10:30 AM | The Great New England Hurricane of 1938

[Photo of Battery Park (Manhattan) during 1938 storm; courtesy National Weather Service]

Discussion

Yesterday marked the 76th anniversary of The Great New England Hurricane of 1938 which is also known as The Long Island Express and the Yankee Clipper. With no warning, the powerful category 3 hurricane (previously a category 5) slammed into Long Island and southern New England causing approximately 700 deaths and massive devastation to coastal cities and became the most destructive storm to strike the region in the 20th century. Little media attention was given to the powerful hurricane while it was out at sea as Europe was on the brink of war. There was no advanced meteorological technology such as radar or satellite imagery to warn of the storm’s approach.

The storm began on September 10th near the Cape Verde Islands in the eastern Atlantic. About a week later, the captain of a Brazilian freighter sighted the storm near Puerto Rico and radioed a warning to the US Weather Bureau and it was expected that the storm would make landfall in south Florida where preparations frantically began. By September 19th, however, the storm suddenly changed direction and began moving north, parallel to the eastern seaboard. It had been many decades since New England had been hit by a substantial hurricane and few believed it could happen again. The storm picked up tremendous speed as it moved to the north following a track over the warm Gulf waters.

[Surface weather map, 9 a.m., September 21, 1938; courtesy National Weather Service]

By the time the fast-moving storm approached Long Island, it was simply too late for a warning. In the middle of the afternoon on September 21st, the hurricane made landfall along the south shore of Long Island right around high tide when there was nearly a new moon (highest astronomical tide of the year). To make matters worse, this part of the country had just been through a long rainy period which saturated grounds before the arrival of this great storm. Waves as high as 40+ feet swallowed up coastal homes and homes that survived the storm surge succumbed to the damaging winds that reached 111-129 mph (lower to the west and higher to the east). By late afternoon, the hurricane raced northward at an amazing 60-70 mph crossing the Long Island Sound and reaching Connecticut. The storm surge of 14-18 feet above normal tide level inundated parts of Long Island and later the southern New England coastline. The waters in Providence harbor rapidly submerged the downtown area of Rhode Island’s capital under more than 13 feet of water and many people were swept away. The accelerating hurricane then continued northward at tremendous speed across Massachusetts generating great flooding in its path. In Milton, a town south of Boston, the Blue Hill Observatory recorded one of the highest wind gusts in history at an incredible 186 mph. Boston was hit hard and “Old Ironsides” – the historic ship USS Constitution – was torn from its moorings in Boston Navy Yard and suffered slight damage. Hundreds of other ships were not so lucky being completely demolished. The hurricane lost intensity as it passed over northern New England, but was still strong enough to cause widespread damage in Canada later that evening before finally dissipating over southeastern Canada later that night. All told, approximately 700 people were killed by the hurricane, 600 of them in Long Island and southern New England, 9000 homes and buildings were destroyed and 3000 ships were sunk or wrecked. It remains the most powerful and deadliest hurricane in recent New England history, eclipsed in landfall intensity perhaps only by the Great Colonial Hurricane of 1635 - the one storm by which all other storms are measured.

[Track of 1938 “Long Island Express” hurricane; courtesy National Weather Service]

In terms of weather forecasting for this storm, while the US Weather Bureau did not predict a hurricane landfall, that decision was not without controversy as a junior forecaster named Charlie Pierce believed the storm would curve into Long Island and southern New England due to blocking high pressure to the northeast and trough of low pressure which would guide the storm inland in his opinion. Mr. Pierce was overruled by the chief forecaster, Charles Mitchell. Shortly thereafter, Charles Mitchell resigned and Charlie Pierce was promoted.

Facts of the 1938 Hurricane (Francis, 1998) • Peak Steady Winds - 121 mph • Peak Gust - 186 mph at Blue Hill Observatory, MA. • Lowest Pressure - 27.94 in (946.2 mb) at Bellport, NY • Peak Storm Surge - 17 ft. above normal high tide (RI) • Peak Wave Heights - 50 ft. at Gloucester, MA • Deaths - 700 (600 in New England) • Homeless - 63,000 • Homes, Buildings Destroyed - 8,900 • Boats Lost - 3,300 • Trees Destroyed - 2 Billion (approx.) • Cost - $620 million (1938)

3:00 PM | The Carrington Event of 1859 - a solar superstorm that took place 155 years ago

[Sunspots sketched by Richard Carrington on Sept. 1, 1859. Copyright: Royal Astronomical Society]

Discussion

It was this time of year 155 years ago when the solar superstorm, now known as the Carrington Event, took place during solar cycle 10. The event has been named for the British astronomer, Richard Carrington, as he observed from his own private observatory the largest solar flare during this event which caused a major coronal mass ejection (CME) to travel directly toward Earth. The 33-year-old astronomer - widely acknowledged at the time to be England’s best - also recorded in detailed fashion the appearance of the sunspot regions that he saw at the time.

