PROB40 in TAF- How to handle for alternate?


New Member
If you need an alternate and the forcast at ETA is OK but includes a PROB40 below the alternate minimums, is it still legal (even though probably not smart) to use as an alternate or not?


New Member
The only portions of the forecast that apply to your alternate planning are FROM and BCMG. Please, someone, correct me if I have misstated this.



New Member
(c) IFR alternate airport weather minima. Unless otherwise authorized by the Administrator, no person may include an alternate airport in an IFR flight plan unless appropriate weather reports or weather forecasts, or a combination of them, indicate that, at the estimated time of arrival at the alternate airport, the ceiling and visibility at that airport will be at or above the following weather minima:

(1) If an instrument approach procedure has been published in part 97 of this chapter, or a special instrument approach procedure has been issued by the Administrator to the operator, for that airport, the following minima:

(i) For aircraft other than helicopters: The alternate airport minima specified in that procedure, or if none are specified the following standard approach minima:

(A) For a precision approach procedure. Ceiling 600 feet and visibility 2 statute miles.

(B) For a nonprecision approach procedure. Ceiling 800 feet and visibility 2 statute miles.

I read it (para c above) reports or weather forecasts, or a combination of them.. I would not choose that as an alternative. when we file our alternatives are significantly above mins or we choose somewhere else usually the nearest VMC airport. the other thing is ask yourself, why are we filing for an alt? because we have to? or because the weather may be crap? company policy is we guarantee we will get our Pax Somewhere

again this is a good example of what is correct as per the FARS and what is correct in the real world.