Kevin Myatt is The Roanoke Times' weather columnist.

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We had a nice rain Friday and a couple of really cool mornings over the weekend.

Surely, that means fall-like weather is setting in for the season, right?

Don't bet on it.

The long-term prognosis remains the same: Hot and dry. Or, at least, unseasonably warm and dry.

The combination of Hurricane Humberto's remnants and a cold front from the upper reaches of Canada succeeded in breaking through the persistent dryness and heat over the weekend.

But the overall atmospheric picture over the United States hasn't really changed that much. Indications are that a hot dome of high pressure will rebuild over us from the west during the next several days, possibly lasting into October.

What is considered "hot" changes with the calendar. The days are getting shorter and the sun angle is lessening, so the available solar heat drops with each day.

Normal temperatures really begin to trail off in the second half of September. In mid-September, the normal high for Roanoke is in the upper 70s, the normal low in the upper 50s. By the end of the month, that falls into the lower 70s and lower 50s.

It appears that high temperatures in the 80s will become commonplace by late this week. If that kind of warmth hangs on, it will be several degrees above normal for many days this month, whether or not there is an infrequent late-September 90-degree day or two thrown in the mix.

A weekend of much-below-normal temperatures has dropped Roanoke's September average temperature to 72.5 degrees, through Monday. Several days of above-normal temperatures to end the month raise the specter of boosting that average back to where this becomes the warmest September on record. The record is 73.6 degrees set in 1998.

If we get in an extremely dry air mass, we may set into a pattern where daytime highs are higher than normal but nighttime lows are near normal or even below normal.

Both heating and cooling of the air is much quicker in a dry air mass, and with longer nights, there is even more opportunity to cool. That could offset the highs enough to keep us out of record territory.

That it will be drier than normal seems an even surer bet than it being a record warm month.

Last week's rains have eased some of the short-term dryness, but long-term, over months and years, the Southeast and mid-Atlantic are still very dry.

There just doesn't seem to be a mechanism available to trigger the kind of repeated, general rains we'll need to really reverse the drought.

Cold fronts that move through from time to time will be working with limited moisture. The subtropical jet stream shows no signs of becoming active in bringing Pacific storms across the southern U.S.

And right now, at the peak of Atlantic hurricane season, there are no new tropical systems with any promise to deliver needed rains -- though as Hurricane Humberto showed last week, that could change in a short time.

So don't expect a lot of crisp, fall mornings in the next couple of weeks, anyway. Warm and dry days are the trend.

We'll start to see some fall colors, but some of those leaves may be turning yellow and brown simply because it is too dry.