Weather - 2008 Audi Hamilton Island Race Week
Weather forecast for Day 1 2008 Audi Hamilton Island Race Week
'WILD OATS X training'
Andrea Francolini / Audi ©
Synoptic Discussion:
A slow moving high pressure system over the Bight will dominate the weather till about Monday. An intense low pressure system to the east of Sydney is moving toward the SE.
A series of upper trough will move across southern Queensland during next week.
The first trough will bring some high cloud on Monday but with no rain expected.
The next trough will begin to intensify over South Australia on Tuesday with
Some isolated showers and possible thunderstorms developing over Whitsundays on Wednesday.
Observations:
At 0600hr, the surface wind at Hamilton Island Airport was from SSE at 22kt, gusting 26kt (temp 18C pressure 1020hPa) indicative of the general synoptic flow, although it does suffer from the effects of topographic forcing. At Hardy Reef, further off the coast, the wind was a S'ly at 22kn (indicative of true surface wind)
Forecast Discussion:
Forecast confidence level: High
The ridge of high pressure has built over the Whitsundays during this morning and is expected to reach maturity over next 24hr. As such the wind is expected to be gradient-driven and you can expect fresh and gusty S-SE'ly over the race area today.
Natural wind oscillations today around 15 to 20 deg away from effects of topography, tending 20 to 50 deg closer to the effects of any land mass.
Expect wind speed to be 3-7kn stronger in channels due to localized funneling and direction flicky. There is a chance that the wind speed may decrease by 3-5kn later this afternoon and direction reach 10-20deg more left than forecast?
Forecast Winds for Hamilton Island Area in open water
0800:MD180 DR(200-160) MS20 SR15-27kn
1000:MD160 DR(180-140) MS20 SR15-27kn
1200:MD150 DR(170-130) MS20 SR15-28kn
1400:MD150 DR(170-130) MS21 SR16-29kn
1600:MD150 DR(170-130) MS21 SR16-28kn
1800:MD150 DR(170-130) MS20 SR15-28kn
Key:First column is mean wind direction in deg Mag (MD). It is the 10min average (mean) value at a height of 10m above the water leading up to the hour quoted. The second cloumn is the directional range (DR) of the wind direction in deg Mag. This takes into account the natural oscillation of the wind and is a function of the atmospheric stability, etc. The third column is the mean speed (MS) in knots (kn) and is the average 10min value leading up to the hour quoted at a height of 10m above the water. The last column is the wind speed range (SR) in knots and is the lowest wind speed to highest wind speed in the 10min leading up to forecast hour.
Other Possibilities:
40% chance that wind speed will be 3-5 knots less than forecast above this afternoon.
40% chance that wind direction reaches 130deg mag. later this afternoon
Weather
Dry and partly cloudy. Take plenty of sunscreen and warm clothing.
Maximum land temperature at Hamilton Island: 21 degrees Sea Temp: 21 degrees
Wind Waves: 1.0 to 2.0 metre. Less near land, more when wind wave opposes tidal stream.
(Wave heights quoted are Significant wave heights).
Current:Quite a strong flood tide for much of the day.
Tide floods to the south and ebbs to the north in the Whitsundays.
Tide: Low of 0.83m at 0858hr and High of 2.85m at 1600hr
Outlook
Sunday: Dry. SE winds 20/25 knots.
Monday: Chance of shower. SE winds 20/25 knots.
by Kenn Batt
Balaclava, VIC
