Aviation Dilemma 101 - How much trust in a 10 day forecast??

[Kyle Boatright]

I"m lookin' at going to Oshkosh towards the end of the show - Thursday
through Sunday. Right now, the weather channel is predicting a pretty good
chance of rain in Wisconsin on Thursday and Friday and is predicting similar
weather for the first couple hundred miles North heading out of Atlanta.

Soooo... Do I bank on the 10 day forcast being way off base, or do I bet on
the forecast, make a drastic change in plans and head to Osh at the
beginning of the week, which looks more favorable from a weather standpoint?

Decisions, decisions...

KB

[Peter R.]

Kyle Boatright > wrote:

<snip>
> Soooo... Do I bank on the 10 day forcast being way off base, or do I bet on
> the forecast, make a drastic change in plans and head to Osh at the
> beginning of the week, which looks more favorable from a weather standpoint?

Regarding long term forecasts, an optimist assumes a 30% level of accuracy
and an pessimist assumes 90%. Who are you? :)



--
Peter

[Robert M. Gary]

Generally weather is considered a "forecast" 8 hours out. Between 8 and
12 hours is an "educated guess". Anything beyond is worth little for
aviation.
I never cancel a trip until an hour before the trip. That includes long
trips down into Mexico, etc. 9 times of out 10 the forecast is wrong
and the weather ends up being different than forcast anyway. I try to
ignore weather reports the week before a large trip because they're not
worth stressing about. The weather will be what it is.
It never seems to amaze me how often my fellow pilots cancel trips the
day before and the weather ends up being awesome.

-Robert, CFII


Kyle Boatright wrote:
> I"m lookin' at going to Oshkosh towards the end of the show - Thursday
> through Sunday. Right now, the weather channel is predicting a pretty good
> chance of rain in Wisconsin on Thursday and Friday and is predicting similar
> weather for the first couple hundred miles North heading out of Atlanta.
>
> Soooo... Do I bank on the 10 day forcast being way off base, or do I bet on
> the forecast, make a drastic change in plans and head to Osh at the
> beginning of the week, which looks more favorable from a weather standpoint?
>
> Decisions, decisions...
>
> KB

[john smith]

My experience... anything beyond 48 hours is beyond belief.

[Don Tuite]

On Wed, 19 Jul 2006 22:02:59 GMT, john smith > wrote:

>My experience... anything beyond 48 hours is beyond belief.

Would depend on time of year, wouldn't it? Equinoctial weather is
changeable; Around the solstices, airmasses tend to be more stable.

Don

[Michael[_1_]]

Kyle Boatright wrote:
> I"m lookin' at going to Oshkosh towards the end of the show - Thursday
> through Sunday. Right now, the weather channel is predicting

A 10 day forecast is a horoscope with numbers.

Michael

[Peter Duniho]

"Kyle Boatright" > wrote in message
. ..
> Soooo... Do I bank on the 10 day forcast being way off base, or do I bet
> on the forecast, make a drastic change in plans and head to Osh at the
> beginning of the week, which looks more favorable from a weather
> standpoint?

As others said, you can't even count on a 5-day forecast, never mind a
10-day.

Beyond that, all the usual GA rules apply. If you *have* to be there, you
need to allow for delays by planning to get there early. If you can afford
to cancel the trip altogether and don't want to show up too early, then plan
for an arrival at your preferred date and time.

You *might* be able to wait until the beginning of the week and base your
decision on the somewhat more usable 5-day forecast. But I refer you to my
first sentence of this post. :)

Pete

[john smith]

In article >,
Don Tuite > wrote:

> On Wed, 19 Jul 2006 22:02:59 GMT, john smith > wrote:
>
> >My experience... anything beyond 48 hours is beyond belief.
>
> Would depend on time of year, wouldn't it? Equinoctial weather is
> changeable; Around the solstices, airmasses tend to be more stable.

Not that I can think of.
This summer's weather pattern is identical to last year's.
There is an upper level High centered over the Four-Corners area that
has been there for a couple of weeks and looks like it is going to stay
there for a couple more.
The jetstream is flowing east-west across southern Canada, contributing
to the drought and high temperatures in the North Coast states.

