STORM COURIER

Significant Weather Events of 2010 By Jon Jelsema - Meteorologist

The 2010 Calendar year will not ing the month of February. In be remembered as an unusually fact, February 2010 was the active year for severe weather, coldest February in the past 30 but did feature a few rather un- years at both the Charleston and usual weather events across Savannah International Airports. southern South Carolina and In addition to the cold conditions, southeast Georgia. These many residents of southern events, in addition to day to day South Carolina and southeast forecasting operations, kept Me- Georgia may remember the teorologists at the National heavy snow event which oc- th Weather Service (NWS) busy curred on February 12 , 2010, NWS Charleston, SC office during the issuing a wide variety of weather when an area of low pressure February 12th, 2010 snowstorm. watches, warnings and adviso- tracked by just off the South ries! Carolina and Georgia coast. The EF0 Tornado 2 miles west of storm initially brought rain to the Bluffton, SC. The tornado Winter 2009/2010 local area, before changing to snapped off the tops of a few Low country residents will likely snow and beginning to accumu- pine trees, a few of which landed remember the rather wet and late. Many locations received on and damaged vehicles, tore cold winter which impacted the enough snow to cover the off some aluminum flashing from southeast United States last win- ground and coat the roads, with homes, knocked down several ter. Many locations across the as much as 6 to 8 inches re- fences, destroyed a shed and local area received 10+ inches of ported across a good portion of damaged a swing set. A more rainfall during December 2009. Colleton, Dorchester, and Berke- widespread severe weather epi- Following the drenching Decem- ley counties. sode occurred on May 23rd, ber, one of the coldest periods in 2010, when numerous reports Spring 2010 recent memory was observed were received from across the during the first half of January Following the unusually cold win- low country, of trees and power 2010, when temperatures strug- ter, temperatures rebounded lines down, as well as large hail. gled to hit 50 degrees during the nicely in March, April, and May. Summer 2010 day and fell below the freezing Despite the warmer weather, the mark consistently at night. Tem- severe weather season was un- Pop-up afternoon thunderstorms peratures rebounded during the usually quiet with only a few se- were nearly a daily occurrence middle to late part of January vere weather episodes impacting throughout June, July and Au- 2010, before another Arctic inva- the region. One particular event gust, keeping NWS forecasters sion made its presence felt dur- on April 8th, 2010, resulted in an busy watching the radar and

Inside this issue: Special points of interest:

The 2010 Atlantic Hurricane Season... 3 Atlantic Hurricane Season kind to U.S.

NOAA Hurricane Hunter Aircraft... 3 2011 Hurricane Awareness Tour stop: Savannah, GA!

Navigating Our Website… 4 A wealth of weather information on the web.

NWS on Twitter… 4 Send in your reports via Twitter.

Science Corner: Atmospheric Optics… 5 Amazing visual effects of the sky!

Using Skype to communicate with the Media… 8 NWS faces seen more frequently on TV?

Deepwater Horizon Oil Spill Support... 9 NWS support during the Gulf Oil Disaster. Page 2 STORM COURIER

