Become familiar with pertinent weather information when coming on duty, and stay aware of current weather information needed to perform ATC duties.
2-6-2 Hazardous Inflight Weather Advisory Service (HIWAS)
Controllers shall advise pilots of hazardous weather that may
impact operations within 150 NM of their sector or area of jurisdiction.
Hazardous weather information contained in HIWAS broadcasts includes: Airmen's
Meteorological Information (AIRMET), Significant Meteorological Information
(SIGMET), Convective SIGMET (WST), Urgent Pilot Weather Reports (UUA),
and Center Weather Advisories (CWA). Facilities shall review alert messages
to determine the geographical area and operational impact for hazardous
weather information broadcasts. The broadcast is not required if aircraft
on your frequency(s) will not be affected.
a. Controllers within commissioned HIWAS areas shall broadcast
a HIWAS alert on all frequencies, except emergency frequency, upon receipt
of hazardous weather information. Controllers are required to disseminate
data based on the operational impact on the sector or area of control jurisdiction.
NOTE -
The inclusion of the type and number of weather advisory responsible
for the HIWAS advisory is optional.
PHRASEOLOGY -
ATTENTION ALL AIRCRAFT. HAZARDOUS WEATHER INFORMATION (SIGMET, Convective
SIGMET, AIRMET, Urgent Pilot Weather Report (UUA), or Center Weather Advisory
(CWA), Number or Numbers) FOR (geographical area) AVAILABLE ON HIWAS, FLIGHT
WATCH, OR FLIGHT SERVICE FREQUENCIES.
b. Controllers outside of commissioned HIWAS areas shall:
1. Advise pilots of the availability of hazardous weather advisories.
Pilots requesting additional information should be directed to contact
the nearest Flight Watch or Flight Service.
2. Apply the same procedure when HIWAS outlets, or outlets with
radio coverage extending into your sector or airspace under your jurisdiction,
are out of service.
PHRASEOLOGY -
ATTENTION ALL AIRCRAFT. HAZARDOUS WEATHER INFORMATION FOR (geographical
area) AVAILABLE FROM FLIGHT WATCH OR FLIGHT SERVICE.
c. Terminal facilities have the option to limit hazardous weather
information broadcasts as follows: tower cab and approach control facilities
may opt to broadcast hazardous weather information alerts only when any
part of the area described is within 50 NM of the airspace under their
jurisdiction.
{New-98-3 Revised February 26, 1998}
REFERENCE -
AIM, Chapter 7, Section 1. Meteorology, paragraph 7-1-5 through
paragraph 7-1-9.
Significant PIREP information includes reports of strong frontal
activity, squall lines, thunderstorms, light to severe icing, windshear
and turbulence (including clear air turbulence) of moderate or greater
intensity, volcanic eruptions and volcanic ash clouds, and other conditions
pertinent to flight safety.
REFERENCE -
FAAO 7110.65, Low Level Wind shear Advisories, paragraph 3-1-8.
{New-98-3 Revised February 26, 1998}
FAAO 7210.3, Handling of SIGMET's, CWA's, and PIREP's, paragraph
6-3-1.
AIM, Flight Operations in Volcanic Ash, paragraph 7-5-7.
FAAO 7210.3, SIGMET and PIREP Handling, paragraph 10-3-1.
a. Solicit PIREPs when requested or when one of the following
conditions exist or is forecast for your area of jurisdiction:
1. Ceilings at or below 5,000 feet. These PIREPs shall include
cloud base/top reports when feasible.
TERMINAL: Ensure that at least one descent/climb-out PIREP,
including cloud base/s, top/s, and other related phenomena, is obtained
each hour.
EN ROUTE: When providing approach control services, the
requirements stated in TERMINAL above apply.
2. Visibility (surface or aloft) at or less than 5 miles.
3. Thunderstorms and related phenomena.
4. Turbulence of moderate degree or greater.
5. Icing of light degree or greater.
6. Windshear.
7. Volcanic Ash Clouds
NOTE -
Pilots may forward PIREPs regarding volcanic activity using the format
described in the Volcanic Activity Reporting Form (VAR) as depicted in
the AIM, Appendix 2.
