April 24, 2024

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.

____________________________

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.



15 comments:

  1. Great update Cliff, let's see if about this Sunday or Monday the front page headline from the Seattle Times will say " due to climate change we will now experience wetter periods in late April and May"

    ReplyDelete
    Replies
    1. Or if the Olympians decree the "drought emergency" (no doubt due to climate change ™, don't repeal the carbon tax) is hereby ended.

      Delete
    2. Nah ST will still be beating the drought drum. Or how terrible the wildfire season will be.

      Delete
  2. Cliff, thanks for sharing this near-term good news. According to the source of your first two data figures, NOAA, the longer-term news isn't quite as rosy - warmer- and drier-than-normal weather considered more likely over the 1- to 3-month range. However, those predictions are a bit older than your near-term prediction. And of course longer-term forecasts have less confidence.

    Do expect that the cool and wet weather will extend beyond 10 days? It seems like that would be necessary to bring the snowpack back up to 80%-100% of normal.

    ReplyDelete
    Replies
    1. Jerry.... the NOAA 8-14 day shows exactly the same thing. The highly skillful ECMWP ensemble system shows wetter than normal over the same period. The next few weeks will be wetter than normal...little doubt about this. ..cliff

      Delete
    2. There may be some increase in the high elevation snowpack across Eastern Washington from this wet period but the mid elevations will probably just get rain. Since the snow has mostly melted up through the mid elevations and many of the high elevation areas, especially across northern sections, are currently 50-55% of normal, I think it would be difficult for these areas to reach 80% of normal considering the lateness of the season.

      Delete
  3. Making it hard to get back into shape on the bike! C'est la vie....

    ReplyDelete
  4. I was wondering how much our late season cool/wet weather was going to impact the snowpack. Thank you for the info!

    ReplyDelete
  5. In the news, NOAA predicts a hot summer 2024. Should we be worried? Or is this just another media frenzy?

    ReplyDelete
    Replies
    1. Yes. If they say you should worry, you should start worrying as soon as possible.

      Delete
    2. Yong, NOAA's prediction is based on probability - it's more likely to be a warm summer than a cool one.

      Delete
  6. Today's 12z gfs model has mid 80's for seattle next Saturday, not unheard-of since record highs are in the mid and upper 80's. I get the feeling it's gonna be a long hot summer this year.

    ReplyDelete
    Replies
    1. Tim...you are reading the model output wrong. You are 20F too high....Maybe 65F...cliff

      Delete
    2. Yeah, and looking reality square in the eye here on May 1, mid 50s are now more likely on Saturday.

      I sometimes wonder about the color gradients used on the maps for LT temp anomalies. Simply using bands to mark different areas of probability, rather than color fills, might force people to think harder about what they are seein...not a bad thing IMzo.

      Delete

Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

More Rain for the Northwest is Good News for Wildfires

After a very pleasant dry spell, another rainy period is ahead for the western side of the region and the Cascades on Friday and Saturday.  ...