<h2>Why Three Different Notice Systems?</h2> <p> Aviation developed three separate notice systems because different categories of information have different urgency levels, geographic scopes, and operational implications. A NOTAM about a crane at a small airport has very different time-criticality than a SIGMET for an embedded supercell. A Presidential TFR has different legal force than a NOTAM about a temporarily closed taxiway. </p> <p> For drone pilots, all three matter — and failing to check any of them before a commercial operation creates liability. DroneSkycast integrates FAA NOTAM data, TFR boundaries, and aviation weather advisories into a single pre-flight check at <a href="https://droneskycast.com/dashboard">droneskycast.com/dashboard</a>, but understanding the underlying systems helps you interpret what you see. </p> <h2>NOTAMs — Notices to Air Missions</h2> <p> A NOTAM (Notice to Air Missions, formerly Notice to Airmen) is a formal notice distributed via the FAA NOTAM system (Lido/NOTAM or the U.S. NOTAM system at notams.faa.gov) that contains information pilots need to know that is not contained in regular aeronautical charts or publications. </p> <h3>What NOTAMs Cover</h3> <ul> <li>Temporary runway closures and taxiway changes</li> <li>Temporary navigation aid outages (VOR, ILS, ATIS offline)</li> <li>Crane and construction activity near airports</li> <li>Parachute jump operations</li> <li>Temporary restricted areas (which are often published both as NOTAMs and as TFRs)</li> <li>Drone-specific NOTAMs (drone test sites, drone events)</li> <li>UAS NOTAM (NOTAM U) — specific to UAS operations</li> <li>Laser hazard NOTAMs</li> <li>Air show and special event airspace</li> </ul> <h3>NOTAM Format</h3> <p> NOTAMs are issued in a coded format. A typical NOTAM looks like: </p> <div class="callout"> <p> <strong>!MIA MIA OBST CRANE (ASN 2023-ASO-18273-OE) 254700.19N0802200.00W (4.4NM E MIA) 148FT (139FT AGL) FLAGGED AND LIGHTED</strong> </p> </div> <p> This reads: At Miami (MIA), there is a flagged and lighted crane 4.4 NM east of Miami Airport at 148 ft MSL (139 ft AGL). For a drone pilot operating at up to 400 ft AGL in that area, this NOTAM identifies a physical obstruction hazard. </p> <h3>How Long Do NOTAMs Stay Active?</h3> <p> NOTAMs include a valid period with a start date/time and either an end date/time or "PERM" for permanent. Most infrastructure-related NOTAMs (cranes, construction) stay active until the work is complete. Always check NOTAMs within 24 hours of your planned flight — they can be issued with very little notice. </p> <h2>TFRs — Temporary Flight Restrictions</h2> <p> A Temporary Flight Restriction is a type of airspace restriction published as a NOTAM (usually a NOTAM FDC — Flight Data Center) but with special regulatory force under 14 CFR 91.137–91.145. TFRs create a hard legal boundary around an area within which flight is prohibited unless you have specific authorisation. </p> <div class="callout callout-danger"> <p> <strong>Legal note:</strong> Violating a TFR is a federal crime that can result in certificate suspension or revocation for manned pilots and significant civil penalties for sUAS operators — even under Part 107. Presidential TFR violations can result in criminal prosecution. </p> </div> <h3>Types of TFRs Drone Pilots Encounter Most</h3> <h4>Presidential TFRs (VIP Movement)</h4> <p> Issued whenever the President, Vice President, or other designated VIPs are traveling. These are the most strictly enforced TFRs. A standard Presidential TFR has two rings: </p> <ul> <li> <strong>Inner ring (0–10 NM):</strong> No flight permitted at any altitude without explicit ATC clearance. This applies to sUAS operations as well. </li> <li> <strong>Outer ring (10–30 NM):</strong> Manned aircraft restrictions; sUAS operations are generally prohibited without coordination. </li> </ul> <p> Presidential TFRs are issued with very little advance notice (sometimes hours before the event) and cover the entire route of travel, not just the destination. The FAA's tfr.faa.gov website shows current TFRs graphically. Always check within 1–2 hours of your flight. </p> <h4>Disaster Area TFRs</h4> <p> Issued around natural disaster sites (wildfires, floods, earthquake zones) to keep the airspace clear for emergency response aircraft. These TFRs are dangerous to violate — emergency helicopters in those areas are often operating at low altitudes in high-stress conditions with reduced communications capacity. </p> <p> Well-intentioned drone pilots have been prosecuted after flying TFR-protected wildfire areas to document conditions. The TFR exists because their drone forced firefighting aircraft to divert or hold. </p> <h4>Stadium TFRs</h4> <p> Automatically active within 3 NM of any major league stadium (NFL, MLB, NCAA Division I football) during games. The TFR extends from the surface to 3,000 ft AGL and begins one hour before the scheduled game time and ends one hour after the game ends. No sUAS operations are permitted within this TFR. </p> <h4>Security TFRs (National Events)</h4> <p> Major national security events — inaugurations, State of the Union addresses, and National Special Security Events (NSSEs) — generate TFRs that may cover entire metropolitan areas for hours or days. </p> <h3>Where to Check TFRs</h3> <ul> <li><a href="https://tfr.faa.gov" style="color: #38bdf8; text-decoration: none;">tfr.faa.gov</a> — official FAA TFR map, updated in real time</li> <li>Aloft (formerly AirMap) — mobile app with TFR overlay</li> <li>B4UFLY — FAA app with TFR and airspace data</li> <li>DroneSkycast — integrates FAA TFR data into the scoring model</li> </ul> <h2>SIGMETs — Significant Meteorological Information</h2> <p> A SIGMET (Significant Meteorological Information) is a weather advisory issued by NOAA Aviation Weather Center warning of weather conditions that are hazardous to all aircraft. SIGMETs are the most serious weather advisories in the system — they indicate that conditions exist that are dangerous regardless of how well equipped your aircraft is. </p> <h3>What Triggers a SIGMET</h3> <ul> <li>Severe turbulence (not associated with thunderstorms)</li> <li>Severe icing (not associated with thunderstorms)</li> <li>Widespread dust storms or sandstorms lowering visibility below 3 miles</li> <li>Volcanic ash clouds</li> <li>Tropical cyclone activity</li> <li>Active thunderstorm lines or areas (Convective SIGMET)</li> </ul> <p> Convective SIGMETs (WST) are the most common and most relevant to drone pilots. They are issued when there are embedded thunderstorms, lines of thunderstorms, areas of thunderstorms covering 40% or more of an area, or thunderstorms with tops above 35,000 ft. A convective SIGMET means the atmosphere within the advisory area is producing or capable of producing severe turbulence, lightning, hail, and microbursts — all immediately fatal to a drone. </p> <div class="callout callout-danger"> <p> <strong>DroneSkycast scoring:</strong> Any active SIGMET covering your operation area triggers an automatic NO_GO verdict, regardless of surface wind, visibility, or other factors. There is no scenario where flying a drone through a SIGMET area is safe or legal. </p> </div> <h3>How Long Do SIGMETs Last?</h3> <p> Convective SIGMETs are issued for two-hour periods and updated every 55 minutes. Non-convective SIGMETs are valid for up to four hours (up to six hours for volcanic ash advisories). Always check for SIGMETs immediately before flight, not hours in advance. </p> <h2>AIRMETs — Airmen's Meteorological Information</h2> <p> One level below SIGMETs are AIRMETs, which warn of conditions that are significant but not as immediately hazardous. The three AIRMET types are: </p> <ul> <li> <strong>AIRMET Sierra (S):</strong> IFR conditions (ceiling below 1,000 ft and/or visibility below 3 SM) and/or mountain obscuration. Directly relevant to drone visibility minimums. </li> <li> <strong>AIRMET Tango (T):</strong> Moderate turbulence, sustained surface winds above 30 knots, and/or low-level wind shear. </li> <li> <strong>AIRMET Zulu (Z):</strong> Moderate icing and/or freezing level information. </li> </ul> <p> In DroneSkycast, an active AIRMET covering your operation area applies a 20-point score deduction. An AIRMET does not trigger an automatic NO_GO — conditions may still be flyable depending on the specific AIRMET type and the exact conditions at your location — but the deduction reflects the materially elevated risk. </p> <h2>Quick Reference: Notice Types and Their Drone Impact</h2> <table> <thead> <tr> <th>Notice Type</th> <th>Issued By</th> <th>Validity</th> <th>DroneSkycast Impact</th> </tr> </thead> <tbody> <tr> <td>NOTAM (general)</td> <td>FAA NOTAM system</td> <td>Hours to permanent</td> <td>Obstructions, closed areas shown in airspace layer</td> </tr> <tr> <td>TFR (Presidential)</td> <td>Secret Service / FAA</td> <td>Hours to days</td> <td>NO_GO — active TFR overlap shown in scoring</td> </tr> <tr> <td>TFR (Disaster)</td> <td>FAA / FEMA</td> <td>Days to weeks</td> <td>NO_GO — shown in airspace layer</td> </tr> <tr> <td>TFR (Stadium)</td> <td>FAA (automatic)</td> <td>Game + 2 hours</td> <td>NO_GO during active window</td> </tr> <tr> <td>SIGMET (convective)</td> <td>NOAA AWC</td> <td>2 hours (renewed)</td> <td>Instant NO_GO verdict</td> </tr> <tr> <td>SIGMET (non-convective)</td> <td>NOAA AWC</td> <td>4–6 hours</td> <td>Instant NO_GO verdict</td> </tr> <tr> <td>AIRMET Sierra (IFR)</td> <td>NOAA AWC</td> <td>6 hours</td> <td>−20 pts; CAUTION flag</td> </tr> <tr> <td>AIRMET Tango (turbulence)</td> <td>NOAA AWC</td> <td>6 hours</td> <td>−20 pts; CAUTION flag</td> </tr> <tr> <td>AIRMET Zulu (icing)</td> <td>NOAA AWC</td> <td>6 hours</td> <td>−20 pts; CAUTION flag</td> </tr> </tbody> </table> <h2>Building a Complete Pre-Flight Check Routine</h2> <p> The most common mistake drone pilots make is checking only one source. A clean weather forecast does not rule out an active TFR. An open airspace map does not mean there are no active SIGMETs. A comprehensive pre-flight check for Part 107 operations includes: </p> <ol> <li>Check weather conditions (METAR, TAF, forecast) — see our <a href="https://droneskycast.com/learn/how-to-read-metar">METAR guide</a> for decoding help</li> <li>Check for active SIGMETs and AIRMETs at aviationweather.gov</li> <li>Check for active TFRs at tfr.faa.gov</li> <li>Check the NOTAM system for obstructions, temporary restrictions, and event NOTAMs</li> <li>Verify your airspace authorization (LAANC or DroneZone) if in controlled airspace</li> <li>Review current <a href="https://droneskycast.com/learn/part-107-weather-requirements">Part 107 weather minimums</a> against forecast conditions</li> </ol> <p> DroneSkycast consolidates steps 1–3 into a single check. NOTAM review and airspace authorization still require separate verification through FAA tools — use the full pre-flight checklist above every time. </p>