How to Read NOTAMs in a Preflight Weather Briefing
Read the keyword first, then the Zulu time block. Which NOTAMs change a flight, where they collide with the weather, and why TFRs hide from an airport search.
Every NOTAM in a US briefing is built in the same order, and once you know the order you stop reading them character by character. The line opens with an accountability identifier and a serial number, then the affected location, then a keyword such as RWY, NAV, SVC or AIRSPACE, then the changed condition, and it closes with a ten-digit start and end time in Zulu. That sequence is set by FAA Order 7930.2U, the order NOTAM originators write to, and a legitimate NOTAM does not depart from it.
The keyword is what you read first. It works like a subject line, telling you in a few characters whether the notice touches the runway, a navaid, a service, or airspace you had planned on. Read keywords first and thirty NOTAMs take about a minute, two of them worth a second pass. Read left to right at an even speed and you go numb around the tenth, which is how a closed runway survives a briefing intact.
NOTAMs sit near the end of the sequence in our preflight weather briefing guide, and they are the step most often skimmed. The reason they can’t be: the graphical forecast will happily show you a clear afternoon over an airport whose only runway is closed until Thursday.
What a NOTAM is, and the two classes you live in
A NOTAM states the abnormal status of a component of the National Airspace System, not the normal status. That inversion is the whole design. A NOTAM file is not a description of an airport, it is a list of what is currently broken, closed, moved, or restricted there. Silence means normal.
AIM 5-1-3 sorts them into four classes: Domestic NOTAMs (NOTAM D), Flight Data Center (FDC) NOTAMs, International NOTAMs, and Military NOTAMs. Flying Part 91 inside the US, you live almost entirely in the first two.
NOTAM D covers the physical and operational state of the system: aerodrome and movement-area conditions, lighting, obstructions, navaids, communications outlets, services, and airspace activity like parachute jumping or unmanned operations.
FDC NOTAMs carry regulatory information. Amendments to published instrument approach procedures, temporary flight restrictions, high barometric pressure warnings, laser light activity, GPS and WAAS service, and special security instructions all arrive as FDC.
The regulatory hook is 14 CFR 91.103, which requires you to become familiar with all available information concerning that flight before you begin it. The rule text never says the word NOTAM. AIM 5-1-3 closes that gap, reading 91.103 as directing pilots to NOTAMs before departure.
Read the keyword, then read the clock
Every NOTAM carries one of twenty keywords as the first part of the text after the location, which is what makes the file sortable at all. These are the ones that matter to a light-aircraft pilot.
| Keyword | What it covers |
|---|---|
RWY | Runway closures, surface condition, thresholds, runway lighting, RVR |
TWY / APRON | Taxiway and ramp closures, edge lighting, markings |
AD | The aerodrome as a whole, including a full airport closure |
OBST | Cranes, towers, and unlit obstruction lights |
NAV | Navaids: ILS components, VOR, and GPS or WAAS availability |
COM | Communications outlets and frequencies |
SVC | Services: tower, approach, Flight Service, and the automated weather |
AIRSPACE | Parachute ops, aerobatics, unmanned aircraft, rockets, active MOAs, TFRs |
IAP ODP SID STAR | FDC amendments to published instrument procedures |
Now a whole NOTAM, plain English first. Runway 18/36 at Nashville is closed from 1400Z on 3 August until 1359Z on 5 August:
!BNA BNA RWY 18/36 CLSD 2608031400-2608051359The leading !BNA is the accountability location, the second BNA is the affected airport, RWY 18/36 is the surface designator, CLSD is the condition, and the two ten-digit groups are YYMMDDHHMM in Zulu. Live search output puts a serial number between the two identifiers, month and sequence, as in 08/014. That is the entire grammar.
