Big breezes at Hamilton Island today

by Kenn Batt, sponsored by North Sails on 24 Aug 2005 Weather Forecast for 2005 Hahn Premium Race Week brought to you by North Sails

'North Sails proudly assisting the Premium Tropical Regatta'

For Wednesday 24th August 2005 Issued at 0600hr

Synoptic Discussion:

A ridge of high pressure is strengthening over the region and will persist for the rest of the race series. SE winds are expected to reach maximum intensity on both Friday and Saturday.

Observations at 0600hr:

There were nil precipitation echoes on the radar.
Surface wind at Hamilton Island was 160deg Magnetic at 16kt.
At Hardy Reef (19:44.04S/149:10.85E)it was 140deg mag at 17kt. Both observations indicative of the developing synoptic situation.

Forecast Winds for Open Sea Area East of Hamilton Island

1000:150/20 gust 30kt

1200:140/22 gust 32kt

1400: 130/24 gust 34kt

1600: 130/24 gust 34kt

1800: 140/22 gust 30kt

NB: Wind direction possibly 5-10 degrees more veered (right) over southern race area at times.

Natural oscillations today around 10 to 15 deg away from effects of topography, tending around 20 to 60 deg closer to the effects of any land mass. Wind speed can be stronger due to effects of channeling between islands, etc and lighter in lee of headlands, etc. Alternate bands of maximum and minimum wind speed, some 5-10 mins apart, normally characterize trade wind flow. Any shower activity can produce squally and erratic winds.

NOTE 1: Wind directions MAGNETIC, first speed is 10 min average and last speed is
maximum one minute gust during the 10min period leading up to the forecast hour. All at a height of 10m.

NOTE 2: The trend in both wind direction and speed is the most important aspect of any marine forecast. Forecast values will differ from observed values from time to time for a number of reasons including yacht’s position within race area, compass calibration, instrument calibration, land mass in the flow, etc


Forecast confidence level: 90%, based on state of art forecast models and grey matter.

Other Possibilities

30% chance that wind direction could reach left as far as 120 deg during mid-afternoon.

Weather

Partly cloudy with the chance of a shower or two developing late today. Take plenty of sunscreen, warm clothes and wet weather gear.

Maximum land temperature at Hamilton Is: 22 degrees. Sea Temp: 21 degrees

Wind Waves: 1.0 to 2.0 metre. Less near land. Note that wind opposing tide can create higher than forecast wave heights Swell: ESE around 1.0m. (Wave heights quoted are Significant wave heights). Current: A very strong tidal influence. Tide floods to the south and ebbs to the north in the Whitsundays generally, marked localised variations occur. Consult chart and 100 Magic Miles for further information.

Outlook

Thursday: Showers. SE winds 20/25, reaching 25/30 knots at times.
Friday: Showers. SE winds 20/25, reaching 25/30 knots at times.
Saturday: Showers. SE winds 20/25, reaching 25/30 knots at times.

Tides for Shute Harbour

Wed 24 Thu 25 Fri 26 Sat 27 Sun 28 Mon 29

Time Ht Time Ht Time Ht Time Ht Time Ht
Time Ht

0131 3.07 0221 2.63 0340 2.27 0528 2.12 0115 1.05

0209 0.83

0759 0.60 0854 0.76 1006 0.88 1124 0.90 0655 2.20

0754 2.35

1424 2.85 1538 2.82 1703 2.88 1824 3.06 1237 0.83

1334 0.72

2020 1.13 2159 1.34 2350 1.29 1926 3.26

2013 3.40