Tuesday Forecast update:

Showers today (Tuesday) and generally cool temperatures.  Drier later this week with a warming trend.  Temperatures should warm to well above average by the weekend.  A deep trough in the Pacific will be pumping a ridge over the western U.S.   At this point, I don't see any definitive end in sight to the ridging.  However, both the GFS and Euro have hinted at a monsoon-like moisture surge around or just after mid-month.   But... as for large winter storms, it looks like we'll have to wait at least until the latter stages of October for that.

The good news is that while there's not much in the forecast right now, things can change quickly this time of year.  I would not at all be surprised to see something develop in the long-range models over the next few days.  Stay tuned...

El Niño:

Continued warming this week in the equatorial Pacific.   3.4 region is up to +2.4C anomalies.  Other regions seeing warming as well.  Strong westerly wind bursts in the coming days will help aid further warming.  The ONI is a 3-month average of the 3.4 region anomalies and it was +1.5C for the July-Sept timeframe.  This is warmer than the 82-83 event (+1.3C) and slightly lower than 97-98 (+1.7C).  Based on where we are currently, I’d expect the Aug-Oct ONI will jump to around +2.0C which would put it right in line with 1997.  Of note, the record ONI was +2.3C, so we are actually currently above the record highest 3-month average.  That means that if we can average this strong or stronger over the next few months, we will be looking at a record El Niño event.

As for the blob, this map show the change in temp anomalies over the past four weeks:

You can see the general warming trend along the Pacific equator, indicative of the strengthening El Niño mentioned earlier.  Equally important, you can see significant cooling in a band from Hawaii up to the PNW coast.  This region has been well above normal for quite awhile so cooling in this area is almost certainly a good thing.  Perhaps the death of “the blob” is underway…?

With Niño getting stronger, and us getting closer to winter, the models have been interesting to watch.  CFSv2 has been trending wetter for west coast.  Here are the current forecasted precip anomalies for the U.S. for the first part of the ski season (Nov-Dec-Jan):

Utah is pretty much 50/50 in this map, but with active weather to our west, the hope would be that we’d get in on some of the action as well.

For the heart of ski season (Jan-Feb-Mar), this is what CFSv2 is projecting:

California really looks like it will likely get hammered.  The good news is that as the precip anomalies have increased to our west, it’s been starting to spill over into Utah a bit.  You can see that the spine of Utah is now forecasted to have slightly elevated precip anomalies.  It’s not nearly as strong a signal as California, but it’s certainly better than nothing, and we are no longer seeing below normal anomalies near us.

I have said all along that anything can happen.  El Niño is not a guarantee of anything!  However, I’ve also always professed that it is my belief that a stronger El Niño does increase our chances of a snowy winter.   As El Niño continues to strengthen, the models are at least reflecting that belief.  What will happen will happen, and of course we will be there to enjoy it when it does.  Still, it’s fun to speculate.

Evan | OpenSnow