METAR POP QUIZ

TangoWhiskey

TangoWhiskey

Touchdown! Greaser!
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3Green
We're always learning, right? So check out today's METARS for KAFW in Fort Worth:

Code: 
KAFW 231453Z 01015KT 1SM R16L/P6000FT -PL BR FEW010 SCT015 OVC025 M04/M06 A3058 RMK AO2 SLP370 P0002 60017 I3000 T10441056 53020
KAFW 231438Z COR 36014KT 1SM BR R16L/P6000FT PL FEW010 BKN025 OVC040 M04/M06 A3058 RMK AO2 P0002 T10441056
KAFW 231414Z 35013G19KT 3SM PL FEW010 BKN025 OVC040 M04/M06 A3058 RMK AO2 PRESRR P0000 T10391061
KAFW 231407Z 01014KT 8SM -PL FEW010 SCT025 OVC055 M04/M06 A3056 RMK AO2 P0000 T10441061
KAFW 231353Z 01017G23KT 1SM R16L/P6000FT PL BR BKN010 OVC025 M04/M06 A3053 RMK AO2 GSE05PLB01 SLP353 CB MOV NE P0002 T10441061
KAFW 231305Z COR 36014KT 1SM R16L/P6000FT PL BR BKN010 OVC020 M04/M06 A3054 RMK AO2 GSE01PLB01 CB DSNT ALQDS MOV NE P0001 T10441056
KAFW 231253Z 36014KT 1SM R16L/P6000FT GS BR BKN013 OVC022 M04/M06 A3053 RMK AO2 FZRAB05E26 SLP354 P0013 I1000 T10441056
KAFW 231240Z 01012G23KT 1 1/2SM GS BR OVC013 M04/M06 A3049 RMK AO2 FZRAB05E26 P0011 I1000 T10441056
KAFW 231227Z 36013KT 2SM GS BR OVC015 M04/M06 A3055 RMK AO2 FZRAB05E26 P0006 I1000 T10391056
KAFW 231208Z 03013G24KT 3SM -FZRAGS BR OVC015 M04/M06 A3048 RMK AO2 FZRAB05 P0001 I1000 T10391056
KAFW 231153Z COR 01016KT 4SM GS BR OVC010 M04/M06 A3052 RMK AO2 FZRAE08B23E52GSB23 SLP349 P0002 60003 70105 I1000 I6002 T10391056 11022 21039 55006

Today's seen I1000, I3000, and I6000 appear on the METAR for Alliance Fort Worth, before the Temperature group in the remarks section. It's not the '1' group, it's the 'I' group. Note the 1153Z observation has more than one 'I' group.

I know what it is now, but had to call the tower, who gave me the number for the NWS observer for the airport, who said it's just recently been added to the ASOS, and he had to call higher up to know what it meant too.

Here's the format, as a clue:
Ihnnn.

Any guesses? Once its solved, I'll throw another one out.
 
I am guessing I stands for ice, so it would be 1-hour, 3-hour, and 6-hour ice accumulation totals?
 
You got it. Seeing I1999 would be very bad. ;-)

FORMAT: Ihnnn; It's an icing accretion amount, for the past 1, 3, or 6 'h'our period, where 'nnn' is the ice thickness accumulated to the nearest 0.01 inches. NICE! And this is a recently added ASOS field, optionally enabled at the installation site, as documented here:

http://www.nws.noaa.gov/.../release_notes_307_draft.pdf
 
Round 2:

You see this in a TAF:

BECMG 1617 29008KT 3200 -RA OVC030 620304

What's the last element mean?
 
TangoWhiskey said:
We're always learning, right? So check out today's METARS for KAFW in Fort Worth:


Today's seen I1000, I3000, and I6000 appear on the METAR for Alliance Fort Worth, before the Temperature group in the remarks section. It's not the '1' group, it's the 'I' group. Note the 1153Z observation has more than one 'I' group.

I know what it is now, but had to call the tower, who gave me the number for the NWS observer for the airport, who said it's just recently been added to the ASOS, and he had to call higher up to know what it meant too.

Here's the format, as a clue:
Ihnnn.

Any guesses? Once its solved, I'll throw another one out.
Click to expand...

Check out my post: http://www.pilotsofamerica.com/forum/showpost.php?p=1667087&postcount=23 There's a link there to a full explanation of the I code.

Jim
 
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TangoWhiskey said:
Round 2:

You see this in a TAF:

BECMG 1617 29008KT 3200 -RA OVC030 620304

What's the last element mean?
Click to expand...