Three conventions in the time block change what that end time means. EST means the originator expects the condition to clear sooner; the NOTAM still expires at the stated time unless someone cancels or replaces it first. PERM replaces the end time when the change is permanent and awaiting publication on a chart, and a PERM NOTAM never auto-expires. A schedule can also sit between the condition and the time block, either as clock times (DLY 1200-2000, MON WED 0900-1300) or as SR-SS for sunrise to sunset, which means you need the actual times for that field on that day. Our sunrise and twilight calculator will give you those.
The contractions are ICAO abbreviations, used to keep transmissions short, and about seven carry most of the meaning: U/S unserviceable, CLSD closed, AVBL available, ACT active, WI within, EXC except, RTS return to service. AIM 5-1-3 tabulates the ones you meet most often, and the complete approved set is FAA Order JO 7340.2, Contractions. The codes you meet elsewhere in a briefing are in our glossary. You do not need the tail of that list memorized. You need to recognize when a NOTAM is saying something is gone.
Which ones actually change a flight
Most of a NOTAM package is irrelevant to you, and the skill is deciding that fast rather than reading everything with equal care. A working priority order:
RWYandADfor every airport you might touch, including the alternate you have not committed to yet. Closures, displaced thresholds, and surface contamination.AIRSPACE, and every FDC restriction along the route. This is the category that turns a legal flight into an illegal one.NAVand GPS. An ILS glideslope out of service, a VOR unusable in the sector you planned to use, or a GPS test that takes WAAS down across three states.SVC. Tower hours, approach control availability, and the automated weather.OBST. The crane that went up on short final last week is the one obstruction NOTAM nobody reads.
Everything else is usually noise for a light single: an edge light out on a taxiway you will never use, an apron NOTAM for the cargo ramp.
One RWY variant packs a lot into a few digits. A field condition report inserts FICON after the surface designator, followed by a runway condition code from 0 to 6 for each third of the runway, written like 3/4/2. Per Order 7930.2U, those codes are only generated for paved runways when more than 25 percent of the full runway is contaminated, so their absence in winter is not proof of a dry surface.
Where NOTAMs and weather collide
Three cases turn a NOTAM into a weather problem, and all three are easy to read past.
The observation source is out. An automated weather system failure is a SVC NOTAM, and the wording tells you how bad it is. SVC AUTOMATED WX BCST SYSTEM U/S is a total outage. Single elements can fail on their own, giving you lines like SVC AUTOMATED WX BCST SYSTEM CEILING UNREL or SVC AUTOMATED WX BCST SYSTEM ALTIMETER SETTING NOT AVBL. The trap is that most apps keep showing the last observation the field managed to send, which can be hours stale and still color-coded green. Check the observation time before you trust the category, and if the date-time group is not yet something you read at a glance, our METAR decoder prints it in plain English.
The RVR is gone. Runway visual range gets its own NOTAM per runway, as RWY 10 RVRT U/S for the touchdown sensor alone, or AD AP RVR ALL U/S when every sensor at the field is out. Read that one twice before a low-visibility approach. RVR is the number your minimums are written against.
The approach changed. FDC procedure NOTAMs rewrite published minimums, and they do it without ceremony. Here is the FAA’s own worked example, from Appendix A of Order 7930.2U. Decoded: the VOR approach to runway 22R at Chicago O’Hare now has a minimum descent altitude of 1,400 ft, which is 750 ft above touchdown, and needs 1½ statute miles visibility for every category. The reason is a temporary crane at 1,100 ft MSL:
!FDC x/xxxx ORD IAP CHICAGO O'HARE INTL, CHICAGO, IL. VOR RWY 22R AMDT 8B...
MDA 1400/HAT 750, VIS 1-1/2 ALL CATS. TEMPORARY CRANE 1100 MSL 1.2 NM SE OF RWY 23A raised minimum can quietly move an airport from usable to unusable in the forecast weather, which is exactly the kind of change that feeds back into alternate planning under the 1-2-3 rule. Brief the procedure NOTAMs for the approach you actually intend to fly, not just the airport.
