The core idea: where the centre goes, and how far the wind reaches
Read the diagram as two layers. The first is position: a cross for the centre now, a line for the track so far, and dashed circles for where the centre should be 12, 24, 48 and 72 hours ahead, each with about a 70 percent chance, says JMA. The circles widen because the forecast grows less certain, not because the typhoon grows.
The second layer is the wind: a solid circle for bōfū-iki (暴風域), literally the storm-wind zone, and a wider one for kyōfū-iki (強風域), the strong-wind zone. The red line that wraps everything is the bōfū keikai-iki, the storm warning area: every place storm winds could reach if the centre moves anywhere inside the circles.
| Japanese | Romaji | Meaning |
|---|---|---|
| 台風十号は、非常に強い勢力で北上しています。 | Taifū jūgō wa, hijō ni tsuyoi seiryoku de hokujō shite imasu. | Typhoon No. 10 is moving north at very strong intensity. |
| 九州南部は、あす暴風域に入る見込みです。 | Kyūshū nanbu wa, asu bōfū-iki ni hairu mikomi desu. | Southern Kyushu is expected to enter the storm-wind area tomorrow. |
| 台風の進路が西にずれました。 | Taifū no shinro ga nishi ni zuremashita. | The typhoon's track has shifted west. |
| 予報円の大きさは、進路の不確かさを表しています。 | Yohō-en no ōkisa wa, shinro no futashikasa o arawashite imasu. | The size of the forecast circle shows how uncertain the track is. |
Numbers, not names: taifū jūgō
Japan numbers its typhoons. The first to form after 1 January is dai-ichi-gō, number one, and the count runs on through the year; a storm that weakens and then strengthens again keeps its number. JMA writes taifū dai-jū-gō (台風第10号), literally typhoon ordinal number ten, often with the era year in formal bulletins. On air and in conversation the dai is dropped: taifū jūgō.
Since 2000 each typhoon also carries an Asian name from a list of 140, and English reports use it; Japanese news almost never does. A tropical depression becomes a taifū when its maximum sustained wind reaches about 17 m/s. On average about 25 form each year, about 12 come within 300 km of Japan and about 3 make landfall.
| Japanese | Romaji | Meaning |
|---|---|---|
| 台風十号が発生しました。 | Taifū jūgō ga hassei shimashita. | Typhoon No. 10 has formed. |
| 今度の台風は何号ですか。 | Kondo no taifū wa nan-gō desu ka. | What number is this typhoon? |
| 今年は台風が多いですね。 | Kotoshi wa taifū ga ōi desu ne. | There are a lot of typhoons this year, aren't there? |
| 台風は温帯低気圧に変わりました。 | Taifū wa ontai teikiatsu ni kawarimashita. | The typhoon has become an extratropical low. |
Reading the map, element by element
JMA updates the position every three hours and issues five-day forecasts, in 24-hour steps, every six. When a typhoon threatens Japan it adds hourly position estimates and three-hourly forecast points, so always check the time printed on the map.
| Japanese | Romaji | Meaning |
|---|---|---|
| 暴風域に入る確率が上がっています。 | Bōfū-iki ni hairu kakuritsu ga agatte imasu. | The probability of entering the storm-wind area is rising. |
| うちの町も暴風警戒域に入ってるね。 | Uchi no machi mo bōfū keikai-iki ni haitteru ne. | Our town's inside the storm warning area too. (casual) |
| Term | Reading | On JMA's map | What it means |
|---|---|---|---|
| 現在の中心 | genzai no chūshin | A cross | Where the centre is now |
| 暴風域 | bōfū-iki | Thick red circle | Winds of 25 m/s or more blowing, or possible |
| 強風域 | kyōfū-iki | Yellow circle | Winds of 15 m/s or more |
| 予報円 | yohō-en | White dashed circles | About 70% chance the centre is inside at that time |
| 暴風警戒域 | bōfū keikai-iki | Red line around the circles | Where storm winds could reach if the centre stays inside the circles |
| 経路 | keiro | Blue line | The track so far |
A separate product, bōfū-iki ni hairu kakuritsu, gives the chance that your area enters the storm-wind zone, in three-hour steps up to five days ahead.
