North Sails Weather Forecast Day Six

by Sail-World on 16 Aug 2006 North Sails Weather Forecast 2006 Airlie Beach Race Week. Issued by Kenn Batt at 0500hr for Wednesday 16th August 2006

Synoptic Discussion:

A strengthening ridge of high pressure over area.

Observations:

At 0500hr surface winds over the Airlie Beach area were out of the SW averaging around 5kn. This was indicative of a land breeze. At Hamilton Island the wind was SE at 4kn, indicative of synoptic flow. Further seawards, Hardys Reef was E 9knots.

Forecast Winds for middle of Pioneer Bay (Check out other possibilities below)
0800: 230/08 gust 12kn
1000: 120/10 gust 15kn (Chance light and variable)
Noon: 110/12 gust 15kn
1400: 090/14 gust 19kn
1600: 070/14 gust 19kn (Chance 150 deg 19 Gust 29kn)
1800: 150/25 gust 32kn (Chance 150 deg 19 Gust 29kn)

Wind direction and speed more variable in the Whitsunday Passage and Molle Channels area. (With the strengthening of ridge the wind would then be 10-20deg more right and 5-10 knots stronger than forecast winds above in this area). Wind can funnel out of bays and can become very variable and squally around some headlands.

NOTE 1: Wind directions MAGNETIC, first speed is 10 min average and last speed is the 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, channeling out of bays and channels, showers, etc.



REMARKS:

Natural oscillations around 15 to 30 deg away from effects of topography, tending around 20 to 50 deg closer to the effects of any land mass.

Other Possibilities:

70% chance that wind direction and speed will be light and variable between 0900 – 1100hr.

50% chance that a sea breeze 010-040 deg at around 8-12kn becomes established for at least part of day.

50% chance that wind will freshen from 160-140deg during the afternoon (after
1400hr?).

Weather

Dry and mostly sunny. Take plenty of sunscreen and warm clothes and wet weather gear.

Maximum land temperature at Airlie Beach: 23 degrees Sea Temp: 21 degrees

Wind Waves: 0.2 to 3.0 metres. Note: that wind opposing tide can create higher than forecast wave heights.

(Wave heights quoted are Significant wave heights). Current: A very strong tidal influence. Tide roughly floods to the south and ebbs to the north in the Whitsundays area (see back page of sailing instructions for further details on tidal flows).

Outlook
Thursday: Chance shower. SE 15-25knots.

Tides for Shute Harbour   

Tue 15		Wed 16		Thu 17
Time	Ht	Time	Ht	Time	Ht
0245	2.74	0411	2.41	0010	1.17
0922	0.65	1034	0.71	0549	2.28
1605	2.91	1730	3.06	1151	0.69
2221	1.26			1847	3.29