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.
The early “baseline” of our ideas focuses on the likelihood of El Nino returning for the upcoming winter season. As we’ve stated many times in the past, each Nino event is different from one another and other ingredients (highlighted above) can play a significant role in ultimately determining the eventual outcome.
That sea surface temperature configuration in the northern Pacific argues for western Canada ridging and downstream troughiness such as the JAMSTEC, European, and CanSIPS would imply.
In addition to the central PAC anomalies, we also are keying in on some other items of interest in the overall SST configuration:
The SST CA model is quickly becoming one of our more trusted seasonal forecast models. We note how it becomes increasingly bullish on a central and eastern trough as winter wears on (by the way, this is likely to go deep into spring this year, too).
Cold overwhelms the pattern and when you combine it with the active storm track (noted by the green hues, suggesting above normal precipitation through our neck of the woods), confidence is continuing to grow for an above normal snow season.
The SST configuration on the JAMSTEC would suggest a cold, stormy set-up, locally. That said, while it sees the above average precipitation, it’s awfully warm at the surface.
The NMME (to no surprise…) would suggest a very warm, wet winter.
As a reminder, our complete and final annual winter outlook will be posted here during the second half of October. That will include additional model data, along with several other points behind our reasoning for our winter forecast. As we always do, we’ll put “pen to paper” when it comes to our winter forecast, including our expected temperature and snowfall anomalies. Given the data above, including the warm JAMSTEC and NMME, it’s going to be very, very hard to see a warm winter here. In fact, our idea is for the exact opposite, given the SST configuration, and lines up more closely with the SST CA idea at this point. We’re also in the camp of a very, very active storm track through the Ohio Valley. “Big-hitter” potential is present from a winter storm perspective, especially given that we are likely to see resistance from the SE ridge.
