You can read a TAF. Then you pull the forecast for Andrews, or Scott, or Patuxent River, and there are groups in it that were in none of the examples you studied. A six digit number with no obvious meaning. A block of plain English at the end that reads like weather but is not.

Nothing about the sky has changed. A military TAF decoder has to handle the same ICAO body you already know, plus four additions. This page covers all four, with the code tables, so you can read one without a manual open beside you.

A military TAF is a normal TAF plus four things: a QNH altimeter group in inches of mercury, an icing group starting with 6, a turbulence group starting with 5, and a plain English trailer about the forecast service. The trailer is the one that catches people, because its times look exactly like visibility in metres. Wind, visibility, weather and cloud are unchanged.

What's New in Military TAF Decoding for 2026

The code has not moved. AFMAN 15-124 set these groups out in 2009 and they are transmitted the same way today.

What changed is who reads them. Joint-use fields put civil traffic onto military airfields, so a GA pilot filing into one meets QNH and 6-groups without ever going looking for them.

The other change is the tools. General purpose TAF decoders now sit at the top of search results, and most of them were built for the civil format. Paste a military TAF into one and the extra groups either vanish or come back as "unrecognised". Neither tells you there is a forecast of ice in the report you just pasted.

What a Military TAF Decoder Has to Handle

Four additions. That is the whole list.

• A QNH altimeter group, once in the initial conditions and once in each BECMG and FM change group
• An icing group, when icing is forecast, starting with the digit 6
• A turbulence group, when turbulence is forecast, starting with the digit 5
• A plain English service trailer at the end, with no RMK marker to introduce it

Everything else is the format you already read. Wind, visibility, weather, cloud, in that order. The same FM, BECMG, TEMPO and PROB change groups. The same WS010/18040KT for low level wind shear.

Here is a real one from Scott Air Force Base, with the additions in bold:

KBLV 051153Z 0512/0612 14005KT 8000 BR FEW030 WS010/18040KT BECMG 0516/0517 29008KT 3200 -RA OVC030 **620304** **QNH2958INS**

Two groups you have not met, in a forecast that is otherwise ordinary.

The QNH Altimeter Group

QNH2958INS is an altimeter setting of 29.58 inches of mercury. Read the four digits with the decimal point two places from the right, and ignore the INS, which just marks the units.

Civil US TAFs do not forecast an altimeter setting at all. They leave it to the METAR, which is why the group looks foreign the first time you see it.

Two details matter. It is the lowest setting expected during that period, not an average, and the lowest setting is the one that puts you closest to terrain if you fly with a stale number in the window. It also never appears inside a TEMPO group, by design.

• QNH2992INS is 29.92 inches
• QNH3001INS is 30.01 inches
• QNH2958INS is 29.58 inches

Icing Groups Start With a 6

An icing group is six characters. The first is always 6. The rest is a complete forecast of ice: what kind, how much, from what height, and how deep.

Take 620065 apart:

• 6 marks it as icing
• 2 is the type and intensity, from the table below
• 006 is the base of the layer in hundreds of feet, so 600 ft
• 5 is the thickness in thousands of feet, so 5,000 ft deep

That puts the top at 5,600 feet. The whole group reads as light rime icing in cloud, from 600 ft up to 5,600 feet.

The intensity digit tells you the kind of ice as well as how much:

• 0 Trace icing
• 1 Light mixed icing
• 2 Light rime icing in cloud
• 3 Light clear icing in precipitation
• 4 Moderate mixed icing
• 5 Moderate rime icing in cloud
• 6 Moderate clear icing in precipitation
• 7 Severe mixed icing
• 8 Severe rime icing in cloud
• 9 Severe clear icing in precipitation

Rime is opaque and milky and builds on the leading edges. Clear ice is glossy and hard and much harder to shed. The code tells you which one to expect, which is more than an AIRMET usually does.

More than one icing group can appear in the same period. Two groups back to back are two separate layers, each with its own base and top.

Turbulence Groups Start With a 5

Same six characters, same layout, leading 5 instead of 6, and a different table for the intensity digit:

• 0 None
• 1 Light turbulence
• 2 Occasional moderate turbulence in clear air
• 3 Frequent moderate turbulence in clear air
• 4 Occasional moderate turbulence in cloud
• 5 Frequent moderate turbulence in cloud
• 6 Occasional severe turbulence in clear air
• 7 Frequent severe turbulence in clear air
• 8 Occasional severe turbulence in cloud
• 9 Frequent severe turbulence in cloud
• X Extreme turbulence

"Occasional" is not a feeling here. It has a definition: occurring less than 1/3 of the time.

So 510009 is light turbulence from the surface up through 9,000 feet. And 540009 over the same band is occasional moderate turbulence in cloud, which is a very different afternoon.

