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Home , Atlantic hurricane, Hurricane Jeanne, Summer

Changing Skies Over Central North Carolina VOLUME 10, ISSUE 2 2013 NOAA’S NATIONAL WEAT HER SERVICE RALEIGH, NC Summer Starts Out Wet in Central NC

Carolina for , 2013. With INSIDE THIS the exception of the Triad ISSUE: area, the rest of the area re- ceived rainfall ranging from 8 inches to over 15 inches for TC Band 2 the . In fact June, 2013 Tornadoes was the 3rd wettest June ever in the Raleigh-Durham NWS Raleigh 3 area (records kept since Forecasters to 1887), with 10.08 inches of Present at rain reported at the RDU NWA Franklin Street in Chapel Hill after flash flooding . (Photo airport. June, 2013 was also Conference courtesy of Jason Baker) the 9th wettest month ever in the Fayetteville area (8.58 2012 Tropical 4 People across central North Great Lakes down the Missis- inches; records have been Review Carolina started this summer sippi River valley. The figure kept since 1998), and 2nd wondering where the sum- below shows the late-June wettest month ever in the NOAA 2013 6 mer had gone! pattern, with the low Rocky Mount/Wilson area Hurricane Rainfall for 2013 had been pressure to our west (9.65 inches; records kept Season Outlook running within a couple of and the deep flow from the since 2000). Chapel Hill was inches of normal through south pumping copious especially hard-hit: during the NWS Raleigh 8 June and had slowly amounts of moisture north- last week of June, nearly 10 on Facebook been easing its grip on the ward over the East Coast, (continued on page 6) and Twitter and the amount of rainfall Tar Heel State. At the end of inches of rain fell in Chapel observed in central North the first week of June, early- season tropical Andrea laid a swath of 3-5+ inches of rain across central NC, wip- ing away lingering abnormally dry conditions for the first time since April 2010.

In addition to Andrea, a stag- nant pattern with little day-to -day change held over the area for most of the month of June. This pattern consisted of very moist air surging into the region from and the , along with a nearly stationary trough to our west, from the

June Weather Pattern Over the Continental P A G E 2 Tropical Rain Band Tornadoes

Tropical cyclone (TC) tor- nados aren’t just a coastal phenomenon. In fact, TC tornadoes can occur well inland from the coast, in- cluding across central North Carolina and even westward. In fact, there has already been a TC- related in central North Carolina in 2013, when shortly after 6 PM on Hurricane Structure (NC State Office) June 10 a rain band associ- ated with the remnants of “While not normally Rain bands are long, arching the area from about noon Tropical Storm Andrea as intense as bands of and thun- to three o’clock in the di- spawned a brief and weak derstorms that spiral out rection the storm is mov- tornado near Louisburg, tornadoes produced from the wall of a hur- ing. While not normally as Franklin County. A couple ricane. Heavy bursts of rain intense as tornadoes pro- other notable TC tornado by non-tropical and wind are usually associ- duced by non-tropical se- events that have happened ated with rain bands. These vere , these across central North Caro- severe structures form the outer tornadoes often move very lina include: most fringes of the tropical fast, at speeds over 50 mph. thunderstorms, these Tropical Storm Fay, August cyclone structure, and the Another common area of 25-28, 2008: Three torna- tornadoes often winds contained within the tornadoes in a hurricane is does were confirmed and bands decrease outward in the far outer rain bands, dozens of spotter reports move very fast, at from the eye wall. With which can be hundreds of of funnel clouds or rotating landfalling hurricanes, tor- miles away from the center speeds over 50 wall clouds were received. nadoes are a common of the storm. mph.” threat associated with rain bands com- ing onshore. Tornadoes associated with tropical systems typi- cally form in the right front quad- rant of the storm, rela- tive to the direction of forward motion. If you were looking at the storm like it was a clock, this would be

