El Nino is Rapidly Collapsing

 It's finally happening.   

The pesky El Nino, with warmer than normal surface waters across the central and eastern tropic Pacific, is finally dissipating.  

And the effects of El Nino, including a wet California and warm Northwest, should be fading.

Consider the temperatures in the Nino 3.4 area of the tropical Pacific shown below (the difference from normal is illustrated).  El Nino peaked in late November at around 2.1C above normal sea surface temperatures.   Right now it is about 0.6C above normal and declining rapidly.

The latest prediction of the NOAA/NWS climate forecast model (CFSV2) is for the El Nino to be gone (0°C anomaly from normal) by the end of May (see below).  And then we move into a strong La Nina (cold tropical Pacific) by autumn.

This model predicts the extension of colder-than-normal surface water over the tropical Pacific during the next few months (see below).  Wow.  Talk about oceanographic whiplash.

With El Nino weakening, the large-scale weather patterns are unlocking and the Northwest weather situation is forecast to be very different during the next weeks compared to earlier in the winter.

During El Nino winters (and this one), southern California is very wet, with the Northwest being on the drier side.  In contrast, the latest forecast of accumulated prediction from the US GFS model through 11 May is shown below.  Virtually nothing will fall over southern California and wet conditions will prevail over the Northwest.   

Something has changed.

And a strong La Nina foretells major changes next winter, greatly increasing the chances for lots of mountain snow and colder-than-normal temperatures.  

My suggestion:  if you can make some good deals on ski equipment, do so....

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Announcement:  I will do a special online zoom session at 10 AM on Saturday for Patreon supporters, with a deep dive into the upcoming wet period and the implications for this summer.  Plus, I will answer your questions.

Drought-Buster Wet, Cool Weather Ahead

 As many suspected, with the rapid collapse of El Nino and the progression into spring, the weather patterns have shifted, opening the door to far wetter weather over the Northwest.

During the next 10 days, expect lots of precipitation, cool to seasonal temperatures, and even a good dump of snow in the mountains.

The official NOAA 6-10 day forecasts say it all (see below), with wetter than normal conditions and colder than normal temperatures over our region.

A vigorous weather system is arriving tomorrow, bringing a wet day.   The total precipitation through Friday morning at 5 AM is shown below.  A nice wetting for the entire region with some western slopes getting 2-3 inches.  That is a lot for late April.

But this is just the beginning, with multiple wet systems arriving over the next week.   The total accumulation through next Saturday morning (4 May) is impressive, with large areas of more than 3 inches.     Keep in mind you need to multiply that by roughly ten to get snowfall in the mountains.

Over the higher elevations, the temperatures will be cold enough for snow, with substantial accumulations through May 4th.  Some mountain locations will get several feet of new snow.

I suspect the snowpack will increase to around 80% of normal over Washington State and more than 100% of normal over much of Oregon within roughly 10 days.  

The latest NOAA River Forecast Center forecasts for 10 days out are for near-normal river levels.   For example, consider the Snoqualmie River (below).  Below normal now, but near normal in a few days...and staying that way.

This and subsequent wet periods are well-timed to ensure sufficient water levels this summer.

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Announcement:  I will do a special online zoom session at 10 AM on Saturday for Patreon supporters, with a deep dive into the upcoming wet period and the implications for this summer.  Plus, I will answer your questons.