On Wed, 14 Jan 2009 21:14:25 -0600, "Dan Luke"
wrote:

Monday, 15:00Z, Tuscaloosa, AL:

Area forecast: VFR

Nearest TAFs: Better than 5,000-and-5 for at least 12 hours.

Nearest METARs: Better than 5,000-and-5.

Surprise! KTCL ASOS: Visibility less than 1/4 mile, freezing fog.
Indefinite ceiling 100. Temperature -2, dewpoint -3.

Passing over Manitawak (sp?) WI ASOS was giving basically clear sky.
We couldn't hardly see the wing tips at 8,000 let alone the ground.
Fortunately we were headed for Oshkosh where it was listed at 2500 and
greater than 6. In actuality ceiling was 2500 with a solid layer only
a few hundred feet thick and visibility virtually unlimited.


The airport's next to a river.

My pax was waiting for me in the FBO, so after a miss on the ILS RWY4, there
was nothing to do but hold for an hour 'til the weather came up.

Moral: never underestimate local weather factors no matter what the forecast
says. Arrive with plenty of fuel, just in case.

I've always been paranoid about fuel. I typically had full tanks when
only going 50 miles. I've seen the weather turn to crap that was un
forecast in very short order. With full tanks I can keep hunting for
alternates out to 500 miles and still have enough gas to come back
home. Things have indeed gone sour if I can't find a place not
weathered in within 1200 miles.

I'd just a soon burn a bit of extra gas to haul the extra gas as to
have the weather go down and be pushing my luck trying to find a place
to land before running out of gas.

IOW, always have an out and longer range gives more choices.
I've lost track of how many times the weather was far different than
what the automated station was reporting.