Meteorological Impact Statements

Introduction to Meteorological Impact Statements

The Meteorological Impact Statements (MIS) is a nontechnical plain language product intended primarily for FAA traffic managers and those involved in planning aircraft routing. MISs are issued by NWS Center Weather Service Units (CWSU)
Test your understanding of Meteorological Impact Statements by completing the knowledge quiz, applying your knowledge in the interactive scenario, comparing your performance against the applicable Airman Certification Standards, and concluding with the topic summary to reinforce the key concepts before moving on to the next lesson.

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Meteorological Impact Statements Key Highlights

Meteorological Impact Statements (MIS) provide aviation weather forecasters and air traffic managers with strategic weather impact information affecting air traffic operations.
MIS products summarize expected weather hazards such as thunderstorms, turbulence, icing, low ceilings, reduced visibility, and convective activity.
Air Route Traffic Control Centers and aviation weather units use MIS information to support traffic flow management and operational planning.
Meteorological Impact Statements help identify weather conditions likely to affect routing, delays, airport capacity, and airspace utilization.
MIS products are generally focused on large-scale operational impacts rather than tactical pilot weather decision-making.
Forecasters develop MIS guidance using weather models, radar imagery, satellite data, pilot reports, and forecast products.
Convective weather, winter storms, volcanic ash, and widespread IFR conditions commonly generate significant MIS operational concerns.
Pilots may encounter MIS-related weather impacts through reroutes, delays, ground stops, or airspace flow restrictions.
Weather conditions described in MIS products can evolve rapidly and should be monitored with current aviation weather information.
Understanding Meteorological Impact Statements improves weather awareness, operational planning knowledge, and overall aviation safety.

Meteorological Impact Statements

Issuance and Validity

A Meteorological Impact Statement's valid period is determined by local policy
A Meteorological Impact Statement cannot be valid for more than 48 hours
- It must be updated or canceled when it no longer describes the expected conditions

Meteorological Impact Statements

Purpose and Content

A Meteorological Impact Statement (MIS) is a plain-language planning forecast for FAA traffic managers and aircraft-routing planners issued by a National Weather Service Center Weather Service Unit (CWSU).
It describes weather that may disrupt air traffic flow, including the cause, affected area, altitudes, movement, and expected operational impact.
A statement may link to an online graphic when it helps explain a complex weather pattern.
Statements are numbered sequentially beginning at midnight local time and issued as replaceable products, so each new statement supersedes the previous one.
A Meteorological Impact Statement supports traffic-flow planning and is not intended to replace pilot weather advisories or a complete preflight briefing.

Meteorological Impact Statements

Meteorological Impact Statement Formatting

The MIS format consists of a communication header line, the words "FOR ATC PLANNING PURPOSES ONLY," and the text
MIR Header:
- zzz MIS ii Valid ddtttt-ddtttt.
- Zzz is the ARTCC identification (i.e. ZJX), MIS is the product type, ii is the 2-digit sequential issuance number, and ddtttt is the valid beginning and ending date/time UTC.
MIR Disclaimer:
- The line immediately below the header line reads "FOR ATC PLANNING PURPOSES ONLY".
MIR Content:
- The maximum length of the MIS is four lines. The MIS is nontechnical in nature to convey expected weather and impacts in the clearest and simplest manner possible to the user. References to a graphical product on the local CWSU website or https://www.aviationweather.gov may be included.

Meteorological Impact Statements

Meteorological Impact Statements Interactive Scenario

Interactive Scenario

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Meteorological Impact Statements

Meteorological Impact Statements Knowledge Check

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Private Pilot

PPL knowledge check

Core Knowledge Review

Review foundational knowledge, key concepts, and practical considerations. Topic: Meteorological Impact Statements.

Immediate feedback
Answer explanations
Account progress tracking

Why Take a Quiz?

Quizzes reinforce key concepts, identify knowledge gaps, and build confidence for real-world decisions. Quiz material is representative of the information provided here and is not based on or sourced from the Federal Aviation Administration test bank.

