Don't trust the TAF based on AUTO OBS

[burhead1]

Thought I would put this in flight training for the newbies, don't always put your trust in the TAF.



TAF CYQA 151238Z 1513/1601 32005KT P6SM -SN OVC070 BECMG 1513/1515 31007KT P6SM NSW SKC RMK FCST BASED ON AUTO OBS. NXT FCST BY 152000Z=
TAF
LOCATION

CYQA - MUSKOKA/ON
VALIDITY [UTC]
15 FEB - 1238 to
16 FEB - 0100

TIMES
[UTC]
WIND
[DEGREES TRUE]
VISIBILITY
[STAT. MILES]
WEATHER
CLOUDINESS
[FEET AGL]

15 FEB - 1300 to
16 FEB - 0100
320 @ 5 KNOTS
6+
LIGHT SNOW
7000 OVERCAST
BECOMING
15 FEB - 1300 to
15 FEB - 1500
310 @ 7 KNOTS
6+
NIL
CLEAR SKY




METAR CYQA 151600Z AUTO 27010KT 240V300 3/4SM -SN CLR M09/M13 A2981 RMK SLP114=
METAR
LOCATION
CYQA - MUSKOKA/ON
DATE - TIME
15 FEBRUARY 2014 - 1600 UTC
WIND
270 TRUE @ 10 KNOTS
VARIATION
240 <-> 300 DEG
VISIBILITY
3/4 STAT. MILE
RUNWAY VISUAL RANGE
WEATHER
LIGHT SNOW
CLOUDINESS
CLEAR SKY
TEMP / DEWPOINT
-9 C / -13 C
ALTIMETER
29.81 IN HG
RECENT WEATHER
WIND SHEAR

[burhead1]

The visibility Was most likely caused by blowing snow as nothing on radar.
Wind is a little more than predicted.


METAR CYQA 151900Z AUTO 31009G15KT 250V340 9SM CLR M08/M14 A2983 RMK SLP118=
METAR
LOCATION
CYQA - MUSKOKA/ON
DATE - TIME
15 FEBRUARY 2014 - 1900 UTC
WIND
310 TRUE @ 9 KNOTS
VARIATION
250 <-> 340 DEG
GUSTS
15 KNOTS
VISIBILITY
9 STAT. MILES
RUNWAY VISUAL RANGE
WEATHER
CLOUDINESS
CLEAR SKY
TEMP / DEWPOINT
-8 C / -14 C
ALTIMETER
29.83 IN HG
RECENT WEATHER
WIND SHEAR

[pelmet]

Going from memory up north, it took more than 10 knots to create a 3/4 vis in blowing snow. I suspect it was mostly from falling snow.

Looks like in the second report, the winds picked up and so did the vis.

[Big Pistons Forever]

I teach my students to look at weather from the general to the specific. Weather analysis starts with going to the GFA and the radar and satellite pictures and asking yourself "what is making the weather in my area" ?

Then you go to the TAF and then finally the METAR. Disconnects between what these products show means it is time to be wary about depending on the forecasts. A common example is the TAF is calling for an improvement but the last METAR has only a 1 degree temp/dew point spread and the radar shows a big band of precip heading your way.

[Colonel Sanders]

There's a name for pilots that trust wx forecasts.

Dead.

[Rookie50]

As I posted somewhere, you don't even trust the atis. It said 1200 scattered -- this is at a large us towered airport -- what I got was 500 overcast. Perhaps it was higher directly over the airport, but not on the approach path.

[Go Guns]

I can see the forecast period you're discussing is after this, but, I had to learn the hard way that if you see this "P6SM -SN", just assume it's going to be IMC/IFR.

[Rookie50]

I can see the forecast period you're discussing is after this, but, I had to learn the hard way that if you see this "P6SM -SN", just assume it's going to be IMC/IFR.

Yeah -- snow seems to be nasty that way. It can go from 9 sm to 1/2 mile, and back again pretty fast.

[iSight]

I teach my students to look at weather from the general to the specific. Weather analysis starts with going to the GFA and the radar and satellite pictures and asking yourself "what is making the weather in my area" ?

Then you go to the TAF and then finally the METAR. Disconnects between what these products show means it is time to be wary about depending on the forecasts. A common example is the TAF is calling for an improvement but the last METAR has only a 1 degree temp/dew point spread and the radar shows a big band of precip heading your way.

Can't agree more. I find many pilots, not just students, can't interpret the weather products available to them. Seems some can't be bothered to learn how or instructors don't put enough emphasis on it.
Study weather & weather charts often (whether flying that day or not) and you will start to understand it better and also see how often the forecasts are completely wrong.

[sidestick stirrer]

There's a name for pilots that trust wx forecasts.

Dead.

Would that not be an adjective?

[sidestick stirrer]

A question for the experienced drivers:
What direction is the wind when Tower or ATIS reports it as "Light and Variable"?

[Colonel Sanders]

Following are names that boys were
actually named in 2013:

Ab
Ajax
Anibal
Apollo
Baobao
Braulio
Bright
Cadence
Caige
Cheese
Chow
Cub
Daxx
Danish
Dragos
Egypt
Enno
Finch
Holmes
Hurricane
Ivory
Jag
Kashmere
Kazz
Kodiak
Lalo
Legend
Leviathan
Lorcan
Miggy
Osbaldo
Panda
Ripley
Rocket
Stetson
Thiago
Thirdy
Tintin
Trace
Yash
Zion

[stone69]

Rule # 1..... "Never trust the met man " worked well for me for forty years......