CHANGING SKIES VOLUME 10, ISSUE 2 P A G E 3

Hurricane Jeanne, September 15 tornadoes with 1 fatality down, offer little protection 27-28, 2004: Rain bands associ- (see figure on Page 2). from tornadoes and should be ated with Jeanne produced sev- abandoned for more sturdy While TC tornadoes tend to be eral tornadoes over the nearby structures. Remember weaker and shorter-lived than Sandhills and Piedmont of to have multiple ways to re- non-TC tornadoes, the same North Carolina. Tornado touch ceive warnings, such as a NO- safety rules apply. Whenever a downs were reported in AA Weather Radio, a battery tornado warning is issued, or if Moore, Richmond and Wake powered TV or radio, or a cell you see threatening weather phone app that delivers warn- Counties approaching, move to a pre- ings to your phone. For more , September 17, designated shelter, such as a information about severe 2004: Tornadoes, varying in basement. If an underground weather safety and planning, intensity from F0 to F2, shelter is not available, move to please visit www.ready.gov/ touched down producing dam- an interior room or hallway on age to homes, businesses, and the lowest floor and get under severeweather. trees in Guilford, Rockingham, a sturdy piece of furniture. Stay Credits: State Climate Office Moore, and Chatham Counties. away from windows. If in a car, of North Carolina, and Florida do not try to outrun the torna- Just last in Climate Center do. Rather, find a suitable busi- Tropical Storm Debby caused ness or building to seek shelter. -Nick Petro Mobile homes, even if tied

NWS Raleigh Forecasters to Share Research at NWA Conference

The NWS Raleigh plans on ments typically result in a much Cirrus Clouds East of the sharing results from four re- improved final project that is Southern Appalachian search projects at the 2013 more complete after being Mountains National Weather Association probed by scientists of varying (NWA) annual meeting in backgrounds who have experi- -Jonathan Blaes Charleston S.C. in October. ence in the topic being pre- The projects reflect a diverse sented. set of topics that pose a signifi- Titles of projects that we cant forecast challenge and/or a hope will be shared at the potentially significant weather impact to central N.C. NWS 2013 NWA conference: Raleigh has an established cul-  A of Cold ture of successful applied re- Air Damming and search that has benefitted oper- Tropical in ational forecasters. the Southeast U.S. Sharing results at conferences is  Developing a Dataset an important part of the re- of Wind Gust Factors search process for several rea- to Improve Forecasts sons. Most importantly, it pro- of Wind Gusts in Trop- vides an opportunity for other ical Cyclones scientists to review and provide feedback including shortcom-  Investigation of Ex- ings, ways to improve the pro- treme Days in ject, and other interpretations North Carolina of the results. These com-  Orographically Induced P A G E 4 A look Back at the 2012 Tropical Season and a Few Changes for 2013

started early with two in May, and Nadine was one of the longest-lived Atlantic storms of record. In fact, Nadine completed three loops over the east- ern subtropical Atlantic, attaining hurricane strength on two occasions a record thirteen days apart. Na- dine’s 22.25 (non- “2012 hurricane consecutive) days as a trop- forecast verification ical cyclone makes it the fourth longest-lived Atlantic shows some impressive basin on statistics. The record. The 20.75 days Selected Wind Gusts From Nadine spent as a tropical forecast track error storm and hurricane makes exceeded records in Looking back at the 2012 the north it the third-longest-lived season, through and named storm on record. many parts of the nineteen tropical storms the , Only the Unnamed 1899 formed, with ten becoming including coastal North hurricane and Ginger forecast period. hurricanes and two becom- Carolina, and then west to (1971) lasted longer. Intensity forecasts ing major hurricanes. The the Great Lakes. number of tropical cyclones also exceeded records Isaac also had significant that formed, as well as the 2012 hurricane forecast impacts particularly from number of hurricanes, were verification shows some from 72 to 120 hours flooding along the Gulf both well above average. In impressive statistics. The Coast in and around Louisi- out.” a typical Atlantic hurricane forecast track error ex- ana. Other tropical sys- season, there are 12 ceeded records in many tems that hit or affected storms, with six becoming parts of the forecast peri- land areas included Beryl, hurricanes and three of od. Intensity forecasts also Debby, Ernesto, Gordon, those developing into major exceeded records from 72 Helene, Leslie, Nadine, and hurricanes. Rafael. The 2012 season to 120 hours out. Sandy was the deadliest and most destructive storm of the season, and the latest statistics show it is now the se- cond costli- est tropical cyclone in U.S. history. Impacts ex- tended from