Meteorological Impact Statements

Meteorological Impact Statements-Related Airman Certification Standards

Sport Pilot (Airplane) Weather Information Practical Test Standards:

Source: FAA-S-8081-29A, Section 1 - Sport Pilot Airplane.
Objective: To determine that the applicant exhibits knowledge of the elements related to weather information.
References: 14 CFR part 91; AIM; FAA-H-8083-25; AC 00-6; AC 00-45; Aviation Weather Reports, Charts, and Forecasts.
Sport Pilot (Airplane) Weather Information Lesson Plan.

Objective Elements 4 PTS Elements

SP.1:
Exhibits knowledge of the elements related to real-time weather information appropriate to the specific category/class aircraft by consulting weather reports, charts, and forecasts from aeronautical weather-reporting sources.
SP.2:
Makes a competent “go/no-go” decision based on available weather information.
SP.3:
Describes the importance of avoiding adverse weather and inadvertent entry into IMC.
SP.4:
Explains courses of action to safely exit from an inadvertent IMC encounter.

Private Pilot (Airplane) Weather Information Airman Certification Standards:

Source: FAA-S-ACS-6C, Private Pilot - Airplane.
Objective: To determine whether the applicant exhibits satisfactory knowledge, risk management, and skills associated with weather information for a flight under VFR.
References: 14 CFR part 91; AC 91-92; AIM; FAA-H-8083-2; FAA-H-8083-3; FAA-H-8083-25; FAA-H-8083-28.
Private Pilot (Airplane) Weather Information Lesson Plan.

Knowledge 4 ACS Elements

PA.I.C.K1:
Sources of weather data (e.g., National Weather Service and Flight Service) for flight planning purposes.
PA.I.C.K2:
Acceptable weather products and resources required for preflight planning and current and forecast weather for departure, en route, and arrival phases of flight, such as:
- PA.I.C.K2a:
  Airport observations (METAR and SPECI) and pilot observations (PIREP).
- PA.I.C.K2b:
  Surface Analysis Chart and Ceiling and Visibility Chart (CVA).
- PA.I.C.K2c:
  Terminal Aerodrome Forecasts (TAF).
- PA.I.C.K2d:
  Graphical Forecasts for Aviation (GFA).
- PA.I.C.K2e:
  Wind and Temperature Aloft Forecast (FB).
- PA.I.C.K2f:
  Convective Outlook (AC).
- PA.I.C.K2g:
  Inflight aviation weather advisories, including Airmen’s Meteorological Information (AIRMET), Significant Meteorological Information (SIGMET), and Convective SIGMET.
PA.I.C.K3:
Meteorology applicable to the departure, en route, alternate, and destination under visual flight rules (VFR) in visual meteorological conditions (VMC), including expected climate and hazardous conditions such as:
- PA.I.C.K3a:
  Atmospheric composition and stability.
- PA.I.C.K3b:
  Wind (e.g., crosswind, tailwind, wind shear, and mountain wave).
- PA.I.C.K3c:
  Temperature and heat exchange.
- PA.I.C.K3d:
  Moisture and precipitation.
- PA.I.C.K3e:
  Weather-system formation, including air masses and fronts.
- PA.I.C.K3f:
  Clouds.
- PA.I.C.K3g:
  Turbulence.
- PA.I.C.K3h:
  Thunderstorms and microbursts.
- PA.I.C.K3i:
  Icing and freezing-level information.
- PA.I.C.K3j:
  Fog and mist.
- PA.I.C.K3k:
  Frost.
- PA.I.C.K3l:
  Obstructions to visibility (e.g., smoke, haze, and volcanic ash).
PA.I.C.K4:
Flight deck displays of digital weather and aeronautical information.

Risk Management 2 ACS Elements

PA.I.C.R1:
Making the go/no-go and continue/divert decisions, including:
- PA.I.C.R1a:
  Circumstances that would make diversion prudent.
- PA.I.C.R1b:
  Personal weather minimums.
- PA.I.C.R1c:
  Hazardous weather conditions, including known or forecast icing or turbulence aloft.
PA.I.C.R2:
Use and limitations of:
- PA.I.C.R2a:
  Installed onboard weather equipment.
- PA.I.C.R2b:
  Aviation weather reports and forecasts.
- PA.I.C.R2c:
  Inflight weather resources.

Skills 3 ACS Elements

PA.I.C.S1:
Use available aviation weather resources to obtain an adequate weather briefing.
PA.I.C.S2:
Analyze the implications of at least three of the conditions listed in K3a through K3l, using actual weather or weather conditions provided by the evaluator.
PA.I.C.S3:
Correlate weather information to make a go/no-go decision.

