A typical fall scene of fallen leaves alongside a tumbling Appalachian creek greeted hikers on the way to Roaring Run falls in Botetourt County near its border with Alleghany County on Friday, Oct. 4. While some new piles of debris were observed in this creek, it was located far enough north not to experience the worst flooding impacts from Hurricane Helene's inland effects. Photo by Kevin Myatt.
A typical fall scene of fallen leaves alongside a tumbling Appalachian creek greeted hikers on the way to Roaring Run falls in Botetourt County near its border with Alleghany County on Friday, Oct. 4. While some new piles of debris were observed in this creek, it was located far enough north not to experience the worst flooding impacts from Hurricane Helene's inland effects. Photo by Kevin Myatt.

September got it backwards. We had the cool, crisp mornings in the first part of the month, and the sticky nights with tropical downpours in the latter part of the month.

We have rolled into October, usually a time of burgeoning autumnal joy as the leaves start turning and the pumpkins start frosting, underneath the dark shadow of the Helene aftermath. But there are blue skies ahead for Cardinal News country, quite literally.

The gusty winds of ex-Hurricane Helene did occur early enough in the season that most trees across Southwest and Southside Virginia were still mostly green and those that weren’t broken or knocked over were not entirely stripped of leaves. So, especially with the renewed moisture and some cool mornings ahead, the prospects are strong for a decent to good foliage show across much of our region in days ahead, wherever the roads, trails, parks and forests are open to allow viewing.

Very serious tropical weather is missing us by a wide margin this week. As this posts late Wednesday, Hurricane Milton is closing in on what could be a destructive landfall along the western coast of the Florida Peninsula. (Click here for the latest from the National Hurricane Center on Hurricane Milton.)

Much attention has been focused on tropical storms in the Gulf of Mexico, but a weekend solar storm of charged particles ejected from the sun triggered a display of the aurora borealis that was briefly visible as far south as North Carolina and central Texas. This photo is from Nelson County on Sunday night, Oct. 6. Photo by Roxzanna Montague.
Much attention has been focused on tropical storms in the Gulf of Mexico, but a weekend solar storm of charged particles ejected from the sun triggered a display of the aurora borealis that was briefly visible as far south as North Carolina and central Texas. This photo is from Nelson County on Monday night, Oct. 7. Photo by Roxzanna Montague.

Let’s be clear that this particular edition of the weekly Cardinal Weather column isn’t an effort to “move on” from Helene. There is not going to be any fully “moving on” from Helene for many thousands of people in the Appalachians, including parts of Southwest Virginia, for months, even years, to come. Towns have been decimated, houses wiped out, infrastructure destroyed, and the very landscape rearranged. Cardinal News will be continuing to cover the recovery from Helene moving forward, and undoubtedly, I will be revisiting aspects of it in this space as well.

For now, let’s look ahead to what the next few weeks may bring, which at least for the next several days, won’t be hurricane remnants inundating our mountains.

Next week's temperature forecast map from the Climate Prediction Center shows a high probability of below-normal temperatures in the Eastern U.S. as hot weather relative to October norms continues out West. Courtesy of Climate Prediction Center, NOAA.
Next week’s temperature forecast map from the Climate Prediction Center shows a high probability of below-normal temperatures in the Eastern U.S. as hot weather relative to October norms continues out West. Courtesy of Climate Prediction Center, NOAA.

Familiar pattern: Hot West, cooler East

The prevailing atmospheric pattern over North America since mid-August has been for hot high pressure to build over the West and a downstream trough to dig into the East.

This pattern became muddier in the latter half of September, but the periods of tropically enhanced rain and stalling fronts kept a late sizzling heat wave from threatening to envelop Virginia anew. Our nights were sticky, and some of our days that weren’t cloudy got quite warm, with some 80s highs. The 90-degree high at the John H. Kerr Dam on Sept. 2 between late August and early to mid-September cool spells is probably the last 90-plus reading we’ll see in Cardinal News’ broad Southwest and Southside Virginia coverage area in the rest of 2024.

