Ntxw wrote:What to look forward to the rest of this month and into November (when wintry precip becomes possible month!). NAO and AO have both tanked. PNA is positive right now but is forecasted to head back negative. The EPO will return to very negative but not this week as we are still in zonal flow. So 2/3 signals point to colder air sliding down. I think the -PNA is likely due to split flow and cutoff lows hanging around the Pacific NW/W so it's not a strong influence (just my opinion it may be completely wrong).
1976 and 2009 are the two best fit analogs for the beginning of Oct.
This was a decent forecast, but I underestimated the power of the warmth mid-month. Oct 2012 did not match 2009 or 1976 when looking at relative to average and remained slightly below. However, the cold shots were intense enough to rival that of the cold shots in those two years, just that the warmth managed to cut into it. The month also remained quite dry (likely from the weakening of El Nino late Sept/early Oct).
For first half of November, it's going to start out mild (obviously-yuck) but the changes are already happening. Right now I think there will be two big storms to look at based on analogs and teleconnections one mid month 10th-20th, and one near Thanksgivings or just a little after. The PNA has been mostly negative so I see little reason to stray from that idea. What this means is look for a full-latitude type trough with said systems and anomalously cold air. EPO will likely remain negative as well.
In the past years we have seen Novembers trend warm so it's unwise to rule out these spells between systems. However this November has the potential to allow early barrages of wintry weather. When looking at weak warm enso states, they like to throw a wrench at us. Early and late season wintry precipitation seems to occur more often when this is the case and this year could be one of those. As for precipitation, it's getting harder to predict so I will stick with near normal or slightly below normal to compliment October.