Commercial Pilot (Airplane) Weather Information Airman Certification Standards:

Source: FAA-S-ACS-7B, Commercial Pilot - Airplane.
Objective: To determine whether the applicant exhibits satisfactory knowledge, risk management, and skills associated with weather information for a flight under VFR.
References: 14 CFR part 91; AC 91-92; AIM; FAA-H-8083-2; FAA-H-8083-3; FAA-H-8083-25; FAA-H-8083-28.
Commercial Pilot (Airplane) Weather Information Lesson Plan.

Knowledge 4 ACS Elements

CA.I.C.K1:
Sources of weather data (e.g., National Weather Service and Flight Service) for flight planning purposes.
CA.I.C.K2:
Acceptable weather products and resources required for preflight planning and current and forecast weather for departure, en route, and arrival phases of flight, such as:
- CA.I.C.K2a:
  Airport observations (METAR and SPECI) and pilot observations (PIREP).
- CA.I.C.K2b:
  Surface Analysis Chart and Ceiling and Visibility Chart (CVA).
- CA.I.C.K2c:
  Terminal Aerodrome Forecasts (TAF).
- CA.I.C.K2d:
  Graphical Forecasts for Aviation (GFA).
- CA.I.C.K2e:
  Wind and Temperature Aloft Forecast (FB).
- CA.I.C.K2f:
  Convective Outlook (AC).
- CA.I.C.K2g:
  Inflight aviation weather advisories, including Airmen’s Meteorological Information (AIRMET), Significant Meteorological Information (SIGMET), and Convective SIGMET.
CA.I.C.K3:
Meteorology applicable to the departure, en route, alternate, and destination under visual flight rules (VFR) in visual meteorological conditions (VMC), including expected climate and hazardous conditions such as:
- CA.I.C.K3a:
  Atmospheric composition and stability.
- CA.I.C.K3b:
  Wind (e.g., crosswind, tailwind, wind shear, and mountain wave).
- CA.I.C.K3c:
  Temperature and heat exchange.
- CA.I.C.K3d:
  Moisture and precipitation.
- CA.I.C.K3e:
  Weather-system formation, including air masses and fronts.
- CA.I.C.K3f:
  Clouds.
- CA.I.C.K3g:
  Turbulence.
- CA.I.C.K3h:
  Thunderstorms and microbursts.
- CA.I.C.K3i:
  Icing and freezing-level information.
- CA.I.C.K3j:
  Fog and mist.
- CA.I.C.K3k:
  Frost.
- CA.I.C.K3l:
  Obstructions to visibility (e.g., smoke, haze, and volcanic ash).
CA.I.C.K4:
Flight deck displays of digital weather and aeronautical information.

Risk Management 2 ACS Elements

CA.I.C.R1:
Making the go/no-go and continue/divert decisions, including:
- CA.I.C.R1a:
  Circumstances that would make diversion prudent.
- CA.I.C.R1b:
  Personal weather minimums.
- CA.I.C.R1c:
  Hazardous weather conditions, including known or forecast icing or turbulence aloft.
CA.I.C.R2:
Use and limitations of:
- CA.I.C.R2a:
  Installed onboard weather equipment.
- CA.I.C.R2b:
  Aviation weather reports and forecasts.
- CA.I.C.R2c:
  Inflight weather resources.

Skills 3 ACS Elements

CA.I.C.S1:
Use available aviation weather resources to obtain an adequate weather briefing.
CA.I.C.S2:
Analyze the implications of at least three of the conditions listed in K3a through K3l, using actual weather or weather conditions provided by the evaluator.
CA.I.C.S3:
Correlate weather information to make a go/no-go decision.

Private Pilot (Helicopter) Weather Information Airman Certification Standards

Area of Operation I: Preflight Preparation.
Task C: Weather Information.
Objective: To determine the applicant exhibits satisfactory knowledge, risk management, and skills associated with weather information for a flight under VFR.
Note: If K2 is selected, the evaluator must assess the applicant's knowledge of at least three sub-elements.
Note: If K3 is selected, the evaluator must assess the applicant's knowledge of at least three sub-elements.
References: 14 CFR part 91; AC 91-92; AIM; FAA-H-8083-2, FAA-H-8083-21, FAA-H-8083-25, FAA-H-8083-28
Private Pilot (Helicopter) Weather Information Lesson Plan.

