JO 7110.65 Air Traffic ControlJO 7110.65BB · Change 3 · Effective 7/9/2026
Chapter 2 · Section 6
Weather Information
6 Paragraphs2-6-1–2-6-6
2-6-1 FAMILIARIZATION
Controllers mustbecome familiar with pertinent weather information when coming on duty, and stay aware of current and forecasted weather information needed to perform ATC duties.
NOTE
Every phase of flight has the potential to be impacted by weather, and emphasis must be placed on gathering, reporting and disseminating weather information.
2-6-2 PIREP SOLICITATION AND DISSEMINATION
Emphasis must be placed on the solicitation and dissemination of Urgent (UUA) and Routine (UA) PIREPs. Timely dissemination of PIREPs alerts pilots to weather conditions and provides information useful to forecasters in the development of aviation forecasts. PIREPs also provide information required by ATC in the provision of safe and efficient use of airspace. This includes reports of strong frontal activity, squall lines, thunderstorms, light to severe icing, wind shear and turbulence (including clear air turbulence) of moderate or greater intensity, braking action, volcanic eruptions and volcanic ash clouds, detection of sulfur gases in the cabin, and other conditions pertinent to flight safety. Controllers must provide the information in sufficient detail to assist pilots in making decisions pertinent to flight safety.
NOTE
Routine PIREPs indicating a lack of forecasted weather conditions, for example, a lack of icing or turbulence, are also valuable to aviation weather forecasters and pilots. This is especially true when adverse conditions are expected or forecasted but do not develop or no longer exist.
REFERENCE
FAA Order JO 7110.65, Para 3-1-8, Low Level Wind Shear/Microburst Advisories. FAA Order JO 7110.65, Para 3-3-4, Braking Action. P/CG Term- Braking Action. FAA Order JO 7210.3, Para 6-3-1, Handling of SIGMETs, CWAs, and PIREPs. AIM, Para 7-5-9, Flight Operations in Volcanic Ash. FAA Order JO 7210.3, Para 10-3-1, Dissemination of Weather Information. FAA Order JO 7110.10, Chapter 8, Section 1, Pilot Weather Reports.
Solicit PIREPs when requested, deemed necessary or any of the following conditions exists or is forecast for your area of jurisdiction:
Ceilings at or below 5,000 feet. These PIREPs must include cloud bases, tops and cloud coverage when available. Additionally, when providing approach control services, ensure that at least one descent/climb–out PIREP and other related phenomena is obtained each hour.
Visibility (surface or aloft) at or less than 5 miles.
Thunderstorms and related phenomena.
Turbulence of moderate degree or greater.
Icing of light degree or greater.
Wind shear.
Braking action reports less than good.
Volcanic ash clouds.
Detection of sulfur gases (SO₂ or H₂S), associated with volcanic activity, in the cabin.
NOTE
1. The smell of sulfur gases in the cockpit may indicate volcanic activity that has not yet been detected or reported and/or possible entry into an ash‐bearing cloud. SO₂ is identifiable as the sharp, acrid odor of a freshly struck match. H₂S has the odor of rotten eggs. 2. 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.
Categorize PIREPs as follows:
URGENT. The following weather phenomena must be classified as an URGENT PIREP (UUA):
Tornadoes, funnel clouds, or waterspouts.
Severe or extreme turbulence (including clear air turbulence).
Severe icing.
Hail.
Low‐level wind shear (LLWS). For the safety of light aircraft, classify low‐level wind shear PIREPs as UUA if the pilot reports airspeed fluctuations of 10 knots or more. Classify reports of low‐level wind shear with airspeed fluctuations less than 10 knots as routine. If airspeed fluctuation is not reported, classify PIREP as UUA.
NOTE
Low‐level wind shear is defined as wind shear within 2,000 feet of the surface.
Volcanic eruption, ash clouds, and/or detection of sulfur gases (H₂S or SO₂) in the cabin, however, if a pilot only reported the smell of H₂S or SO₂ in the cabin and confirmed no volcanic ash clouds were present, classify the report as a ROUTINE PIREP.
