Our abnormally dry conditions are small potatoes compared to the severe to extreme drought reigning in rainless southern California and much of the west. And our conditions are unlikely to compare to a serious four- to five-year drought that gripped the Northeast in the early- to mid-1960s.
That perspective aside, Western New York is suffering from a serious rainfall deficit, about 6 inches or one third below average liquid precipitation for the year as of this writing. The water table is undoubtedly dropping in interior locations off the Erie County Water authority supply grid, and stress is affecting many crops and gardens. We can all see the crunchy brown lawns everywhere.
The much more serious drought in the west is associated with what meteorologists are calling a Ridiculously Resilient Ridge of high pressure, stacked up in the atmosphere like a mountainous boulder in a stream. That ridge caps off upward motion in the atmosphere with a sinking motion that “squishes” the clouds, as I used to say on TV. When the air aloft is sinking, rainfall becomes close to impossible.
At times, something of a monsoonal flow will bring some thunderstorms into Arizona, but California will stay parched with the wildfire season growing even worse than it already has been. This boulder-in-a-stream forces any kind of a persistent flow of moisture to move around it. The now-past El Niño brought average Pacific moisture to the Sierras and the northwest, but southern California rainfall was very disappointing.
For us, the situation is quite different. We don’t have such a persistent ridge over the Great Lakes or over the southeast United States, but the northern storm track is displaced a little farther north than usual. The cold fronts crossing the eastern Great Lakes have generally been starved for any significant Gulf moisture by the time they approach Western New York. They bring some scattered showers and thunderstorms from time to time, but coverage for the rainfall can range from spotty to downright sparse.
Upper level winds have steered excessive moisture to our south, as in the disastrous flash flooding in West Virginia a few days ago and earlier during the spring into south Texas and parts of the south and southeast.
I’m not seeing signs in extended range computer guidance of a fundamental change to this pattern in our region in the next couple of weeks. There will occasional showers and thunderstorms, but the precipitation they bring won’t be heavy or widespread enough to stem the deficit.
And low soil moisture adds to the dryness already present. Evaporation from moist soil and vegetation adds to the supply of water vapor in the air for approaching showers or thunderstorms. The dryness we have now works against us. Drought begets more drought in the summer months.
However, what works in our favor is that we don’t a Ridiculously Resilient Ridge in place, and there is no sign yet of such a development occurring here in the eastern Great Lakes. It would not take as a dramatic pattern shift to produce more convection and rainfall later in the summer as it would out west.
For now, if you can afford to water tender vegetation, you should keep it up. The Cornell Cooperative Extension recommends watering lawns between 4 a.m. and 8 a.m. The drying of the grass after sunrise will make the development of grass disease unlikely. You won’t be wasting it even if your neighborhood gets some heavy showers. The rainfall deficit is large enough that your soil will soak up as much as it can with nature unable to fill the bill.
Grass can be quite resistant to dry weather for short periods. However, as the dry pattern persists, if you see footprints when you cross your lawn, that grass may be living on the edge at best.
Bottom line: I expect our abnormally dry pattern to persist much of the time for at least several weeks, and possibly longer. However, we are unlikely to slip into a more damaging drought comparable to anything out west.