TAF Trend at Hakodate
Pilot plans a VFR flight from Sapporo Okadama (RJCO) to Hakodate (RJCH), 90 NM, departure 13:00 JST, arrival 14:30 JST. METAR RJCH 120300Z 15012G18KT 6000 -SHRA SCT012 BKN025 14/12 Q1008. TAF RJCH 1200/1209 15010KT 9999 SCT020 TEMPO 1203/1206 4000 SHRA BKN008 BECMG 1206/1208 30020G30KT 6000 -SHRA BKN015. Local time is UTC+9. The route crosses water; the pilot has no alternate selected and 2 hours of fuel. The aircraft is VFR-only, no deicing, and the pilot has 120 hours total time. The pilot's personal minimum is 5 km visibility and a 1,500 ft ceiling; the aircraft's crosswind limit is 15 kt. Destination forecast after 15:00 JST includes a 30 kt gusting crosswind.
1. Decode the TAF for the planned arrival time and identify the main hazards.
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Arrival 14:30 JST is 05:30 UTC. The TAF TEMPO 1203/1206 is active from 12:00 to 15:00 JST and forecasts 4,000 m visibility, showers of rain, and broken cloud at 800 ft. That is below the pilot's personal minimum of 5 km visibility and 1,500 ft ceiling, and marginal for VFR in controlled airspace. The main hazards are low ceiling and reduced visibility in showers, plus a risk of wind shear near the showers. After 15:00 JST the BECMG group brings 300° at 20 kt gusting 30 kt, which is a strong crosswind and low-level shear risk at Hakodate.
2. Should the pilot depart with no alternate and 2 hours fuel? Explain.
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No. The flight is only about 0.8-0.9 h at typical PA-28 cruise, so 2 h fuel leaves a reasonable reserve, but the destination forecast can go below VFR at the planned arrival time. With no alternate selected, the pilot has no pre-briefed diversion, no verified weather at an alternate, and no fuel plan to alternate plus 45 minutes. A VFR-only aircraft cannot descend through an 800 ft ceiling. The gusty crosswind after the front may also exceed the pilot's 120-hour experience and personal limits. The correct decision is to delay, choose an alternate, or cancel.
3. What alternate and operational plan would you make?
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Select an alternate with a forecast VFR ceiling and visibility, for example New Chitose or Aomori, check its TAF and NOTAMs, and carry fuel for destination, alternate, and 45-minute reserve. Brief the diversion before departure. If the front is the main issue, delay until after it passes and the gusty crosswind is within limits, or cancel. Monitor METAR/TAF and be prepared to divert early rather than press into showers. The decision should be made on the ground, not over water with no alternate.