Any other weather phenomena reported which in your opinion may be hazardous, or potentially hazardous, to flight operations.
ROUTINE. Classify as ROUTINE (UA) all PIREPs received except those listed above.
Record with the PIREPs:
Time.
Aircraft position.
Type aircraft.
Altitude or range of altitudes.
When the PIREP involves turbulence, include:
Duration (occasional, intermittent, or continuous).
Intensity (light, moderate, severe, or extreme).
NOTE
The duration and intensity of turbulence is determined by the pilot.
When the PIREP involves icing, include:
Icing type and intensity (trace, light, moderate, or severe).
Air temperature in which icing is occurring.
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/SAY FLIGHT CONDITIONS. Or if appropriate, REQUEST/SAY (specific conditions; i.e., ride, cloud, visibility, etc.) CONDITIONS. If necessary, OVER (fix), or ALONG PRESENT ROUTE, or BETWEEN (fix) AND (fix).
Disseminate PIREPs as follows:
Relay pertinent PIREP information to concerned aircraft in a timely manner.
NOTE
Use the word gain and/or loss when describing to pilots the effects of wind shear on airspeed.
EXAMPLE
“Delta Seven Twenty-one, a Boeing Seven Thirty-seven, previously reported wind shear, loss of two five knots at four hundred feet.” “Alaska One, a Boeing Seven Thirty-seven, previously reported wind shear, gain of two-five knots between niner hundred and six hundred feet, followed by a loss of five zero knots between five hundred feet and the surface.”
REFERENCE
AIM, Para 7-1-22, Wind Shear PIREPs.
EN ROUTE. Relay all operationally significant PIREPs to the facility weather coordinator.
REFERENCE
FAA Order JO 7210.3, Para 6-3-1, Handling of SIGMETs, CWAs, and PIREPs.
TERMINAL. Relay all operationally significant PIREPs to:
The appropriate intrafacility positions.
The OS/CIC for long line dissemination via an FAA approved electronic system (for example, AIS-R, or similar systems); or,
Outside Alaska: The overlying ARTCC's Flight Data Unit for long-line dissemination.
Alaska Only: The FSS serving the area in which the report was obtained.
NOTE
The FSS in Alaska is responsible for long line dissemination.
REFERENCE
FAA Order JO 7110.65, Para 2-1-2, Duty Priority.
Other concerned terminal or en route ATC facilities, including non-FAA facilities.
2-6-3 REPORTING WEATHER CONDITIONS
When the prevailing visibility at the usual point of observation, or at the tower level, is less than 4 miles, tower personnel must take prevailing visibilityobservations and apply the observations as follows:
Use the lower of the two observations (tower or surface) for aircraft operations.
Forward tower visibility observations to the weather observer.
Notify the weather observer when the tower observes the prevailing visibility decrease to less than 4 miles or increase to 4 miles or more.
Describe the wind as calm when the wind velocity is less than three knots.
REFERENCE
FAA Order JO 7110.65, Para 3-5-3, Tailwind Components. FAA Order JO 7110.65, Para 3-10-4, Intersecting Runway/Intersecting Flight Path Separation.
Forward current weather changes to the appropriate control facility as follows:
When the official weather changes to a condition:
Less than a 1,000-foot ceiling or below the highest circling minimum, whichever is greater.
Where the visibility is less than 3 miles.
Where conditions improve to values greater than those listed in (a) and (b).
When 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.
Towers at airports where military turbo-jet en route descents are routinely conducted must also report the conditions to the ARTCC even if it is not the controlling facility.
If the receiving facility informs you that weather reports are not required for a specific time period, discontinue the reports.
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.
REFERENCE
FAA Order JO 7110.65, Para 3-10-2, Forwarding Approach Information by Nonapproach Control Facilities.
2-6-4 ISSUING WEATHER AND CHAFF AREAS
Controllers must issue pertinent information on observed/reported weather and chaff areas to potentially affected aircraft. Define the area of coverage in terms of:
Azimuth (by referring to the 12‐hour clock) and distance from the aircraft and/or
The general width of the area and the area of coverage in terms of fixes or distance and direction from fixes.
