Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-26
Figure 9-22. FIP Example
9.4.3 Strengths and Limitations
Strengths
The FIP can be used to help determine the forecast for potential for icing through the entire vertical depth of the atmosphere.
The product is updated hourly.
Limitations
The product does not display any information about the severity of icing.
The product only displays the forecast potential for icing, not the absolute probability.
It is only approved for use by meteorologists and dispatchers.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-27
The product is generated without human modification. Therefore, the forecasts are only as accurate the computer model output used to create them.
9.4.4 Use The FIP is primarily used to help determine the likelihood of icing at the specified forecast valid times.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-28
9.5 Graphical Turbulence Guidance (GTG) The Graphical Turbulence Guidance (GTG) product suite provides a three-dimensional diagnosis and forecast of Clear Air Turbulence (CAT) potential. The GTG is created using a combination of computer model output and turbulence observations. The GTG product suite, which consists of the GTG analysis and forecast and Composite analysis and forecast, is automatically generated with no human modifications. It may be used as a supplement to AIRMETs and SIGMETs but is not a substitute for them. It is authorized for operational use only by meteorologist and dispatchers. The GTG is available for the 48-contiguous states, much of Canada and Mexico and their respective coastal waters.
9.5.1 Issuance The GTG analysis is issued hourly. The 3-, 6-, 9-, and 12-hour forecasts are issued every three hours beginning at 00Z. For example, a forecast suite issued at 0600Z would have valid times at 0900Z, 1200Z, 1500Z, and 1800Z respectively. The GTG Analysis and Forecasts, along with the Composite products, are issued by the Aviation Weather Center (AWC) and are available through the Aviation Digital Data Service (ADDS) web site at:
http://adds.aviationweather.noaa.gov/turbulence/turb_nav.php.
9.5.2 Content
9.5.2.1 GTG Analysis and Forecast The GTG Analysis and Forecast graphics depict the location and intensity of potential Clear Air Turbulence (CAT) (Figure 9-18). Standard intensity terminology is used. The GTG output is available for 1,000 foot vertical intervals between FL200 and FL450. ADDS turbulence page displays every third level starting at FL210 level, while the ADDS Flight Path Tool provides access to all levels.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-29
Figure 9-23. GTG Example
9.5.2.2 GTG Composite Analysis and Forecast The GTG Composite products display the maximum intensity of potential turbulence between FL200 and FL450 (Figure 9-19). In other words, at any given location, the displayed value represents the maximum potential turbulence between FL200 and FL450. Single altitude graphics must be examined to determine the altitude of the potential turbulence.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-30
Figure 9-24. GTG Composite Example
9.5.3 Strengths and Limitations The GTG provides an hourly, high resolution analysis and forecast of clear-air turbulence potential at and above FL200. However, the product is only for turbulence associated with upper level fronts and jet streams while other known causes of turbulence are not forecasted.
Strengths
The product is issued hourly
Turbulence is plotted to a high resolution.
Limitations
The accuracy of the analysis is dependent on the number of PIREPs available.
Typically at night fewer pilot reports are received, so the accuracy decreases.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-31 For the GTG forecast, the product is only as accurate the computer model output used to create them.
The product only displays clear air turbulence (CAT) for upper-level fronts and the jet stream. Other known causes of turbulence are not included in the product.
Data and forecast are only available for FL200 and above.
It is only approved for use by meteorologists and dispatchers.
9.5.4 Use The Composite product can provide a quick method to determine what the greatest potential of current or forecast turbulence is at a given location. However, to determine the turbulence potential at any given altitude, the individual altitude products must be viewed.
The ADDS web site allows users to overlay turbulence PIREPS on the single altitude graphics.
