Information Shown on Composite Weather Maps:
West Coast Overview

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(1) Contours of sea-level pressure (at intervals of 4 millibars).
The analyses come from the eta-model initialization (00Z and 12Z maps) or the meso-eta-model initialization (6Z and 18Z maps), each performed twice daily by the National Centers for Environmental Prediction (NCEP--formerly the National Meteorological Center, NMC);

(2) Either a visible or a color-enhanced infrared satellite image from the GOES-West satellite, usually recorded at the same time as the analyses in (1) above (except for the visible image for the 12Z map, which is too early--instead, a 14Z or 15Z image is used with the 12Z analysis, which is later replaced by an 18Z image and analysis when they become available); and

(3) Plots of surface winds and cloud cover recorded at the same time as the satellite image in (2) above. The wind information includes:

• wind speed (in knots); and
• wind direction.

The time and date appearing on these maps is in Universal Time Coordinates (UTC), formerly known as Greenwich Mean Time (GMT). (See comments about time labels for more information.)