and Numerical Weather (NWP) and Oceanographic Prediction (NWOP) charts at:

Analysis charts are time stamped in "UTC" (Coordinated Universal Time), which is equivalent to GMT (Greenwich Mean Time) This is the time of observations on which the chart is based. The issue time is normally around two hours after the time of the base observations.

Below is a comparison of current UTC to current Eastern Standard Time (EST), Central Standard Time (CST) and Western Standard Time (WST) or for Daylight Saving equivalent add 1 hour to the local time.

Saturday 21 November 2009 03:24 UTC -- 21 November 2009 13:24 EST -- 21 November 2009 12:54 CST -- 21 November 2009 11:24 WST

Upper air charts are labelled with the pressure level in hectopascals (hPa) e.g. 500 hPa. The pressure decreases upwards in the atmosphere e.g. the 250 hPa level is higher than the 500 hPa level.

Numerical Model Prognosis charts may be labled with the time at which the forecast is valid or with a +12 hr, +24 hr, +36hr , +48 hr, +72 hr etc from the base observation time for the relevant model. The LAPS model charts are available on the Web 4 hours [04 & 16 UTC ] after base observation time [00 & 12 UTC ], the TLAPS and Meso LAPS model after 6 hours [06 & 18 UTC] , GASP after 10 hours [ 10 & 22 UTC ].