Forecast hour +3

Tue 15 Sep, 05:10

Generated 02:17
Marginal
Mean wind14.8 ktLikely 12.5–15.0 kt
Wind directionW281° true · 285° magnetic
Gust23.6 kt25+ kt risk 90%
Possible wind range7.5–18.4 ktCalibrated uncertainty
Temperature15.6°CFeels like 12.6°C
Rain probability2%Met Office guidance
Wave height1.3 m5.4 s period
Wave directionSW224° · swell 1.1 m

Weather detail

Forecast assessment
Marginal because upper wind range reaches 18.4 kt.
Wind change
Falling (-4.4 kt)
Direction-change risk
100%
Weather regime
Showery / unstable
Provider agreement
Significant disagreementSource wind spread 4.4 kt; direction spread 80°.
Selected sources
Corrected 100%

Gust probability

18+ kt99%
20+ kt97%
25+ kt90%
30+ kt77%

TBSC course selection

Short course285° magnetic
Why this course set?Short selected because the forecast mean is 14.8 kt and gust 23.6 kt, outside the Force 3-4 band; the card uses Short for Force 1-2 or Force 5 conditions.The 281 degree true forecast converts to approximately 282 degrees magnetic and uses the nearest 15 degree matrix column: 285 degrees.
FleetCourse
Oppy 21Y
Optimist2
Feva7
Slow Misc7
Myth7
Misc19
1/2 Rater19
StartG/W

Wind-based selection; shorten for poor visibility, rough sea or other race-management concerns.

Trearddur Bay Sailing Club

Sailing area

Tue 15 Sep, 05:10 · Wind W 281 deg T at 14.8 kt, gust 23.6 kt · Short course, 285 deg magnetic
Course overlay ready
Trearddur Bay Sailing Club sailing area showing racing marks and magnetic bearings WIND FROM W / 281 deg T
Course 1YOppy 2Route diagram referenced as page 27 but not included in the supplied scan

Why: The 2026 selector assigns Course 1Y to Oppy 2 for this course length and magnetic-bearing column. Its route refers to page 27, which was not included in the supplied scan.

Course 2Optimist4 rounds · Outer Bay · start G/W

Why: The Short matrix at 285 degrees magnetic assigns Course 2 to Optimist. The normal published mark sequence applies. The route starts at the midpoint of the G/W line, uses Outer Bay as its Bay Mark and finishes at the midpoint of the white line.

Course 7Feva2 rounds · Green Bay · start G/W

Why: The Short matrix at 285 degrees magnetic assigns Course 7 to Feva. The normal published mark sequence applies. The route starts at the midpoint of the G/W line, uses Green Bay as its Bay Mark and finishes at the midpoint of the white line.

Course 7Slow Misc, Myth2 rounds · Outer Bay · start G/W

Why: The Short matrix at 285 degrees magnetic assigns Course 7 to Slow Misc, Myth. The normal published mark sequence applies. The route starts at the midpoint of the G/W line, uses Outer Bay as its Bay Mark and finishes at the midpoint of the white line.

Course 19Misc1.5 rounds · Green Bay · start G/W

Why: The Short matrix at 285 degrees magnetic assigns Course 19 to Misc. The normal published mark sequence applies. The route starts at the midpoint of the G/W line, uses Green Bay as its Bay Mark and finishes at the midpoint of the white line.

Course 191/2 Rater1.5 rounds · Inner Bay · start G/W

Why: The Short matrix at 285 degrees magnetic assigns Course 19 to 1/2 Rater. The normal published mark sequence applies. The route starts at the midpoint of the G/W line, uses Inner Bay as its Bay Mark and finishes at the midpoint of the white line.

The blue wind arrow points downwind; its label states the direction the wind comes from. Each coloured course begins at the midpoint of its selected Red or G/W start line and ends at the midpoint of the white finish line. Coloured arrowheads show the order of travel. Lines show the mark sequence once; follow the number of rounds in the key. Published port/starboard rounding instructions remain authoritative.

Forecast sources

SourceWindGustDirection
Local19.2 kt34.8 ktSSW 201°
Corrected14.8 kt23.6 ktW 281°
Met Office15.0 kt22.4 ktW 281°
Persistence19.2 kt34.8 ktSSW 201°
Residual Shadow19.8 kt23.7 ktW 281°

Guidance only. The race officer's decision, current observations, sea state, visibility, tide, official warnings and local safety procedures take precedence over this experimental forecast.