NOTE
Weather significant to the safety of aircraft includes conditions such as funnel cloud activity, lines of thunderstorms, embedded thunderstorms, large hail, wind shear, microbursts, moderate to extreme turbulence (including CAT), and light to severe icing.
REFERENCE
AIM, Para 7-1-12, ATC Inflight Weather Avoidance Assistance.
PHRASEOLOGY
WEATHER/CHAFF AREA BETWEEN (number) O'CLOCK AND (number) O'CLOCK (number) MILES, and/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).
Inform any tower for which you provide approach control services of observed precipitation on radar which is likely to affect their operations.
Use the term “weather” when describing satellite‐derived weather, e.g., Offshore Precipitation Capability (OPC), using the phraseology in subparagraph a above. Do not issue intensity based on satellite‐derived weather.
Use the term “precipitation” when describing radar-derived weather. Issue the precipitation intensity from the lowest descriptor (LIGHT) to the highest descriptor (EXTREME) when that information is available. Do not use the word “turbulence” in describing radar-derived weather.
LIGHT.
MODERATE.
HEAVY.
EXTREME.
NOTE
Light precipitation is not displayed in ERAM.
PHRASEOLOGY
AREA OF (Intensity) PRECIPITATION BETWEEN (number) O'CLOCK AND (number) O'CLOCK, (number) MILES, MOVING (direction) AT (number) KNOTS, TOPS (altitude). AREA IS (number) MILES IN DIAMETER.
EXAMPLE
1. “Area of heavy precipitation between ten o'clock and two o'clock, one five miles. Area is two five miles in diameter.” 2. “Area of heavy to extreme precipitation between ten o'clock and two o'clock, one five miles. Area is two five miles in diameter.”
REFERENCE
P/CG Term - Precipitation Radar Weather Descriptions.
TERMINAL: In STARS, correlate precipitation descriptors from subparagraph d as follows:
Level 1 = LIGHT
Level 2 = MODERATE
Levels 3 and 4 = HEAVY
Levels 5 and 6 = EXTREME
When precipitation intensity information is not available.
PHRASEOLOGY
AREA OF PRECIPITATION BETWEEN (number) O'CLOCK AND (number) O'CLOCK, (number) MILES. MOVING (direction) AT (number) KNOTS, TOPS (altitude). AREA IS (number) MILES IN DIAMETER, INTENSITY UNKNOWN.
EXAMPLE
“Area of precipitation between one o'clock and three o'clock, three five miles moving south at one five knots, tops flight level three three zero. Area is three zero miles in diameter, intensity unknown.”
NOTE
Phraseology using precipitation intensity descriptions is only applicable when the radar precipitation intensity information is determined by NWS radar equipment or NAS ground based digitized radar equipment with weather capabilities. This precipitation may not reach the surface.
EN ROUTE. When issuing precipitation intensity, use the following:
Describe the lowest displayable precipitation intensity as MODERATE.
Describe the highest displayable precipitation intensity as HEAVY to EXTREME.
PHRASEOLOGY
AREA OF (Intensity) PRECIPITATION BETWEEN (number) O'CLOCK and (number) O'CLOCK, (number) MILES, MOVING (direction) AT (number) KNOTS, TOPS (altitude). If applicable, AREA IS (number) MILES IN DIAMETER.
EXAMPLE
1. “Area of moderate precipitation between ten o'clock and one o'clock, three zero miles moving east at two zero knots, tops flight level three seven zero. 2. “Area of moderate precipitation between ten o'clock and three o'clock, two zero miles. Area is two five miles in diameter.”
Controllers must ensure that the highest available level of precipitation intensity within their area of jurisdiction is displayed unless operational/equipment limitations exist.
When requested by the pilot, provide radar navigational guidance and/or approve deviations around weather or chaff areas. In areas of significantweather, plan ahead and be prepared to suggest, upon pilot request, the use of alternative routes/altitudes.
An approval for lateral deviation authorizes the pilot to maneuver left or right within the lateral limits specified in the clearance.