Even the fate of Hurricane Helene involved some elements of the lingering pattern, as the sluggish low-pressure trough that absorbed Helene wobbled over the central and eastern U.S., forced there partly by the hot high in the West.

Bright sun in blue , such as seen in this shot near Montvale in Bedford County on Sunday, Oct. 6, will be the norm for many days ahead, but with pleasant afternoon temperatures and cool mornings. Photo by Kevin Myatt.
Bright sun in blue skies, such as seen in this shot near Montvale in Bedford County on Sunday, Oct. 6, will be the norm for many days ahead, but with pleasant afternoon temperatures and cool mornings. Photo by Kevin Myatt.

Just as offsetting penalties in a football game can bring the ball back to the original line of scrimmage, the cool first half of September and the warm second half of the month balanced out to an essentially normal month of temperature at Roanoke, Lynchburg and Danville, the month’s average within a degree of normal. Blacksburg ran a bit warmer relative to history, about 2 degrees above the 1991-2020 September average that is considered normal.

Now, the pattern of western heat ridge and eastern cool trough is back, just in time that some areas especially west and north of Roanoke may see patchy frost the next couple of mornings, with comfortable highs in the 60s and lower 70s.

After a slight weekend warmup that may scrape 80 at a few spots by Sunday, there appears likely to be another even colder shot next week.

Pumpkins will frost and leaves will turn.

No rain is forecast for Virginia or a large part of the Central and Eastern U.S. through next Wednesday. Courtesy of Weather Prediction Center, NOAA>
No rain is forecast for Virginia or a large part of the central and eastern U.S. through next Wednesday. Courtesy of Weather Prediction Center, NOAA.

Dryness could yet be a problem

This seems like a ludicrous thing to say after the widespread flooding downpours of Helene and the preceding rains along a stalled front.

But it can be surprising how fast surface fuels like fallen leaves and weeds dry out within several days of having no rain, which looks strongly like what we are entering now, with cool, dry northwest flow. Down the road, if this were to continue, wildfires could again become an issue with windy cold fronts in late October and November.

Giles County may best exemplify the strange juxtaposition of drought and deluge our region has experienced. While nearly 50 people lost their homes to flooding with Helene, the county also remained within the “abnormally dry” zone on the U.S. Drought Monitor, the southeast fringe of severe to extreme drought covering much of the northern two-thirds of West Virginia. Our region’s neighbors to the northwest are still parched while those to the south are flooded out.

This chart was issued by the National Weather Service's Blacksburg office on Monday -- explaining the wording about a few showers -- but the maps display the juxtaposition of severe drought over West Virginia, edging slightly into western and northern Virginia as abnormally dry to moderate drought conditions, and large areas of Virginia and North Carolina now removed from drought in last week's U.S. Drought Monitor. Courtesy of National Weather Service.
This chart was issued by the National Weather Service’s Blacksburg office on Monday — explaining the wording about a few showers — but the maps display the juxtaposition of severe drought over West Virginia, edging slightly into western and northern Virginia as abnormally dry to moderate drought conditions, and large areas of Virginia and North Carolina now removed from drought in last week’s U.S. Drought Monitor. Courtesy of National Weather Service.

The flooding along the New River in Giles County was more about the 10-plus inches of rain in the North Carolina mountains flowing downstream than it was about local rain. While Pearisburg in Giles County measured nearly 7 inches of rain Sept. 24-28, almost 5 of that in two days, Virginia’s western fringe counties like Giles got less in early August’s Tropical Storm Debby and mid-September’s Potential Tropical Cyclone 8 than areas along and east of the Blue Ridge, leaving some of the parameters determining dryness still marginal as of last week’s Drought Monitor.

The ideal pattern of moisture is getting about three-quarters of an inch per week in one or two periods of showery rain. Having weeks of dry weather followed by thunderous downpours dumping multiple inches, as has been the pattern of late summer and early fall, is not ideal in any sense, and can be the worst of both worlds, alternating dryness with flooding.