Signifcant Weather Events of 2010 continued…

assessing storm severity. farther between. There were ceived a quick dusting of Numerous Severe a couple events worth noting snow accumulation and a Weather episodes im- during the fall months how- couple locations had an pacted the local area, re- ever. One event that a few inch of snow deposited on sulting in sporadic reports residents may have wit- grassy surfaces. Thankfully of downed trees and nessed occurred on Septem- much of the snow fell dur- power lines, structural ber 2nd, 2010, when powerful ing the daylight hours, damage to homes and 8 to 10 foot swells lapped keeping road surfaces wet businesses, large hail, as onto area beaches as Hurri- and drivable for the most well as flash flooding. cane Earl passed by well part. Swell impacting the Folly Beach, SC Pier east of the South Carolina from distant Hurricane Earl, September Besides the typical pulse and Georgia coast. Mother Nature wasn’t as 2nd, 2010. severe thunderstorms, low kind to the region on Janu- country residents may Another event occurred on ary 10th, 2011, when a remember the persistently October 25th, 2010, when a storm system moved hot conditions last sum- strong cold front resulted in a through the region and re- mer. To put the heat into late season severe weather sulted in freezing rain. The “NWS perspective, NWS fore- event. Numerous reports of freezing rain and ice accu- forecasters casters issued a total of golf ball to baseball size hail mulation caused all types of 39 Heat Advisories and 5 were received, along with a headaches across much of issued a total of Excessive Heat Warnings few reports of trees and the low country. Numerous 39 Heat for the local area, nearly power lines down. Following power outages occurred as the same number as the the late season severe the additional weight from Advisories and previous 4 years com- weather event, the weather ice accumulation caused 5 Excessive bined. Heat Advisories became much quieter with many tree branches and are issued when the com- below normal rainfall and a limbs to be knocked down Heat Warnings bination of heat and hu- gradual transition into the on power lines. Traffic be- for the local midity results in apparent winter months. came nearly impossible temperatures of 105 to across portions of the area area, nearly the 114 degrees and Exces- Winter 2010/2011 as well, with ice accumulat- same number sive Heat Warnings when Arctic chill descended on the ing on roads, bridges and apparent temperatures region once again this win- overpasses. This resulted as the previous exceed 114 degrees. ter, resulting in soaring en- in the delay or closure of many area schools and 4 years The summer of 2010 went ergy bills during the months of December 2010 and Janu- businesses. combined.” down in the record books as the warmest on record ary 2011. In fact, the aver- For a more thorough review at both the Charleston and age temperature during the of several of the more sig- period beginning December Savannah International st nificant weather events Airports. The Savannah 1 , 2010 and ending on which impacted the low January, 31st, 2011 was the International Airport also nd country in 2010, visit the recorded an impressive 2 coldest on record for the following web page : combined months of Decem- stretch of days with high temperatures at or above ber and January, at both the 90 degrees, ending on Charleston and Savannah http://www.erh.noaa.gov/ August 14th, 2010 at 40 International Airports. chs/events.shtml. consecutive days. This is In addition to the cold tem- nd the 2 most consecutive peratures, a couple winter Throughout 2010, a total of 90+ degree days dating weather events unfolded 211 Severe Thunderstorm back to 1874. Unusually Hot Temperatures affect the across the region. Many Warnings, 11 Tornado residents will likely remem- southeast United States during the Fall 2010 Warnings, 109 Special Ma- summer of 2010. ber snow flakes flying rine Warnings, 13 Flash Weather conditions through the air on the day Flood Warnings, and a host slowed down during the after Christmas, as a storm of other advisory products fall as pop-up afternoon system moved through the were issued by the Charles- showers and thunder- area changing rain over to ton, SC NWS Forecast Of- storms became fewer and snow. Many locations re- fice. Page 3

Very Active 2010 Atlantic Hurricane Season Was Kind To U.S. By Robert Bright - Meteorologist