TFRs hide under the Center, not the airport
Temporary flight restrictions are FDC NOTAMs filed under the ARTCC whose airspace they sit in, not under the nearest airport. Nothing else in this post will save you more grief. The FAA files them as Center Area NOTAMs, and AIM 5-1-3 tells pilots to review NOTAMs for the ARTCC area the flight will operate in, listing TFRs among the reasons.
The consequence is blunt. Query NOTAMs for departure, destination and alternate and stop there, and you have retrieved zero TFRs for the 200 miles between them. On 3 August 2026 the FAA’s graphical TFR list held 122 active restrictions, filed under facility codes like ZSE, ZLC and ZLA rather than under any airport identifier. All but sixteen were hazard or security areas, and the hazard ones clustered over Oregon, Washington, Idaho and Montana, which in early August means fires.
A pointer NOTAM can put a TFR under an airport identifier, and Order 7930.2U now limits pointers to traffic management alerts, TFRs and temporary special use airspace. But pointers are only originated at aerodromes directly impacted by the activity, so they do nothing for airspace you merely fly through.
Size is the other half of the problem. Airspace set aside to protect people on the ground or to give relief aircraft room to work, under 14 CFR 91.137(a)(1) and (a)(2), is normally limited to 2,000 ft above the surface within a 3 NM radius. That is small enough to miss on any chart, and it can appear a few hours before you launch. The same AIM paragraph puts compliance with 91.137, 91.138, 91.141 and 91.143 on the pilot and says to check the appropriate NOTAMs during flight planning.
So pull the ARTCC areas you will cross, use the graphical list as a cross-check rather than a substitute, and query wide. The FAA tells pilots to check 25 NM either side of the full route of flight so that relevant navaid NOTAMs display at all.
What changed in 2026, and what didn’t
If you learned NOTAMs before this year, the good news is that nothing on your screen has moved. The classification scheme in the current AIM is still Domestic, FDC, International and Military, and the keyword-first domestic format is still what you read.
What changed is the plumbing. The FAA shut down the legacy US NOTAM System in mid-April 2026 and moved users onto the cloud-hosted NOTAM Management Service, completing phase one of the modernization. The second legacy system, the Federal NOTAM System, retires later in 2026, after which NMS is the single authoritative source. The old DINS query page went with the first phase. The pilot-facing search stays where the AIM points it, at FAA NOTAM Search.
The format change is still ahead of us. The FAA has committed to adopting the ICAO NOTAM format and retiring the current domestic one, but as of the agency’s own modernization FAQ, the date for the ICAO transition has not been announced. When it lands, the keyword line gives way to a machine-readable Q line and lettered fields: A location, B start, C end, D schedule, E the description, F and G for the altitude band. The AIM already describes them, because that is what International NOTAMs use today. Until then, treat any source telling you US domestic NOTAMs are now in ICAO format as ahead of the FAA.
Keyword, then clock, then decide. It takes about a minute per airport, and it is the part of the briefing that catches the failures no forecast can warn you about.
Common questions
- Do I have to check NOTAMs for a flight that stays in the pattern?
- 14 CFR 91.103 requires the pilot in command to become familiar with all available information concerning the flight, and the FAA states in AIM 5-1-3 that this includes NOTAMs. There is no local-flight exemption. A pattern flight can still meet a closed runway, a lit crane on the downwind, an airshow restriction over the field, or a tower that went to CTAF an hour ago.
- What do EST and PERM mean at the end of a NOTAM?
- EST follows the end time when the originator expects the condition to clear earlier than the stated expiry. The NOTAM still auto-expires at the end of validity unless it is cancelled or replaced first, so an EST time is an estimate rather than a promise. PERM replaces the end time entirely when the condition is permanent and headed for a chart, and a PERM NOTAM never auto-expires.
- Are NOTAMs still called Notices to Air Missions?
- No. The FAA changed the term back to Notice to Airmen on 10 February 2025 and retitled the governing order to match. The abbreviation never changed, so anything written between 2021 and early 2025 that spells out Notice to Air Missions is describing the same product under its old name. The current order is FAA Order 7930.2U, Change 1.