A-10
Revision 6 Feb/2009
9.
Moderate (
MOD
) turbulence (
TURB
) below (
BLW
) 10,000 feet
expected (
EXPCD
).
10.
Conditions (
CONDS
) improving (
IPVG
) after (
AFT
) the 16th day (
16
)
of the month
0000
UTC.
If conditions end more than one hour prior to the indicated expiration
time, an amended AIRMET will be issued stating it’s cancellation. If con-
ditions end within one hour of the indicated expiration time, the AIRMET
will be allowed to expire without cancellation. Once the report is can-
celled or expires, the FIS system no longer broadcasts the report.
UNDERSTANDING SIGMETS
The following is an example of a typical SIGMET issued for turbulence
with an explanation of the elements.
1.
Forecast Area:
CHIR
This is the forecast area identifier of the issuing Weather Service
Forecast Office.
BOS
Boston
CHI
Chicago
DFW
Dallas/Ft. Worth
MIA
Miami
SFO
San Francisco
SLC
Salt Lake City
The
R
denotes report ROMEO. A new alphabetic designator is
given each time a SIGMET is issued for a new weather phenom-
enon. The order of issuance is as follows:
N
NOVEMBER
O
OSCAR
P
PAPA
Q
QUEBEC
R
ROMEO
U
UNIFORM
V
VICTOR
W
WHISKEY
KMD 550/850 FIS Addendum
Appendix A
Understanding Weather Reports
CHIR UWS 041430
SIGMET ROMEO 1 VALID UNTIL 041830
KY TN WV VA OH
FROM CVG TO EKN TO PSK TO VXV TO CVG
OCNL SEV TURB BTN 300 AND 360. RPRTD BY AIRCRAFT.
CONDS CONTG BYD 1830Z.
SLM/GTB
1
3
4
5
2
6
7
8