[sidestick stirrer]

Following are names that boys were
actually named in 2013:

Ab
Ajax
Anibal
Apollo
Baobao
Braulio
Bright
Cadence
Caige
Cheese
Chow
Cub
Daxx
Danish
Dragos
Egypt
Enno
Finch
Holmes
Hurricane
Ivory
Jag
Kashmere
Kazz
Kodiak
Lalo
Legend
Leviathan
Lorcan
Miggy
Osbaldo
Panda
Ripley
Rocket
Stetson
Thiago
Thirdy
Tintin
Trace
Yash
Zion

So, I don't see "Dead" amongst those...

[zulutime]

I met a meteoroligist from London some time ago and he was suggesting that Nav Canada needed to do a better job of depicting the GFA's. He was talking about a "simpler", clearer, and thus, better understandable format. Over the years many instructors I have spoken with have expressed similar concerns. To date I haven't seen any changes come through. Has anyone else heard of a possible change to the GFA format? I'm no expert but I suspect there are many ways to clean up a GFA so that all pilots, not just the really experienced ones, have a clear understanding of what is being shown on a GFA.

[Colonel Sanders]

Nav Canada needed to do a better job of depicting the GFA's.

Are you old enough to remember the "wall of text"
FA's that we used to have decades ago, that pre-dated
the GFA's? Now, they were a treat.

[Big Pistons Forever]

Following are names that boys were
actually named in 2013:

Ab
Ajax
Anibal
Apollo
Baobao
Braulio
Bright
Cadence
Caige
Cheese
Chow
Cub
Daxx
Danish
Dragos
Egypt
Enno
Finch
Holmes
Hurricane
Ivory
Jag
Kashmere
Kazz
Kodiak
Lalo
Legend
Leviathan
Lorcan
Miggy
Osbaldo
Panda
Ripley
Rocket
Stetson
Thiago
Thirdy
Tintin
Trace
Yash
Zion

This list got me thinking. I bet some of these names could be the first names of some well known avcanada posters:

Hurricane = Trey kule
Stetson = Brown Bear
Danish = Pop n Fresh
tintin = Photofly
Legend = CS
Yash = Nark

[photofly]

I'm flattered.

[MyMeowCat]

Following are names that boys were
actually named in 2013:

Ab
Ajax
Anibal
Apollo
Baobao
Braulio
Bright
Cadence
Caige
Cheese
Chow
Cub
Daxx
Danish
Dragos
Egypt
Enno
Finch
Holmes
Hurricane
Ivory
Jag
Kashmere
Kazz
Kodiak
Lalo
Legend
Leviathan
Lorcan
Miggy
Osbaldo
Panda
Ripley
Rocket
Stetson
Thiago
Thirdy
Tintin
Trace
Yash
Zion

Are you saying that you know of 41 people who died in 2013 from weather related GA accidents??

[pelmet]

A common example is the TAF is calling for an improvement but the last METAR has only a 1 degree temp/dew point spread and the radar shows a big band of precip heading your way.

Time of day matters as well. 1 degree spread in the morning seems better than in the evening.

Up north the forecasts were more appropriately called aftercasts. The weather would all of a sudden get worse and you would see the familiar words of TAF AMD followed by a bunch of information that was longer than previous. Not good when the destination and alternate are non-precision approaches with high minimums.

[Docbrad]

A question for the experienced drivers:
What direction is the wind when Tower or ATIS reports it as "Light and Variable"?

Degrees magnetic

[triplese7en]

And nobody has pointed out that this forecast was based on AUTO OBS.... ?

Sure, be skeptical of everything. Look at all the weather products and make sure they add up. But this title is a little misleading... it should say "be very careful when using a TAF based on AUTO OBS.

[CpnCrunch]

And nobody has pointed out that this forecast was based on AUTO OBS.... ?

Sure, be skeptical of everything. Look at all the weather products and make sure they add up. But this title is a little misleading... it should say "be very careful when using a TAF based on AUTO OBS.

Even when there is a forecaster doing the TAF it can still be completely wrong. They seem to have particular difficulty predicting fog.

[Rookie50]

A common example is the TAF is calling for an improvement but the last METAR has only a 1 degree temp/dew point spread and the radar shows a big band of precip heading your way.

Time of day matters as well. 1 degree spread in the morning seems better than in the evening.

Up north the forecasts were more appropriately called aftercasts. The weather would all of a sudden get worse and you would see the familiar words of TAF AMD followed by a bunch of information that was longer than previous. Not good when the destination and alternate are non-precision approaches with high minimums.

+1. I am learning that as I begin to do flights up north. Keeps me wary.

[burhead1]

And nobody has pointed out that this forecast was based on AUTO OBS.... ?

Sure, be skeptical of everything. Look at all the weather products and make sure they add up. But this title is a little misleading... it should say "be very careful when using a TAF based on AUTO OBS.

Added "based on AUTO OBS" to the title.

Robots lie too I guess.