FOUS HELP: Numerical Output
The following is an ETA Model Numerical Output for O'Hare Airport. This is NOT Model Output Statistics, but direct numerical output from the model.

TT PTT R1R2R3 VVV LI PS DDFF HH T1T3T5
ORD//865049 -0829200814 51979596
06000865157 -4025161105 47999696
12004846554 -0325161111 47009697
18000857338 00920150912 43009696
24000847415 -1321190908 41009796
30000885211 -0821180106 43009795
36000954517 -0623203206 43019793
42000973837 00226203114 43009693
48000942632 -1626243117 41949393
TT is the time the output in that row is valid. (except where it says 0RD..that is just the station ID, O' Hare, placed in the area that would be considered the zero hour). The value is simply the amount of hours from the current time.
  • example:36. If the model run is the 00z run..then this would be the forecast for 36 hours from that time.
    PTT is the precip totals in tenths of inches for 6 hour intervals..ending at the time specified.
  • example:004. This would mean .04" of liquid precip fell in the previous 6 hours up to this point.
    R1R2R3 are the relative humidity values for 3 different layers of the atmosphere. R1 being the lowest layer, R2 the mid levels of the atmosphere and R3 the upper levels.
  • example:327654. This would mean the lowest layer has 32% RH, the middle layer at 76% RH, and the upper levels have 54% RH.
    VVV is for Vertical Velocity Values. The value's are either positive values which is rising motion and would begin with a zero or negative, which infers sinking motion and begin with a "-" (dash, or negative sign). The values are measured in microbar per second (which is about 1.12 cm/sec at 700 mb).
  • example: 009. This would indicate VV's of +.9, and slight rising motion.
  • example: -12. This would indicate sinking motion of 1.2.
    LI is for Lifted Index Values. The values may be positive and will be represented by 0-?? based on the value (altough it would be odd to see it more than 30) which represents positive values. The values may also be negative and will be represented by decreasing numbers from 99. 99 means -1, 98 means -2, etc. This is indicitive of instability. For more info, please take Severe and Unusual Weather (ES 115).
    PS is for Surface Pressure to the nearest millibar. The nmber represents the last two digits in the pressure. The value should be near 1000, so simply place a 9 or 10 in front of the number to see which one makes the value near 1000.
  • example: 49 would be 1049 (1049 is closer to 1000 than 949). This represents the forecast surface pressure for that station at that time.
    DDFF is for the wind direction and speed. The first two numbers represent the direction and the next two represent the speed. Wind direction is measured in degrees, from 0-350. This is the output for winds in the boundary layer
  • example:3120 should be read as 310 degrees and 20 knots, a northwest wind at 20 knots.
  • example:0925 is 25 knot winds from the east, or from 90 deegrees (09=090 degrees)
    HH is for the average 1000-500 mb thickness. These are the last two numbers so simply add a 5 in front of it to get the value (measured in meters). Occasionally, if the value is in the 90's, you must add a 4 in front of it for very low thicknesses..but this is rare.
  • example:51= 551 decameters (5510 meters)
  • example:46= 546 decameters (5460 meters)
    T1T2T3 is the temperatures of the (T1) lowest layers, or boundary layer, the (T2) middle layers, and the (T3) upper layers of the atmosphere. The temperatures will be in degrees Celsius. The only values one must figure out are negative temperatueres. Numbers below 100 should be subtracted from 100 to get the value.
  • example: 09 = 9 degrees celsius
  • example: 98 = -2 degrees celsius

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