Metars

[GrahamC]

Not quite, since I've lived in MA, CA, and FL where I saw the same thing. I'd considered Variation being rounded into the direction, but it didn't quite explain it away.

 

[RyanB]

I understand that, but when ATIS says winds are 150 at 8 and the METAR reads winds 150 at 8, they cant both be in Magnetic and True direction, respectively.

Why can't they? If the magnetic variation is a low number (ex. 4 or less) than the two will commonly be the same. Go to a place like ME or WA where the magnetic variation is greater than 10 or 12, and you will never run into this issue. Keep in mind that all winds are rounded to the nearest 10deg. A wind that is blowing 183 will get rounded to 180deg etc.

Edit: Dmspilot already explained it, needed a refresh

 

[RyanB]

Not quite, since I've lived in MA, CA, and FL where I saw the same thing. I'd considered Variation being rounded into the direction, but it didn't quite explain it away.

Are you sure that the ATIS and Metar reports you read and listened to were valid for the same time periods? It's not uncommon for winds to change during reporting periods.

 

[GrahamC]

Pretty positive. I'll have to take another look.

 

[dmspilot]

Not quite, since I've lived in MA, CA, and FL where I saw the same thing. I'd considered Variation being rounded into the direction, but it didn't quite explain it away.

I know the AWOS converts it, at least the one at my airport for sure. Perhaps the controller is just being lazy when they record the ATIS.

 

[MAKG1]

Not quite, since I've lived in MA, CA, and FL where I saw the same thing. I'd considered Variation being rounded into the direction, but it didn't quite explain it away.

You're not remembering correctly. Declination is greater than 10 deg everywhere in California, and METARs are always different from ATIS.

 

[denverpilot]

Always been a complaint of a lot of pilots for years, and we all have bitched about it for years. Still the government doesn't simplify weather reports in plain ole English.

The forecast discussion is in plain English.

In the last two weeks it has had such gems here locally as...

"Forecaster is not confident in wind forecast."

... after three straight days of missing it by huge margins.

And...

"Precipitation shall remain mostly south of I-25."

Think about that last one for a minute... hmmm.

That's still in the long range discussion as I type this. Right below that "quasi-geostrophic energy" will be increasing.

(Yeah, the first time I saw that one I had to go look it up, too.)

Careful what you wish for. I think most pilots when they say they want "plain English" want exactly what's in the METAR converted to English, but you KNOW that's not how government works... LOL.

You'd get gobbledegook like the above.

 

[LongRoadBob]

When you need to know wind direction as it relates to your landing runway which would be best? True or Magnetic?

ATIS and AWOS/ASOS winds are magnetic north. ATC reporting winds are magnetic north. “Long-lines” reports, METARs, TAFs, Winds Aloft, etc. are true north. Wind direction for PIREPs is magnetic.

Great point! That is definitely going to help me remember in the future. I need true when planning wind vectors, and I need magnetic when landing. Thanks for that.