Light Rime icing in cloud, base at 3000 feet, 4000 foot thickness.

So, light rime icing in cloud from 3000 to 7000 feet.

(Page 27 of this link: http://www.desu.edu/sites/default/files/u725/METAR%20and%20TAF%20codes.pdf

I put some useful METAR and TAF links in this post a while back: http://www.pilotsofamerica.com/forum/showpost.php?p=1631962&postcount=22


Code: 
If forecasted, the icing group will be prefixed by the number 6, and follows
the cloud group. To decode, follow these instructions:
1. Find the icing designator “6” following the cloud group (620304).
2. The next digit gives icing type and intensity (620304). See Figure 3.
3. The next three digits give the base of the icing layer in hundreds of feet
(620304).
4. The last digit provides the icing layer depth in thousands of feet
(620304), so add this value to the base height to determine the top limit
of the icing conditions.
In the above example, the icing forecast will read, “light rime icing (in
cloud) from 3,000 to 7,000 feet.”

Figure 3., Icing code meaning.
CODE DECODE
0 Trace Icing or None (see note)
1 Light Mixed Icing
2 Light Rime Icing In Cloud
3 Light Clear Icing In Precipitation
4 Moderate Mixed Icing
5 Moderate Rime Icing In Cloud
6 Moderate Clear Icing In Precipitation
7 Severe Mixed Icing
8 Severe Rime Icing In Cloud
9 Severe Clear Icing In Precipitation
Note: Air Force code “0” means a trace of icing,
 World Meteorological Organization code “0” means no icing
 
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933002 is two tenths of an inch of water equivalent of snow (does that mean .2" of snow? Or the melted snow would measure .2" deep?).
 
And I think 931052 is 5.2 inches of snow fell in the past six hours... But not certain on that.
 
TangoWhiskey said:
And I think 931052 is 5.2 inches of snow fell in the past six hours... But not certain on that.
Click to expand...

Yep, 5.2 inches of new snow in the past six hours.

From: http://www.aviationsystemsdivision.arc.nasa.gov/publications/2015/NASA-TM-2014-218385.pdf

Code: 
5.1 Depth of New Snow (931nnn)
Depth of new snow (snowfall) is reported every 6 hours at 0000, 0600, 1200, and 1800 UTC,
when any amount of snow has fallen in the past 6 hours. 931 is the group indicator and nnn
represents the depth of new snow in the past 6 hours reported in tens, units, and tenths of
inches, using three digits. The new snow includes snow pellets, snow grains, ice pellets, ice
crystals, and hail. For example, during the 6-hour period it snows two times. After the first snow
there are 2.3 inches of new snow. Before the second snow, 0.5 inches of the new snow melts.
The second snow adds another l.4 inches of new snow. The new snow depth is the sum of 2.3
and 1.4 inches, or 3.7 inches. The reported value of new snow does not include melted snow so
the group "931nnn" would be coded "931037". Further details are described in the NOAA's
Supplementary Climatological Data [9].
 
jimhorner said:
Correct! 0.2" water equivalent. My understanding is that the melted snow would be 0.2" deep.
Click to expand...


How is that useful?? Except to scientists? Not sure why I'd care as a pilot that if you took the snow on the ground and melted it all, you'd get .2" of water. I'd rather know there was 8" of snow (or whatever that number would be).
 
TangoWhiskey said:
How is that useful?? Except to scientists? Not sure why I'd care as a pilot that if you took the snow on the ground and melted it all, you'd get .2" of water. I'd rather know there was 8" of snow (or whatever that number would be).
Click to expand...

Scientists use METARs.
 
TangoWhiskey said:
How is that useful?? Except to scientists? Not sure why I'd care as a pilot that if you took the snow on the ground and melted it all, you'd get .2" of water. I'd rather know there was 8" of snow (or whatever that number would be).
Click to expand...

About the only use I can think of to pilots is being able to correctly decode a METAR.given by a fiendish DPE on an instrument oral! At least that was the use to me.....
 
TangoWhiskey said:
How is that useful?? Except to scientists? Not sure why I'd care as a pilot that if you took the snow on the ground and melted it all, you'd get .2" of water. I'd rather know there was 8" of snow (or whatever that number would be).
Click to expand...

We in the heavies use it for TOLD computations. With that snow, I know I can run TOLD numbers with 2/10th of an inch of standing water.
 
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These are some good codes I have not encountered yet (especially down here in the warm south).
Keep 'em coming, gentlemen, I like learning.
 
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