Hi Longjon,
Any one can help with information on changing the Crz temp on the fuel Pred. Page when in reaching Crz alt .
FCOM FCTM 070 Cruise FMS use:
"WIND AND TEMPERATURE
When reaching cruise FL, the crew will ensure that the wind and temperatures are correctly entered and the lateral and vertical F-PLN reflect the CFP. Wind entries should be made at waypoints when there is a difference of either 30 ° or 30 kt for the wind data and 5 °C for temperature deviation. These entries should be made for as many levels as possible to reflect the actual wind and temperature profile. This will ensure that the FMS fuel and time predictions are as accurate as possible and provide an accurate OPT FL computation."
You insert the forecast winds and temperature along the route (i.e. in the future), not at your present position.