Kevin Myatt is The Roanoke Times' weather columnist.

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It might be the biggest "no duh" moment in the history of local weather, but as of Thursday, all of Southwest Virginia was finally upgraded to moderate drought.

For most of the summer, the U.S. Drought Monitor had been placing most of Southwest Virginia in the "abnormally dry" category, with the boundary for moderate drought lapping back and forth around Giles and Pulaski counties. That boundary is now much farther east, roughly along a Lexington to Bedford to Brookneal line. Areas to the west and southwest of that line, through the Roanoke and New River valleys and south to include Martinsville, are considered to be in moderate drought. The drought is considered to be severe to extreme west of Interstate 77.

Since the remnants of Tropical Storm Barry provided the last widespread rain on June 3, localized thunderstorm downpours have been the only relief. Sudden, heavy rain like that often just runs off of the hard, crusty ground, which helps reservoir levels and stream flow some, but not soil moisture.

Rainfall for the year to date is nearly 9 inches below normal in Roanoke, following two years that were together about 9 inches below normal in rain. Since a two-year wet period ended in 2004, we've had about a foot and a half less rain than we should, according to climatic norms.

It could be much worse. Parts of Alabama are running that far behind normal just for the first eight months of this year. But their drought has become our drought, too, expanding gradually north and east throughout the summer. All that dry ground and air to our southwest isn't going to help us get moisture-bearing systems in here.

Historically, the fall-winter period is not a good time of year to be needing to catch up on rainfall. On the meteorological calendar, fall begins Saturday, the first day of September.

Roanoke's four driest months on average, using the 1971-2000 climate averages that are considered our norms, are December (2.86 inches), February (3.08 inches), October (3.15 inches) and November (3.21 inches).

Fall also has a greater propensity to produce extremely dry months than any other time of year. Roanoke's two driest months since weather records began at the Roanoke Regional Airport in 1948 were both Octobers (0.02 inch in 2000 and 0.04 inch in 1991). Two of its next three driest after that were Septembers (0.15 inch in 1991, 0.23 inch in 2005).

Interestingly, though, the threat of tropical systems during the peaking Atlantic hurricane season always offers the possibility of autumn deluges.

Four of Roanoke's eight months that have had more than 10 inches of rain have been in the fall, including the rainiest month on record, November 1985 (the flood of '85) with 12.36 inches. Three Septembers are on that list, including two of three months (aside from November 1985) that topped 11 inches: September 2004 (11.72 inches) and September 1987 (11.09 inches).

Fall has been a feast or famine period for rainfall in Roanoke. Getting any kind of rain that would make a significant dent in the deficit may require the kind of storm that could severely damage a coastal city. And often, the kind of rains tropical systems provide lead to flash flooding even during a long-term dry spell.

A better solution would be for the southern branch of the jet stream to become active, feeding a steady diet of wet storm systems from the Pacific Ocean across the southern United States, through the Gulf Coast states and up the East Coast. This is exactly what happened in late 2002 to break us out of a three-year dry period.

That would provide periodic rains of 1 to 2 inches each over several weeks. It would be a kinder, gentler, much more effective way to lift the region out of drought.

But at this point, there is no sign of any such weather pattern developing. September appears as if it will be cooler than normal for at least the first half of the month, but not really much wetter than it's been.

Unfortunately, our ideal rain scenario would also bring additional rain to Texas and Oklahoma, states that don't need it.

A year ago, those now-waterlogged states were in a long-term drought, wondering whether it would ever end.