New Podcast: How Far Out in Time Can We Skillfully Predict the Weather?

 This is a question I am often asked?   How far out into the future can we predict the weather?

Listen to my podcast and I will provide the surprising, and complex, answer.

But first a few hints....

The National Weather Service has a website that shows how weather forecast skill declines over time (see below).  This figure indicates how the forecast skill at roughly 18,000 ft (500-hPa) declines over time for the U.S. global model (NCEP), the Canadian model (CMC), and the gold-standard European Center (ECMWF).   1 indicates a perfect forecast.  When this measure (the anomaly correlation) drops to 0.6 the forecast becomes only marginally useful.

Forecasts are very good through 3 days.  Quite good though five days, but then rapidly declines after that.   Some skill continues even two weeks out, but it is very marginal.

   How far out into the future can we predict the weather New Podcast: How Far Out in Time Can We Skillfully Predict the Weather?
Another way to see the decline in skill is to look at a series of weather forecast maps for increasing forecast projection.

Here is the analysis (truth) for sea level pressure (solid lines) and low-level temperatures (colors) for 4 AM on 24 February.


The 144-hour (6 day) forecast has some noticeable issues, such as the low off the California coast being radically weakened.    The big high offshore is in both.



Strangely enough, the low is back in the 180 hr (7-day) forecast, but too far offshore.


In contrast, the 240 hr (10-day forecast) has the high-pressure area hugely in error and shifted northward, and cold air (blue) flooding the northeast Pacific.    Not good.

   How far out into the future can we predict the weather New Podcast: How Far Out in Time Can We Skillfully Predict the Weather?

I generally don't trust forecasts beyond 7-8 days unless the ensembles of multiple forecasts are on the same page.

To listen to my podcast, use the link below or access it through your favorite podcast service.


Some major podcast servers:

    How far out into the future can we predict the weather New Podcast: How Far Out in Time Can We Skillfully Predict the Weather?    How far out into the future can we predict the weather New Podcast: How Far Out in Time Can We Skillfully Predict the Weather?
Like the podcast? Support on Patreon 


   How far out into the future can we predict the weather New Podcast: How Far Out in Time Can We Skillfully Predict the Weather?

PS:   Here are the snow totals for last night.  There was some snow everywhere but measurable snowfall was mainly north of Seattle.  In most locations, it melted rapidly after it fell.




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