Knowledge 4 ACS Elements

PH.I.C.K1:
Sources of weather data (e.g., National Weather Service, Flight Service) for flight planning purposes.
PH.I.C.K2:
Acceptable weather products and resources required for preflight planning, current and forecast weather for departure, en route, and arrival phases of flight such as:
- PH.I.C.K2a:
  a. Airport Observations (METAR and SPECI) and Pilot Observations (PIREP)
- PH.I.C.K2b:
  b. Surface Analysis Chart, Ceiling and Visibility Chart (CVA)
- PH.I.C.K2c:
  c. Terminal Aerodrome Forecasts (TAF)
- PH.I.C.K2d:
  d. Graphical Forecasts for Aviation (GFA)
- PH.I.C.K2e:
  e. Wind and Temperature Aloft Forecast (FB)
- PH.I.C.K2f:
  f. Convective Outlook (AC)
- PH.I.C.K2g:
  g. Inflight Aviation Weather Advisories including Airmen's Meteorological Information (AIRMET), Significant Meteorological Information (SIGMET), and Convective SIGMET
PH.I.C.K3:
Meteorology applicable to the departure, en route, alternate, and destination under visual flight rules (VFR) in Visual Meteorological Conditions (VMC), including expected climate and hazardous conditions such as:
- PH.I.C.K3a:
  a. Atmospheric composition and stability
- PH.I.C.K3b:
  b. Wind (e.g., windshear, mountain wave, factors affecting wind, etc.)
- PH.I.C.K3c:
  c. Temperature and heat exchange
- PH.I.C.K3d:
  d. Moisture/precipitation
- PH.I.C.K3e:
  e. Weather system formation, including air masses and fronts
- PH.I.C.K3f:
  f. Clouds
- PH.I.C.K3g:
  g. Turbulence
- PH.I.C.K3h:
  h. Thunderstorms and microbursts
- PH.I.C.K3i:
  i. Icing and freezing level information
- PH.I.C.K3j:
  j. Fog/mist
- PH.I.C.K3k:
  k. Frost
- PH.I.C.K3l:
  l. Obstructions to visibility (e.g., smoke, haze, volcanic ash, etc.)
PH.I.C.K4:
Flight deck instrument displays of digital weather and aeronautical information.

Risk Management 2 ACS Elements

PH.I.C.R1:
Making the go/no-go and continue/divert decisions, including:
- PH.I.C.R1a:
  a. Circumstances that would make diversion prudent
- PH.I.C.R1b:
  b. Personal weather minimums
- PH.I.C.R1c:
  c. Hazardous weather conditions, including known or forecast icing or turbulence aloft
PH.I.C.R2:
Use and limitations of:
- PH.I.C.R2a:
  a. Installed onboard weather equipment
- PH.I.C.R2b:
  b. Aviation weather reports and forecasts
- PH.I.C.R2c:
  c. Inflight weather resources

Skills 3 ACS Elements

PH.I.C.S1:
Use available aviation weather resources to obtain an adequate weather briefing.
PH.I.C.S2:
Analyze the implications of at least three of the conditions listed in K3a through K3l, using actual weather or weather conditions provided by the evaluator.
PH.I.C.S3:
Correlate weather information to make a go/no-go decision.

Sport Pilot (Helicopter) Weather Information Airman Certification Standards

Area of Operation I: Preflight Preparation.
Task C: Weather Information.
Objective: To determine the applicant exhibits satisfactory knowledge, risk management, and skills associated with weather information for a flight under VFR.
References: 14 CFR part 91; AC 91-92; AIM; FAA-H-8083-2, FAA-H-8083-21, FAA-H-8083-25, FAA-H-8083-28
Sport Pilot (Helicopter) Weather Information Lesson Plan.

