Transient or persistent? 60 minutes with a TEMPO but only 30 with an INTER? Did someone say that we Yanks make things complicated?
Not to be outdone, however, we do have the exemption. This is ATA Exemption 3385. It is available to any operator who can convince their certificate management office to issue an ops spec for it, but is most commonly found with the large carriers as BigDuke6 had mentioned. The actual language is a bit hard to find, but I have pasted it below from a 2001 Nick Sabatini letter. It almost inevitably adds one to two hours onto any ground training program!
The upshot is that with this, you can accept weather forecasts down to one half of the standard requirement, provided you tack on an extra alternate that meets all of your standard requirements. Why you wouldn't do that in the first place is clearly a discussion for the accounting department.
Each certificate holder must list one additional alternate airport in the dispatch release whenever the METAR, TAF, or any combination thereof for the destination airport or first alternate airport indicate, by the use of conditional words in the remarks section of such METAR or in one or more time increments of the TAF, that the forecast weather conditions for the destination and the first alternate airport could be less than the authorized weather minimums for those airports. However, the METAR or TAF must indicate in another time increment that the weather conditions for the destination, first alternate, and second alternate airports are forecast to be not less than the applicable authorized weather minimum values as follows:
(a) With respect to the destination airport, the forecast weather conditions must not be less than one-half of the lowest weather minimum visibility value established for the instrument approach procedure expected to be used for an instrument approach at the destination;
(b) With respect to the first alternate airport, the forecast weather conditions must not be less than one-half of the alternate weather minimum ceiling and visibility values specified in the certificate holder's operations specifications for that airport; and
(c) With respect to the second alternate airport listed in the dispatch release pursuant to this exemption, the METAR, the appropriate time increment of the TAF, or any combination thereof for that airport must indicate in the main body and remarks section of the METAR or TAF that the forecast weather conditions will be at or above the alternate airport weather minimum ceiling and visibility values specified in the certificate holder's operations specifications for that airport.
