Summer to arrive ... just in time for school?

I spent last week at the North Carolina coast and had planned to write about the big difference in weather this summer between the Piedmont and the beaches, but that will have to wait for another day.

There's a bigger story to talk about -- a potential shift in the weather pattern next week.

Both the Global and European weather models are predicting a big change, starting about the middle of next week (sometime around Aug. 21). If you believe what the models are saying, we'll see the start of some typical summer weather in the Carolinas.

Naturally!  It'll arrive near the end of meteorological summer, just in time for school to start.

Since the beginning of June, we've been locked -- most of the time -- in a pattern dominated by a trough in the eastern United States and Bermuda high pressure. The trough has allowed the jet stream to dip into the Southeast, and that has produced frequent rounds of stormy weather and plenty of days when high temperatures fell short of seasonal averages.

We've finally hit a string of 90-degree days, but that has been the exception. For the most part, it has been a cloudy, stormy summer.

The GFS and Euro models indicate that will change next week -- after the cold frontal passage late Tuesday, then the two or three days of unseasonable cold air damming, and then a possible tropical system over the weekend.

The Global model predicts high pressure will establish itself somewhere near the Mississippi River and dominate our weather for at least several days.  That would indicate hot and dry weather for the latter one-third of August.  The European model predicts the jet stream will be pushed back into Canada (where it typically exists in the summer), and the Southeast will be under the influence of a Bermuda high.  That would mean hot, sultry conditions, with a few afternoon and evening storms.

Either of those solutions would be a lot more typical of what we expect in the Carolinas during the summer.

Of course, those are 10-day forecasts, and the accuracy is a lot less stellar than short-range predictions.  It will be interesting to see how this develops.

What happens in August?

There are several things I'm certain about in August.

School will start, and the many thousands of students headed to the classrooms will include my granddaughter Gracie, entering kindergarten.

The Panthers will win a couple exhibition games, and some of their fans will predict a 13-3 season and a Super Bowl appearance. The Tampa Bay Rays and Pittsburgh Pirates will keep winning. My Cleveland Indians won't.

And I'm pretty certain -- based on everything I've seen -- that August weather in the Charlotte region will look a lot like June and July.

Oh -- and your August vacations at the Carolinas beaches probably won't be impacted by tropical storms or hurricanes.

In short, August looks like another month of no heat waves and a lot of unsettled weather.  I fear we haven't seen the last of severe thunderstorms and flash flooding.

Our summer weather so far has been the result of a blocking pattern. For most of the past two months, we've had a Bermuda high pressure, another high pressure system in the western United States, and an area of weakness (a trough, or dip in the atmospheric currents) in the eastern United States.

That dip has brought a string of low pressure systems into the Southeast.  Sometimes they've been accompanied by cold fronts, most of which dissipate somewhere in the Carolinas.

That has produced some monumental rainfall totals, like the 25-plus inches since June 1 in Hickory. Some areas in the North Carolina mountains have exceeded their average annual rainfall totals, with five months still to go.

The long-range computer models point to a continuation of the pattern.

If this type of pattern develops in winter, those of us in the Carolinas are using snow shovels and ice scrapers.  In the summer, it means moderate temperatures and a lot of rain.

Tropical weather activity should be quiet in the Atlantic for the next few weeks. Satellite photos show a lot of dry air being blown westward into the Atlantic from Saharan Africa.  That usually puts a lid on the development of tropical storms and hurricanes, and forecasters seem to think it will continue into at least the middle of August.

That won't stop the development of tropical systems in the Gulf of Mexico, but the Carolinas coast should catch a break for at least a few weeks.

Remember, though. Once conditions become more favorable for development in the Atlantic, the current pattern over the eastern United States (Bermuda high and eastern U.S. trough) would favor tropical storms and hurricanes making a run at the Southeast coast.

OK ... Where are the 90s?

I've resisted getting sucked into this "where are the 90s?" talk, because I figured that was a foolproof way of triggering an all-out heat wave.

But we're approaching the end of July, and it appears almost certain that we'll finish the month with only four 90-degree days.

Clouds and rain, possibly heavy, are likely Wednesday, for the last day of the month.

That will give us a grand total of eight 90-degree days so far this summer -- four each in June and July. We had 23 days of 90 or hotter at this point last year, and that wasn't a terribly unusual summer.

So I'm game ... where are the 90-degree days?