8. TERMINAL: Braking Action Advisories are in effect.
REFERENCE -
FAAO 7110.65, Braking Action Advisories, paragraph 3-3-5.
P/CG TERM - Braking Action Advisories.
b. Record with the PIREPs:
1. Time.
2. Aircraft position.
3. Type aircraft.
4. Altitude.
{New-98-3 Added February 26, 1998}
5. When the PIREP involves icing include:
(a) Icing type and intensity.
(b) Air temperature in which icing is occurring.
c. Obtain PIREPs directly from the pilot, or if the PIREP has
been requested by another facility, you may instruct the pilot to deliver
it directly to that facility.
PHRASEOLOGY -
REQUEST FLIGHT CONDITIONS.
or if appropriate,
REQUEST (specific conditions; ie., ride, ceiling, visibility,
etc.) CONDITIONS.
if necessary,
OVER (fix),
or
ALONG PRESENT ROUTE,
or
BETWEEN (fix) and (fix).
d. Handle PIREPs as follows:
1. Relay pertinent PIREP information to concerned aircraft in
a timely manner.
2. EN ROUTE: Relay all operationally significant PIREPs to the
facility weather coordinator.
3. TERMINAL: Relay all operationally significant PIREPs to:
(a) The appropriate intrafacility positions.
(b) The FSS serving the area in which the report was obtained.
NOTE -
The FSS is responsible for long line dissemination.
(c) Other concerned terminal or en route ATC facilities,
including non-FAA facilities.
(d) Use the word gain and/or loss when describing to pilots
the effects of windshear on airspeed.
EXAMPLE -
"Delta Seven Twenty-one, a Boeing Seven Twenty-seven, previously reported
windshear, loss of two five knots at four hundred feet."
"U.S. Air Seventy-six, a D-C Niner, previously reported windshear gain
of twenty-five knots between niner hundred and six hundred feet, followed
by a loss of five zero knots between five hundred feet and the surface."
{New-98-3 Revised February 26, 1998}
REFERENCE -
AIM, Wind Shear PIREPS, paragraph 7-1-21.
2-6-4 Weather and Chaff Services
a. Issue pertinent information on observed/reported weather or
chaff areas. Provide radar navigational guidance and/or approve deviations
around weather or chaff areas when requested by the pilot. Do not use the
word "turbulence" in describing radar-derived weather.
1. Issue weather and chaff information by defining the area
of coverage in terms of azimuth (by referring to the 12-hour clock) and
distance from the aircraft or by indicating the general width of the area
and the area of coverage in terms of fixes or distance and direction from
fixes.
2. Issue the level of echo intensity when that information is
available. When utilizing ASR-9 radar equipment, controllers shall ensure
that the highest available level of echo intensity within their area of
jurisdiction is displayed.
3. When a deviation cannot be approved as requested and the
situation permits, suggest an alternative course of action.
b. In areas of significant weather, plan ahead and be prepared
to suggest, upon pilot request, the use of alternative routes/altitudes.
NOTE -
Weather significant to the safety of aircraft includes such conditions
as tornadoes, lines of thunderstorms, embedded thunderstorms, large hail,
windshear, moderate to extreme turbulence (including CAT), and light to
severe icing.
c. Inform any tower for which you provide approach control services
if you observe any weather echoes on radar which might affect their operations.
PHRASEOLOGY -
WEATHER/CHAFF AREA BETWEEN (number) O'CLOCK AND (number) O'CLOCK (number)
MILES,
or
(number) MILE BAND OF WEATHER/CHAFF FROM (fix or number of miles and
direction from fix) TO (fix or number of miles and direction from fix),
or
LEVEL (number) WEATHER ECHO BETWEEN (number) O'CLOCK AND (number) O'CLOCK,
(number) MILES. MOVING (direction) AT (number) KNOTS, TOPS (altitude).
or
DEVIATION APPROVED, (restrictions if necessary), ADVISE WHEN ABLE TO:
RETURN TO COURSE,
or
RESUME OWN NAVIGATION
or
FLY HEADING (heading)
or
PROCEED DIRECT TO (name of NAVAID). UNABLE DEVIATION (state possible
alternate courses of action).