From August 28, 1859 to September 2, 1859 numerous sunspots and solar flares were observed on the sun and auroras were being observed in different parts of the world. Just before noon on September 1st, Richard Carrington was using his telescope to project an 11-inch wide image of the sun on a screen and he carefully drew the sunspots that he saw. Suddenly, two brilliant beads of blinding white light appeared over the sunspots and he realized that he was witnessing something unprecedented. He left for about one minute to find another witness and found upon their return that much had already subsided.

Just before dawn the next day, skies all over Earth erupted in red, green and purple auroras - even in tropical locations like Cuba, the Bahamas and Hawaii. The massive solar flare caused a major CME that reached the Earth some 17.6 hours later. Normally such a journey takes 3 or 4 days, but an earlier CME actually cleared the way of the ambient solar plasma for the second blast to move so quickly. The auroras were so bright over the Rocky Mountains that their glow awoke gold miners who began preparing breakfast because they thought it was morning. People in the northeastern US could read a newspaper by the aurora’s light. Telegraph systems all over Europe and North America went haywire and, in some cases, telegraph operators were literally shocked as sparks were flying and telegraph paper was often set on fire. Some systems continued to work despite being disconnected from their power supplies as aurora-induced electric currents still allowed messages to be transmitted.

Now we know that solar flares happen frequently, especially during solar sunspot maximums, but in those days there were no X-ray satellites or radio telescopes and no one knew flares existed until that September morning. “It is rare that one can actually see the brightening of the solar surface which takes a lot of energy to heat up the surface of the sun” says a modern day NASA astronomer. “In the 160-year record of geomagnetic storms, the Carrington event is the biggest.” In fact, going back farther in time by examining Arctic ice (energetic particles leave nitrates in ice cores), it is estimated that this event may have been the biggest in 500 years and nearly twice as big as the runner-up.

In today’s world, electronic technologies have become embedded into everyday life and are, of course, quite vulnerable to solar activity. Power lines, long-distance telephone cables, radar, cell phones, GPS, satellites – all could be significantly affected by an event like this one. The good news is that observations of the sun are a constant in today’s world with a fleet of spacecraft in position to monitor the sun and gather data on solar flares. The bad news is that the Carrington Event occurred during a weak solar cycle (10) which actually resembles rather closely our current solar cycle (24) so we always have to stay on guard for a potential powerful solar storm - even during times of weak solar cycles.

12:30 PM | 75th Anniversary of "The Wizard of Oz" and the incredible tornado scene

Discussion

Overview Last Friday was the 75th anniversary of the release of "The Wizard of Oz" which was the first movie to depict an authentic looking tornado using improbable “1930’s style” special effects. Through the decades, this all-time classic has inspired movie-goers and “weather weenies” alike with the scene of a twister lifting Dorothy’s home into the sky over rural Kansas farm land.

Background The movie was based on a novel called "The Wonderful Wizard of Oz" written by L. Frank Baum in the year 1900. The setting of the movie in rural Kansas and the name of its main character, Dorothy Gale, were not just random choices. Baum had been a newspaper editor in the "Dakota Territory” (now South Dakota) and recalled the story of twin tornadoes that destroyed the rural town of Irving, Kansas in May of 1879. The name of one of the victims of this tornado outbreak was found in a mud puddle - and her name was Dorothy Gale.

The tornado scene As far as the tornado scene is concerned, it is still regarded as incredibly realistic – even in today’s era of computer-generated special effects. The first attempt at a tornado by the movie’s special effects director, Arnold Gillespie, was to use a 35-foot tall rubber cone, but this turned out to be too rigid and simply wouldn’t move. Next, the special effects director recalled from his experience as a pilot (even had his own airplane) that wind socks at airports had the classic funnel-shape of a tornado. He decided to make a tornado out of muslin (plane woven cloth) which would allow it to twist, bend and move from side-to-side. He built a 35-foot long tapered muslin sock and connected the top of it to a steel gantry suspended at the top of the stage. The gantry alone cost more than $12,000 (in 1938 dollars) and was specifically built for the tornado by Bethlehem Steel. It was a mobile structure similar to those used in warehouses to lift heavy objects and could travel the entire length of the stage. The bottom of the sock disappeared into a slot on the stage floor where it connected to a rod which came up through the base of the tornado to pull it from side-to-side. By moving the gantry and rod in different directions, the tornado appeared to "snake" across the stage.