The 2010 Atlantic hurricane wind shear over the tropical (Bonnie and Hermine) made season turned out to be very Atlantic Ocean. Other con- landfall in the U.S. while Ma- busy with 19 tropical storms, tributing factors were the jor Hurricane Earl stayed just which tied with 1887 and 1995 record warm ocean tempera- offshore the East Coast. How- for third most on record. tures and an abundance of ever, Earl brought tropical Twelve of those tropical storms weak low pressure systems storm- force winds to North became hurricanes, which tied coming off the west coast of Carolina and Massachusetts as with 1969 for second highest on Africa which are often the well as deadly rip currents record. Five of the hurricanes “seedlings” of tropical cy- along much of the East Coast. reached major hurricane clones. Although there was For more information on the strength (Category 3, 4 or 5 on an unusual number of tropical the Saffir-Simpson Hurricane storms, the weather patterns 2010 Atlantic hurricane sea- Wind Scale). An average sea- through the summer and fall son, check out the National son produces just 11 tropical were such that most were Hurricane Center’s website. Visible satellite image of Hurricane Earl as it moved up the Eastern U.S. Coast storms, 6 hurricanes and 2 ma- steered away from the U.S.. For a local tropical cyclone on September 3rd, 2010. jor hurricanes. This included a deep high climatology, check out… As expected by the National pressure system over the East Oceanic and Atmospheric Ad- Coast, which kept the region http://weather.gov/chs/ ministration (NOAA), La Nina warmer and drier than nor- tropical/hurrstats_web.shtml. played a role in creating less mal. Only 2 tropical storms “Savannah, GA NOAA’s Hurricane Hunter Aircraft Coming To Savannah! has been By Ron Morales - Warning Coordination Meteorologist selected to be one of the stops Savannah, GA has been se- in many other national and show. There will also be lected to be one of the stops on international research mis- some other static displays and on the annual the annual Hurricane Aware- sions. Some recent missions information booths. Although Hurricane ness Tour! The event will take and experiments that the P-3 the target audience for this place at the Savannah Hilton has been involved in include: event will be a select group of Awareness Head International Airport in a climate study off the west approximately 500 4th and 5th Tour!” Savannah, GA on May 5, 2011. coast of Mexico, a low level grade elementary school stu- wind jet experiment over The highlight of the tour will be dents, there will also be an central and South America, a the arrival and display of the opportunity for the general study of bow echoes and Lockheed WP-3D Orion, which public to view and tour the mesoscale convection in the is NOAA’s Hurricane Hunter aircraft and other exhibits. U.S. Midwest, and several aircraft. The event will be This will be a well publicized others. event, with local media cover- hosted by both NOAA’s Na- tional Weather Service Office For more information about age and likely several VIPs in in Charleston, South Carolina NOAA’s WP-3D Orion and attendance from state, local and the Savannah Hilton Head other research aircraft, please and city level. Airport, in conjunction with the visit NOAA’s Aircraft Op- NOAA’s National Hurricane erations Site at:

Center out of Miami Florida, http://www.aoc.noaa.gov/ NOAA’s Airport Operations aircraft.htm Center at MacDill Air Force Base located in Tampa Florida, In addition to the Hurricane and the Chatham county Emer- Hunter aircraft, there will gency Management Division. likely be vehicles and/or This specially equipped P-3 aircraft on display from other Orion aircraft not only plays a agencies such as local Coast vital role in helping NOAA’s National Hurricane Center fore- Guard, Marine and Fire/ cast the track and strength of Emergency services, giving hurricanes, but also participates the experience of a mini air Page 4 STORM COURIER

Inside Story Headline Navigating Our Website By Robert Bright - Meteorologist/Webmaster

Have an event planned over Back on our homepage under “Forecasts” subheader. the next 7 days and want the the map, you can obtain These include Aviation weather forecast? Wonder- “Graphical Forecast Images”, Weather, Fire Weather, ing how cold the winter is which display the forecast of Hydrology, Marine expected to be? Need to plan various weather parameters Weather, and Tropical an outdoor event but can in graphical format. You can Weather. One of the most only do it when rain chances also access the “Weather popular sections of our web- and temperatures are low Activity Planner” which al- site is the climate webpage, enough? Well, you can get lows you to query our fore- which can be accessed by all of this information and cast database to see when and clicking on “Local” under more on our website: if certain forecast parameters the “Climate” subheader. will be met. For example, From this page you can http://weather.gov/chs. you may be looking to plan access a wealth of climate The map on the home page an outdoor event and want to information, including cli- shows you if and where any see when we are forecasting mate outlooks from the advisories, watches, warn- temperatures above 70 de- NOAA Climate Prediction ings and statements are cur- grees in coincidence with Center. In addition, you can rently in effect. You can also rain chances below 30 per- obtain climate data for many click on the map to obtain a cent. Current radar and satel- locations across southern "point" forecast for that loca- lite imagery is also available South Carolina and south- tion, which comes from our further down the page, as east Georgia by selecting the “the National National Digital Forecast well as climate plots for “NOWData” tab. Database (NDFD). Once at Charleston, SC and Savan- Hopefully you will enjoy all Weather the point forecast page you nah, GA. of the information on our can access other ways of Service is now The left-hand menu contains website. If you have any displaying the forecast from links to current conditions/ comments or questions following the the links under the hazards, forecasts, climate while surfing, feel free to let “Additional Forecasts & #wxreport hash data, weather safety us know by sending an Information” section on the (including our SKYWARN email to: tag on bottom right. These include spotter page), local research, the “Tabular Forecast”, [email protected] and information pertaining to Twitter.” “Hourly Weather Graph”, our office, among other and we will respond as soon “Quick Forecast”, and things. In addition, many of as possible. You can also “Interactive Forecast Map”. our office programs have fill out a short survey which You should select each of their own webpages, which can be accessed near the these options to see which are listed under the bottom of the left menu. one best suits your needs.

