Deciphering Wx
 

Hi All

Just browsing Reporting Points, in particular the B727 crash in Florida. Some weather information was posted.

While I see many similarities to the weather presentation in my part of the woods, some things are different :(

After the date/time group on line 1, what is "9SM", and on the finish of line 1, "A3013"
On line 2, after the Remark, "A02 SLP200" and "CB DSNT SE CB DSNT SW FU"

Could someone please explain these elements, and I am sure the others in the weather I can work out from there. :D

The 3rd Axis

Mostly differences due to US use of Imperial measurements.

Look here.
http://www.n0esg.com/decodemetar.htm

At a guess, 3013 is the Pressure Setting [QNH] in inches
9SM 9 Statute Miles? FU is SMOKE
Visibilty in [Quadrant] SW-NW 1/2 Mile vis CB in the distance?
I might be talking boldocks, but I hope this helps a bit
we aim to please, it keeps the cleaners happy

Weather at Tallahassee Regional

Date: The 26. of the month at time 10:53 GMT
Wind: 000 degrees at 00Kts
Visibility: 9 Statute Miles
Clouds: Few at 100 feet, scattered at 1500 feet, scattered at 15000 feet, broken at 25000 feet.

Temperature 22, dewpoint 22
Altimeter: 30.13 InHg

Remark:
A02 = recorded by an automated station with precipitation measurement capability
SLP= Sea level pressure = 200 tenths of a HPa more than reported at the station.
VIS= visibility in SW-NW sector 1/2 SM
CB observed more than 10 miles away from station (DSNT=Distant) towards the SE, and CB observed more than 10 SM towards the SW with smoke(FU) and scattered cloudbase at 1500 feet.
Smoke plume over approach RWY 09 specific temperature 22,2 and dewpoint 21,7 degrees celcius

The other reports are the same but with different values, one and two hours earlier.

Thanks for your help dechipering that guys.

It brings me to the question: How many other countries use Imperial measurements, (that is other than the ICAO standard feet for altitude etc), such as statute miles and InHg for pressure.

Is there any talk of aligning all measurements worldwide, including countries using metres to measure altitude? Some sort of standard?

Do pilots having to deal with these changes in units of measurements get confused from time to time.

Thanks

3rd Axis

3A,
Here in the Uk we have a mix. [As does most of Europe]:)
Windspeed is in Knots. Vis in Metres/Kilometres. Cloud now Few Scatt, etc in Feet. Alimiter in Millibars [1013Mb = 29.92In Hg :D
Hope this helps
we aim to please, it keeps the cleaners happy

Fuel measurement is the biggest pain in the @rse.

Could be bought in L or US Gal, weighed in lbs or Kg, consumed in Kg, L, US Gal or Imp. gal.

Next is horizontal measurement.

Navigate in Nm (usually), vis. measured in Km or m. , runways in m or ft. Except USA where it's navigate in Nm or Sm, vis in Sm & fractions, runways in ft.

3A, the "Jeppesen Supplement" or "Aerad", or whatever your company uses has all the differences from ICAO standard for each country. For example, some countries in Europe use wind speed in metres/sec instead of knots, and cloudbase in metres instead of feet.

Fokker-Jock gave an excellent decode, with one little exception:

SLP200 is a sea-level pressure of 1020.0 hPa.

If the sea-level pressure were 20 hPa greater than the altimeter setting, it would have to be rather chilly at an airport with an elevation of 81 ft. :)

The FMH is useful for decoding US reports.

I stand corrected. You are absolutely right.