Strength and size: ōgata de hijō ni tsuyoi
The news describes a typhoon with two words from two separate scales. Strength, tsuyosa, is set by the maximum sustained wind; size, ōkisa, by the radius of the 15 m/s gale area. Below the lowest step JMA uses no word, so a plain taifū is neither large nor strong by these measures. The words combine before taifū: ōgata de hijō ni tsuyoi taifū, a large, very strong typhoon.
JMA does not use sūpā taifū, super typhoon; its top class is mōretsu na, violent. Nor does it call a compact storm a mame taifū, bean typhoon, because a small typhoon's wind can strengthen very suddenly near the centre.
| Japanese | Romaji | Meaning |
|---|---|---|
| 大型で非常に強い台風十号が、日本の南を北上しています。 | Ōgata de hijō ni tsuyoi taifū jūgō ga, Nihon no minami o hokujō shite imasu. | Large, very strong Typhoon No. 10 is moving north, south of Japan. |
| 中心気圧は九百四十ヘクトパスカル、最大風速は四十五メートルです。 | Chūshin kiatsu wa kyūhyaku yonjū hekutopasukaru, saidai fūsoku wa yonjūgo mētoru desu. | Central pressure is 940 hectopascals; maximum sustained wind is 45 metres per second. |
| 最大瞬間風速は六十メートルです。 | Saidai shunkan fūsoku wa rokujū mētoru desu. | The maximum gust is 60 metres per second. |
Confusable pairs in typhoon news
Each pair below sits side by side on the screen but differs in one clear way.
| Pair | Reading | What differs |
|---|---|---|
| 予報円 / 暴風域 | yohō-en / bōfū-iki | Where the centre may be, against how far storm winds reach |
| 暴風域 / 強風域 | bōfū-iki / kyōfū-iki | 25 m/s or more against 15 m/s or more; the gale area sets the size class |
| 接近 / 上陸 | sekkin / jōriku | Centre within 300 km of a place, against centre reaching a main-island coast |
| 上陸 / 通過 | jōriku / tsūka | Reaching a main-island coast, against crossing a small island or peninsula |
| 暴風域 / 暴風警報 | bōfū-iki / bōfū keihō | A zone on the typhoon map, against an official warning for your area |
| 台風 / 熱帯低気圧 | taifū / nettai teikiatsu | The same kind of storm; below about 17 m/s it is a tropical depression |
Beyond the basics: sekkin, jōriku and tsūka
JMA defines three verbs for how a typhoon meets land. Sekkin (接近), literally close approach, means the centre comes within 300 km of a place. Jōriku (上陸), literally going up onto land, is kept for the coasts of Hokkaido, Honshu, Shikoku and Kyushu. Tsūka (通過), passing through, is for a centre that crosses a small island or peninsula and soon returns to sea.
Landfall times follow a fixed code. JMA divides each hour into four quarter-hour windows and reports go-ji goro, around five, go-ji sugi, just after five, go-ji han goro, around half past, or roku-ji mae, just before six. Movement has its own words: hokujō, heading north; tenkō, curving north-east as the westerlies take hold; yukkuri, 9 km/h or less.