CHANGING SKIES VOLUME 10, ISSUE 2 P A G E 5

Another active season is pre- dicted for the 2013 Atlantic hurricane season, and some changes by the National Hurri- cane Center (NHC) for this season include the definitions of tropical storm and hurricane watches and warnings being broadened, and issuance criteria of advisories being changed, to allow NHC the option to use tropical-type watches and warn- ings for post-tropical cyclones* that pose a significant threat to life and property. This is a re- sult of events that took place with Sandy as it lost tropical characteristics while moving toward the shore, and the new criteria has already Be sure to review information been used this season with An- In addition, the NHC forecast from the NHC, your local NWS cone size has again been re- drea. forecast office, and community duced for the 2013 season. leaders if another tropical cy- Later in the season, the NHC Compared to the cone used in clone approaches this season. plans to extend the Tropical the 2012 hurricane season, the Away from the coast, primary Weather Outlook (TWO) out cone size has been reduced at threats include heavy re- to five days. Currently, the all valid forecast hours from 2% sulting in flash flooding and TWO goes out to 48 hours, to nearly 10%. This is a func- swollen rivers and streams, brief but after the NHC completes tion of improved track accuracy but still dangerous tornadoes, some development and testing, over the . What we need and strong, gusty winds. Re- it is hoped that by August the to keep in mind, though, is that member that heavy rains can NHC will note the potential for the size of the storm has no saturate the ground and make it systems to become tropical relationship to the size of the easier for trees to fall in winds within the next five days. You cone. The cone represents the that might not be considered can find the latest TWO on line probable track of the tropical very strong. This was the case at: cyclone center. The cone does in some areas of central North http://www.nhc.noaa.gov/text/ not tell anything about impacts. Carolina with Andrea. As part refreshMIAT- As cones shrink, the larger the of your safety considerations WOAT+shtml/171742_MIAT storm, the more the storm’s for this and future hurricane impacts will be felt outside of WOAT.shtml , you will want to keep the cone. in mind reconsidering outdoor activities in gusty winds during and immediately following wide- *Post-tropical cyclone definition: This generic term describes a spread, very heavy rainfall. cyclone that no longer possesses sufficient tropical characteris- tics to be considered a tropical cyclone. Post-tropical cyclones Much of the information in this can continue carrying heavy rains and high winds. Note that article is courtesy of the Na- former tropical cyclones that have become fully extratropical, as tional Hurricane Center’s Hur- well as remnant lows, are two specific classes of post-tropical ricane Specialist Unit. cyclones. -Darin Figurskey (source:NHC) P A G E 6 NOAA Predicts Active 2013 Hurricane Season In its 2013 Atlantic hurri- (Category 3, 4 or 5; winds administrator. “As we saw cane season outlook, NO- of 111 mph or higher). first-hand with Sandy, it’s AA’s Climate Prediction important to remember that Center is forecasting an These ranges are well above tropical storm and hurricane active or extremely active the seasonal average of 12 impacts are not limited to season this year. named storms, 6 hurricanes the coastline. Strong winds, and 3 major hurricanes. torrential rain, flooding, and For the six-month hurri- tornadoes often threaten cane season, which begins “With the devastation of inland areas far from where June 1, NOAA’s Atlantic Sandy fresh in our minds, the storm first makes land- Hurricane Season Outlook and another active season fall.” says there is a 70 percent predicted, everyone at NO- likelihood of 13 to 20 AA is committed to provid- Three climate factors that named storms (winds of 39 ing life-saving forecasts in strongly control Atlantic hur- mph or higher), of which 7 the face of these storms and ricane activity are expected to 11 could become hurri- ensuring that Americans are to come together to produce canes (winds of 74 mph or prepared and ready ahead an active or extremely active higher), including 3 to 6 of time.” said Kathryn Sulli- 2013 hurricane season. These major hurricanes van, Ph.D., NOAA acting are: (continued on page 7)

Summer Starts out Wet in Central NC (from page 1)

flooding with many roads closed or even washed away. Plenty of people “This was the 2nd across the area wettest June ever in are hop- ing for Chapel Hill where drier records have been weather through kept since 1891.” August, as the peak of the hur- ricane Hill, most of it within just ate their homes, and parts of season approaches and we a couple of days. This was Franklin Street near the start to focus on the growing the 2nd wettest June ever UNC campus were under- potential for tropical systems, in Chapel Hill, where rec- water, as shown in the pic- which often bring heavy rain ords have been kept since ture on page 1. Areas of to North Carolina. 1891. Several neighbor- Stanly county and Anson -Gail Hartfield and hoods were badly flooded, county, just east of Char- forcing residents to evacu- lotte, were also hard hit by Mike Moneypenny

