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Put not thy faith in the weather prophets...

Desert Rat

Well Known Member
...For they shall not come to thy aid when the firmament riseth up to smite thee.

Not specifically RV related, but I thought I'd share. Back in the old days, weather prep for local flights frequently consisted of going outside & looking up. if it was questionable, you might take a peek at the temp/dew point. With that being said, one of the things that was hammered into me 30+ years ago was to always have an out, and be ready to use it, which is why I typically have a plan B airport in mind (not just for weather, but you get the idea). I also typically carry an Ipad with local approach plates in my bag, no matter how great the weather. Even with that said, with all the tools at our disposal now it's easy to put more faith in forecasting that ever before, but it's also easy to get burned by that if the forecast turns out to be inaccurate.

I had 3 training flights scheduled today, with the first one scheduled at 0600. Cold, but clear forecast. We got metars & TAFs for the local area at 0600 and they were showing good VFR conditions. The temp dew point was about 2 degrees apart, but it was predicted to go in the right direction as the sun came up. The TAF for both Wichita Mid-Continent and McConnel AFB predicted "Few at 7500" and visibility +6 until 1500 local, then scattered 1,200' gradually going IFR over the following few hours.

Took off in CAVU conditions and went about 10 miles east for Private pilot maneuvers, and saw that there was some ground fog in the low-lying areas, but no big deal, then I looked back west and saw a few scattered low level clouds starting to come in from the west side of Wichita. A few minutes later I looked again and saw that they were now more widespread and appeared to be heading east, where they would soon be rolling over my home airport.

I cut the lesson short and headed for home, with plan B to land at the closest airport (K3AU) if Beech field closed in before we got there. Plan C would have been to pick up a local IFR and shoot an LPV approach back into Beech or an ILS into Mid-Continent, but I can't say I'm thrilled by the idea of a precision approach potentially down to minimums in a non-FIKI airplane in widespread un-forecast weather with an OAT of 28 degrees, so plan B was going to be my out.

We landed with time to spare, but not much. 1/2 hour after I was back in the chocks, the AWOS at BEC was saying 300 BCN. 1/2 hour after that, Mid-Continent was reporting 300 Overcast, with 0.75 visibility. At 0915 local, Mid Continent issued a New TAF that predicted 400' Ceilings and 2 miles vis. Not much of a prediction since that weather had occurred an hour prior to them issuing it.

I've got around 2,500 hours total time in all sorts of conditions, but I can count on one hand the number of times the weather has closed in on me that fast. Also, I don't recall ever seeing the forecasters, especially the military ones, missing the mark so badly. I'm not complaining or criticizing them. Mostly I'm sharing all this as a reminder that weather forecasting is a prediction, not a guarantee. No matter how good the forecasting gets, sometimes there's still no substitute for just looking out the window and saying "hey what's that cloud doing out there?"
 
I've been bit twice by weather being drastically mis-forecasted.

This is my day job, and I'm accustomed to and comfortable flying down to ILS minimums, and do it semi-regularly.

The first time I got bit I knew the weather was quite marginal over a wide area. So I tankered up with almost 1200nm of range (about 4.5hrs fuel). Plan A was to take off and fly to the destination. Weather was holding and forecast to stay slightly above minimums, probably about 400-500' all night. Plan B was another airport about 45 minutes away with an ILS. Again it was forecast to stay 100' above minimums all night long. Plan C and my legal alternate was back to the departure airport. I had sufficient fuel to try the destination, plan B and then plan C. Well we took off and entered cloud below minimums, well that was the legal alternate and I knew all the pre-planning in the world wasn't going to help anymore. Just was now happy there was a lot of fuel in the tanks. Got closer to destination and the weather report was now below minimums. To recap, Plan A is below minimums. Plan C is the legal alternate and now below minimums. Plan B is still holding at 100' above ILS minimums, and the only option really left. Watching all my options fall apart enroute, I came up with plan D, another airport about 400' above minimums, but very near the limit of the fuel range. Well fortunately plan B worked, and we broke out about 150' above minimums on the ILS.

Second time I got bit, the destination was around minimums, so didn't really expect much out of that. But plan B was the legal alternate forecasting ceilings between 2000 and 3000' and visibility 5 miles or greater so I had great confidence in that. Well we couldn't land at the destination, so off to the alternate. Problem is that the weather at the alternate is now 1/4 miles visibility in heavy snow. Forecast was 2000-3000' and 5+ miles visibility, and now it's 1/4 mile. Yikes! We were able to land at another airport about 100nm away with 30 minutes of fuel left in the tanks. That's why you always bring a little extra fuel.


Part of experience isn't just flight hours, it's knowing the weather in the area you fly. Can call it a "spidey sense", but sometimes it's best just not to trust the weather products. Always carry extra fuel, monitor every option.
 
Better forecasting is part of the problem

Part of the problem, in California at least, is that current forecasting has become very good. You can get use to it.

If something is right 95% of the time you can become complacent.

I've gotten bit more than once because of this. Getting a little more skeptical as time goes on...
 
Good story. I always carry a "hip pocket" alternate on top of whatever I've got in the books for the legalities. Sometimes it requires a little extra fuel though most times it doesn't. The price for feeding the spider sense and having a quick out is keeping an eye on the trends of actual METARS, pressure gradients (for fast moving air mass changes / winds / etc) and don't forget keeping your notam SA in the loop as that may have effect on what resources you think you have.

Fly long enough and the spare stories to tell the right people in the right pubs start to become voluminous.
 
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