Good afternoon everyone. Below is our latest September forecast update:
Temperatures:
No changes here to our September outlook. Overall our top analogs remains consistent on notable warmth for the month of September (2017, 2016, 2005).
Taking into account recent climatology, the last 5 September’s have overall average out very hot with the last two years being the warmest September’s on record. Our current September CDD forecast puts us at the third warmest on record.
One of the factor to consider is the global AAM. The oceans are undoubtedly continuing to trend in the direction of a La Niña and it’s unlikely the upcoming +AAM state can sustain for very long. Data is already hinting at another drop which should allow things to start to warm up late August and right in time for September where the –AAM is very warm.
An active tropical Atlantic can also help pump up additional warm north of the storm track.
Precipitation:
No major changes to our rainfall outlook, however, we did trend a touch less dry in the Ohio Valley given no strong signal for dryness at this point on analogs. There is some dryness on the 2017, 2016, 2005 analog, but not enough confidence at this point to keep that signal.
With that being said, our analogs do continue to strongly suggest a very active tropical season. Given the similarities in the MJO and oceanic patterns, 2005 remains a top tropical analog. This naturally presents major risks as much will depend on where these systems track. We tried to keep some dryness under the ridge north of the Gulf, but one system could easily bust that forecast.
Conversely, if storms remain out to sea or on the East Coast, the Eastern Ag Belt could trend much drier.
We favor wetter risks with a better gradient for rain in the Northern Plains into parts of the Upper-Midwest north of the main ridge of heat.