For the PIREP to be plotted on the single altitude product, it must be located within 1,000 feet vertically of the altitude and have been reported within 90 minutes of the chart time. For example, if a user viewed the FL240 GTG product with a valid time of 1400Z the displayed PIREPS could be located between FL230 and FL250 and reported between 1230Z and 1400Z.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-32
9.6 Meteorological Impact Statement (MIS) A Meteorological Impact Statement (MIS) is an unscheduled flow control and flight operations planning forecast issued by Center Weather Service Units (CWSUs) (Figures 9-21 and 9-22). It is a forecast and briefing product for personnel at Air Route Traffic Control Centers (ARTCCs), Air Traffic Control System Command Center (ATCSCC), Terminal Radar Approach Control Facilities (TRACONS) and Airport Traffic Control Towers (ATCTs) responsible for making flow control-type decisions.
A MIS may be tailored to meet the unique requirements of the host ARTCC. These special requirements will be coordinated between the host ARTCC and the CWSU.
MISs are available on the Aviation Weather Center (AWC) web site at:
http://aviationweather.gov/products/cwsu/.
9.6.1 Valid Period A MIS is valid up to 12 hours after issuance time and details weather conditions expected to adversely impact air traffic flow in the CWSU area of responsibility. The MIS can be immediately effective for existing conditions when CWSU operations begin or for rapidly deteriorating conditions or be effective up to two hours in advance of expected conditions.
9.6.2 MIS Criteria A MIS enables Air Traffic Control (ATC) facility personnel to include the impact of specific weather conditions in their flow control decision-making. At a minimum, a MIS should be issued when:
Any of the following conditions occur, are forecast to occur, and, if previously forecast, are no longer expected:
o Conditions meeting convective SIGMET criteria (Section 5.1.8)
o Icing - moderate or greater
o Turbulence - moderate or greater
o Heavy precipitation
o Freezing precipitation
o Conditions at or approaching Low IFR
o Surface winds/gusts >30 knots
o Low Level Wind Shear (surface - 2,000 feet)
o Volcanic ash, dust storms, or sandstorms; and
In the forecaster's judgment, the conditions listed above, or any others, will adversely impact the flow of air traffic within the ARTCC area of responsibility.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-33
9.6.3 MIS Issuance MIS phenomena forecasts use the location reference point identifiers depicted on the In-Flight Advisory Plotting Chart (Appendix F), and include the height, extent, and movement of the conditions. MIS product issuances are numbered sequentially beginning at Midnight local time each day. The MIS is disseminated and stored as a "replaceable" product. Therefore, each issuance will contain the details of all pertinent known conditions meeting MIS issuance criteria, including ongoing conditions described in previously issued MISs.
The MIS is distributed to ARTCC personnel, including Traffic Management Unit (TMU) personnel.
9.6.4 Format
Figure 9-25. Meteorological Impact Statement (MIS) Decoding Example
Table 9-5. Meteorological Impact Statement (MIS) – Decoding
LINE CONTENT DESCRIPTION 1 ZFW ARTCC Identification MIS Product type 01 Issuance number VALID 190200-191200 Valid period UTC date/time 2 …FOR ATC PLANNING PURPOSES ONLY… Product use statement 3 FROM OKC TO CDS TO GAG TO END TO OKC Phenomenon location 4 LLWS BLO 020 AGL DUE TO LLJ.
CONDS GRDLY IPVG AFT 10Z Phenomenon description
Any remarks such as “SEE CONVECTIVE SIGMET 8W"; "NO UPDATES AVBL AFT 0230Z";
and forecaster initials and/or facility identifier may be placed at the end of the MIS.
If the phenomenon described in a MIS is no longer expected, a cancellation MIS message may be issued. The FAA header does not contain an issuance number. If the phenomenon described in the MIS is expected to continue beyond the operating hours of the CWSU, then the remark "NO UPDATES AFT ttttZ" (where "ttttZ" is the UTC closing time of the CWSU) is added at the text end.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-34
9.6.5 Examples
ZOA MIS 01 VALID 041415-041900 ...FOR ATC PLANNING PURPOSES ONLY...
FOR SFO BAY AREA BR/FG WITH CEILING BLW 005 AND VIS OCNL BLW 1SM.
ZOA CWSU
Meteorological Impact Statement issued by the Freemont, California CWSU. First MIS issuance of the day, valid from the 4th day of the month at 1415 UTC, to the 4th day of the month at 1900 UTC. For air traffic control planning purposes only. For the San Francisco Bay Area…mist and fog with ceilings below 500 feet MSL and visibility occasionally below 1 statute mile.
