Frigid temperatures this weekend prompt cold weather advisories

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You’re a commuter, snowplow driver, or just a fellow weather geek. You check your weather app. You check out the TV and radio meteorologists’ weather blogs and broadcasts. You might even browse through some of the dozens of forecast models. (Buyer beware!) And then you click on your local National Weather Service (NWS) 

Suddenly, you’re in weather geek heaven.

Your local NWS area forecast discussion pages layout the forecaster reasoning behind the latest forecast. It’s a technical discussion intended mainly for meteorologists. But the astute weather consumer can learn a lot from these discussions.

Let’s break down some of the elements in a typical forecast discussion.

The first part of the AFD typically focuses on the short term forecast. Precise timing may vary, but generally, this section focuses on the first day or two of the forecast. Here’s the short term AFD from the Twin Cities NWS Wednesday afternoon.

 National Weather Service Twin Cities/Chanhassen MN 331 PM CST Wed Jan 15 2020 .

This one is fairly non-technical and pretty self-explanatory. It’s a good summary of what to expect in the first 24 hours. Note that some words are highlighted with links to 

As you might expect this section focuses further out in the forecast cycle. It’s often looking at days 3 through 7. Here’s a clip from the early Wednesday morning AFD. 

(I’ve inserted a few comments in bold that give insight into what the discussion is telling us as meteorologists.)

So this section breaks down several elements that forecasters are assessing to make their forecast with Friday’s upcoming snow event.

It’s interesting to me that the process of forecasting is often subjective pattern recognition. Different forecasters often place greater emphasis on different elements of an inbound storm system. That can lead to different forecasts.

There’s plenty of model input and science in making a forecast. But thankfully there’s also still some art involved. And good forecasters at NWS and elsewhere are able to recognize how to improve a forecast beyond the raw model outputs.

Weather and Climate News

Updraft® - Minnesota Weather News

Paul Huttner

Author

NWS technical area forecast discussions give meteorologists and others deeper insight into NWS forecast thinking and mechanics.

Forecaster at the National Weather Service in Phoenix, AZ

Decoding National Weather Service forecast discussions

Go Deeper.

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