Weather service lingo can be confusing to casual reader.By FRANK DELANO
Weather service lingo can be confusing to casual reader. By FRANK DELANO
By FRANK DELANO
Date published: 6/9/2003
OU MAY NOT need a weatherman to know which way the wind blows, but you may need a glossary to know what he's talking about.
Consider this recent area forecast discussion from the National Weather Service office in Wakefield:
CHCS POPSESP OVR VA/MD CTYS OF FA. LLVL FLO TURNS TO WKLY OFFSHR (GRDLY) TDA IN MOST PLCSAND LEADS TO A LTL WRMR TEMPSFRI LUKS TO BE A BRK IN THE WET WX (AFT PSBL CHC SHRAS ERY).
Translated into plain English, the discussion says: "Chances of precipitation especially over Virginia and Maryland counties of forecast area. Low-level flow turns to weakly offshore (gradually) today in most places and leads to a little warmer temperatures. Friday looks to be a break in the wet weather (after a possible chance of showers early)."
According to Tony Siebers, meteorologist in charge of the Wakefield office, the abbreviations used in weather service discussions allow forecasters to write and transmit discussions quickly to other forecasters.
The discussions help forecasters resolve differing opinions when various weather outcomes may be possible in a region, he said.
"Internally, we know what the discussions mean," he said.
But the abbreviations forecasters use can puzzle even other meteorologists.
"The abbreviations used by the weather service are not for the faint of heart," said Jerry Stenger, research coordinator of the Virginia Office of Climatology at the University of Virginia in Charlottesville. "Sometimes we have to scratch our heads trying to figure out what the discussions mean."
Now that the discussions are online, Siebers said, he gets about one message a month from "someone with a beyond-casual interest in the weather delving into the discussions and the reasoning behind the forecasts."
To help decipher the abbreviations, Siebers refers beyond-casuals to a four-page list of "Common Contractions and Acronyms" found at the National Oceanographic and Atmospheric Administration Web site: srh.noaa.gov/tlh/tlh/contractions.html.
There, links to aviationweath er.gov/info/domestic_contrac tions produce a 27-page list of about 1,350 contractions used by the weather service.
Stenger believes the use of contractions in weather forecasts goes back to "a time not that long ago" when forecast stations communicated with each other by Teletype.
"Teletype machines had a baud rate of about 75," he said, "which is about one ten-thousandth the speed of a typical university Internet connection."
"Economy of letters was paramount to getting messages across in a timely fashion on a teletype machine," he said.
The tradition of abbreviated weather messages has persisted. Some individual forecasters occasionally add to the confusion with their unique contractions, said Stenger.
Forecasters now talk to each other in Internet chat rooms, Siebers said. And a puzzled public has prompted some weather sites to issue discussions in plain English, he said.
"It is because the AFD [area forecast discussion] has become such a public product that forecasters have been discouraged from using abbreviations and contractions whenever possible. Nevertheless, certain common contractions are still used," says NWS' Tallahassee Web site.
Date published: 6/9/2003
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