[Wizard of Draws[_1_]]

On 7/19/06 5:40 PM, in article ,
"Kyle Boatright" > wrote:

> I"m lookin' at going to Oshkosh towards the end of the show - Thursday
> through Sunday. Right now, the weather channel is predicting a pretty good
> chance of rain in Wisconsin on Thursday and Friday and is predicting similar
> weather for the first couple hundred miles North heading out of Atlanta.
>
> Soooo... Do I bank on the 10 day forcast being way off base, or do I bet on
> the forecast, make a drastic change in plans and head to Osh at the
> beginning of the week, which looks more favorable from a weather standpoint?
>
> Decisions, decisions...
>
> KB
>
>
>
I usually find the 10th day of a 10-day forecast to be a day off, (forward
or back, your choice) if it's to be believed at all.
--
Jeff 'The Wizard of Draws' Bucchino

Cartoons with a Touch of Magic�
http://www.wizardofdraws.com

More Cartoons with a Touch of Magic�
http://www.cartoonclipart.com

[Mortimer Schnerd, RN[_1_]]

Kyle Boatright wrote:
> Soooo... Do I bank on the 10 day forcast being way off base, or do I bet on
> the forecast, make a drastic change in plans and head to Osh at the
> beginning of the week, which looks more favorable from a weather standpoint?
>
> Decisions, decisions...


Back in the days when I was making regular diving trips in the Bahamas I used to
start to sweat the weather days ahead of time, following every day's forecast
and constantly replanning my trip. Eventually I came to the conclusion that the
actual go-no go decision was the one taken right before the trip. All those
others were wasted effort and unnecessary stress.

At some point I'm going to drive down to the airport to fly. Immediately before
that is the only weather forecast that matters. If it sucks, I change my plans
and don't go. If it only sucks a little, I look at my options: maybe there's an
alternative route that avoids heavy weather. Then I go.

You haven't made it clear what your abilities are but if I were flying further
than 200 miles and didn't have an instrument rating, I'd find somebody with one
and who is current to come along. Otherwise your attempt to fly cross country
VFR on a time schedule is really just a crap shoot.



--
Mortimer Schnerd, RN

[Robert M. Gary]

Mortimer Schnerd, RN wrote:
> You haven't made it clear what your abilities are but if I were flying further
> than 200 miles and didn't have an instrument rating, I'd find somebody with one
> and who is current to come along. Otherwise your attempt to fly cross country
> VFR on a time schedule is really just a crap shoot.

In the summer you can fly out West all you want w/o an instrument
rating. Just avoid the coast.

-Robert

[Mortimer Schnerd, RN[_1_]]

Robert M. Gary wrote:
> Mortimer Schnerd, RN wrote:
>> You haven't made it clear what your abilities are but if I were flying
>> further than 200 miles and didn't have an instrument rating, I'd find
>> somebody with one and who is current to come along. Otherwise your attempt
>> to fly cross country VFR on a time schedule is really just a crap shoot.
>
> In the summer you can fly out West all you want w/o an instrument
> rating. Just avoid the coast.


I think the original posting indicated he was planning to go to Oshkosh, WI.
They get their share of crappy weather there just like much of the rest of the
country.



--
Mortimer Schnerd, RN

[Cub Driver]

On Wed, 19 Jul 2006 22:02:59 GMT, john smith > wrote:

>My experience... anything beyond 48 hours is beyond belief.

I live in New Hampshire, where the rule of thumb is 12 hours.


-- all the best, Dan Ford

email: usenet AT danford DOT net

Warbird's Forum: www.warbirdforum.com
Piper Cub Forum: www.pipercubforum.com
In Search of Lost Time: www.readingproust.com

[Peter R.]

"Mortimer Schnerd, RN" > wrote:

> I think the original posting indicated he was planning to go to Oshkosh, WI.
> They get their share of crappy weather there just like much of the rest of the
> country.

This time of year (at least during the day) the type of IMC they get is in
the form of t-storms, is it not? An IFR rating won't really help here.

--
Peter

[Journeyman]

On 2006-07-19, Kyle Boatright > wrote:
[snip]
> Soooo... Do I bank on the 10 day forcast being way off base, or do I bet on
> the forecast, make a drastic change in plans and head to Osh at the
> beginning of the week, which looks more favorable from a weather standpoint?

As everyone else has said, the 10-day forecast is generally a steaming
pile of bovine fecal matter.

What I've done with the 10-day forecast is compare yesterday's 10-day
with today's 9-day, then wait a day and compare that with the next
day's 8-day, etc., all the way down to the the day of the trip.

I also do the same thing at AOPA's web site, which has prog charts
going out 5 days.

This gives you a trendline, indicating how stable the weather guessers
think the pattern is.

There are a few things they're particularly bad at estimating,
including the speed of frontal passage and the exact time the fog
will burn off.