NWS on Twitter By Ryan Aylward - Meteorologist

In an effort to obtain timely trees and/or power lines Now anyone can send re- significant weather reports down, storm damage, and ports into the NWS! We from the public, the Na- flooding. look forward to seeing your tional Weather Service reports in the near future! (NWS) is now following The process is very simple the #wxreport hash tag on and only requires you to For more information on Twitter. include your location, storm reports via Twitter, weather report, and the go to this website:

Everyone is encouraged to #wxreport hash tag. By “tweet” any significant sending in a report via Twit- weather events including, ter, NWS forecasters in http://www.weather.gov/ but not limited to, snow and/ Charleston, SC will instantly stormreports/. or other wintry precipitation, be alerted and see your strong winds, large hail, “tweet” on their computers. Page 5

Science Corner: Atmospheric Optics By Peter Mohlin - Meteorologist

While many of you may be familiar with the various differ- ent types of clouds, when conditions are just right, there are other phenomena that can occur in the sky. Some of them are fairly common, while others might only be seen once or twice in a lifetime at best. Collectively, anything having to do with light and color in the atmosphere and usually produced by water droplets, ice crystals and/or dust are called atmospheric optics.

The most recognizable atmospheric optic is probably the rainbow, which most of you have likely seen at least once, perhaps even on multiple occasions. However, there are several other visual spectacles that are less familiar, and all of which occur through 4 different methods: reflection, Circumzenithal Arc refraction, scattering and/or diffraction of light. If you ever saw something in the sky that looked strange, yet magnifi- The Circumzenithal Arc, also called the Bravais’ Arc or “a cent or beautiful, you might have been looking at some smile in the sky” is similar to a rainbow, but develops type of atmospheric optic. through the refraction of sunlight through one side and one

face of horizontally oriented ice crystals. It is generally observed in Cirrus clouds, and its colors are similar to a Next we will briefly discuss several different types of at- rainbow, ranging from violet on the inside to red on the mospheric optics, indicating how they form and showing a outside. photo of each.

Belt of Venus Corona The Belt of Venus, also called the Anti-Twilight Arch or Venus’s Girdle is visible many times just before sunrise or Although similar in appearance to a Halo, the Corona is just after sunset, and occurs just above the horizon in the formed by the diffraction of light passing through clouds direction opposite the sun. It is slightly off-color, pinkish containing small water droplets of a fairly uniform size. to brownish border separating the dark shadow band of the They occur with Altocumulus and Altostratus clouds and are earth from the sky above. While the blue sky is normal seen as a white or colored circle, or a set of concentric cir- sunlight reflecting off the atmosphere, in the Belt of Venus cles of light visible around the sun or the moon. Their oc- there is backscattering of reddish light from the setting or currence can also be an indication of precipitation arriving at rising sun. It is best visible when the sky is clear, yet dusty your location within 6 to 12 hours. and extends approximately 10 to 20 degrees above the horizon. Page 6 STORM COURIER

Science Corner: Atmospheric Optics Continued...

Glory A Glory is produced by light that is backscattered (a com- Crepuscular Rays bination of diffraction, reflection and refraction) towards Crepuscular Rays, also called Shadow Bands, Solar Rays its source by a cloud of uniformly sized water droplets. or Sunrays, are usually produced by an obstruction to The phenomenon appears much like the halo of a saint, can sunlight. The obstruction can be caused by Cumuliform have multiple colored rings and can fluctuate greatly in clouds, dust or other particles in the atmosphere where the their size. However, most people only see one ring and light becomes scattered. The rays are parallel to each other they are usually only visible from an airplane or on a and their source can be traced back to the sun. mountaintop, where the clouds are below your point of view and you are located between the sun and the clouds. They are sometimes called an Anticorona or a Brocken Bow.

