Be sure you use the version of the web tool at:
http://wx.gmu.edu/pix/case1.html
On the provided map, plot the following features for 18Z April 24, 2010. This is time=23 on the web tool. The plot for 12Z is provided below. Look at the 12Z plot carefully and compare it to the data provided by the web tool. Use this as a guide for determining the feature location for the 18Z map.
The 12Z plotted solution is linked HERE
You will be given two blank maps. Do your draft analysis on one map. Show this analysis to the instructor for review. Then do your final plotting of features on the 2nd map.
It is a good idea to set the lon and lat ranges of the web tool 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. A plot of surface stations is HERE for 18Z. The 12Z map is HERE. On the web tool, use surface variables t2m (2 meter temperature), q2 (2 meter specific humidity), u10m and v10m (10 meter wind components), and of course slp.
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 of that field.
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 12Z 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