Knowledge 4 ACS Elements

SH.I.C.K1:
Sources of weather data (e.g., National Weather Service, Flight Service) for flight planning purposes.
SH.I.C.K2:
Acceptable weather products and resources required for preflight planning, current and forecast weather for departure, en route, and arrival phases of flight such as:
- SH.I.C.K2a:
  Airport Observations (METAR, SPECI, AWOS, ASOS) and Pilot Weather Reports (PIREPs)
- SH.I.C.K2b:
  Surface Analysis Chart, Ceiling and Visibility Chart (CVA)
- SH.I.C.K2c:
  Terminal Aerodrome Forecasts (TAF)
- SH.I.C.K2d:
  Graphical Forecasts for Aviation (GFA)
- SH.I.C.K2e:
  Wind and Temperature Aloft Forecast (FB)
- SH.I.C.K2f:
  Convective Outlook (AC)
- SH.I.C.K2g:
  Inflight Aviation Weather Advisories including Airmen's Meteorological Information (AIRMET), Significant Meteorological Information (SIGMET), and Convective SIGMET
SH.I.C.K3:
Meteorology applicable to the departure, en route, alternate, and destination under visual flight rules (VFR) in Visual Meteorological Conditions (VMC), including expected climate and hazardous conditions such as:
- SH.I.C.K3a:
  Atmospheric composition and stability
- SH.I.C.K3b:
  Wind (e.g., windshear, mountain wave, factors affecting wind, etc.)
- SH.I.C.K3c:
  Temperature, heat exchange, and temperature inversion
- SH.I.C.K3d:
  Moisture/precipitation
- SH.I.C.K3e:
  Weather system formation, including air masses and fronts
- SH.I.C.K3f:
  Clouds
- SH.I.C.K3g:
  Turbulence
- SH.I.C.K3h:
  Thunderstorms and microbursts
- SH.I.C.K3i:
  Icing and freezing level information
- SH.I.C.K3j:
  Fog/mist
- SH.I.C.K3k:
  Frost
- SH.I.C.K3l:
  Obstructions to visibility (e.g., smoke, haze, volcanic ash, etc.)
SH.I.C.K4:
Flight deck instrument displays of digital weather and aeronautical information.

Risk Management 2 ACS Elements

SH.I.C.R1:
Making the go/no-go and continue/divert decisions, including:
- SH.I.C.R1a:
  Circumstances that would make diversion prudent
- SH.I.C.R1b:
  Personal weather minimums
- SH.I.C.R1c:
  Hazardous weather conditions, including known or forecast icing or turbulence aloft
SH.I.C.R2:
Use and limitations of:
- SH.I.C.R2a:
  Installed onboard weather equipment
- SH.I.C.R2b:
  Aviation weather reports and forecasts
- SH.I.C.R2c:
  In-flight weather resources

Skills 3 ACS Elements

SH.I.C.S1:
Use available aviation weather resources to obtain an adequate weather briefing.
SH.I.C.S2:
Analyze the implications of at least three of the conditions listed in K3a through K3l, using actual weather or weather conditions provided by the evaluator.
SH.I.C.S3:
Correlate weather information to make a go/no-go decision.

Meteorological Impact Statements

Meteorological Impact Statements Conclusion

For more information, a paper copy of Aviation Weather Services: FAA Advisory Circular 00-45H, Change 1&2 (FAA Handbooks series) [Amazon] is available for purchase
- A digital copy of Federal Aviation Administration (FAA-H-8083-28) Aviation Weather Handbook is available from the FAA's website
Improve your weather skills with FAA provided (and WINGS credited) resources by going to https://www.faasafety.gov/ and type "weather" into the search bar
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Meteorological Impact Statements

Meteorological Impact Statements

Introduction to Meteorological Impact Statements

Meteorological Impact Statements Key Highlights

Issuance and Validity

Purpose and Content

Meteorological Impact Statement Formatting

MIR Header:

MIR Disclaimer:

MIR Content:

Meteorological Impact Statements Interactive Scenario

Interactive Scenario

Scenario Complete

Meteorological Impact Statements Knowledge Check

Core Knowledge Review

Advanced Application

Why Take a Quiz?

Sport Pilot (Airplane) Weather Information Practical Test Standards:

Private Pilot (Airplane) Weather Information Airman Certification Standards:

Commercial Pilot (Airplane) Weather Information Airman Certification Standards:

Private Pilot (Helicopter) Weather Information Airman Certification Standards

Sport Pilot (Helicopter) Weather Information Airman Certification Standards

Meteorological Impact Statements Conclusion

Meteorological Impact Statements References