There is presently no sign of a more progressive pattern of occasional moderate rains developing. In fact, there is no strong indication yet of when our next regional rain might come, which for now, is more welcome news than would be facing downpours.

Drought is not going to be on the tip of our tongue for a while in Southwest and Southside Virginia, but don’t think having a hurricane-charged downpour provides a get-out-of-drought-free card for the rest of 2024 and beyond.

Much flotsam and jetsam washed into Claytor Lake shortly after the flooding rains of Hurricane Helene. Courtesy of Ralph Berrier.
Much flotsam and jetsam washed into Claytor Lake shortly after the flooding rains of Hurricane Helene. Courtesy of Ralph Berrier Jr.

Tropical impacts may not be over for us

Didn’t we just say dryness could become a problem again? Well, so could tropical downpours.

The Atlantic hurricane season will not live up to some of the numbers prognosticated before the season by various experts, largely because there was an odd lull in late August and early September, usually the prime time for tropical activity.

One factor in the slow start to the fall hurricane cycle may be the north-shifted rain pattern in northern Africa, which brought unusually large amounts of rain to the Sahara Desert but pushed the storm track farther north than is optimal for disturbances moving off Africa to become Atlantic hurricanes.

Roanoke-based storm chaser Chris White captured this low-hanging funnel cloud with strong rotation near Climax in Pittsylvania County on Friday, Sept. 26, as the remnant circulation of Hurricane Helene was moving just west and south of our region. Courtesy of Chris White.
Roanoke-based storm chaser Chris White captured this low-hanging funnel cloud with strong rotation near Climax in Pittsylvania County on Friday, Sept. 26, as the remnant circulation of Hurricane Helene was moving just west and south of our region. Courtesy of Chris White.

But the season seems to be making up for lost time now, with hurricanes Helene, Isaac, Kirk, Leslie and Milton (plus Tropical Storm Joyce) having all formed in barely more than two weeks. You didn’t hear much about any of those but Helene and Milton because they plied open water in the Atlantic Ocean.

Busy tropical seasons can linger into November. The remnants of Hurricane Juan triggered our region’s 1985 flooding in the first week of November, and remnants of Hurricane Nicole affected our region as recently as the second week of November in 2022.

So while the current atmospheric pattern is likely to suppress any tropical activity well below our latitude for at least another 10 days, probably longer, we’ll need to keep an eye on weather pattern changes and any continued threat for tropical systems to form over or move into the Gulf of Mexico and western Atlantic to see if there might be another tropical intrusion into our region.

Water begins to overrun a bridge at Konnarock along the Washington-Smyth county line on Friday, Sept. 26, as inland effects of Hurricane Helene begin to be felt in Virginia. Courtesy of Virginia State Police.
Water begins to overrun a road at Konnarock along the Washington-Smyth county line on Friday, Sept. 26, as inland effects of Hurricane Helene begin to be felt in Virginia. Courtesy of Virginia State Police.

La Niña or not?

Experts have been projecting La Niña — the irregularly recurring cooling of a strip of equatorial Pacific sea surface temperatures — to develop for fall and winter since last winter’s El Niño — the warm water opposite of La Niña — began dwindling. And NOAA still gives it a 71% chance of developing this fall. But it’s struggling to get going.

La Niña generally correlates with mild, dry weather during our cooler months, usually interspersed with one or two short but sharp Arctic cold outbreaks. But this already fairly loose correlation breaks down significantly if La Niña only reaches a weak level in the Pacific. Winters during weak La Niñas have a lot more variety over the past several decades in our region than do those during moderate to strong La Niña.

Perhaps La Niña will be a little like Atlantic hurricane season, delayed but not denied. It will be one of many factors to consider this fall as we begin to ponder what the 2024-25 winter might hold for us.

Kevin Myatt has written about Southwest and Southside Virginia weather for the past two decades, previously...