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Dark And Stormy

By Jim Skorulski, agronomist, Northeast Region

| Jul 7, 2017

Ominous storm clouds signal an oncoming front and the potential for dangerous lightning.

Wet and soggy conditions have been common across most of the Northeast Region this season. Wet weather has saturated many golf courses and flooded others, disrupting maintenance and course-conditioning efforts. Fortunately, the wet weather has not severely affected turf conditions because temperatures have mostly remained moderate. However, continued wet weather combined with warming soil temperatures will reduce turfgrass rooting and could prove fatal. Turf managers are taking advantage of any dry weather to catch up on spraying and topdressing practices that have been disrupted by the rain. Hopefully the weather will also allow an opportunity to vent putting greens. Venting will help soils dry and re-establish gas exchange in the root zone. The USGA webcast, “Venting Aeration – A Benefit to Putting Greens,” further illustrates this popular cultivation technique.

Stormy weather patterns also bring concerns about lightning and the dangers it presents for workers and golfers. A properly functioning lightning detection system is the best defense against lightning. Lightning detection systems provide advance warning of incoming storms and let facilities know when conditions are safe to resume outside activities. However, not all golf facilities have lightning detection systems and there may be times when workers and golfers have to determine for themselves when it is time to seek shelter. Here are a few tips that workers and golfers can use when severe weather approaches:

1. The time between a lightning flash and thunder can be used to determine how far away the lightning strike occurred. Sound travels at a speed of about 1,125 feet per second (343 meters per second), equating to about a five-second count per mile (three seconds per kilometer) from the time of a lightning flash until the clap of thunder is heard. A count of 10 seconds between a flash of lightning and the clap of thunder means the lightning strike was approximately 2 miles away. Many were taught to count one second for each mile between a lightning flash and thunder, which greatly overestimates how far away the lightning strike occurred.

2. The “30/30 rule” is used by many to determine when it is time to head for shelter. The rule says that lightning poses a threat if it takes less than 30 seconds to hear thunder after a lightning flash and people should wait 30 minutes after a storm passes before resuming outdoor activities. The problem with the 30/30 rule is that the numbers are arbitrary. Using this method does not help to determine if a storm has sufficiently passed or if another storm is approaching. The best approach is to take cover as a lighting storm approaches and remain there until you are sure the storm has passed or until an all-clear signal is provided.

3. Lightning will often strike a tall object, but not always. Taking cover near smaller trees or objects hoping the lightning will strike a taller object may get you in trouble. Lightning can strike the ground or smaller trees, endangering anyone close to those areas. The only safe place to take cover from a storm is indoors or inside a closed vehicle.

4. Lightning never strikes twice is an old myth. Lightning can indeed strike the same spot multiple times if conditions are right.

July is also the time for field day demonstrations at Rutgers University and the University of Massachusetts. Field days provide an opportunity to see research in progress, to observe the newest grasses and to view the effectiveness of various control agents. Field days also provide an opportunity to interact with colleagues, which seems to be more and more difficult to do with everyone’s busy schedules. It is never easy to leave your golf course during midsummer, but try to attend one of the university field day events even if just for a few hours in the morning to support the university and gain valuable information that will make you a better manager. We hope to see you there.


Northeast Region Agronomists:

David A. Oatis, regional director –

Adam Moeller, director, Green Section Education –

James E. Skorulski, agronomist –

Elliott Dowling, agronomist –

Addison Barden, agronomist –

Paul Jacobs, agronomist –

Information on the USGA’s Course Consulting Service 

Contact the Green Section Staff

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