Weather Blog

Sound the trumpets? Current La Nina near extinction

Sound the trumpets? Current La Nina near extinction
Haili Walsh, 5, hangs onto her mom as they walk past an animatronic Styracosaurus dinosaur being moved to an exhibit at the Woodland Park Zoo Monday, April 4, 2011, in Seattle. (AP Photo/Elaine Thompson)

SEATTLE -- Ready for La Nina to end? Snow in the lowlands in mid-April. Monthly rainfall averages reached in the first 10 days of the month. More days in the 40s in spring than in the 60s. A nearly two month stretch since we've had an official sunny day.

While there are a vast number of people who live in the Northwest who love the cool, cloudy and wet weather (I'm one of them) I can understand that even long-time Seattleites are probably craving some sun and warmth.

The long range models still indicate that as a general rule, we're going to remain cooler and wetter than normal through at least the end of April, but there is a ray of light at the end of the tunnel: La Nina is just about done.

La Nina is the name we give when the waters of the equatorial Pacific Ocean cool to below normal levels (It's the opposite of the warming episode known as El Nino). But climate experts with NOAA's Climate Prediction Center say that La Nina conditions have been weakening in the Pacific Ocean and water temperatures in that region have been rising.

In fact, they say that ocean models indicate La Nina will be over and we'll be in what's known as "neutral" conditions by June. (Neutral means neither La Nina nor El Nino conditions).

Now that said, we were probably due to warm up either way because the whole La Nina/El Nino events typically do not give any noticeable effect to Northwest summers. The jet stream is the main item affected by La Nina/El Nino and the jet stream is usually not around our neck of the woods in the summer to be affected.

But I think many people will be put at ease just to know that cooling effect won't be around, just in case.

What does this mean for summer, then?

NOAA's 90 day climate outlooks are not picking up a warmer or cooler signal for the summer -- but for sun fans, that is an improvement from the consistent "cool and wet" forecasts these maps have been painting the past several weeks for late winter and spring (and a forecast that has more than verified).

That means summer has just as much chance to be hotter than normal than cooler than normal. I know, not much to hang a hat on, but this is about the best you get for long range forecasting: Either better odds for warmer, cooler, or no signal to tell either way. We're in the latter.

What does this mean for next winter?

If neutral conditions are indeed what we have next winter, it's typically an "all bets are off" winter. Some of our greatest storms have come in neutral winters, but there is no overriding "cool/wet" (La Nina) or "warm/dry" (El Nino) theme. We could go through a very cold stretch for a couple weeks, then a dry, stagnant streak, or a warm and wet stretch.

La Ninas typically have more frequent snow events but neutral winters have had larger snow events. Not to say that this winter is doomed to repeat 2008, but usually active winters -- be it snow events, wind events, flooding events -- or really long, boring, dry stretches -- have been the neutral ones. We'll see.

What does this mean for next week?

In the short term, La Nina still has a grip on the Northwest. While the end of this week does show promise for dry, sunny and reasonably mild weather, the overall theme of the next two weeks remains cool and showery, especially once we get into Easter Weekend and beyond.

Some of the gloomy statistics from this "spring"

As of April 18:

  • Seattle has yet to reach 60 in April. Seattle has never failed to reach 60 degrees in April. The record fewest are two set in 1954.
     
  • Seattle has just two days over 55 degrees this year.
     
  • The average high temperature this April so far (50.4 degrees) is a full degree lower than this past March's average (51.4), which was below normal in and of itself.
     
  • March's rainfall was 6.29" -- 7th wettest on record at Sea-Tac Airport and 2.5" above normal. Of March's 31 days, 24 had measurable rain and four others had a trace.
     
  • April's rain so far was 3.13" -- already the monthly quota. And it's rained on 15 of 18 days in April.
     
  • The last official sunny day was Feb. 25, defined as 30% or less cloud cover through the day. The streak is at 52 days through Monday. The longest stretch in the last 15 years was 73 days, and that was in the heart of winter.
     
  • Snoqualmie Pass had over 450 inches of snow this season -- already above the average of 431 inches with more to come. Crystal Mountain said they were 150" above average for seasonal snow fall and will be having spring skiing on select dates through June 12!
     
  • Mountain snowpack in general is running 130-150 percent of normal, with many sites actually reporting more snow on April 15 than they did on April 1.

Get real time updates on La Nina -- and all the other crazy Northwest weather events and forecasts from Scott -- by following him on Twitter (@ScottSKOMO) or on Facebook.