CHANGING SKIES VOLUME 10, ISSUE 2 P A G E 7

time from NOAA’s Hurricane Hunter aircraft. This will help forecasters better analyze rapid- ly evolving storm conditions, and these data could further im- prove the HWRF model fore- casts by 10 to 15 percent. The has also made changes to allow for hurricane warnings to re- main in effect, or to be newly issued, for storms like Sandy that have become post-tropical. This flexibility allows forecasters to provide a continuous flow of forecast and warning infor- mation for evolving or continu- ing threats. “The start of hurricane season is a reminder that our families, businesses and communities need to be ready for the next big storm,” said Joe Nimmich, FEMA associate administrator for Response and Recovery. Hurricane Sandy as Seen From Space “Preparedness today can make a big difference down the line, so A continuation of the atmos- NOAA’s seasonal hurricane update your family emergency pheric climate pattern, which outlook is not a hurricane land- plan and make sure your emer- includes a strong west African fall forecast; it does not predict , that is responsible how many storms will hit land for the ongoing era of high ac- or where a storm will strike. 2013 Hurricane Season Forecast Highlights tivity for Atlantic hurricanes Forecasts for individual storms that began in 1995; and their impacts will be provid- Warmer-than-average water ed throughout the season by  70% Chance of 13-20 Named Storms temperatures in the tropical NOAA’s National Hurricane and Caribbean Center.  7-11 Hurricanes Sea; and New for this hurricane season El Niño is not expected to de- are improvements to forecast  3-6 Major Hurricanes velop and suppress hurricane models, data gathering, and the formation. National Hurricane Center com- “This year, oceanic and atmos- munication procedure for post- Seasonal Averages pheric conditions in the Atlantic tropical cyclones. In July, NOAA basin are expected to produce plans to bring online a new su- 12 Named Storms, 6 Hurricanes, more and stronger hurricanes,” percomputer that will run an said Gerry Bell, Ph.D., lead sea- upgraded Hurricane Weather 3 Major Hurricanes sonal hurricane forecaster with Research and Forecasting NOAA’s Climate Prediction (HWRF) model that provides gency kit is stocked. Learn more Center. “These conditions in- significantly enhanced depiction about how you can prepare for clude weaker , of storm structure and im- hurricane season at warmer Atlantic waters and proved storm intensity forecast www.ready.gov/hurricanes.” conducive winds patterns com- guidance. -NOAA ing from Africa." Also this year, Doppler radar data will be transmitted in real NOAA’s National Weather Service Raleigh, NC

1005 Capability Drive Suite 300 Centennial Campus Raleigh, NC 27606 Phone: 919-515-8209 Fax: 919-515-8213 Forecast Line: 919-515-8225

NWS Raleigh Taking Facebook and Twitter by Storm

Do you use Facebook or Twit- https://www.facebook.com/ tinues to grow! Our Twitter ter? These social media sites US.NationalWeatherService.Ralei handle is @NWSRaleigh. continue to grow by leaps and gh.gov bounds, and NWS Raleigh fore- While there is sometimes some casters are in on the action. As of the summer of 2012, we’ve overlapping information between Since we started our Facebook also entered the world of Twit- our Facebook and Twitter posts, page in the summer of 2011, ter! In just the last several we try to reserve Twitter for NWS Raleigh has posted a wide , we have tweeted up-to- quick-hitting, rapid-update infor- variety of information including the-minute information on se- mation, while on Facebook we storm surveys; briefings on up- vere weather and flooding, tor- might post a more detailed brief- coming significant weather such nado track information live from ing or case study. So if you are as storms, severe weath- the survey itself, and breaking on either Facebook, Twitter, or er, and tropical systems; details news on developing tropical sys- both, please consider bringing on our new dual-polarization tems. We’ve recently sought the NWS Raleigh into your social radar technology, interesting assistance of a North Carolina media world! weather happenings around the State University graduate stu- -Gail Hartfield country, even a photo contest in dent, Keith Sherburn, who has helped out with social media at which the winners were fea- tured on the top of our page. our office during We’re very pleased to have outbreaks, working with fore- amassed over 3,200 dedicated casters to provide moment-by- fans so far! And we don’t just moment updates on storm loca- “push” information – we want tions, paths, eyewitness reports, to hear from you about our and impacts. With Keith’s help, forecasters can provide crucial products and services, as well as gather your severe weather details quickly to the public and reports, and our Facebook page our other partners such as the is a great means to do just that. DOT, county officials, and local If you are on Facebook and not media. We really appreciate our yet a fan of NWS Raleigh, please more than 1,250 Twitter follow- check us out at ers, and hope that number con-