The Spaceflight Meteorology Group

Interpreting SMG's Shuttle Landing Site Forecasts

Cloud heights are reported in hundreds of feet.  To de-code 
the cloud height, add two zeros to the right side of the 
forecast height.  
                (5 = 500 feet while 150 = 15,000 feet)
 
    CLR --- Clear     --- No Cloud Coverage
    FEW --- Few       --- Greater than 0/8 and less than 3/8 Cloud Coverage
    SCT --- Scattered --- 3/8 or 4/8 Cloud Coverage
    BKN --- Broken    --- 5/8 through 7/8 Cloud Coverage
    OVC --- Overcast  --- Total Cloud Coverage 

    A cloud "ceiling" is the lowest BKN or OVC layer.

Following the cloud section, visibility is reported in statute
miles.

Follwing visibility, wind direction and speed are reported.  
The first three digits are the wind direction, (the direction 
the wind is coming FROM), reported to the nearest ten degrees
on a magnetic compass. (050 = 50 degrees while 360 = 360 degrees)

Wind speed and peak winds are reported in knots.  Peak winds 
refer to the highest wind speed expected to occur during the 
forecast period. 

The final optional group contains any remarks that the 
forecaster feels to be important.  
   (SHRA WI 30NM = rain showers within 30 nautical miles)

A sample forecast might read: 
              KSC FEW020 SCT080 OVC100  7+  15007P13   
              SHRA WI 30NM

This would be decoded:  Landing site - KSC
   Sky Conditions: 2,000 feet FEW (0/8 through 2/8 Cloud Coverage)
                   8,000 feet SCT (3/8 or 4/8 Cloud Coverage)
                   10,000 feet OVC (Total Cloud Coverage)
                      (The "ceiling" would be at 10,000 feet 
                      because that is the first layer of >= 
                      5/8 cloud coverage.)

       Visibility: Greater than 7 Statute Miles

             Wind: From 150 Degrees (SE) at 7 knots, peaking to 
                   13 knots.      
                              
          Remarks: Rain showers within 30 nautical miles.

Following the forecast section, flight rule violations are 
highlighted on a station by station basis.  
       Violations Include:  CIG = Ceiling
                           SHRA = Rain Showers
                           TSRA = Thunderstorms
                          XWIND = Crosswinds