Are you wondering how likely it is going to remain clear, or are you considering packing it in for the night? The wdisplay task in the nlocal package may help you decide what to do. Three times an hour, 24 hours a day, a new GOES weather satellite picture in one of three wavelength bands (visible, IR, and a water-vapor narrow-IR band) is downloaded. It is fun, easy, and informative to display the last four images, and quickly blink between to see what's coming your way, or leaving you alone. Simply run
wdisplay ir four+
to load the last four images into your ximtool window. (You may have to select the menu item "FitFrame".) Hit CNTL-F repeatedly to make a little movie. Further information can be gleaned from the help page.
If you would like to compare your guessimate with that of an expert, you can also easily retrieve the most recent weather prediction. Put the mouse in a blank area of the screen and select ``Weather Forecast" under ``Astronomer Tools". You'll be presented with a map of the US with little dots on it; place the cursor near Tucson, and click. You can check the weather back home the same way, of course.