Also query is, are TAFs in AGL or MSL?
Ground stations report AGL; pilots report MSL (what they see on their altimeter). So, METARs and TAFs are AGL, whereas UAs are MSL.
what’s the distinction between AGL and MSL? Above Ground Level, or AGL, describes the literal peak above the bottom over which you are flying. Mean Sea Level, or MSL, is your true altitude or elevation. It’s the typical peak above normal sea stage the place the atmospheric strain is measured to be able to calibrate altitude.
Simply so, are winds aloft true or magnetic?
If you learn it, it is true. If you hear it, it is magnetic. All charts and textual sources (METAR, TAF, winds aloft, floor evaluation charts, and so on) use true north because the reference. ATIS/AWOS/ASOS broadcasts, or any data a controller offers you over the radio, is magnetic.
What does 9900 imply on winds aloft?
9900+10 means wind mild and variable, temperature +10°. c. 7735–07 means the wind path is from 270° (i.e., west), the wind velocity is 135 knots, and the temperature is minus 7°C. WINDS AND TEMPS ALOFT FORECAST (FB)