Correcting for Wind.
Checking an AWOS, METAR or ATIS report for wind direction and speed on the surface doesn't give you the whole weather picture. Winds aloft forecasts can tell a very different story of what the air is doing just a few hundred or a few thousand feet above the surface.
The NWS National Centers for Environmental Prediction produces scheduled Wind and Temperature Aloft Forecasts (FB) four (4) times daily for specified locations in the Continental United States.
LINK HERE for WINDS ALOFT FORECAST.Interpreting the coding is simple:Example: 1312+05
The wind direction is from 130 degree (TRUE not Magnetic) i.e. -southeast, the wind speed is 12 knots and the temperature is 5 degrees Celsius.
Example: 9900+10
Wind light and variable, temperature +10 degrees Celsius.
Forecast wind speeds of 100 through 199 knots.
Example: 7735-07
The wind direction is from 270 degrees (i.e. west), the wind speed is 135 knots and the temperature is minus 7 degrees Celsius. [Subtract 50 from 77 and add 100 to 35]
Forecast wind speeds of 200 knots or greater are indicated as a forecast speed of 199
knots. Example 7799, is decoded as 270 degrees at 199 knots or greater.
"When everything seems to be going against you, remember that the airplane takes off against the wind, not with it." Henry Ford
There are two excellent (short) video training courses produced by the National Weather service specifically for pilots. One video covers weather theory, the other is on understanding weather forecasts. Best viewed on desk top or lap top computer. (Requires Adobe Flash, for iPad users we suggest the Browser "Photon" found in the App store).
Here are the links to each course:
FOG or BR (MIST)?So what's the difference between fog and mist? Fog "FG" is only reported when the visibility is less than five-eights of a mile.
With visibility five-eights or greater mist "BR" designates the phenomena. In METAR mist refers to a restriction to visibility, not precipitation its generic definition. Allegedly the distinction between fog and mist came about because the British didn't consider it fog unless you could "cut it with a knife." Source FAA. Why five-eights of a mile, that's equivalent to 1000 meters.
