Chapter 2. Broadcast Procedures

Section 1. General

2-1-1. TYPES OF BROADCASTS

Weather and flight information shall be broadcast/ recorded by one or more of the following categories:

a.Transcribed Weather Broadcast (TWEB). (Alaska only.)

b.Telephone Information Briefing Service (TIBS).

c.Hazardous Inflight Weather Advisory Service (HIWAS).

d.Meteorological Information for Aircraft in Flight (VOLMET ICAO).

2-1-2. SPEECH RATE

Data shall be spoken at a rate of 100 to 120 words-per-minute.

2-1-3. INTERRUPTION OF BROADCAST

Interrupt broadcast only when you believe that a pilot requires immediate attention; e.g., to issue an airport advisory. When a pilot calls during a broadcast:

a.Broadcast for a short interval on the frequency to which the pilot is listening simultaneously with the broadcast frequencies, and complete the aircraft contact immediately after the broadcast.

b.If the pilot repeats the call, interrupt the broadcast and answer the call.

2-1-4. REDUCING RECORDED WEATHER INFORMATION SERVICES

Recorded weather information services (TWEB and TIBS) may be reduced during the hours of 1800-0600 local time only. Resumption of full broadcast service should be adjusted seasonally to coincide with daylight hours. During the period of reduced broadcast, record a statement indicating when the broadcast will be resumed and to contact Flight Service for weather briefing and other services.

PHRASEOLOGY-
THE TIBS RECORDING IS SUSPENDED. REGULAR RECORDED WEATHER SERVICE WILL BE RESUMED AT (time) ZULU/ (time) LOCAL. FOR PILOT WEATHER BRIEFING AND OTHER SERVICES CONTACT A FLIGHT SERVICE FACILITY (phone number or additional telephone instructions, as appropriate).

PHRASEOLOGY-
THE TWEB RECORDING IS SUSPENDED. REGULAR RECORDED WEATHER SERVICE WILL BE RESUMED AT (time) ZULU/ (time) LOCAL. FOR PILOT WEATHER BRIEFING AND OTHER SERVICES CONTACT A FLIGHT SERVICE FACILITY (frequency or phone number, as appropriate).

2-1-5. ANNOUNCING MISSING ITEMS

With the exception of RVR, announce the word "MISSING" when any items or components of a weather report are not reported, or in place of unreadable or obviously incorrect items or portions of weather reports. If the complete report is not available for broadcast, state the location and the word "MISSING." When appropriate, instead of speaking the name of several locations with missing reports, announce: "OTHER SCHEDULED REPORTS MISSING."

NOTE-
On occasion, a parameter from an automated observation may be reported as missing in the body of the report but is available as a manually reported parameter in the remarks section. When the report is spoken, include the manually reported element in its proper sequence within the report.

2-1-6. WEATHER REPORT PHRASEOLOGY

Use the following phraseology and procedures for radio-telephone communications and broadcast of surface weather observations:

a.Location.

1.Announce the geographic name (not the identifier) once for broadcasts.

2.When the location name is duplicated within 500 miles, follow the location name with the state name.

EXAMPLE-
"Wilmington, North Carolina."
"Wilmington, Delaware."

3.When weather reports originate at more than one airport at the same geographical location, identify the airport.

EXAMPLE-
"Chicago Midway."
"Chicago O'Hare."

4.Where it is considered necessary and is requested by the military base commander, broadcast military observations by stating the location, the name of the airport if different, and the controlling military branch.

EXAMPLE-
"Fort Riley, Marshall Army Air Field."
"Andrews Air Force Base."
"Norfolk Naval Air Station."

b.Automated Observation.If AUTO appears after the date/time element, follow the location announcement with the phrase "AUTOMATED."

PHRASEOLOGY-
(Location) AUTOMATED.

c.Special Reports. If a special report is available at the time of the broadcast, follow the location with the words "SPECIAL REPORT, (last two digits of the time) OBSERVATION."

d.Wind Direction and Speed. Announce wind direction and speed by stating the word WIND followed by the separate digits of the wind direction to the nearest 10 degrees and the separate digits of the speed. A "G" between two wind speed values is announced as GUSTS. Broadcast local wind as it appears in the report. Announce the variability of wind at the end of the wind group. (See TBL 2-1-1.)

TBL 2-1-1
Wind Direction and Speed

Wind	Phraseology
VRB04KT	WIND VARIABLE AT FOUR.
00000KT	WIND CALM.
26012KT	WIND TWO SIX ZERO AT ONE TWO.
29012KT 260V320	WIND TWO NINER ZERO AT ONE TWO WIND VARIABLE BETWEEN TWO SIX ZERO AND THREE TWO ZERO.
30008KT	WIND THREE ZERO ZERO AT EIGHT.
36012G20KT	WIND THREE SIX ZERO AT ONE TWO GUSTS TWO ZERO.

e.Visibility. Announce visibility as follows:
(See TBL 2-1-2.)