I was looking at some long-range forecasts for August, and while I'll focus more on that tomorrow or Thursday, suffice to say that there are no major changes in sight.  It looks like we'll continue the current pattern for a week or two, then perhaps slide back into a real stormy and wet period (similar to late June and early July).

We certainly won't tie the all-time record for fewest 90-degree days. That mark is eight, set in 1967. We're already there, and it's not reasonable to expect we won't get another 90-degree day this summer. That also probably puts the No. 2 mark (nine, in 2003) and the No. 3 mark (11, in 1910) out of reach.

But we might be somewhere in the neighborhood of 12 to 14 days of 90 or warmer this summer, and that would be in the top 10 (or bottom 10) of 90-degree days in Charlotte.

The tropics: The Carolinas' 'elephant in the room'

As the absolutely insane rainfall numbers continue to mount this summer across the western Carolinas, the tropics loom increasingly large as a source of concern for the next few months.

The hurricane season likely will be ramping up during the next several weeks, and we should be concerned with then activity we've already seen.

In short, an active hurricane season along the Southeast coast could be absolutely devastating in the western Carolinas, given the heavy precipitation we've already received.

The tropical pattern so far:  Systems have formed in the Cape Verde area of the eastern Atlantic (a lot earlier than is usual in the season). They've followed a generally westward path, in a corridor that includes Hispaniola and Puerto Rico. So far, strong westerlies and dry air have shared apart the systems, and that was the case with Tropical Storm Dorian last week.

Eventually, however, those westerlies are expected to relax. Westward-moving tropical systems will be able to intensify as they approach the continental United States, and we could be looking at a steering pattern similar to September 2004, when several storms made landfall in eastern Florida before sweeping across Georgia and the western Carolinas.

The remnants of hurricanes Frances, Jeanne and Ivan caused major flooding in the Carolinas foothills and mountains that year.

Now, fast-forward to 2013.  We've already received staggering amounts of rainfall in the region.

WCNC meteorologist Brad Panovich has been keeping tabs on Brevard, west of Asheville. He notes that Brevard's rainfall total this year is 72.02 inches. That's more than 17 inches above the record total for the WHOLE YEAR!  Greenville-Spartanburg and Asheville have received about 10 inches more than average rainfall in July.

Take a look at this chart on Panovich's Facebook page -- it's a list of where various reporting stations stand, at this point in the year, for rainfall. If you see a "1" next to a city, it means that reporting station is on track for its rainiest year ever (Brad Panovich's page).

In the last week, automated gauges have reported more than 6 inches of rain at Triplett (Watauga County) and at Claremont (Catawba County). There are several reports of 12 to 15 inches of rain having fallen since late June in parts of northern Mecklenburg and Cabarrus counties.

There are places in my yard where my lawnmower hasn't reached since June.  It's simply too wet to mow.

Add a dying tropical storm, with its 6 to 12 inches of rain, and you have catastrophic flooding.

The tropics are always important to people in the Carolinas, but they'll be even more important this year.

First take on Dorian ...

Tropical Storm Dorian has been a threat only to fish so far, as it remains far out in the Atlantic Ocean.  It will be a few days before the storm nears any land masses, and by that time, it might have dissipated.

Most of the computer models take Dorian on a west-northwest track for the next couple days, but its future is really a question mark.

Working in favor of the storm's development ... Dorian is working with a moist atmosphere, and there is little wind shear to disrupt its organization.

Working against development ... Marginal surface sea temperatures (although Dorian will be moving into warmer waters later today and Friday), and the forecast of stronger wind shear and drier air later in the week.

Historically, most storms forming in the Cape Verde area this early in the year curve away from the Southeast coast, and that's entirely possible this time.  For the next few days, Dorian will be steered to the west, along the south side of a high pressure ridge in the Atlantic.

A trough is forecast to develop along the East Coast this weekend.  If the trough is deep, it would capture Dorian during the weekend and steer the storm northward, away from the United States. But there are some forecasts of a weak trough. In that case, the storm would continue westward, possibly threatening the Bahamas and the Florida coast by early next week.

As you all know, it's far too early to make a solid prediction.  But we should have a much better idea by late Friday or Saturday.  By then, the "wild" guesses will turned into "educated" guesses.

July 1916 -- Carolinas' monster flood

Round after round of heavy rain belted the western Carolinas from early June through the middle of this month, washing out roads and causing plenty of damage across the region.

Some of the flooding along Mountain Island Lake was the result of heavy rain falling in the mountains, then coming down the Catawba River and its chain of reservoirs.

