Yesterday, Typhoon “Usagi” struck Hong Kong. All takeoffs were suspended starting from 6:00 PM, and landings stopped after 7:00 PM. A total of 370 flights were canceled during the day, leaving the Runway in silence. What did the METAR routine aviation weather report look like at this time?

Let’s first look at the weather at 18:00 yesterday: 221100Z 31030KT 7000 -SHRA FEW015 SCT025 27/24 Q0990 TEMPO 3500 SHRA

Wind speed exceeded 55 km/h, which is indeed quite strong; Visibility was 7 km, moderate; rain showers, but the volume wasn’t heavy; cloud cover wasn’t too extensive; temperature was 27°C, dew point 24°C, indicating extremely high air humidity; pressure was 990 hPa, clearly a low-pressure system.

Half an hour later: 221136Z 32033KT 3800 SHRA FEW015 SCT030 27/24 Q0990 TEMPO 3500 SHRA

You can see the visibility dropped dramatically to 3800 meters, and the rain intensified. Other data remained largely unchanged.

After this, the weather didn’t change much, but by 22:00, the wind speed reached its maximum: 221430Z 28035G46KT 5000 -SHRA FEW015 SCT030 27/24 Q0987 RERA TEMPO 3500 SHRA 221522Z 28033G45KT 5000 SHRA FEW015 SCT030 26/24 Q0987 TEMPO 3500 SHRA

Gusts exceeded 90 km/h, and pressure was 987 hPa. Other data remained basically constant.

The data released at 00:20 was the most detailed, providing the RVR (Runway Visual Range) for each Runway: 221620Z 26030KT 2800 1100N R07R/P2000 R25L/P2000 R07L/1600VP2000D R25R/1900VP2000U +SHRA FEW015 SCT025 26/24 Q0988 TEMPO 3500 SHRA

• Wind Direction/Speed: 260 degrees at 30 knots (56 km/h).
• Visibility: 2800 meters.
• RVR Runway Visual Range: Runway 07R at 2000m, Runway 25L at 2000m, Runway 07L varying between 1600m and 2000m and decreasing, Runway 25R varying between 1900m and 2000m and increasing.

Other data showed little variation.

The shortest Visibility occurred at 02:47 AM, reaching 2400 meters: 221847Z 22031G45KT 2400 +SHRA FEW010 SCT025 25/24 Q0991 TEMPO 3500 SHRA

Let’s look at the latest data now: 222223Z 22017KT 4800 SHRA FEW015 SCT030 26/24 Q0995 TEMPO 3500 SHRA 222230Z 23016KT 5000 SHRA FEW015 SCT030 26/24 Q0995 TEMPO 3500 SHRA

Wind speed has weakened to 17 knots (30 km/h). Assuming this trend continues, flights should be able to resume shortly.

A summary of yesterday’s data:

○ Reference METAR Aviation Routine Weather Report Format Summary What is the ATIS like at Haneda Airport during a typhoon?

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