It is dry in Southwest Virginia as September winds down, and likely to get drier as October rolls in.
As defined by the U.S. Drought Monitor, nearly 80% of Virginia and everything within a 50-mile radius of Roanoke is at least at level “D0,” considered “abnormally dry,” or in early drought conditions.
However, a narrow strip from southern Franklin County across most of Floyd County into the southeast corner of Montgomery County has progressed to “D1” or “moderate drought.”
The Drought Monitor describes “D1” as the stage at which crops like corn, cotton and soybeans are stressed with lower yield, wildlife may eat those crops, fire danger increases to the point of burn bans being issued (several of those have been issued this week by localities even outside the area of worst dryness) and voluntary water restrictions may be necessary as river and stream levels drop to very low levels.
The current dryness is the result of the weather patterns over the past three months.
Over much of the summer, only spotty thunderstorms occurred on many days, the typical result of afternoon heat and moderately high humidity, with heavy amounts of rain on small areas for brief periods of time and only minor amounts or nothing on most areas.
That pattern has yielded in September to an even drier one, with little in the way of even spotty showers and storms most days.
The developing drought is in stark contrast to where we were a year ago, and indeed the entirety of 2018 and much of the first half of this year as well.
A year ago at this time, the remnants of Hurricane Florence had just poured 2 to 7 inches of rain on much of our region. Many locations were already over their yearly annual average rainfall on the way to record or near-record rainfall for the year.
Roanoke, for instance, had more than 45 inches of rainfall by this time a year ago, when about 42 is normal for all 12 months, on the way to a record 62.45 inches of rain for the year.
Owing to ample rainfall in the first half of the year and occasionally getting a quick downpour from a summer thunderstorms, most locations in our region have had about 30 inches of rain so far this year, which is not far off pace of what is considered normal in nine months.
While the super-soaked preceding conditions have kept us out of a lot of problems with reservoirs and water tables drying out — the D2-D4 levels of drought — other aspects of drought are more about “what have you done for me lately” rather than total precipitation over a year or two.
Almost every gauge in our region has had less than an inch of rain so far in September, some with mere hundredths of an inch. Most of what has fallen came with a period of showers and storms near midmonth when extreme heat gave way to a cooler air mass for a few days.
Strong high pressure building in overhead over the next several days promises to continue unseasonably warm — downright hot at times — and dry conditions into the first week of October, if not longer.
Unless Tropical Storm Karen, now in the Caribbean, can intervene, which is a long shot, we could easily go the next two weeks without any appreciable rainfall.
Beyond that, at some point, there will be Canadian and Arctic cold fronts diving across the region, once the heat dome high finally relents. That will eventually make it cooler, but won’t necessarily do much for rainfall, and will stir gusty winds across an extremely dry surface.
Besides whatever garden or crop troubles the dryness is causing, the potential exists for a ramped-up fall wildfire season.
It is a pretty bleak forecast right now for anyone who wants classic autumn weather to take hold in earnest soon, or anyone who just wants a decent rain.
It is important to note that hot, dry weather in September has little or no correlation, historically, with what happens in the following winter, locally. A hot, dry September doesn’t mean a mild, dry winter will follow, nor does it mean the opposites of those conditions will necessarily cycle through by winter.
Weather patterns can shift, rather suddenly sometimes, especially as we move deeper into the cooler side of the calendar. Don’t be surprised if we flip from flirting with 90 to frost advisories or even mountain snow showers in a few days sometime in October. A wet pattern of frequent low-pressure troughs scooping Gulf of Mexico moisture over us doesn’t look to be anywhere in sight, but could yet develop later this fall or winter.
If the general dryness does hang on through winter, we’ll have a lot bigger drought problems to deal with in 2020.
Weather Journal appears on Wednesdays.