Anti- crepuscular Rays Anti-Crepuscular rays are much like Crepuscular Rays, Halo except they are bands of light or shadows that are observed A Halo is usually a bright circle centered on the sun or on the opposite horizon from where the sun is found. moon, but can be a variety of bright circles or arcs. The Halo results from the refraction of light by ice crystals that are suspended in the atmosphere and exhibits a prismatic coloration ranging from red on the inside to blue on the outside. They most commonly occur with Cirrostratus clouds and can be used to predict the weather. If they are seen with these clouds it is often an indicator that precipita- tion will occur within 12 to 24 hours. Page 7

Science Corner: Atmospheric Optics Continued...

Secondary Rainbow Rainbows are caused by the refraction, total reflection and Iridescence scattering of light, and are always observed in the opposite These are brilliant spots or borders of colors in clouds, direction from the sun. While a single or primary Rainbow usually red and green, caused by diffraction of light by features all the colors of the spectrum from violet on the small cloud particles. This phenomenon is usually ob- inside to red on the outside, the secondary Rainbow shows served in Cirrus or Cirrocumulus clouds within about 30 these same colors, but in reverse order. The secondary degrees of the sun and is characterized by bands of color in Rainbow is about 10 degrees further out from the primary the cloud that contour the cloud edges. The Iridescence is Rainbow, and is about twice as wide. The light of the sec- sometimes referred to as Irisation. ondary Rainbow is much less intense than that of the pri- mary bow, given the same viewing conditions. A third or tertiary Rainbow, and higher order rainbows are also possi- ble, but due to their low luminosity are rarely seen. If they do occur they are found on the same side as the sun, mak- ing them much more difficult to see.

Parhelion Parhelion is the scientific name for Sun Dogs, and is also known as Parhelia and Mock Suns. They appear as lumi- nous spots at the same elevation and roughly 22 degrees to Sun Pillar the right and left of the sun. They result from the refrac- tion of sunlight passing through ice crystals. At times This phenomenon is also called a Sub-Sun or a Light Pillar, however, only one Parhelion or Sun Dog will be visible and is caused by the reflection of light off the surfaces of dependent upon the cloud cover, and they are exclusively falling ice crystals that are associated with Cirriform associated with Cirriform clouds. clouds. The Sun Pillar is a vertical shaft of light extending upward or downward from the sun, usually when the sun is low in the horizon. Page 8 STORM COURIER

Science Corner: Atmospheric Optics Continued...

Green Flash The Green Flash results from the refraction of light. It is Tangent Arc also called a Blue Flash, a Blue-Green Flame and a Green Segment. Light moves slower in the lower and denser air The Tangent Arc is caused by the refraction of light above near the earth’s surface than in the thinner air above, so the and below the sun, through horizontally oriented ice crystal sunlight will follow paths that curve slightly in the same columns. It is similar to a Halo, but it appears over and direction as the curvature of the earth. The higher fre- tangent to the Halo around the sun. The shape of the arc quency green and blue light will curve more than the lower will vary with the elevation of the sun, with the arc form- frequency red and orange light, so the blue and green rays ing a sharp angle when the sun is low in the sky. Like from the upper edge of the setting sun will remain visible other Halos the Tangent Arc is red on the inner edge and after the red and orange rays are obstructed by the curva- blue on the outer edge because the red light is refracted ture of the earth. The Green Flash is only visible for about more than the blue light. a second and they are best seen on an unobstructed view of the horizon. If you are fortunate enough to witness its occurrence, it is said to bring you good luck.

Using Skype To Communicate with T.V. Media Partners By Ron Morales - Warning Coordination Meteorologist

Our local T.V. media partners have ex- pressed a strong interest in using Skype for live, video interviews. If you are not fa- miliar with Skype, it allows you to have live video phone conversations with any- one else that has the software loaded on their PC, laptop or even smart phone. The software is available for download free on the web (www.skype.com).

