TAF was a little off

Groundpounder

En-Route
Joined
Jan 27, 2013
Messages
2,951
Location
New Hampshire
Display Name

Display name:
Emerson Bigguns
I was in bed last night, and all of a sudden there was a tremendous amount of rain and wind. I had all the windows open because there was nothing in the forecast. After I ran around like a fool closing everything up, I decided to look at Foreflight to see how long it was going to last. The TAF was off by just a little bit....

IMG_0244.jpgIMG_0245.jpg
 
Did it offer any hints in the forecast discussion?
 
Did it offer any hints in the forecast discussion?

Showers are on Northern New Hampshire`s doorstep at this hour
as a shortwave trough beings its approach. This area along with
the western Maine mountains will have the best chance to see
showers and even an isolated thunderstorm through this evening.
There is a chance for showers to drift through central New
Hampshire and Maine as well overnight, as an upper low moves
closer to our area, however this is less certain as the better
forcing remains to the north.
 
Tafs have sucked here in nh, especially further north. The discussions have been closer to reality. We’ve been getting a lot of rain this summer.
 
I have a family member who has worked for 20+ years for NWS as forecaster based out of the Midwest. They said that junior forecasters usually do the TAF’s. Experienced ones do the TEMPO’s. Not that this makes them inaccurate. More concerning is how lacking they are in staffing. They have been writing IOU’s to vendors for the past couple of months because of budget cuts/constraints.
 
...but the TAF was legal to dispatch...<snark snark>
 
Did it offer any hints in the forecast discussion?
I check the discussions, too. There are times where the forecasters have a feeling something is going to happen but they just don’t have enough hard data to justify putting it into the TAF.

I modified my instrument XC route when I read a discussion like that. I can’t remember the exact wording the forecaster used, but it was along those lines. It turns out his gut feeling was right.
 
Wonderful comment from scottd. :) Consider a dispatcher working 40 or 50 flights a shift (less than 10 minutes to plan a flight when ya consider eating, peeing, and pooping). They don't have time to read comments on a forecast, just scan the TAF and go. If there is the possibility of MVFR then the tempo would at least flag it for anyone planning a flight.
 
I was trying to remember my instrument xc. All the TAFs where I was flight planning were good, even the enroute. I can’t remember the exact circumstances, but the forecast discussion mentioned the potential for wide area pop-up TS. Not enough certainty of when or where to put it in a TAF, but enough gut feeling to mention a possible time. That was enough for me and I went the opposite direction that day. Turns out the TS popped up when and where the forecaster figured. Those folks are very good at what they do, but there is a lot riding on an accurate forecast and I understand where they have to be careful about intuition.
 
The opposite occurs as well. A forecaster who is a little on the conservative side adds a TEMPO for TSRA to the TAF when there's a fair amount of uncertainty of it occurring. When that convection doesn't materialize, then the airlines complain since it required them to file an alternate and carry extra fuel.
Of course that's the nature of a forecast, uncertainty. It's always entertaining when the MBA types want to complain about a forecast and don't understand the true risk and costs involved. I was once told in a rather exasperated tone that the estimated return to service for an aircraft on maintenance had to be accurate. Hey, I was just passing along the estimated return to service time that the maintenance controller gave me. The moral of the story is that people don't understand/accept the nature of a forecast (an estimate) and refuse to deal with the uncertainty. Typically, because they can't handle that uncertainty they vent on whoever is available. In other words, the complaint is frequently a response because the complainant doesn't understand the nature of the system and/or can't deal with uncertainty. Should we track forecast failures and try to improve? certainly. I think many businesses overlook that opportunity.

That failure of a forecast isn't the fault of the forecaster and the forecaster needs to continue to do what they've been trained to do. The training of the person providing the forecast is an important part and is often overlooked and underfunded. I still say that training a new engineer is the most expensive thing a business does whether the business wants to admit it or not. Sure carrying extra thousand pounds or so of fuel costs something. So does a door plug departing the aircraft in flight or software deciding an aircraft shouldn't be climbing...
 
Back
Top