ZOA MIS 02 VALID 041650 ...FOR ATC PLANNING PURPOSES ONLY...
FOR SFO BAY AREA CNL ZOA MIS 01. CONDS HAVE IMPRD.
ZOA CWSU
Meteorological Impact Statement issued by the Freemont, California CWSU. The second MIS issuance of the day, valid the 4th day of the month at 1650 UTC. For air traffic control planning purposes only. For the San Francisco Bay Area. Cancel Freemont, California Meteorological Impact Statement number 1. Conditions have improved.
ZID MIS 03 VALID 041200-042330 ...FOR ATC PLANNING PURPOSES ONLY...
FROM IND TO 17WSW APE TO LOZ TO 13NE PXV TO IND TIL 21Z MOD TURB FL310-390 DUE TO JTST WS.
ZID W OF A LINE FM FWA TO BWG AFT 18Z OCNL SEV TSGR TOPS TO FL450. MOV FM 24035KT. MAX SFC WINDS 60KT.
ZID E OF A LINE FM FWA TO 35SE BKW MOD MXD ICE IN CLDS/PRECIPITATION 020-120. CONDS ENDING W OF A 40S CLE TO 20NE BKW LINE BY 19Z.
ZID CWSU
Meteorological Impact Statement issued by the Indianapolis, Indiana CWSU. The third MIS issuance of the day, valid from the 4th day of the month at 1200 UTC to the 4th day of the month at 2130 UTC. For air traffic control planning purposes only. From Indianapolis, Indiana to 17 nautical miles west-southwest of Appleton, Ohio to London, Kentucky to 13 nautical miles northeast of Pocket City, Indiana to Indianapolis, Indiana. Until 21Z, moderate turbulence between flight level 310 and flight level 390 due to jet stream wind shear.
For the Indianapolis ARTCC airspace west of a line from Fort Wayne, Indiana to Bowling Green, Kentucky. After 18Z, occasional severe thunderstorms, hail, tops to flight level 450. Moving from 240 degrees at 35 knots. Maximum surface winds 60 knots.
For the Indianapolis, Indiana ARTCC airspace east of a line from Fort Wayne, Indiana to 35 nautical miles southeast of Beckley, West Virginia. Moderate mixed icing in clouds and precipitation between 2,000 feet to 12,000 feet MSL. Conditions ending west of a line from 40
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 nautical miles south of Cleveland, Ohio to 20 nautical miles northeast of Beckley, West Virginia by 1900Z.
Anchorage CWSU Seattle Chi/S U Minneapolis CurSU * ¡levelanc Salt Lake Thy Cusu Cuusti Dakland Denver ChiS U Chicago CựiSu * D.C.
Los Prigel CứSỦ * Memphis CurSU Abuquerque ChriS U * Fort worth Chi/s Honclulu CWSU * Houston CVSU Figure 9-26. Center Weather Service Unit (CWSU) Areas of Responsibility - CONUS Figure 9-27. CWSU Anchorage, AK (PAZA) Area of Responsibility AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-35
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 10 APPENDIX A: ASOS AND AWOS LOCATIONS ASOS and AWOS Locations HPET HPB2
• PASY SNP
• ASOS
• AWOS FED
NATIONAL WEATHER SERVICE OCTOBER 2004 ALASKA REGION
MIRS GIS GROUP Figure A-1. ASOS and AWOS Locations - NWS Alaska Region AC 00-45F (July 2008) Appendix A: ASOS and AWOS Locations Page 10-1
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 ASOS and AWOS Locations LIH PHNG HNL OGG
KOA BRADS ITO HAWAII GUAM and MARIANA ISLANDS PGSN PGUM
• ASOS
NATIONAL WEATHER SERVICE OCTOBER 200 PACIFIC REGION
MIRS GIS GROU Figure A-2. ASOS and AWOS Locations - NWS Pacific Region AC 00-45F (July 2008) Appendix A: ASOS and AWOS Locations Page 10-2