DJ's uses Spraywise Decisions to predict weather events as they are forecast.
Spray Wise 10112010
The weather expected on Friday the 12th of November and Saturday the 13th of November has some chance of being a Downy Mildew Primary Event (10:10:24) and / or a Downy Mildew Secondary Event (Warm, wet night).
For the McLaren Vale / southern Adelaide Hills region, rain is predicted to begin at 10am on Friday the 12/11. This is expected to last until 9pm the same day.
Looking at the data as predicted, weather conditions will ONLY be favourable for Downy Mildew if vineyards stay wet between 10am Friday and the start of the rain on Saturday. If they dry out in between the 24 hours of leaf wetness needed for a Downy Mildew Primary Event(10:10:24) is unlikely.
A Downy Mildew Secondary Event (Warm. wet night) may occur if rain is still falling during the four hours before dawn on Sunday morning. This is concern of the Adelaide Hills region including Range Rd, which MIGHT have Downy Mildew oilspots from a probable Primary Event on the 27th/28th of October, and also McLaren Flat which has had a confirmed oilspot.
For most vineyards the threat of Downy Mildew is low, but it pays to get specific advice and keep up Downy Mildew protection if more rain events occur in the next month.