The in cloud and in clear air distinction is worth reading twice. Clear air turbulence gives you no visual warning at all, so you cannot see it coming and plan around it the way you can with a line of cumulus.

The Trailer That Looks Like Weather

At the end of a military TAF, after the temperature groups, the forecast stops and plain English about the forecast service starts. There is no RMK marker to tell you it has happened.

LAST NO AMDS AFT 2820 NEXT 3112 means this is the last forecast for the field. It will not be amended after 2000Z on the 28th, and the next one is due at 1200Z on the 31st.

AMD NOT SKED means amendments are not scheduled. Nobody is on duty. Read that one slowly, because it is easy to skim as "amended" and take away the exact opposite of what it says.

AUTOMATED SENSOR METWATCH 2903 TIL 2911 means that between those hours the field is watched by sensors with no forecaster behind them.

Two more trailer entries turn up often enough to know on sight.

WSCONDS means conditions are favourable for low level wind shear, without a specific height and wind to attach to it. It is the softer cousin of a WS010/18040KT group, and it usually sits in the trailer rather than the body.

FN00328 or FS30067 is a forecast service indicator. It is an internal routing and service level code for the weather flight that issued the forecast. It tells you nothing about the weather, and the only reason to recognise it is so you stop trying to decode it.

Now look again at AFT 2820 NEXT 3112. Those are day and hour stamps. But four digits in a TAF is also how visibility in metres is written, which is why the line above already gave you 8000 and 3200 as visibilities. A decoder that does not know where the forecast ends will read 2820 as a visibility that nobody forecast. So will a pilot reading quickly.

That is the single most useful thing to take away from this page. When the report turns into words, the weather has stopped.

Reading a Real Military TAF End to End

Back to Scott Air Force Base:

KBLV 051153Z 0512/0612 14005KT 8000 BR FEW030 WS010/18040KT BECMG 0516/0517 29008KT 3200 -RA OVC030 620304 QNH2958INS

Group by group:

• KBLV 051153Z Scott AFB, issued at 1153Z on the 5th
• 0512/0612 valid from 1200Z on the 5th to 1200Z on the 6th
• 14005KT wind from 140 degrees at 5 knots
• 8000 visibility 8000 metres
• BR mist
• FEW030 few cloud at 3,000 feet
• WS010/18040KT low level wind shear at 1,000 feet, wind from 180 at 40 knots
• BECMG 0516/0517 becoming, between 1600Z and 1700Z on the 5th
• 29008KT wind from 290 at 8 knots
• 3200 -RA visibility 3200 metres in light rain
• OVC030 overcast at 3,000 feet
• 620304 light rime icing in cloud, based at 300 feet and 4 thousand feet thick
• QNH2958INS lowest altimeter setting 29.58 inches

Only the last two groups needed anything new. The wind shear group was already in your civil vocabulary, and so was everything before it.

Icing and Turbulence in the Same Forecast

Both groups can appear together, and when they do the order is fixed: icing first, turbulence second, then the altimeter. Here is the Ramstein example the manual itself uses:

ETAR 0116/0215 28012G25KT 8000 -RASN SCT006 BKN015 OVC020 620208 540009 QNH2960INS

Working through the two hazard groups:

• 620208 icing. The 2 is light rime icing in cloud, 020 is a base of 2,000 ft, and the final 8 is 8,000 feet of thickness, so the layer runs to 10,000 feet
• 540009 turbulence. The 4 is occasional moderate turbulence in cloud, 000 is a base at the surface, and the 9 is 9,000 feet of thickness

Read together with the cloud, that is a picture rather than a list. Overcast at 2,000 feet with rain and snow. Ice in the cloud from 2,000 to 10,000 feet, and bumps from the ground up through 9,000 feet. A departure into it is in icing conditions almost immediately after entering cloud.

What Carries Forward Between Change Groups

This is the part that is genuinely easy to get wrong, and it is not written down anywhere in the report itself.

A BECMG group only states what changes. Anything it does not mention carries forward from the conditions already in force. So when a BECMG gives you a new wind and a new cloud base but no icing group, the icing forecast from the initial conditions is still running.

In the Ramstein forecast, the BECMG that follows repeats 620208 540009 unchanged. The manual is explicit that this means the icing and turbulence remain as forecast by the initial condition, and repeating them is how the forecaster says so out loud.

Two smaller rules go with it:

• The altimeter group appears in the initial conditions and in every BECMG and FM group, but never inside a TEMPO. A temporary condition does not get its own altimeter setting
• An FM group is a clean break. It restates everything, so nothing carries across it the way it does across a BECMG

The practical version: if you are reading a period and cannot see an icing group, look back up the forecast before concluding there is no ice in it.

Visibility in Metres, Not Statute Miles

This one trips up US pilots more often than the icing groups do, because it does not look like an error. It looks like a small number.