REFERENCE
AIM, Para 7-1-12, ATC Inflight Weather Avoidance Assistance, Subpara b1(b).
When approving a weather deviation for an aircraft that had previously been issued a crossing altitude, including climb via or descend via clearances, issue an altitude to maintain and, if necessary, assign a speed along with the clearance to deviate. If you intend on clearing the aircraft to resume the procedure, advise the pilot.
PHRASEOLOGY
DEVIATION (restrictions, if necessary) APPROVED, MAINTAIN (altitude), (if necessary) MAINTAIN (speed), (if applicable) EXPECT TO RESUME (SID/STAR, etc.) AT (NAVAID, fix/waypoint).
NOTE
After a climb via or descend via clearance has been issued, a vector/deviation off of a SID/STAR cancels all published altitude and speed restrictions on the procedure. The aircraft's Flight Management System (FMS) may be unable to process crossing altitude restrictions once the aircraft leaves the SID/STAR lateral path. Without an assigned altitude, the aircraft's FMS may revert to leveling off at the altitude set by the pilot, which may be the SID/STAR published top or bottom altitude.
REFERENCE
FAA Order JO 7110.65, Para 4-2-5, Route or Altitude Amendments. FAA Order JO 7110.65, Para 5-6-1, Application. FAA Order JO 7110.65, Para 5-6-2, Methods.
If a pilot enters your area of jurisdiction already deviating for weather, advise the pilot of any additional weather which may affect the route.
NOTE
When aircraft are deviating around weather and transitioning from sector to sector, unless previously coordinated, the receiving controller should not assume that the transferring controller has issued weather affecting the aircraft's route of flight.
If traffic and airspace (i.e., special use airspace boundaries, LOA constraints) permit, combine the approval for weather deviation with a clearance on course.
PHRASEOLOGY
DEVIATION (restrictions if necessary) APPROVED, WHEN ABLE, PROCEED DIRECT (name of NAVAID/WAYPOINT/FIX) or DEVIATION (restrictions if necessary) APPROVED, WHEN ABLE, FLY HEADING (degrees), VECTOR TO JOIN (airway) AND ADVISE.
EXAMPLE
1. “Deviation 20 degrees right approved, when able proceed direct O'Neill VORTAC and advise.” En Route: The corresponding fourth line entry is “D20R/ONL” or “D20R/F.” 2. “Deviation 30 degrees left approved, when able fly heading zero niner zero, vector to join J324 and advise.” En Route: In this case the free text character limitation prevents use of fourth line coordination and verbal coordination is required.
If traffic or airspace prevents you from clearing the aircraft on course at the time of the approval for a weather deviation, instruct the pilot to advise when clear of weather.
PHRASEOLOGY
DEVIATION (restrictions if necessary) APPROVED, ADVISE CLEAR OF WEATHER.
EXAMPLE
“Deviation North of course approved, advise clear of weather.” En Route: In this case the corresponding fourth line entry is “DN,” and the receiving controller must provide a clearance to rejoin the route in accordance with paragraph 2-1-15c.
When a deviation cannot be approved as requested because of traffic, take an alternate course of action that provides positive control for trafficresolution and satisfies the pilot's need to avoid weather.
PHRASEOLOGY
UNABLE REQUESTED DEVIATION, FLY HEADING (heading), ADVISE CLEAR OF WEATHER or UNABLE REQUESTED DEVIATION, TURN (number of degrees) DEGREES (left or right) VECTOR FOR TRAFFIC, ADVISE CLEAR OF WEATHER,
EXAMPLE
“Unable requested deviation, turn thirty degrees right vector for traffic, advise clear of weather.”
When forwarding weather deviation information, the transferring controller must clearly coordinate the nature of the route guidance service being provided. This coordination should include, but is not limited to: assigned headings, suggested headings, pilot-initiated deviations. Coordination can be accomplished by: verbal, automated, or predetermined procedures. Emphasis should be made between: controller assigned headings, suggested headings, or pilot initiated deviations.
