Telcoinabox Airlie Beach Race Week - Day 2 forecast

by Kenn Batt on 11 Aug 2012 Telcoinabox Airlie Beach Race Week - Day 2 forecast: Nil Warnings current at time of writing for this area.

Synoptic Discussion: A ridge of high pressure lies over Queensland.

Observations:

At 0600hr Hamilton Island was reporting the following conditions:

Wind 150deg at 24kn (ave) gusting to 36kn, Temp 15C, Pressure 1021hPa).

Forecast Winds for Middle of Pioneer Bay (Read Discussion below)

1000:MD190 DR(210-170) MS16 SR13-24kn
1200:MD130 DR(150-110) MS15 SR12-22kn
1400:MD120 DR(140-100) MS13 SR09-19kn
1600:MD120 DR(140-100) MS12 SR08-18kn
1800:MD120 DR(140-090) MS10 SR06-15kn

Note: Direction trending 20-30deg more left than above closer to coast after about 1100hr.

Whitsunday Passage and Molle Channel: Wind speeds 3 to 5kn stronger at times than those above first up this morning, before easing late morning. Winds can be gusty and erratic around some headlands and in more constrained locations.

Note: First column is mean wind direction in deg Magnetic (MD). It is the 10min average (mean) value at a height of 10m above the water leading up to the hour quoted. The second column 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.

Discussion: A ridge of high pressure lies along the Q’ld coast. Like yesterday though, a bubble high is expected to form over the general area during the afternoon (see forecast chart valid for 1600hr today). This situation (like yesterday) should see the SE winds ease during the morning and trend more left under the influence of the sea breeze component.

Other possibilities: 45% chance that bubble high doesn’t form. If this happens then winds would hang in from 140-120deg at 14-22kn (ave) and 3-5kn stronger in the Whitsunday Passage and Molle Channel at times.

Note: Wind will be lighter in the lee of any landmass and stronger and more gusty between islands (in channels and passages) and around some headlands.

Natural oscillations today around 15 to 25 deg away from effects of topography, tending 30 to 50 deg closer to the effects of any land mass (including islands and headlands).

Weather: Cool, dry and sunny. Maximum land temperature at Airlie Beach: about 21 degrees.

Wind Waves: 0.5 to 2.0 metres. Less in lee of land, more when wind wave opposes tidal current and further offshore. (Wave heights quoted are significant wave heights).

Tide at Shute Harbour: High of 2.19m at 0631hr, Low of 0.94m at 1226hr and High of 2.98m at 1915hr.

Tidal Stream: A good ebb this morning becoming slack before flooding this afternoon. Be very careful particularly in passages, channels, close to islands, etc.

Remember: Tidal currents generally flood to the south and ebb to the north in the Whitsundays (with a multitude of local effects and eddies. So be prepared!).

Sea Temperature: about 20 degrees.

Outlook:

Sunday: Dry and cool. SW to SE 8 to 15 kn (ave), reaching 15 to 20 kn (ave) and gusty at times during the morning, particularly offshore. Direction trending SE to NE at 8 to 14kn (ave) during the afternoon

Wind speeds are expected to be 3-5kn stronger at times in the Whitsunday and Molle Passages during the morning Airlie Beach Race Week website