EXAMPLE -
1 - "Level five weather echo between eleven o'clock and one o'clock,
one zero miles. Moving east at two zero knots, tops flight level three
niner zero."
2 - "Level four weather echo between ten o'clock and two o'clock, one
five miles. Weather area is two five miles in diameter."
NOTE -
Phraseology using level number is only applicable when the radar weather
echo intensity information is determined by NWS radar equipment or ASR-9
radar equipment.
REFERENCE -
P/CG TERM - Radar Weather Echo Intensity Levels.
d. The operational supervisor / operations manager / controller-in-charge
shall verify the ASR-9 weather information by the best means available
(e.g., pilot reports, local tower personnel, etc.) if the weather data
display by the ASR-9 is reported as questionable or erroneous. Errors in
weather radar presentation shall be reported to the AF technician and the
AT supervisor shall determine if the ASR-9 derived weather data is to be
displayed and a NOTAM distributed.
NOTE -
Anomalous propagation (AP) is a natural occurrence affecting radar
and does not in itself constitute a weather circuit failure.
TERMINAL
Describe the wind as calm when the wind velocity is less than
three knots.
REFERENCE -
FAAO 7110.65, Tailwind Components, paragraph 3-5-3.
FAAO 7110.65, Intersecting Runway Separation, paragraph 3-10-4.
2-6-6 Reporting Weather Conditions
a. When the prevailing visibility at the usual point of observation,
or at the tower level, is less than 4 miles, tower personnel shall take
prevailing visibility observations and apply the observations as follows:
1. Use the lower of the two observations (tower or surface)
for aircraft operations.
2. Forward tower visibility observations to the weather observer.
3. Notify the weather observer when the tower observes the prevailing
visibility decrease to less than 4 miles or increase to 4 miles or more.
b. Forward current weather changes to the appropriate control
facility as follows:
1. When the official weather changes to a condition which is
below 1,000-foot ceiling or below the highest circling minimum, whichever
is greater, or less than 3 miles visibility, and when it improves to a
condition which is better than those above.
2. Changes which are classified as special weather observations
during the time that weather conditions are below 1,000-foot ceiling or
the highest circling minimum, whichever is greater, or less than 3 miles
visibility.
c. Towers at airports where military turbojet en route descents
are routinely conducted shall also report the conditions to the ARTCC even
if it is not the controlling facility.
d. If the receiving facility informs you that weather reports
are not required for a specific time period, discontinue the reports. The
time period specified should not exceed the duration of the receiving controller's
tour of duty.
e. EN ROUTE: When you determine that weather reports for an airport
will not be required for a specific time period, inform the FSS or tower
of this determination. The time period specified should not exceed the
duration of receiving controller's tour of duty.
REFERENCE -
FAAO 7110.65, Forwarding Approach Information by Nonapproach Control
Facilities, paragraph 3-10-2.
2-6-7 Disseminating Weather Information
TERMINAL
Observed elements of weather information shall be disseminated
as follows:
a. General weather information, such as "large breaks in the
overcast," "visibility lowering to the south," or similar statements which
do not include specific values, and any elements derived directly from
instruments, pilots, or radar may be transmitted to pilots or other ATC
facilities without consulting the weather reporting station.
b. Specific values, such as ceiling and visibility, may be transmitted
if obtained by one of the following means:
1. You are properly certificated and acting as official weather
observer for the elements being reported.
NOTE -
USAF controllers do not serve as official weather observers.
2. You have obtained the information from the official observer
for the elements being reported.
3. The weather report was composed or verified by the weather
station.
4. The information is obtained from an official Automated Weather
Observation System (AWOS) or an Automated Surface Observation System (ASOS).
c. Differences between weather elements observed from the tower
and those reported by the weather station shall be reported to the official
observer for the element concerned.