But the real king of July floods came 97 years ago.

A reader in Catawba County reminded me of the July 1916 floods, which were responsible for some of the worst storm-related damage ever in the Carolinas.

And as I've written many times before, it all was the result of a dying tropical weather system -- not a full-fledged, land-falling hurricane, but what was left of one. Tropical systems that move inland are capable of producing gigantic rain totals, as we learned a couple times since Tropical Storms Jerry (1995) and Danny (1997) came through the Charlotte area.

The 1916 flood was caused by the remnants of a hurricane which made landfall early Friday, July 14, near Charleston. There was little damage in the Lowcountry of South Carolina, but as the hurricane moved inland and weakened, the heavy rains spread rapidly and intensified in the mountains.

Charlotte got only 5.15 inches of rain from the storm, although sustained winds of 40 to 50 mph caused plenty of problems with downed trees and structural damage.

In the mountains, the orographic effect of incredibly moist air rising in altitude triggered extremely heavy rains. There were measurements of 20 to 24 inches in some mountain areas from July 14-16.

A recording station at Alta Pass in the mountains logged 22.22 inches, a record for a 24-hour period in the United States.

Damage, in 1916 dollars, was estimated at more than $21 million. The death toll was a guesstimate, but the number of 80 fatalities was mentioned in several reports.

Extreme flooding was reported in places like Lenoir, Taylorsville, Statesville and in the mountain counties. Dozens died, roads were completely wiped away, and businesses were destroyed. I read one account of flooding washing away a cemetery, leaving nothing behind -- not even the graves.

Just as was the case this summer, the heavy mountain rain drained into the Catawba River's headwaters and rushed downstream.  In 1916, however, there was no chain of reservoirs.  Duke Energy this month was able to regulate the water flow through the various reservoirs and prevent a widespread outbreak of serious flooding. That wasn't possible in 1916.

So the Catawba River roared out of its banks, washing away bridges and roads.

Residents near Mount Holly stood a distance away from the raging river and watched debris float downstream. They say livestock, parts of houses, sections of bridges, trees.  All of that had been uprooted farther up the river and was headed toward South Carolina.

The Southern Railway bridge north of Mount Holly collapsed on the evening of Sunday, July 16, with 18 reported deaths.  As darkness fell, according to reports, some of the men grabbed on to trees in the river in an effort to survive. By the next morning, the trees were submerged.

By some estimates, the river rose 50 feet above its usual level.

Late on the 16th, the Southern Railway bridge in Rock Hill collapsed.  When that 500-foot span went down, rail traffic between Charlotte and Jacksonville was halted.

You can find a number of accounts of the flooding, but two that I found interesting were from UNC-Asheville and from a historical study in Catawba County.

If you're not a native of the Carolinas -- as many of us are not -- the July 1916 flood gives you a healthy respect for the incredible amounts of rain that can fall in a hurry around here, especially when the tropics are involved.

Rip current deaths 'shocking'

Rip current deaths along the Carolinas coast are a sad part of the annual vacation season, but the number of fatalities this month is really staggering.

By my count, there have been at least nine people killed on Carolinas beaches since July 3, and a 10th person is missing.  Dozens of rescues have been reported, and a number of people were hospitalized with serious complications from their time in the surf.

The deaths have ranged geographically from the beaches north of Wilmington down to near the South Carolina-Georgia border.

Interestingly, there have been no reports of rip currents deaths from the area where they are most dangerous -- the Outer Banks.

It's almost a cliche to say that people don't understand rip currents, but I'm most surprised at how many of the victims are Carolinas residents who should be more familiar with the risk.

One official of a small town along the Carolinas coast told me last week that "it's one thing to understand what to do in a rip current, but quite another when you're actually being dragged into deeper water."  I understand that point.  Fear and panic make us forget what we should know.

The high death toll this month caught the attention of Dr. Robert Brander, a professor at the University of New South Wales in Sydney, Australia.  He wrote me last week, saying he is a surf scientist who focuses on rip currents and has set up a safety program titled "The Science of the Surf."

"We have made great inroads educating people about rips here in Australia," Brander said, "but the drownings in the U.S. this year have been shocking."

Brander has assembled an interesting rip current website, and I recommend you take a look at it -- especially if you're planning a beach trip anytime soon (and don't forget that rip currents also take place in the Great Lakes).

While you're at it, you can participate in Brander's survey on rip current awareness. You'll find it here.