Have a blessed weekend! -Kirk
Temperatures:
- Very little change vs. our previous September updated outlook, which also looks very similar to September 2019.
- We continue to favor the central to southern US to run above / much above average in terms of temperatures from normal, cooler to the west.
- The main drivers here look to be the drop in atmospheric angular momentum (AAM – less active jet streams – La Nina), which historically favors warmth central and east for Sept, and the tropical forcing (MJO) potential looking to set up more in phases 3/4/5.
- Risk: a major risk will be needing to watch especially the western Pacific typhoon activity (or lack there-of). If we start seeing multiple typhoons hinting at recurves into the north Pacific, that could lend a colder risk for the central US.
Precipitation:
- Virtually no change in precipitation risks vs. our previous outlook.
- We continue to favor some decent precipitation chances across the north-central to northern Plains/southern Canadian Prairies where the northerly jet stream is placed, as well as the increased potential in the Southeast due to tropical potential.
- The drier signal in the east will likely depend on the extent of the tropical risks to the south.
- We favored drier conditions also in the western Plains with reduced jet stream influence.
- Risk: a major risk here is how the Atlantic/Gulf regions develop the tropical risks; if they develop more towards the Gulf and get scooped up by troughs, it could pose a wetter risk to the East. Also, if the trough in the west trends stronger and the ridge in the east-central US is slightly more suppressed south, it could set-up for a greater rainfall risk for the Plains for the start of Harvest season.