This is a set of contour plots using data from the GFS model. The output fields are consistent with other models so the models can be compared. This model gives forecast information out to 240 hours and plots are 48 and 96 hour 4 panel plots where each plot has a panel data for a specific forecast time (12-48 and 60-96 hrs) and individual forecast times from initialization to 240 hours in 12 hour increments. These plots are updated every 12 hours at roughly 0500 UTC and 1700 UTC.
500mb Heights and SLP
Sample MRF 500 mb Plot
The 500mb/SLP plots show two parameters: 500 mb heights (in color contours) and sea level pressure (in black line contours).
Sea level pressure
The sea level pressure field can be used to find low and high pressure systems as well as the location of cold fronts. The highs and lows can be located by the white H and L symbols on the map. Cold fronts will generally start from areas of low pressure and follow the trough of low pressure south and to the west of the low. Rain and/or snow is likely in the regions directly around the low and somewhat less likely along the cold front.
500 mb heights
The 500 mb heights are often referred to as the sterring winds of the atmosphere. Following a specific color will show where the winds and thus pressure systems (cyclones and anticyclones) will move. If the flow is from north to south, the weather will be genreally collder than normal. If the flow is from south to north, the weather will be warmer than normal.
The heights can also be used to estimate surface temperatures since height of a pressure surface is related to the mean temperature of the air below it. Here is a rough estimate of temperatures based on color. The variability is on the order of +-10 degrees F: