Synoptic Scale Drivers...Weather Mags to the White Courtesy Phone

[NWFlow]

Ok folks, so with all the hype about another La Nina things appear to have gotten off to a slow start across the West ... with some snow in AK and the SW recently. Long range forecasts seem to show persistent ridging across the interior west and some talk of a split jet stream -- factors typically associated with an El Nino event.

So my question is: what synoptic scale drivers are creating these patterns (NAO, AO etc.) Specifically, can the active MJO significantly affect ENSO? that is can the MJO be superimposed upon ENSO variability and either magnify or subtract from the "expected conditions" given the current cold phase ENSO state?

[gratzo]

From my limited knowledge of climate patterns, the short answer to your last question is "yes". The factors the govern how ENSO affects storm tracks which are then moderated (or enhanced) by the MJO signal are super complex. There are probably 100 people in the world that really know this stuff, and I'm not one of them.

My general take on long-range forecasting is this. Having a great knowledge of MJO, ENSO, AO, PNA, and other climate factors can help you figure out general trends (ridge in this area, trough in this area, stormy in the "west"), but it will never let you hone in on forecasting a powder day. That requires knowledge of the specific storm track of a single storm, and this is often impossible more than a few days away, though 5-8 days out you can often time generally forecast that "a storm" will be coming somewhere close by.

Super good question and wish I had a better answer.