Forecast hour +5

Tue 15 Sep, 07:10

Generated 02:17
Likely suitable
Mean wind14.3 ktLikely 12.3–14.8 kt
Wind directionW259° true · 255° magnetic
Gust21.3 kt25+ kt risk 74%
Possible wind range10.9–16.1 ktCalibrated uncertainty
Temperature15.6°CFeels like 12.7°C
Rain probability0%Met Office guidance
Wave height1.2 m5.1 s period
Wave directionSW229° · swell 0.8 m

Weather detail

Forecast assessment
Upper wind range remains below 18 kt and gusts remain below 25 kt.
Wind change
Falling (-5.0 kt)
Direction-change risk
100%
Weather regime
Showery / unstable
Provider agreement
Moderate agreementSource wind spread 5.0 kt; direction spread 58°.
Selected sources
Corrected 85%Met Office 15%

Gust probability

18+ kt97%
20+ kt94%
25+ kt74%
30+ kt58%

TBSC course selection

Short course255° magnetic
Why this course set?Short selected because the forecast mean is 14.3 kt and gust 21.3 kt, outside the Force 3-4 band; the card uses Short for Force 1-2 or Force 5 conditions.The 259 degree true forecast converts to approximately 260 degrees magnetic and uses the nearest 15 degree matrix column: 255 degrees.
FleetCourse
Oppy 21Y
Optimist3
Feva8
Slow Misc8
Myth8
Misc20
1/2 Rater20
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, 07:10 · Wind W 259 deg T at 14.3 kt, gust 21.3 kt · Short course, 255 deg magnetic
Course overlay ready
Trearddur Bay Sailing Club sailing area showing racing marks and magnetic bearings WIND FROM W / 259 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 3Optimist4 rounds · Outer Bay · start G/W

Why: The Short matrix at 255 degrees magnetic assigns Course 3 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 8Feva2 rounds · Green Bay · start G/W

Why: The Short matrix at 255 degrees magnetic assigns Course 8 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 8Slow Misc, Myth2 rounds · Outer Bay · start G/W

Why: The Short matrix at 255 degrees magnetic assigns Course 8 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 20Misc1.5 rounds · Green Bay · start G/W

Why: The Short matrix at 255 degrees magnetic assigns Course 20 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 201/2 Rater1.5 rounds · Inner Bay · start G/W

Why: The Short matrix at 255 degrees magnetic assigns Course 20 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°
Corrected14.2 kt21.5 ktW 259°
Met Office14.5 kt20.5 ktW 259°
Persistence19.2 kt34.8 ktSSW 201°
Residual Shadow16.1 kt20.3 ktW 259°

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.