Pretty close to true, but not really, from what I undersatnd they do semi-educated guesses.
I would dare you to take the long range forecast of ANY weather service, take screen shots every 8 hours for a month, then compare that with what actually happens.
It's about like the Almanac's record.
I can't say what's real for NYC area, but I do know that in the midwest, we have not changed all that much. Sometimes we have "normal" weather, and sometimes its hotter than normal, or colder than normal. All in all the past 15 years has not registered a change at all towards warmer, colder, more, or less precipitation.
I'm guessing if you did a genuine study on your area it would actually show the same.
Urk.