TBL 2-1-2
Visibility

Contraction	Phraseology
M¹/₄SM	VISIBILITY LESS THAN ONE QUARTER.
0SM	VISIBILITY ZERO.
¹/₁₆SM	VISIBILITY ONE SIXTEENTH.
¹/₈SM	VISIBILITY ONE EIGHTH.
³/₄SM	VISIBILITY THREE QUARTERS.
1¹/₂SM	VISIBILITY ONE AND ONE-HALF.
8SM	VISIBILITY EIGHT.
25SM	VISIBILITY TWO FIVE.

NOTE-
When visibility is less than 3 miles and variable, the variable limits will be reported in the remarks.

f.RVR.When RVR is reported, announce in accordance with TBL 2-1-3. Omit RVR when it is not reported. Do not announce as missing.

TBL 2-1-3
RVR

Contraction	Phraseology
R16/M0600FT	RUNWAY ONE SIX VISUAL RANGE LESS THAN SIX HUNDRED.
R17L/2400V 3000FT	RUNWAY ONE SEVEN LEFT VISUAL RANGE VARIABLE BETWEEN TWO THOUSAND FOUR HUNDRED AND THREE THOUSAND.
R28L/3500FT	RUNWAY TWO EIGHT LEFT VISUAL RANGE THREE THOUSAND FIVE HUNDRED.
R35R/P6000FT	RUNWAY THREE FIVE RIGHT VISUAL RANGE MORE THAN SIX THOUSAND.
Note: "R-V-R" may be spoken in lieu of "visual range."

g.Weather Elements.TBL 2-1-4 depicts sample phraseology for weather element contractions. Intensity refers to precipitation, not descriptors. Proximity is spoken after the phenomenon to which it refers. Descriptors are spoken ahead of weather phenomenon with the exception of "showers" which is spoken after the precipitation. Table TBL 2-1-8 contains a complete list of weather elements and appropriate phraseology.

TBL 2-1-4
Examples of combining intensity, descriptors and weather phenomenon.

Contractions	Phraseology
BLSN	BLOWING SNOW.
FZDZ	FREEZING DRIZZLE.
FZRA	FREEZING RAIN.
-FZRAPL	LIGHT FREEZING RAIN, ICE PELLETS.
MIFG	SHALLOW FOG.
SHRA	RAIN SHOWERS.
+TSRA	THUNDERSTORM, HEAVY RAIN (SHOWERS)^1.
TSRA	THUNDERSTORM, RAIN.
+TSRAGR	THUNDERSTORM, HEAVY RAIN, HAIL.
-SHRA	LIGHT RAIN SHOWERS.
SHSN	SNOW SHOWERS.
VCSH	SHOWERS IN THE VICINITY.
¹Since thunderstorms imply showery precipitation, "showers" may be used to describe precipitation that accompany thunderstorms.

h.Ceiling and sky coverage.

1.Broadcast Sky Coverage in the same order as reported on the weather observation. Announce ceiling as follows: (See TBL 2-1-5.)

TBL 2-1-5
Ceiling and Sky coverage

Contraction	Phraseology
BKN000¹	SKY PARTIALLY OBSCURED.
BKN000²	CEILING LESS THAN FIVE ZERO BROKEN.
FEW000¹	SKY PARTIALLY OBSCURED.
FEW000²	FEW CLOUDS AT LESS THAN FIVE ZERO.
SCT000¹	SKY PARTIALLY OBSCURED.
SCT000²	LESS THAN FIVE ZERO SCATTERED.
(lowest layer aloft) BKN/OVC	(precede with) CEILING.
VV	INDEFINITE CEILING.
¹ Surface-based obscurations. Requires remarks, i.e. RMK FG SCT000, FU BKN000, etc. ² No remark means the layer is aloft.

2.State cloud heights in tens, hundreds and/or thousands of feet. (See TBL 2-1-6.)

TBL 2-1-6
Cloud Heights

Number	Phraseology
000¹	ZERO.
003	THREE HUNDRED.
018	ONE THOUSAND EIGHT HUNDRED.
200	TWO ZERO THOUSAND.
¹ Spoken as zero only when used with VV.

NOTE-
When the ceiling is less than 3,000 feet and variable, the variable limits will be reported in the remarks.

3.Announce sky conditions as indicated.
(See TBL 2-1-7.)

TBL 2-1-7
Sky Conditions

Contraction	Phraseology
BKN	(height) BROKEN.
CLR¹	CLEAR BELOW ONE TWO THOUSAND.
FEW	FEW CLOUDS AT (height).
SCT	(height) SCATTERED.
SKC	CLEAR.
OVC	(height) OVERCAST.
¹ Automated weather reports.