| Japanese | Romaji | Meaning |
|---|---|---|
| 台風は午前五時頃、鹿児島県に上陸しました。 | Taifū wa gozen go-ji goro, Kagoshima-ken ni jōriku shimashita. | The typhoon made landfall in Kagoshima Prefecture at around 5 a.m. |
| 台風は沖縄本島を通過しました。 | Taifū wa Okinawa hontō o tsūka shimashita. | The typhoon passed over Okinawa Island. |
| 関東に最も接近するのは、あすの夜の見込みです。 | Kantō ni mottomo sekkin suru no wa, asu no yoru no mikomi desu. | It is expected to come closest to Kanto tomorrow night. |
| 台風は速度を上げながら北東へ進むでしょう。 | Taifū wa sokudo o agenagara hokutō e susumu deshō. | The typhoon will speed up as it heads north-east. |
| 台風はほとんど停滞しています。 | Taifū wa hotondo teitai shite imasu. | The typhoon is almost stationary. |
Warnings and bulletins: the names changed in 2026
The map is information; warnings are the official call. From 29 May 2026 JMA renamed its rain, landslide, storm-surge and river-flood warnings with level numbers and added a new tier, kiken keihō, danger warning, at level 4. The storm-wind warning, bōfū keihō, and its emergency form carry no level number. The typhoon bulletin itself is now titled zenpan kishō kaisetsu jōhō, general weather commentary, with the typhoon number in brackets.
Evacuation decisions come from your city, town or village, not from the map. Alert levels, evacuation signs and earthquake alerts have their own articles.
| Japanese | Romaji | Meaning |
|---|---|---|
| 暴風警報が発表されました。 | Bōfū keihō ga happyō saremashita. | A storm-wind warning has been issued. |
| レベル４大雨危険警報が出ています。 | Reberu yon ōame kiken keihō ga dete imasu. | A level 4 heavy-rain danger warning is in effect. |
| Name | Reading | What it is |
|---|---|---|
| レベル２大雨注意報 | reberu ni ōame chūihō | Heavy-rain advisory |
| レベル３大雨警報 | reberu san ōame keihō | Heavy-rain warning |
| レベル４大雨危険警報 | reberu yon ōame kiken keihō | Heavy-rain danger warning, new tier since 2026 |
| レベル５大雨特別警報 | reberu go ōame tokubetsu keihō | Heavy-rain emergency warning |
| 暴風警報 | bōfū keihō | Storm-wind warning, with no level number |
What people say as a typhoon approaches
Before a big typhoon, the same practical words come up at work, at the station and next door. Railways announce keikaku unkyū, planned suspension, often the day before; shops post rinji kyūgyō, temporary closure; schools declare kyūkō. What you should do is for JMA and your municipality to say. These are the words you will hear around you.
| Japanese | Romaji | Meaning |
|---|---|---|
| 明日は計画運休の可能性があります。 | Ashita wa keikaku unkyū no kanōsei ga arimasu. | A planned suspension of services is possible tomorrow. (railway notice) |
| 台風のため、本日は臨時休業いたします。 | Taifū no tame, honjitsu wa rinji kyūgyō itashimasu. | Because of the typhoon, we are closed today. (shop sign) |
| 明日は在宅勤務にしましょう。 | Ashita wa zaitaku kinmu ni shimashō. | Let's all work from home tomorrow. (manager) |
| ベランダの物、中に入れた？ | Beranda no mono, naka ni ireta? | Did you bring the things in from the balcony? (flatmate) |
| スーパーで水とパンが売り切れていました。 | Sūpā de mizu to pan ga urikirete imashita. | The supermarket had sold out of water and bread. |
| 市のホームページで避難情報を確認しました。 | Shi no hōmupēji de hinan jōhō o kakunin shimashita. | I checked the evacuation information on the city's website. |
Common mistakes reading a typhoon forecast
Reading the growing circles as a growing storm. The cause is that bigger usually means stronger on a map. The yohō-en widens because the position is less certain. Read size from ōgata and strength from the class word.
Watching only the centre line. The cause is that a line looks like a prediction. JMA notes the centre does not necessarily follow the line joining the circles, and storm winds reach far beyond the centre.
Assuming you are safe because the centre will not make jōriku near you. The cause is treating landfall as the moment of danger. A sekkin within 300 km can bring storm winds and heavy rain.
Saying taifū jū, typhoon ten. The cause is dropping the counter. The number needs gō: taifū jūgō.