Monday, July 29, 2013

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.


Anonymous said...

That's incredible! Good work Steve. Seems like the pattern we're in has really kept the temps down but humidity up. So far it's been a lot cooler summer than last year.

Anonymous said...

Cooler summer due to "insane amounts of rain" is nice, but not if it also means flooding, rotting crops, increased bugs and mildew, and toppling trees due to saturated soil.

"My corn crop is ruined, and that giant oak on the house produced a nice sky light..but hey, my electricity bill is down by $35."

Anonymous said...

I think I see Mecklenburg County mentioned once in this article.

Ever think about giving us some input on the know, where Charlotte is?

Anonymous said...

"and we should be concerned with then activity we've already seen."


"So far, strong westerlies and dry air have shared apart the systems, and that was the case with Tropical Storm Dorian last week."

I think you meant "sheared"

Where is your handler, er, copy editor?

Wade said...

It has been 7 years or so since a major hurricane (Cat 3+) has made landfall in the US. This is the longest major hurricane drought on record. Statistically speaking, we are years overdue. That has me worried. New York City was also long overdue for a hurricane, the last one to hit there was the 1938 Cat-3 "Long Island Express", which was stronger than Hurricane Sandy. 1951-1960 had several Cat-3 hurricanes in New England, and 1954 Hazel is still the strongest recorded hurricane to make landfall in North Carolina.

Weather history tells us that we should expect some bad hurricane years soon. If one happens this year, we will have another Hurricane Floyd on our hands. Even though NOAA now names storms that they didn't 5 years ago, hurricane activity is way down. History says it will ramp up soon.

Anonymous said...

"History" says it will ramp up, or modern forecasting technology?? Or, should we rely on the farmer's almanac?