Isolated thunderstorms went through the area and Winchester area received a short shower last night from 12:55AM. The relative humidity remained high (>90%) until 6:55AM, thus, it accounted for 6 hours of an estimated wetness period with an average temperature of 65F. It is long enough for light infection for Phompsis, and infection for downy mildew.
These isolated thunderstorms are difficult to predict and as the name implies, it could affect only a limited area. For example, I was watching dark cloud passing through last evening, but we did not receive any rain at my place. Please check your local weather closely and make an adjustment to your spray program, if needed.
Many of us are about to have bloom soon. Please keep in your mind that from bloom to 4-5 weeks after bloom is a critical period of cluster infection by downy mildew, powdery mildew, and black rot.