Say What?????

Lots of e-mail today about the terms I use in the video and on the blog. Great questions... here are a few answers that might help:

GFS: Global Forecast System. The GFS is one of the main computer models we use for the short term, and into the medium range time period beyond 48 hours into the future. The GFS has output to 384 hours.

UKMET/ECMWF: We also use two European models to forecast in the medium range time period. One of models, known as the UKMET model, was developed in the United Kingdom. The other model, known as the ECMWF, is based in the European Meteorological Center.

ETA: A higher resolution model that has output for the U.S. only. The ETA has output to 84 hours.

540 line: Where the distance between a pressure of 1000 millibars and 500 millibars in the atmosphere is 5,400 meters. This is often used to define the rain-snow line in winter weather events.

Zero at 850 line: The freezing line (0 degrees C) where the pressure is 850 millibars, or about 5,000 feet off the ground. Another good way to determine the rain-snow line.

12Z run, 00Z run, etc: The computer models in America are run four times each day: 00Z, 06Z, 12Z, and 18Z... They are available around 10:00 a.m., 4:00 p.m., 10:00 p.m., and 4:00 a.m.

See model output from NCEP here:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/

Will add to this later...