March 25, 2022

How far into the future are weather forecasts skillful? And the weekend forecast.

 My new podcast addresses a question I am often asked.  How far into the future are weather forecasts skillful?  

The answer has changed radically during the past three decades and I tell you why.   Just to motivate the discussion, here is a plot of the skill of the National Weather Service global model (GFS) for various lead times (blue bar).   The skill holds up well for the first four days, but you see a big drop during the second week.   This plot also shows the skill of ensemble systems in which many forecasts are made and averaged: the skill holds longer.

My podcast also provides the weekend weather forecast and tells you where you can drive to experience the mid-70s!  See below on how to access the podcast.

Some major podcast servers:

 HTML tutorial HTML tutorial
Like the podcast? Support on Patreon 


With COVID declining, the department is starting public lectures, and the first one is a very good one (see below).  You must register to attend.
April 7, Thursday, 7 – 8:30 p.m.Sign up for event 'Peter Hobbs Endowed Lecture "Staring Into the Fire: Using Observations to Understand Wildfires and Smoke" - Assoc. Prof. Emily Fischer, CSU' or here.
Location: Kane Hall (KNE)
Campus room: 110

Staring Into the Fire: Using Observations to Understand Wildfires and Smoke

Recent increases in western U.S. wildfire activity have made wildland fires and the associated smoke a significant challenge for society. This problem will only grow as the climate warms. I will discuss how the atmospheric science community has used both new in situ observations and operational datasets to answer important questions about wildfires and how smoke evolves in the atmosphere.


And the Northwest Weather Workshop will occur (online) on May 7th.   Information is here.

This meeting is open to everyone and covers the big weather events of the year, plus much more.  The June heatwave will be a major topic this year!


  1. Seeing in the figure that ensemble forecasts are consistently better beyond 5 days, does any weather predicting service actually use them?

  2. Hi Cliff,
    Is the last frost for this season over?

  3. Hi Cliff,
    Is the last frost for this season over?

    1. I'm not Cliff but I did some looking at our frost dates. If memory serves, we are in zone 8b and 50% chance of frost has already passed. I think it was March 15th. The 10% is on April 4th, but you want to go by the 50% point. Here is a link to Dave's Garden and he talks about this for our state.

      If you are in the western side of the state, go by the rough area where you live, so if in the Seattle/Tacoma area, use that to get your frost dates.

      I am seeding Brandywine tomatoes in a tray inside my house with a grow light and won't begin to put them out to harden until likely mid May when the soils overnight are around 50F and need to get my grow bags ready to go out to acclimate to the temps outside (they are stored in a shed). I'll put the plants out towards the end of May. Typically, first frost comes in from mid to late October for 32*, or early Nov for 50% chance. By Dec 21 when you go below freezing to 28*.


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