AIM
4/3/14
7−1−16
Meteorology
or unscheduled bulletins are numbered sequentially
for easier identification.
(a)
AIRMET Sierra describes IFR conditions
and/or extensive mountain obscurations.
(b)
AIRMET Tango describes moderate
turbulence, sustained surface winds of 30 knots or
greater, and/or nonconvective low−level wind shear.
(c)
AIRMET Zulu describes moderate icing
and provides freezing level heights.
EXAMPLE
−
Example of AIRMET Sierra issued for the Chicago FA
area:
CHIS WA 131445
AIRMET SIERRA UPDT 2 FOR IFR AND MTN OBSCN
VALID UNTIL 132100.
AIRMET IFR...KY
FROM 20SSW HNN TO HMV TO 50ENE DYR TO20SSW
HNN
CIG BLW 010/VIS BLW 3SM PCPN/BR/FG. CONDS
ENDG BY 18Z.
.
AIRMET IFR....MN LS
FROM INL TO 70W YQT TO 40ENE DLH TO
30WNW DLH TO 50SE GFK TO 20 ENE GFK TO
INL
CIG BLW 010/VIS BLW 3SM BR. CONDS ENDG 15
−
18Z.
.
AIRMET IFR....KS
FROM 30N SLN TO 60E ICT TO 40S ICT TO 50W
LBL TO 30SSW GLD TO 30N SLN
CIG BLW 010/VIS BLW 3SM PCPN/BR/FG. CONDS
ENDG 15
−18Z.
.
AIRMET MTN OBSCN...KY TN
FROM HNN TO HMV TO GQO TO LOZ TO HNN
MTN OBSC BY CLDS/PCPN/BR. CONDS CONTG
BYD 21Z THRU 03Z.
.....
EXAMPLE
−
Example of AIRMET Tango issued for the Salt Lake City
FA area:
SLCT WA 131445
AIRMET TANGO UPDT 2 FOR TURB VALID UNTIL
132100.
AIRMET TURB...MT
FROM 40NW HVR TO 50SE BIL TO 60E DLN TO
60SW YQL TO 40NW HVR
MOD TURB BLW 150. CONDS DVLPG 18
−21Z.
CONDS CONTG BYD 21Z THRU 03Z.
.
AIRMET TURB....ID MT WY NV UT CO
FROM 100SE MLS TO 50SSW BFF TO 20SW BTY
TO 40SW BAM TO 100SE MLS
MOD TURB BTN FL310 AND FL410. CONDS
CONTG BYD 21Z ENDG 21
−00Z.
.
AIRMET TURB...NV AZ NM CA AND CSTL WTRS
FROM 100WSW ENI TO 40W BTY TO 40S LAS TO
30ESE TBE TO INK TO ELP TO 50S TUS TO BZA
TO 20S MZB TO 150SW PYE TO 100WSW ENI
MOD TURB BTWN FL210 AND FL380. CONDS
CONTG BYD 21Z THRU 03Z.
....
EXAMPLE
−
Example of AIRMET Zulu issued for the San Francisco
FA area:
SFOZ WA 131445
AIRMET ZULU UPDT 2 FOR ICE AND FRZLVL VALID
UNTIL 132100.
NO SGFNT ICE EXP OUTSIDE OF CNVTV ACT.
.
FRZLVL....RANGING FROM SFC
−105 ACRS AREA
MULT FRZLVL BLW 080 BOUNDED BY 40SE
YDC
−60NNW GEG−60SW MLP−30WSW BKE−
20SW BAM
−70W BAM−40SW YKM−40E HUH−
40SE YDC
SFC ALG 20NNW HUH
−30SSE HUH−60S SEA
50NW LKV
−60WNWOAL−30SW OAL
040 ALG 40W HUH
−30W HUH−30NNW SEA−40N
PDX
−20NNW DSD
080 ALG 160NW FOT
−80SW ONP−50SSW EUG
40SSE OED
−50SSE CZQ−60E EHF−40WSW LAS
....
3. Graphical AIRMETs (G
−AIRMETs),
found on the Aviation Weather Center webpage at
http://aviationweather.gov, are graphical forecasts of
en−route weather hazards valid at discrete times no
more than 3 hours apart for a period of up to 12 hours
into the future (for example, 00, 03, 06, 09, and 12
hours). Additional forecasts may be inserted during
the first 6 hours (for example, 01, 02, 04, and 05). 00
hour represents the initial conditions, and the
subsequent graphics depict the area affected by the
particular hazard at that valid time. Forecasts valid at
00 through 06 hours correspond to the text AIRMET
bulletin. Forecasts valid at 06 through 12 hours
correspond to the text bulletin outlook. G−AIRMET
depicts the following en route aviation weather
hazards:
(a)
Instrument flight rule conditions (ceiling
< 1000’ and/or surface visibility <3 miles)
(b)
Mountain obscuration
(c)
Icing
(d)
Freezing level