We have been very fortunate this August with the majority of the month being relatively comfortable with low humidity and no extreme heat. I haven't heard any complaints about our weather pattern with how it pertains to temperatures (predominant upper level trough overhead keeping heat and humidity to our south), but now a few concerns are rolling in about rainfall. Yes, we all enjoy these fine August days, but after a while, there comes a point when the focus shifts to rainfall.

Sprinklers have gotten quite a workout this August with no widespread soakers or tropical systems to give our lawns and gardens a drink. Instead, we have relied on a few thunderstorms containing heavy but highly isolated and brief downpours, and even the frontal passages have been uneventful. Additionally, when considering the lower humidity levels this August, we haven't had abundant moisture available (precipitable water) in our air to contribute to thunderstorms no matter what the trigger...fronts, lee troughs, orographic lift, daytime heating, etc.

At Reagan National Airport, so far this August we are nearly 2 inches below normal with only 0.56 inches of rain. Three days have contained measurable rainfall with the highest daily total amounting to 0.23" on the 2nd. Hardly enough to give your lawn a good drink when most other days are dry and sunny.

According to David Yost of Merrifield Garden Center, "To keep lawns green and growing they should have 1" of water each week. Ideally, this would be one long, slow rainfall, or watering that would allow the water to soak deep into the soil." Dulles airport and the surrounding community is in a slightly better position at nearly one and a half inches below normal in the rainfall department with a total of 1.22 inches so far this month. Nearly all of that rain came on a single day, which was the result of a thunderstorm with a heavy downpour.

With the development of Tropical Storm Fay several days ago, I had hopes of our region receiving at least some moisture from this storm, but that obviously hasn't been the case yet. Ideally, while in a dry stretch of summer days, the remnants of a tropical storm or hurricane will move through our region and drop steady, light rain for a day or two. Remember, hurricanes and tropical storms aren't always bad as they do transport much needed moisture to areas that otherwise wouldn't receive it and help drought stricken areas. Some, however, bring more rain than folks would like, which is the case with Fay in Florida because it is nearly stationary along the Gulf coast, and most of Florida pulled out of a drought months ago.

As of now, it doesn't look as though moisture from TS Fay will make it's way into our region anytime soon. A high pressure system over our area, which is causing more sunny and comfortable days, will keep Fay and it's remnants in the southeastern U.S. through the weekend. This high is expected to slide east early next week, and this could transport some moisture northward from Georgia, through the Carolinas, and into our backyard by late next week. Though even if moisture makes it here, the amount is very uncertain as of now. Otherwise, our dry weather pattern should will persist for the forseeable future. Keep the sprinkler out for now.