In the near future, you will likely see some of the faces of the National Weather Ser- vice Forecast Office in Charleston on your local T.V. weather broadcast, especially during severe or unusual weather events. Page 9

Deepwater Horizon Oil Spill Support

People across the nation will and Atmospheric Admini- Weather information was critical during this disaster, as it al- undoubtedly remember the stration (NOAA) line offices lowed officials to make informed decisions on the safest, most disaster which struck the called upon to provide tech- effective, and timely methods to respond to the crisis and work Gulf of Mexico April 20th, nical support during the toward restoring the environment. 2010, when the Deepwater Deepwater Horizon oil spill Horizon Oil Rig exploded response. killing 11 men, injuring 17 others, and sending a con- NWS Incident Meteorolo- tinuous stream of oil into the gists were summoned from water for nearly 3 months. across the country to pro- vide detailed weather sup- The oil streaming into the port information to key offi- Gulf, was finally halted on cials. The information, July 15th, 2010 when a cap assisted officials in making was placed on the failed important decisions on how well head, and was declared to respond and where to “effectively dead” by fed- allocate resources to maxi- eral government officials mize efficiency and effec- after relief wells were filled tiveness. with cement sealing the blown out well thousands of Meteorologist Jon Jelsema, feet below the ocean floor a forecaster at the Charles- Satellite Image of Oil Slick seen from NASA’s Terra satellite on May 24, on September 19th, 2010. ton, SC NWS office, was 2010. Before the well head was one of a handful of NWS contained, oil was flowing Meteorologists that were “The National Weather Service (NWS) was one into the Gulf of Mexico at dispatched to the northern of a number of National Oceanic and Atmos- an estimated rate of 62,000 Gulf coast to respond to the barrels or 2.6 million gal- oil spill. His duties included pheric Administration (NOAA) line offices lons per day. Over the working for the NWS office called upon to provide technical support during course of the disaster, 4.9 in Mobile, AL as an opera- the Deepwater Horizon oil spill response.” million barrels or 206 mil- tional forecaster issuing lion gallons of oil was re- weather forecasts and warn- leased into the Gulf of Mex- ings for the FL panhandle, ico, making it the largest oil southern AL, southern MS, spill in United States con- and the adjacent marine area trolled waters and the largest along the northern Gulf in the Gulf of Mexico. coast. In addition to these duties, Jon worked on the The disaster resulted in an Decision Support desk re- unprecedented response, laying current radar infor- calling experts from many mation on the location and professions to help resolve movement of thunderstorms the problem, and restore the over the northern Gulf Coast damage done to the environ- and adjacent coastal waters, ment and the economy of and provided 3 to 6 hour the northern Gulf Coast. thunderstorm forecasts to incident support personnel, The National Weather Ser- to help ensure the safety of vice (NWS) was one of a those involved in the Photo showing degraded oil taken along the northern Gulf of Mexico number of National Oceanic cleanup efforts. coast, in Dauphin Island, AL on July 4, 2010.

Mission: “Protection of Life and Property and Enhancement of the National Economy”

NATIONAL WEATHER SERVICE CHARLESTON, SOUTH CAROLINA 5777 South Aviation Avenue North Charleston, SC 29406 Phone: (843) 744-0303

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Whenever severe weather clouds or waterspouts, pick up home. When in doubt, please strikes, remember, as a trained the phone and give us a call. In call us! weather spotter we want to hear addition, if you see or hear of any from you! injuries, fatalities, or damage You can reach us by calling the from lightning, give us a call. toll free number which we pro- If you measure or estimate winds vided to you during the spotter of 50 mph or greater, observe Your valuable reports help us training session you attended. trees and/or power lines down, confirm what we’re detecting on structures damaged, hail (any radar, and could make a life-or- You can also leave a report on size), flooding (water running death difference for the people in our severe weather answering across the road, ditches over- the next town or in the next machine: 1-888-383-2024. flowing, creeks/streams out of county in the path of the severe For Forecast and Current Condi- their banks), tornadoes, funnel storm that just went over your tions call: 1-843-744-0303.