EXAMPLE
“(call sign) assigned heading three three zero for weather avoidance” “(call sign) deviating west, pilot requested…”
REFERENCE
FAA Order JO 7110.65, Para 2-1-14, Coordinate Use Of Airspace. FAA Order JO 7110.65, Para 5-4-5, Transferring Controller Handoff. FAA Order JO 7110.65, Para 5-4-6, Receiving Controller Handoff. FAA Order JO 7110.65, Para 5-4-9, Prearranged Coordination. FAA Order JO 7110.65, Para 5-4-10, En Route Fourth Line Data Block Usage.
En Route Fourth Line Data Transfer
The inclusion of /(NAVAID) or /(waypoint), when preceded by the designated characters for weather deviations, indicates that a pilot has been authorized to deviate for weather and rejoin the route at the specified NAVAID or waypoint. The use of /F, following the designated weather deviation characters, indicates that a pilot has been authorized to deviate and rejoin the route of flight at the next NAVAID or waypoint in the flight plan.
REFERENCE
FAA Order JO 7110.65, Para 5-4-10, En Route Fourth Line Data Block Usage.
EXAMPLE
“Deviation twenty degrees right approved, when able proceed direct O'Neill VORTAC and advise.” In this case, the corresponding fourth line entry is “D20R/ONL,” or “D20R/F” if O'Neill is the next NAVAID in the flight plan.
The absence of a NAVAID, waypoint, or /F in the fourth line indicates that:
The pilot has been authorized to deviate for weather only, and the receiving controller must provide a clearance to rejoin the route in accordance with paragraph 2-1-15c.
EXAMPLE
“Deviation twenty degrees right approved, advise clear of weather.”
The free text character limitation prevents the use of fourth line coordination. Verbal coordination is required.
EXAMPLE
“Deviation 30 degrees left approved, when able fly heading zero niner zero, vector to join J324 and advise.”
The supervisory traffic management coordinator-in-charge/operations supervisor/ controller‐in‐charge must verify the digitized radar weather information by the best means available (e.g., pilot reports, local tower personnel, etc.) if the weather data displayed by digitized radar is reported as questionable or erroneous. Errors in weather radar presentation must be reported to the technical operations technician and the air traffic supervisor must determine if the digitized radar 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.
2-6-5 DISSEMINATING OFFICIAL WEATHER INFORMATION
TERMINAL. Observed elements of weather information must be disseminated as follows:
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.
Specific values, such as ceiling and visibility, may be transmitted if obtained by one of the following means:
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.
You have obtained the information from the official observer for the elements being reported.
The weather report was composed or verified by the weather station.
The information is obtained from a FAA approved automation surface weather system.
Differences between weather elements observed from the tower and those reported by the weather station must be reported to the official observer for the element concerned.
2-6-6 HAZARDOUS INFLIGHT WEATHER ADVISORY
Controllers must advise pilots of hazardous weather that may impact operations within 150 NM of their sector or area of jurisdiction. Hazardous weather information contained in the advisories includes Airmen's Meteorological Information (AIRMET) (except over the CONUS), Significant Meteorological Information (SIGMET), Convective SIGMET (WST), Urgent Pilot Weather Reports (UUA), and Center Weather Advisories (CWA). Facilities must review alert messages to determine the geographical area and operational impact of hazardous weather information. Advisories are not required if aircraft on your frequency(s) will not be affected.
NOTE
In recognition that there are several uses/definitions for the acronym CONUS, references herein to CONUS are specific to the contiguous United States (i.e., “lower 48”).
Controllers must broadcast a hazardous inflight weather advisory 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. Pilots requesting additional information must be directed to contact the nearest Flight Service.
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 (specific weather phenomenon) WITHIN (geographical area), AVAILABLE ON FLIGHT SERVICE FREQUENCIES.
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.
REFERENCE
AIM, Chapter 7, Section 1, Meteorology, Para 7-1-5 through Para 7-1-7.
EN ROUTE. ERAM. Controllers must electronically acknowledge hazardous weather information messages after appropriate action has been taken.
NOTE
EN ROUTE. While hazardous weather information is commonly distributed via the SIGMET View, it is possible to receive the information via the GI View.