The tundra isn’t rolling chilly air masses our way yet, and the tropics haven’t poured on our parched soil.
So, almost two weeks deep into September, we’re still stuck in a hot, dry, stagnant summer seemingly without end.
Wednesday and Thursday will likely bring Roanoke its 55th and 56th 90-degree days of 2019, tying the year for 10th place for most 90-degree days in a year since official local weather records begin in 1912. If that happens, this year would tie 2007, the only year since the 21st century began with that many 90-degree days.
High pressure at the surface and aloft is expanding and deepening over much of the U.S., and it appears likely this will be the dominant weather pattern through the next couple of weeks, at least.
Occasionally, there will be weak cold fronts chewing into that heat dome, as will happen late this week, increasing the chances of showers and thunderstorms to something a little beyond meager and pulling the thermometer back a few degrees.
But the sweaters can stay in the closet.
There is no air mass of Canadian or Arctic origin on the horizon that appears likely to dig far enough south with a deep enough pool of cool air to initiate autumn in earnest.
After slight temperature downturns, maybe a random “wedge” day when the cool, damp air banked against the mountains even holds it into the 70s, we’ll see rebounds back into the 80s and even lower 90s for highs, with nighttime lows generally in the muggy 60s.
Perhaps even more ominously, there is no obvious chance of widespread, soaking rain on the horizon, either.
Many localities south and west of Roanoke are already considered to be “abnormally dry,” the lowest stage of drought, by the U.S. Drought Monitor.
July 8 was the last time our region had what could be described as a widespread rainfall, and even that was generally under an inch.
Since then, what rain we’ve had has been almost entirely hit-and-miss, pop-up showers and storms, boiling upward with afternoon heat and humidity. A few spots get poured on for a short time but most get much lighter amounts on the fringes of the storms, or missed altogether.
There may be some of those scattered storms with the hot days ahead, and the weekend front may augment those chances some. But these are not the kind of rains that provide significant, widespread relief of dryness.
As we move into fall, there are generally two sources to look toward for that kind of rain.
The first are jet stream troughs that loop far enough south to scoop up Gulf of Mexico moisture and spin up low-pressure systems that ride across the South or up the East Coast. With the high pressure so anchored over the continental U.S., there is little hope of this occurring in the next couple of weeks, and honestly, it’s a little too early on the calendar to expect these kind of systems, anyway.
The second are tropical systems.
Wishing Hurricane Dorian inland to spread destruction across the Carolinas last week just so we could get some rain might have been a little much, but certainly anyone could be forgiven hoping for a juicy tropical storm or maybe even a low-end hurricane making landfall in marshland somewhere to spread needed moisture our way. A depression or tropical wave getting pulled north along a slow-moving frontal boundary would work.
Frankly, some kind of tropical system is our best chance of getting substantial rainfall in the next couple of weeks.
High pressure extending beyond the U.S. into the Gulf of Mexico and the western Atlantic is actually quite conducive to potential tropical development near our shores.
The National Hurricane Center is tracking multiple disturbances crossing the Atlantic, and forecast models hint at systems popping nearer the U.S. down the road. At this point there is no obvious candidate for the next big tropical weather obsession, but with the peak of hurricane season approaching and lots of warm water in the Atlantic basin, something almost certainly will develop and pose some risk for the U.S. sooner rather than later.
So that’s where we are — sweating rather than sweaters, no sign of either chilly air masses or widespread rainfall on the horizon, and keeping an eye on the tropics for the next storm that could bring coastal misery and/or much-needed rainfall to our region.
Weather Journal appears on Wednesdays.