The Weather Notebook: Weather Abbreviated

Weather Abbreviated
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When you first look at Area Forecast Discussion issued by your local National Weather Service office, you may feel as if you've stumbled on the ravings of a mad atmospheric scientist. In all upper case text it reads: "PERSISTENT LOW/MID Q-VECT DIVERGENCE AND SUBSIDENCE". Another forecast office discussion shouts back "ISENTROPIC LIFT AND DEEP SW UPPER FLOW"

And you just wanted to know whether you could play golf tomorrow.

Hi, I'm Bryan Yeaton and this is the Weather Notebook.

Actually, forecast discussions offer fascinating glimpses into how meteorologists think - once you get the hang of the jargon. Here are a few abbreviations decoded:

NGM, ETA, MRF and AVN are all numerical forecast models; FROPA is frontal passage, SHRA are showers. Now you need to master a few meteorological terms. Q VECT is short for Q Vector, a mathematical term that forecasters use to identify areas of vertical motion - rising or falling air. Isentropic lift refers to warm air riding over cooler air in the lower level of the atmosphere - also known as overrunning, or OVRN for short. So, PERSISTENT LOW/MID Q-VECT DIVERGENCE AND SUBSIDENCE simply means clouds are dissipating, while ISENTROPIC LIFT AND DEEP UPPER FLOW means rain or snow is coming.

Thanks today to writer David Laskin of Seattle, Washington. The Weather Notebook is a production of the Mount WashingtonObservatory and is suported generously by Subaru of America. To get in on the discussion, go to our website at www.weathernotebook.org. Thanks today to Producer, Margaret Landsman.