METAR Question

Hello, I was wondering what the "I####" code in the remaks section of a METAR means.

Example:
kbis 111650Z 36009kt 1 1/2sm r31/5500vp6000ft -sn br bkn009 ovc014 m09/m11 a2962 rmk ao2 upb11e13fzrae1554snb1554e11b13 cig 008v012 p0000 I1000

At the very end there is I1000, because there is a 1 directly after the "I" that makes me think that it may be related to a negative temperature but I am not sure especially sense there is just 000 that comes after.
Any help you guys can provide will be greatly appreciated!

I wanted to add that I have another example:

KBIS 230852Z AUTO 32008KT 10SM CLR M12/M15 A3018 RMK AO2 SLP257 I3000 T11171150 53014

In this one the remark in question is now "I3000" so I know it can't be temperature.
I have looked many places and can't figure out what this is.

I thought I would let you all know that I figured out what that code means in the METAR.

The code deals with Ice Accretion:

Hourly Ice Accretion Amount:
Ice accretion for the current hour encoded in hundredths of an inch (0.01 in.) has the following format:
• I1nnn Whe “I” - is the icing indicator for the group “1" - is the reported time period (one hour) “nnn” - is the thickness accumulated to the nearest one-hundredth of an inch (0.01 in.). A trace amount is encoded as “000.”

Three (3-) Hourly Ice Accretion Amount:
• The accretion of ice over the past three hour time period in one-hundredths of an inch (0.01 in.) would have the format: I3nnn Whe “I” - is the icing indicator for the group “3" - is the reported time period (three hours) “nnn” - is the thickness accumulated to the nearest one-hundredth of an inch (0.01 in.). A trace amount is encoded as “000.” The remark may be encoded at the intermediate synoptic times (0300, 0900, 1500, or 2100 UTC). When conditions warrant, the “I3nnn” remark will be encoded immediately following the hourly ice accretion amount (I1nnn).

Six (6-) Hourly Ice Accretion Amount:
• The accretion of ice over the past six hour time period in one-hundredths of an inch (0.01 in.) will have the format: I6nnn Whe “I” - is the icing indicator for the group “6" - is the reported time period (six hours) “nnn” - is the thickness accumulated to the nearest one-hundredth of an inch (0.01 in.). A trace amount is encoded as “000.” The remark may be encoded at the mandatory synoptic times (0600, 1200, 1800, or 0000 UTC). When conditions warrant, the “I6nnn” remark will be encoded immediately following the hourly ice accretion amount (I1nnn).

This could be very helpful to us but the NWS has not installed this update to all stations yet.

Where did you find that defined? I looked in all the spots I
normally used and none of them had Ixxxx.


test_driver wrote:

I thought I would let you all know that I figured out what that code
means in the METAR.

The code deals with Ice Accretion:

Hourly Ice Accretion Amount:
Ice accretion for the current hour encoded in hundredths of an inch
(0.01 in.) has the following format:
? I1nnn Whe ?I? - is the icing indicator for the group ?1" - is the
reported time period (one hour) ?nnn? - is the thickness accumulated to
the nearest one-hundredth of an inch (0.01 in.). A trace amount is
encoded as ?000.?

Three (3-) Hourly Ice Accretion Amount:
? The accretion of ice over the past three hour time period in
one-hundredths of an inch (0.01 in.) would have the format: I3nnn Whe
?I? - is the icing indicator for the group ?3" - is the reported time
period (three hours) ?nnn? - is the thickness accumulated to the nearest
one-hundredth of an inch (0.01 in.). A trace amount is encoded as ?000.?
The remark may be encoded at the intermediate synoptic times (0300,
0900, 1500, or 2100 UTC). When conditions warrant, the ?I3nnn? remark
will be encoded immediately following the hourly ice accretion amount
(I1nnn).

Six (6-) Hourly Ice Accretion Amount:
? The accretion of ice over the past six hour time period in
one-hundredths of an inch (0.01 in.) will have the format: I6nnn Whe
?I? - is the icing indicator for the group ?6" - is the reported time
period (six hours) ?nnn? - is the thickness accumulated to the nearest
one-hundredth of an inch (0.01 in.). A trace amount is encoded as ?000.?
The remark may be encoded at the mandatory synoptic times (0600, 1200,
1800, or 0000 UTC). When conditions warrant, the ?I6nnn? remark will be
encoded immediately following the hourly ice accretion amount (I1nnn).

This could be very helpful to us but the NWS has not installed this
update to all stations yet.




--
test_driver

--
Don Poitras

It was a simple process but I didn't think of it at first because nobody on several forums had any idea and all I thought it would be was a simple "ah someone on a forum will know". So today I decided to called an airport and the lady there didn't know, so then I talked to one of the guys in the tower he wasn't sure but suggested I contact the NWS, the guy there wasn't sure but he said that it just started showing up after an update with the software on their ASOS. That answer gave me the extra piece of info that seems very simple in hind sight, all I had to do was search google for "ASOS I3000" (click the "Search only for ASOS I3000" link) and the first non-ad listing is a pdf from the NOAA about the new software and what the new groups mean, including the ice accretion one.

It goes to show that forums and the internet are great but sometimes you have to go a little beyond to find the answers.

test_driver wrote:

It was a simple process but I didn't think of it at first because nobody
on several forums had any idea and all I thought it would be was a
simple "ah someone on a forum will know". So today I decided to called
an airport and the lady there didn't know, so then I talked to one of
the guys in the tower he wasn't sure but suggested I contact the NWS,
the guy there wasn't sure but he said that it just started showing up
after an update with the software on their ASOS. That answer gave me the
extra piece of info that seems very simple in hind sight, all I had to
do was search google for "ASOS I3000" (click the "Search only for ASOS
I3000" link) and the first non-ad listing is a pdf from the NOAA about
the new software and what the new groups mean, including the ice
accretion one.

It goes to show that forums and the internet are great but sometimes you
have to go a little beyond to find the answers.

Excellent. I did that search, but only found pdfs discussing the
testing of the new ASOS software and how the presence of I3000 etc.
was normally an error. e.g.:

http://www.nws.noaa.gov/ops2/Surface..._307_draft.pdf
---
Please Note: In situations when FZRASN is manually entered in the
Present Weather field, an inappropriate trace accretion amount (I1000,
I3000, I6000) might be entered in the remarks section of the METAR /
SPECI reports. This is a known issue and will be addressed at a later
time.
---

This is the page I usually go to, but it hasn't been updated since
2008: http://www.ncdc.noaa.gov/oa/climate/...ardecoder.html

The link at the bottom is dead. I tried to get to the "National Weather
Service Office of Systems Operations" pages, but most required a NOAA
login.

I also found this very official looking "handbook", but it's from 2005:
http://www.ofcm.gov/fmh-1/pdf/FMH1.pdf

--
Don Poitras