To produce the dust and debris that makes a real tornado visible, they used compressed air hoses to spray a powdery brown dust known as “Fullers Earth” from both the top and bottom of the funnel. The muslin sock was sufficiently porous that some of the dust sifted through giving a blur or softness to the material and a fuzziness to the edges so that it didn’t look like a hard surface.

Four or five feet in front of the cameras were two panels of glass on which gray balls of cotton (great for mammatus clouds) had been pasted. The two panels moved in opposite directions adding to the boiling sensation and, at the same time, they obscured the steel gantry and top portion of the tornado. Dense clouds of yellow-black smoke made from sulfur and carbon were injected onto the set from a catwalk above the gantry. The stage hands had no respirators and stayed up there breathing the stuff until they couldn't stand it. Many of them became ill and some coughed up black-yellow mucous even days after the tornado was photographed.

Once the tornado had been filmed, there was still plenty of work to be done. Rear- projection was used to transfer the previously shot tornado image onto a translucent screen while actors such as Dorothy were placed in front of it. Wind machines provided the big blow while stage hands threw dried leaves and other debris in the air. When the tornado came real close to the house at the end of the scene, more debris and dirt were added in the foreground to obscure the fake tornado while providing more realism. The tornado scene in "The Wizard of Oz" ended up costing more money than any other special effect in the movie. So essentially, "The Wizard of Oz" tornado was nothing more than a large tapered cloth sock with lots of wind and dirt thrown at it.

Awards "The Wizard of Oz" was nominated for six Academy Awards and won two including “Best Original Song” (Over The Rainbow), but it did not win an Oscar for its amazing special effects and it did not win the Oscar for “Best Picture”. That honor went to another famous movie from 1939 with coincidentally a “weather-related” name - "Gone with the Wind". For additional information, check out the Penn State Department of Meteorology “Weather World” video presentation by Dr. Jon Nese (http://www.meteo.psu.edu/~j2n/WxYz.htm).

10:00 AM | The toughest weather forecast of all-time: D-Day, June 6, 1944

Discussion

Friday, June 6th, marks the seventieth anniversary of the D-Day invasion in Normandy, France during World War II and the weather forecast for that historic event makes for quite an interesting story in what turned out to be a pivotal moment in world history. Defying his colleagues, Captain James Martin Stagg advised General Dwight “Ike” Eisenhower to postpone the invasion of Normandy by one day from June 5, 1944 to June 6 because of uncertain weather conditions.

There were no computer forecast models, no satellites, radar was in its infancy and being used primarily for military purposes only, and yet General Dwight “Ike” Eisenhower wanted a definitive weather forecast for the planned invasion of Normandy, France with no “ifs”, “maybes” or “possibles” attached to the wording. With absolute forecast information required and thousands of lives on the line, it is an underestimate to say that the task was daunting for chief meteorologist, Group Captain James Martin Stagg, of the British Royal Air Force. Stagg ultimately persuaded General Eisenhower to change the date of the Allied invasion of Europe during World War II due to weather concerns from the 5th of June to the 6th of June in 1944. There were actually three different teams of weather forecasters involved with the Normandy invasion including the British Royal Navy, British Met Office and the US Air Force, but Stagg was given the role as the chief meteorologist.

The opportunity for launching an invasion was limited to only a few days in each month to take advantage of the moon and tide. Darkness was needed when the airborne troops went in, but moonlight once they were on the ground. Spring low tide was necessary to ensure extreme low sea level so that the landing craft could spot and avoid the thousands of mined obstacles that had been deployed on the beaches. If this narrow time slot was missed, the invasion would have been delayed for two weeks. Eisenhower had tentatively selected June 5th as the date for the assault which was one of the few days in early June that met these criteria.

By Saturday, June 3rd, the forecasts began to be highly unfavorable for a June 5th invasion. High pressure areas were over Greenland and the Azores, with low pressure centers moving east-northeast across the Atlantic. It seemed probable that the high winds and sea would rule out the 5th as D-day. Nevertheless, “Ike” pushed ahead for now with his plans for a June 5th invasion.

