When using the web tool, it is a good idea to set the lon and lat ranges to match the range of the provided blank map.

1) Locate and plot centers of high and low pressure at the surface. Use variable slp (sea level pressure). Plot these as blue "H"s and red "L"s.

2) Locate and plot surface fronts. As a starting point, look at the fronts as plotted by the NWS, using their surface map archive: HERE

On the web tool, you can use surface variables from the model analysis to help fine tune front location: t2m (2 meter temperature), q2 (2 meter specific humidity), u10m and v10m (10 meter wind components), and of course slp. Finally, use the surface station data plots to fine tune your front locations.

When using the web tool to look at winds, it is useful to display the magnitude of the wind as Expr1 and display the streamlines as Expr2. Eg, mag(u10m,v10m) as Expr1 and u10m;v10m as Expr2. Set GXout1 to shaded, and GXout2 to stream. When looking at other variables, it is usually best to set GXout to contours. If you accidentally display a scalar field with GXout set to stream or vector, you may not get a plot at all.

3) Plot the areas of maximum temperature advection at 850mb. Use as Expr1: hadv(t,u,v) and set GXout1 to contours or shaded. Plot on the map the areas over 10. This is in units of 10's of degrees per hour, so over 10 is more than 1 degree per hour. On the 12Z example, these areas are plotted as yellow shaded blobs.

4) Plot the areas of maximum vorticity advection at 500mb. Use as Expr1: hadv(vort,u,v) and set the level to 500. Plot on your map areas where the values are greater than 1. (This is in units of 10^-4 per hour). On the 12Z example, this is plotted as red shaded blobs.

5) Plot the area where the precipitable water is greater than 40mm. Use variable pwat. This is plotted as the green shaded region on the example.

6) Plot 500mb troughs and ridges. It is useful to plot vort as Expr1 and z as expression 2. Use the vorticity (vort) to fine tune the locations of the troughs. The vorticity is less useful for fine tuning ridge locations. These are plotted as red dashed lines for troughs, and blue zig-zag lines for ridges.

7) Plot areas of strong diffluence at the 300mb level (note: 300mb, not 500mb). It is best to plot streamlines of the winds to see the areas of strongest diffluence. This is plotted as the purple shaded blob on the 12Z example.

8) Plot the 300mb jet streaks. Plot these as long arrows. These are also plotted to be streamlines -- the arrows follow the wind direction. Look closely at the 12Z example where the 300mb jet streaks are plotted as purple arrows. It is best to display the wind speed as Expr1 (mag(u,v)) and the wind streamlines as Expr2 (u;v). Use shaded for GXout1 and stream for GXout2.

9) Plot the low level jet streaks. Plot these as long arrows. These are also plotted to be streamlines -- the arrows follow the wind direction. Look closely at the 12Z example where the low level jets are plotted as red arrows. Use the bottom 30mb winds: Expr1 mag(ub,vb) Expr2 ub;vb

10) For the winter weather cases, plot the 540 thickness line (this is the 5400m thickness of the 1000mb to 500mb layer). Also plot the 0°C isotherm at the 850mb level.