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