There were two official weather briefings given by weather forecasters on June 4th. At the early weather briefing on that day, the weather prospect seemed completely hopeless for a June 5th invasion. All weather experts predicted seas heavy enough to swamp landing craft and a low ceiling, which would prevent the air forces from carrying out their part of the assault. Under these circumstances, the air commanders were unwilling to take off, and Admiral Ramsey, after being advised that the winds would reach 25 to 30 miles per hour, feared that the channel would be too rough for small craft. Only "Monty" (General Montgomery of England) wished to still carry out the schedule. At the later briefing on June 4th, Captain Stagg predicted good prospects for a favorable break on the 6th of June and for heavy bombers to be able to fly during the preceding night. As a result, General Eisenhower decided to postpone the operation for 24 hours to June 6th. For the Navy, this weather forecast given at the second briefing on June 4th was the moment of decision since orders were then issued for all vessels to resume sailing to meet the new D-Day date of June 6th.

The 5th of June was indeed a miserable day and soldiers were cooped up in small beaching craft under lashing rain, and a day of intense anxiety for the top commanders watching from shore. The surface weather chart for 4 June 1944 showed an intense low pressure system centered to the west of England and a cold front extending southeast from the low pressure center to Ireland. The foul weather that set in on June 4th threw all German commanders off their guard since, lacking weather observation stations west of the European continent; they were unable to predict the favorable weather that would follow the frontal system. The German weather station in Greenland had been evacuated at the beginning of June, and no weather reporting U-boats were in a position to detect the small area of high pressure. Hitler had long understood that the key to anticipating the timing of the invasion would be good weather forecasting. General Rommel, who was in charge with the defense of the invasion beaches, was certain that there would be no invasion between June 5th and 8th because the tides were "not right." He also thought that the Allies would not attempt and invasion without a guarantee of about six days of fine weather. He was actually at home in Germany on the morning of D-Day when news of the landing caught up with him and only made it to the front at the end of the first day.

On June 6th, the weather was more tolerable, but certainly not ideal. A gusty wind blowing from the west at 15 to 20 knots produced a moderately choppy sea with waves of from 5 to 6 feet in height. This was a heavy sea for the small craft, which had some difficulty in making way. Even the assault area was rough for the shallow-draft vessels, although there the wind did not exceed 15 knots, and the waves averaged 3 feet. Visibility was 8 miles with a cloud ceiling at 10,000 to 12,000 feet. Scattered clouds from 3000 to 7000 feet covered almost half the sky over the channel, becoming denser farther inland. Maritime polar air had moved over the channel behind the cold front as the low of 4 June that was west of England moved eastward; the deep low that was off Labrador on 4 June moved north-northeast to just off the southeast coast of Greenland (surface map shown below for 6 June 1944). This was the key to the clearing weather: if the Labrador low had tracked eastward, foul weather would have prevailed. The midlevel overcast was most serious for air operations. Heavy bombers assigned to hit the coastal fortifications at Omaha Beach had to bomb by instruments through the overcast. With concurrence of General Eisenhower, the Eighth Air Force ordered a delay of several seconds in its release of bombs, in order to insure that they were not dropped among the assault craft. The result was that the 13,000 bombs dropped by 329 B-24 bombers did not hit the enemy beach and coast defenses at all, but were scattered as far as 3 miles inland. The weather also contributed to navigational difficulties. Mist mixed with the smoke and dust raised by the naval bombardment obscured landmarks on the coast; additionally, a lateral current of from 2 to 3 knots tended to carry craft east of their touchdown points by 1500 to 2000 yards and this caused some confusion. Their difficulties were compounded by the heavier enemy opposition, which isolated boat sections only a few hundred yards apart and at first made reassembly and reorganization or improvised missions almost impossible. Unloading at Utah beach proceeded in an orderly fashion, the chief distractions being an intermittent shelling of the beaches and air raids in the early morning hours.

By D-Day plus 12 days, the flow of men and supplies over the beaches was running smoothly: 314,514 troops, 41,000 vehicles, and 116,000 tons of supplies had been landed on the American beaches, with almost identical figures for the British beaches. Had General Eisenhower postponed the invasion, the only option would have been to go two weeks later, and this would have encountered the “worst channel storm in 40 years” as Churchill later described it, which lasted four days between 19 and 22 June. In fact, Eisenhower sent a letter to Captain Stagg saying in reference to the major storm that occurred in the potential second time slot for the invasion, “I thank the Gods of war we went when we did.” For the rest of his life, in moments of stress, Group Captain Stagg would remember some words spoken to him by General Morgan, Eisenhower's Chief of Staff, in the tension-filled days leading up to the postponement: "Good luck Stagg: may all your depressions be nice little ones, but remember, we'll string you up from the nearest lamp post if you don't read the omens right."

Years later, during their ride to the Capitol for his inauguration, President-elect John F. Kennedy asked President Eisenhower why the Normandy invasion had been so successful.

Ike's answer: "Because we had better meteorologists than the Germans!"

SURFACE MAP 0700 GMT 06 JUNE 1944