More info to help you interpret the weather maps.......

Satellite Photos
are from the main satellite system used by the National Weather Service. Most of these photos concentrate on the western U.S. and Pacific Ocean. The NW Wyoming view (2km) is centered near Jackson Hole.  The Western U.S. view
(4km) covers most of the Rockies to the coast.  The Pacific view (16 km) takes in most of the  U.S., Canada, Alaska and the Pacific. The Pacific view (28km) extends all the way to Japan. Several types of photos and loops to choose from::

  1. Visible photos are only good for daylight hours.
  2. Infrared photos (color enhanced), sense temperature differences. Follow color/temperature scale at bottom of photo, colder is generally higher level clouds. Low clouds appear as dim gray.
  3. Water Vapor photos see invisible water vapor high in the atmosphere. Good for finding upper air circulations and jet stream locations.

Radar Images used are from Intellicast and the NWS.   Radar can be as tricky to interpret as satellite photos, coverage from individual radar sites is out to about 100 to 140 miles. A radar "mosaic" is made up of all of the available individual sites. Understand that there are some "dead spots" in the coverage, especially over the western U.S., such as, Sun Valley and over SW Montana.   Mountains also block the radar beam and won't show clouds at or below mountain-top level very well, if at all. 

Bottom-line with radar images is, not all precipitation shows up on radar, and not all the precipitation that does show up is necessarily hitting the ground.  Again there are several types worth looking at:

  1. The big picture of the United States, put it in motion and get a feel for where it has been precipitating the most. Green is rain drops. Pink is a rain/snow mix. Blue is snow, on Itellicast's radar. (Note: Color codes may differ from one provider to another).
  2. The Regional Image gives a closer view, and show locations of radar stations, usually marked with a "+". If a station is not operating, a pink box will appear near the station identifier.
  3. Radial Velocity shows movement towards and away from the individual radar sites.

Surface Maps and Upper Air Maps are courtesy of   Unisys Corporation, the NWS, and WSI Corporation.  There is a variety of info available here, but reading some of these plots is not all that straightforward.   Unisys has more help and information about how to decipher some of these more complicated maps on their web pages.  Check that out.

Note: The Jet Stream map indicates where the fastest "stream" of wind is, usually up at about the 30,000 foot elevation.

Surface Maps come in a variety of types, most will depict current hourly surface observations (most from airports). For help interpreting the maps from Unisys, which is in standard reporting format used by the National Weather Service, go to their help page..........Unisys Surface Data Details.

Upper Air Maps show plots and maps derived from twice daily balloon soundings, which profile the atmosphere across the country and around the globe. Go to..........  Unisys Upper Air Details for more info on these maps and how to interpret them. (Excellent tutorial!)


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