Category: Ensemble Discussion

Unfortunately there likely won’t be any significant changes to our precipitation pattern until late autumn and winter. Until then, we’ll have to take any drop of rain we can find. Once the pattern flips though, it may do so in quick and rather dramatic fashion (still expecting a wet winter).

The consensus of long range data shows the dry pattern continuing over the upcoming few weeks, including the JMA Weeklies, CFSv2 Weeklies, and ensemble products.

Analogs and other teleconnections support this dry theme. At least in the immediate range (through mid October) the only way to bust up this dry pattern is to get tropical moisture involved.

The new JMA Weeklies maintain the ‘mean’ ridge position across the West for the majority of the upcoming few weeks, but there will likely be attempts to expand the ridge across the northern tier Week 2 and 3 that would lead to at least transitional periods of much warmer air, after the cool period in the short term.

The model sees the ridge expanding Weeks 3-4 and the associated warmth that spreads east after the chilly regime.

The new JAMSTEC seasonal data is also in and maintains a warm look this winter. A lot of this has to do with an expected persistent southeastern ridge. We agree with this but, as is the case each winter, there will be challenges that have to be dealt with.

We also agree with the active storm track through the Ohio Valley and associated well above normal precipitation in the December through February period.