TBL 2-1-8
Weather Elements

QUALIFIER				WEATHER PHENOMENA
INTENSITY or PROXIMITY 1		DESCRIPTOR 2		PRECIPITATION 3		OBSCURATION 4		OTHER 5
-	Light	MI	Shallow	DZ	Drizzle	BR	Mist	PO	Well- Developed Dust/Sand Whirls
		BC	Patchy	RA	Rain	FG	Fog	SQ	Squalls
	Moderate (No Qualifier)	DR	Low Drifting	SN	Snow	FU	Smoke	FC +FC	Funnel Cloud, Tornado or Waterspout
		BL	Blowing	SG	Snow Grains	DU	Dust	SS	Sandstorm
+	Heavy	SH	Showers	IC	Ice Crystals	SA	Sand	DS	Duststorm
		TS	Thunderstorm	PL	Ice Pellets	HZ	Haze
VC	In the Vicinity	FZ	Freezing	GR	Hail	PY	Spray
		PR	Partial	GS	Small Hail or Snow Pellets (<1/4")	VA	Volcanic Ash
				UP	*Unknown Precipitation
* Automated stations only.

4.The following are examples of broadcast phraseology of sky and ceiling conditions:
(See TBL 2-1-9.)

TBL 2-1-9
Sky and ceiling conditions

Condition	Phraseology
BKN000 BKN010 BKN050 RMK FG BKN000	SKY PARTIALLY OBSCURED, CEILING ONE THOUSAND BROKEN, FIVE THOUSAND BROKEN. FOG OBSCURING FIVE TO SEVEN EIGHTS OF THE SKY.
BKN010	CEILING ONE THOUSAND BROKEN.
SCT000 SCT020 OVC035 RMK FG SCT000	SKY PARTIALLY OBSCURED, TWO THOUSAND SCATTERED, CEILING THREE THOUSAND FIVE HUNDRED OVERCAST. FOG OBSCURING THREE TO FOUR EIGHTS OF THE SKY.
SCT020 OVC250	TWO THOUSAND SCATTERED, CEILING TWO FIVE THOUSAND OVERCAST.
VV000	INDEFINITE CEILING ZERO.
VV012	INDEFINITE CEILING ONE THOUSAND TWO HUNDRED.

i. Temperature and Dew Point. Announce temperature and dew point in degrees Celsius. Temperatures below zero are preceded with an M and are announced by prefixing the word MINUS to the values. When the temperature and dew point spread is greater than 3 degrees, broadcast only the temperature. (See TBL 2-1-10.)

TBL 2-1-10
Temperature and Dew Point

Value	Phraseology
02/M01	TEMPERATURE TWO, DEW POINT MINUS ONE.
14/09	TEMPERATURE ONE FOUR.
36/34	TEMPERATURE THREE SIX, DEW POINT THREE FOUR.

j.Altimeter Setting. Announce the four digits of the altimeter setting. (See TBL 2-1-11.)

TBL 2-1-11
Altimeter Setting

	Phraseology
A2989	ALTIMETER TWO NINER EIGHT NINER.
A3025	ALTIMETER THREE ZERO TWO FIVE.

k.Remarks. Announce pertinent remarks. Do not broadcast additive data or other information intended for NWS analysis or processing that does not contribute to the description of the weather occurring at the station. (See TBL 2-1-12.)

TBL 2-1-12
Remarks

Remarks	Phraseology
ACSL OVR RDG SW	STANDING LENTICULAR ALTOCUMULUS OVER RIDGE SOUTHWEST.
FG SCT000	FOG OBSCURING THREE TO FOUR EIGHTHS OF SKY.
FU SCT012	SMOKE LAYER ONE THOUSAND TWO HUNDRED SCATTERED.
SCT020 V BKN	TWO THOUSAND SCATTERED VARIABLE BROKEN.
OCNL LTGCG OHD TS OHD MOV E	OCCASIONAL LIGHTNING CLOUD TO GROUND OVERHEAD. THUNDERSTORM OVERHEAD MOVING EAST
VIS 3/4V1 1/2	VISIBILITY VARIABLE BETWEEN THREE QUARTERS AND ONE AND ONE HALF.
VIS NE 3 S 2	VISIBILITY NORTHEAST THREE, SOUTH TWO.

2-1-7. CURRENT DATA

An aviation surface report is considered current for 1 hour beyond the standard time of observation (H+00) unless superseded by a special or local observation or by the next hourly report. Do not broadcast obsolete data.

Go to Chapter 2 Table of Contents

Go to Chapter 2 Section 2