There are numerous times when I've called for an outlook briefing
24 hours in advance and concluded that I'd have to wait for the
12-hour forecast for more information. And there are times when
I've gone to the airport and hung around for hours waiting for the
next weather set of weather observations (and the next, and the
next, ...).

Time to spare, go by air. I missed half of the annual Pinkneyville
fly-in this year because, even with a current instrument rating,
we couldn't get out on the Friday. Next day, the entire trip was
VMC.


Morris

[Morgans[_3_]]

"Peter R." > wrote

> This time of year (at least during the day) the type of IMC they get is in
> the form of t-storms, is it not? An IFR rating won't really help here.
\
I have seen OSH go IFR only, with no T-storms around, but that is the
exception to the rule. Usually, you are right.

The one day I am thinking of, it went from closed to VFR, in a period of
about 3 minutes, then closed again.

I wonder if the two Harriers, reporting at 5 miles out, coming in low fuel
had anything to do with that? <vbg> It did close again, less than a minute
after they were on the ground! <g>
--
Jim in NC

[Mortimer Schnerd, RN[_1_]]

Peter R. wrote:
>> I think the original posting indicated he was planning to go to Oshkosh, WI.
>> They get their share of crappy weather there just like much of the rest of
>> the country.
>
> This time of year (at least during the day) the type of IMC they get is in
> the form of t-storms, is it not? An IFR rating won't really help here.


Not all the IFR flying in the summertime is in the middle of cells. Summertime
haze in the proper direction will also render you IFR without a cloud in the
sky. I used to fly IFR every afternoon between RDU (Raleigh, NC) and CLT
(Charlotte, NC)... a route of flight that put me into the sun in the late
afternoon. Sometimes there were clouds; sometime there was rain; but there was
almost always really poor visibility in the summer. You could see straight down
fine but nothing in front of you.

And if you do manage to stumble into an embedded cell, you'll find the rating
damned handy. I'm living proof if nobody else will admit it. Without the
rating you'd just be another statistic. Hell, *with* the rating you may become
a statistic also but so far, so good (at least for me).



--
Mortimer Schnerd, RN

[Gene Seibel]

Yeah, I've noticed predicted spells of bad weather drift forward or
backward.
--
Gene Seibel
Tales of Flight - http://pad39a.com/gene/tales.html
Because I fly, I envy no one.


Wizard of Draws wrote:
> On 7/19/06 5:40 PM, in article ,

> >
> I usually find the 10th day of a 10-day forecast to be a day off, (forward
> or back, your choice) if it's to be believed at all.
> --
> Jeff 'The Wizard of Draws' Bucchino
>
> Cartoons with a Touch of Magic�
> http://www.wizardofdraws.com
>
> More Cartoons with a Touch of Magic�
> http://www.cartoonclipart.com

[Gene Seibel]

A ten day forecast WILL change, probably drastically. A one day
forecast has a good chance of changing.
--
Gene Seibel
Hangar 131 - http://pad39a.com/gene/plane.html
Because I fly, I envy no one.




Kyle Boatright wrote:
> I"m lookin' at going to Oshkosh towards the end of the show - Thursday
> through Sunday. Right now, the weather channel is predicting a pretty good
> chance of rain in Wisconsin on Thursday and Friday and is predicting similar
> weather for the first couple hundred miles North heading out of Atlanta.
>
> Soooo... Do I bank on the 10 day forcast being way off base, or do I bet on
> the forecast, make a drastic change in plans and head to Osh at the
> beginning of the week, which looks more favorable from a weather standpoint?
>
> Decisions, decisions...
>
> KB

[Ash Wyllie]

Cub Driver opined

>On Wed, 19 Jul 2006 22:02:59 GMT, john smith > wrote:

>>My experience... anything beyond 48 hours is beyond belief.

>I live in New Hampshire, where the rule of thumb is 12 hours.

I thought it was "if you don't like the weather, wait 5 minutes..."

-ash
Cthulhu in 2005!
Why wait for nature?

[.Blueskies.]

"Morgans" > wrote in message ...
:
: "Peter R." > wrote
:
: > This time of year (at least during the day) the type of IMC they get is in
: > the form of t-storms, is it not? An IFR rating won't really help here.
: \
: I have seen OSH go IFR only, with no T-storms around, but that is the
: exception to the rule. Usually, you are right.
:
: The one day I am thinking of, it went from closed to VFR, in a period of
: about 3 minutes, then closed again.
:
: I wonder if the two Harriers, reporting at 5 miles out, coming in low fuel
: had anything to do with that? <vbg> It did close again, less than a minute
: after they were on the ground! <g>
: --
: Jim in NC
:

The down vectored thrust burned a hole that made it VFR. Of course it closed back in after they landed, the heat was
gone...

