Sizzle returns for Fourth of July after cool respite

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Two days before the Fourth of July, some needed jackets in parts of western Virginia.

A hot, dry June gave way to a brief cool spell — brought to you by extremely dry air from Canada — early this week, but the heat and humidity are returning just in time for fireworks that will require a great deal of caution to avoid causing fires across still mostly parched Southwest and Southside Virginia.

Another heat spike is on the way for the Fourth of July and into the weekend beyond, with many mid-to-upper 90s in the lower elevations of our region (think Roanoke Valley’s urban floor and most places east of the Blue Ridge), with upper 80s-lower 90s elsewhere except those always-cooler high ridges.

This will contrast sharply with recent mornings. Lows dipped into the 40s at places like Burke’s Garden (48), Pulaski (49), Radford (49) and Wytheville (49) on Tuesday morning. (West Virginia icebox Canaan Valley, as measured by a Virginia Tech-operated remote sensor , dropped to the freezing mark!)

This fall-like chill came two days after Lynchburg reached 98, the Hill City’s third time at 98 or above in nine days (99 on June 22 and 26) while capping its driest June on record with just 0.04 inch of rain at the official gauge at the Lynchburg Regional Airport on the south edge of the city.

Roanoke (57), Lynchburg (54) and Danville (53) each had their coolest lows on Tuesday morning since June 12, less than two days after 96-98 highs and only two days before similar highs are likely on Fourth of July.

We’ll see if any location in our region can scrape 100, beside the John H. Kerr Dam in Mecklenburg County, which reached 101 on June 26 (recorded as June 27 at the co-op site’s 8 a.m. to 8 a.m. reporting cycle). Whatever your home weather sensor may have shown (as our family’s did south of Roanoke on June 26 ), there has been no other official 100-degree reading in the Cardinal News coverage area yet this season. Lynchburg, Appomattox, and South Boston, have each reached 99 at least once, but as far as I can find, no other official 100 has hit the books in our region — yet.

Our nation’s 248 ^th birthday will also bring more of those hit-and-miss storms that might wash out one location’s fireworks display while just providing a distant-horizon secondary light show for others.

It wasn’t a bonus rainfall month anywhere in Southwest or Southside Virginia, but some places happened to get under the sparse downpours on one or more days of the month, while others never did.

At this point, there is every meteorologically synoptic reason to believe the cycle we’ve had the latter half of June — the heat spikes, humidity builds, scattered storms develop, a cold front pushes through, the heat and humidity back off, repeat the cycle — will continue at least halfway into July and possibly beyond.

One subtle but significant change could be that the fronts that have been pushing through start stalling and washing out near our region, which might extend thunderstorm chances for needed rain but do less to curb the heat and humidity for short spells.

The “heat-dome” high-pressure system is becoming rooted over the south-central U.S., close enough to expand heat over us every few days but far enough to keep it from becoming locked in. Once parked in early to middle July, the heat dome is often difficult to budge until mid-August or later, though as with everything in weather, such semi-permanence isn’t etched in stone.

( UPDATE 6:30PM, 7/3/2024: Newer data since this was written suggests the heat-dome high will shift west next week, taking the hottest temperatures into the arid areas west of the Rockies and allowing cooler air to dip into the Central U.S. For our region, this could open the door for at least slightly cooler temperatures than we’ve had in late June and, perhaps, a somewhat better chance of more frequent showers and thunderstorms into the middle and latter part of next week. We’ll see.)

The southern U.S. position of the heat-dome high is also important in the developing hurricane season, providing stable air aloft over the Gulf of Mexico and Caribbean needed for rapid development of tropical systems into hurricanes, and also steering those tropical systems westward across the Caribbean toward Mexico with its clockwise rotation.

As a result, Hurricane Beryl has almost no chance to have a direct impact on Virginia or any of the beaches Virginians tend to gravitate to along the East Coast. It’s still too far away to say whether it might affect the Texas coast and also what if any indirect effect it might have on our weather.

Beryl became the first Category 4 hurricane in the Atlantic to form in June and then, to start July, the earliest Category 5 hurricane on record in the Atlantic, much farther south and east than is typical this early in the season, tracking west out of the open Atlantic through the Caribbean more like a September hurricane than one on the fringe between June and July.

Besides the likelihood of striking or making a close pass of Jamaica on this Wednesday and a hit on Mexico’s Yucatan Peninsula by Friday, Beryl’s early intensity may be a harbinger of what is expected to be an especially busy and intense hurricane season , with factors of exceptional ocean heat and a developing La Niña pattern in the Pacific Ocean converging. (La Niña tends to correlate with a more intense Atlantic hurricane season, as high-level westerly winds that can shred developing tropical cyclones are typically not as strong.)

There is no guarantee at all that an extreme tropical season, if it in fact develops, will mean that any system will affect Virginia, either as a rainy inland system from the Gulf of Mexico or a more direct impact with a Southeast U.S. or Mid-Atlantic landfall. But just by mathematics, it is true that the more tropical systems there are, the greater chance that one or two or a few of them will eventually affect us.

There may be the chance, with a little shifting of the atmospheric furniture, that tropical moisture even outside of well-developed named cyclones becomes a frequent visitor to our region in late summer and autumn — 2018 and 2020 both brought lots of rain when the Atlantic tropical season got more active.

So the big question that hangs over the second half of 2024 is: Drought or deluge?

It doesn’t have to be fully either, and the widespread hope would be that it is something in between. But we are at a place now that could easily slide into deep drought with a few more weeks of the hot, dry regime that dominated June, or where other developing factors could flip the switch into frequent soaking and even flooding rain in weeks and months ahead.

Drought always ends with flash flooding, the old saying goes. We’ll see.

Journalist Kevin Myatt has been writing about weather for 20 years. His weekly column, appearing on Wednesdays, is sponsored by Oakey’s, a family-run, locally owned funeral home with locations throughout the Roanoke Valley.

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