A civil US TAF gives you visibility in statute miles: P6SM for better than 6, 3SM for three. A military TAF gives you metres, with no unit marked at all.

• 9999 means 10 kilometres or more, which is the top of the scale
• 8000 is 8000 metres, about 5 statute miles
• 3200 is 3200 metres, about 2 statute miles
• 1600 is 1600 metres, about 1 statute mile
• 0800 is 800 metres, about half a mile

So 3200 in a military TAF is not three thousand two hundred of anything you were expecting. It is IFR visibility. The number to keep in your head is that 1600 metres is roughly a statute mile, which makes the rest easy to approximate.

Cloud has a small difference too. Where a US TAF writes SKC or CLR you will see SKC in a military one, and where a US TAF might use P6SM with no cloud group at all, the military format states the sky explicitly.

Temperature Groups at the End

After the last change group, before the service trailer, come the forecast temperature extremes.

• TX26/2919Z maximum temperature 26 degrees Celsius, expected at 1900Z on the 29th
• TN16/2910Z minimum temperature 16 degrees Celsius, expected at 1000Z on the 29th
• TNM04/0512Z the M means minus, so minus 4 degrees

Maximum comes first, minimum last. Older forecasts and some overseas fields use a shorter form, T03/0121Z, which means the same thing with the max and min told apart by their order rather than by an X or an N.

These are useful beyond curiosity. Read the minimum against the forecast cloud base and you have a rough answer to whether the icing group is telling you something you were already going to work out.

What a Good Military TAF Decoder Should Show You

Most general TAF tools were built for the civil format, so the test of a military TAF decoder is what it does with the groups that format does not have.

Three things are worth checking before you trust one:

• It shows the raw group next to the plain English. If you cannot see 620065 beside "light rime icing from 600 ft to 5,600 feet", you cannot check the decode, and a decode you cannot check is worse than no decode.
• It stops at the trailer. Paste a forecast ending in LAST NO AMDS AFT 2820 NEXT 3112 and see whether a visibility appears out of 2820. If it does, the tool is inventing weather.
• It says when it does not know. A group left visibly undecoded is honest. A group dropped in silence looks identical to a forecast with no icing in it.

Military TAFs come through the same public channel as civil ones. The AviationWeather.gov data API serves them by ICAO identifier, so KBLV, KADW and overseas fields such as Ramstein all come back through the same request a civil TAF does. You do not need special access to read them, only a decoder that handles the extra groups.

FAQ

What does QNH2992INS mean in a TAF?

It is the lowest altimeter setting forecast for that period, 29.92 inches of mercury. Military TAFs carry the altimeter in the body of the forecast. Civil US TAFs leave it to the METAR, which is why the group is unfamiliar to most pilots.

What does 620065 mean in a TAF?

It is an icing group. The 6 marks icing, 2 is light rime icing in cloud, 006 is the base in hundreds of feet, and 5 is the thickness in thousands. So light rime icing in cloud from 600 ft up to 5,600 feet above ground level.

Does AMD NOT SKED mean the TAF was amended?

No, it means the opposite. Amendments are not scheduled because the field has no forecaster on duty. The forecast will not be updated if conditions change, so treat it as ageing from its issue time and lean harder on the METAR.

Are military TAFs different from civil TAFs?

The body is the same ICAO format. Military TAFs add an altimeter group, optional icing and turbulence groups, and a plain English service trailer. Nothing about wind, visibility, weather or cloud is encoded differently.

Why is visibility a four digit number in a military TAF?

Military TAFs report visibility in metres rather than statute miles. So 8000 is 8000 metres, about 5 miles, and 9999 means 10 kilometres or more. A US pilot used to P6SM can read 3200 as a large number when it is IFR visibility.

Where do the icing and turbulence code tables come from?

AFMAN 15-124, the Air Force manual of meteorological codes, published in 2009. Tables 1.4 through 1.7 define the height, the icing type, the layer thickness and the turbulence intensity. The Navy uses the same encoding.

Why does a general TAF decoder skip these groups?

Most were built for the civil format, where the groups never appear. An unrecognised group is usually dropped in silence, so a forecast of severe icing can disappear from the output without any warning that something was lost.

Verdict on Military TAF Format

A military TAF decoder is not a different skill. It is the civil TAF you already read, plus an altimeter group, two numeric hazard groups and a trailer that is not weather at all.

The two hazard groups are the reason to bother. A 6-group and a 5-group give you forecast ice and forecast turbulence with a type, an intensity, a base and a top, stated outright rather than inferred from cloud and temperature. Very little else in a routine briefing does that.

The trailer is the reason to be careful. When the coded groups stop and the words start, the forecast has ended, and any four digit number after that point is a time. Paste one into the WxDecoder decoder and it reads all four additions, showing the raw group next to the plain English so you can check the decode rather than trust it.

Last updated August 29, 2026