;-)

[Morgans[_3_]]

> The down vectored thrust burned a hole that made it VFR. Of course it
closed back in after they landed, the heat was
> gone...

Yea, they did use some downward thrust, for that landing. Did you happen to
see it? I think it was '03.

I happen to be out there flagging 18 traffic on Papa Center, (the next
intersection North of the West Ramp) and they touched down with about half
down thrust, about even with where I was. It had rained, so the runway was
wet, and they kicked up quite a cloud of spray. You couldn't get any
closer, unless you were in the plane! It was _way_ too cool!
--
Jim in NC

[john smith]

> The down vectored thrust burned a hole that made it VFR. Of course it
> closed back in after they landed, the heat was gone...

There was a book I read 30+ years ago that related the operational
development of radar at an English airfield during WWII. I want to say
Arthur C Clark was the author, but I am not certain.
One of the tales that was related told about an idea someone in the war
ministry had.
The idea was to set out smudge pots along the sides of the runway in a
manner similar to runway lights.
When there was heavy fog and it was necessary to land aircraft, the
ground support crews would drive down the runway and light all the
smudge pots.
The heat generated by the smudge pots would then dissipate the fog along
the runway, allowing aircraft to land.
The smudge pots were lit and the fog did dissipate.
The surprise came when the first aircraft attempted to land. As it
approached the flair, it began to go out of control. The pilot managed
to regain control and successfully land.
Everyone gathered around him as he climbing out of the cockpit, asking
what had happened.
It seems the smudge pots were generating so much heat that the localized
air along the runway became turbulent.
Thus ended the experiment.

[john smith]

In article >,
T o d d P a t t i s t > wrote:

> A link showing it in use with a Lancaster bomber:
> http://www.fpp.co.uk/overflow/Dresden_gallery/pages/0042.html

Aircraft circling above airfield, fog along the runway begins to clear,
pre-landing briefing...
Scientist to Pilot: "Just land between those two rows of fire."
Pilot: "You want me to what!!!"

[.Blueskies.]

"T o d d P a t t i s t" > wrote in message
...
: john smith > wrote:
:
: >The idea was to set out smudge pots along the sides of the runway in a
: >manner similar to runway lights.
: >When there was heavy fog and it was necessary to land aircraft, the
: >ground support crews would drive down the runway and light all the
: >smudge pots.
:
: The system was known as FIDO - Fog Intensive Dispersal Of.
: It used perforated pipes along the runway and usually burned
: the local petrol supply. Problems were encountered in the
: early tests, but it was ultimately put to use and developed
: further after the war.
:
: A link showing it in use with a Lancaster bomber:
: http://www.fpp.co.uk/overflow/Dresden_gallery/pages/0042.html
: --


They did something similar with ground based jet engines at Heathrow back in the '60s. Don't know the details...

[Jim Macklin]

I seem to remember reading in one of Robert Buck's books
that the airlines were grounded because the weather was
below take-off minimums at some airport in the east, perhaps
JKF. They had several 747s taxi on the runway and that
heated the air enough to raise the RVR to take-off minimums.
As soon as they all started taking off, the heat cleared the
runway.

The FAA tried to violate the crews for "weather
modification, taking off below minimums. They dropped the
case because it was stupid, the weather did improve.



--
James H. Macklin
ATP,CFI,A&P

".Blueskies." > wrote in
message
. net...
|
| "T o d d P a t t i s t" >
wrote in message
| ...
| : john smith > wrote:
| :
| : >The idea was to set out smudge pots along the sides of
the runway in a
| : >manner similar to runway lights.
| : >When there was heavy fog and it was necessary to land
aircraft, the
| : >ground support crews would drive down the runway and
light all the
| : >smudge pots.
| :
| : The system was known as FIDO - Fog Intensive Dispersal
Of.
| : It used perforated pipes along the runway and usually
burned
| : the local petrol supply. Problems were encountered in
the
| : early tests, but it was ultimately put to use and
developed
| : further after the war.
| :
| : A link showing it in use with a Lancaster bomber:
| :
http://www.fpp.co.uk/overflow/Dresden_gallery/pages/0042.html
| : --
|
|
| They did something similar with ground based jet engines
at Heathrow back in the '60s. Don't know the details...
|
|