.