Winter Storm Athena Heading for East Coast

First Hurricane Sandy, now Winter Storm Athena for the Eastern U.S.

Published: 2:57 PM GMT on November 07, 2012

Winter Storm Warnings are up for Southwest New Jersey, Northern Delaware, and Southeast Pennsylvania, including Philadelphia, PA, where Winter Storm Athena is expected to drop 3 – 5″ of snow today through Thursday morning. Slushy accumulations of up to 1″ are likely in Baltimore, and non-accumulating snow will fall as far south as Washington, DC. Athena, the season’s first Nor’easter and first winter storm to get a name under The Weather Channel’s new naming system, is spreading rain and high winds into Southern New Jersey and Eastern Long Island, NY this morning. Winds at buoy 44025, about 40 miles offshore from the coast of Central New Jersey, reached 40 mph, gusting to 49 mph, with a significant wave height of 14′, at noon EST. Winds at Nantucket, MA have gusted as high as 54 mph this morning. Athena is building a storm surge that has already reached 2.2′ at Atlantic City and 1.8′ at New York City as of noon EST. A storm surge of 2 – 3.5′ is likely along the section of coast most heavily damaged by Sandy’s storm surge, and battering waves up to 20′ high will cause moderate beach erosion along much of the New Jersey and New York shoreline. The storm surge will cause minor to moderate flooding during this afternoon’s high tide cycle near 1 pm EST, and again at the next high tide, near 1 am EST Thursday morning. Fortunately, the high tides this week will be some of the lowest of the month, since we are midway between the new moon and full moon. Wind gusts from Athena will likely reach 50 mph along the coasts of New Jersey and Southern Long Island, NY, and could hit 60 mph on Cape Cod, Massachusetts. I expect that Athena’s winds, rains, and wet, heavy snows will cause up to 50,000 new power outages today. As of early Wednesday morning, 676,000 customers were still without power in the wake of Hurricane Sandy (down from a peak of 8.5 million customers.)


Figure 1. Winter Storm Athena as seen at 9:01 am EST November 7, 2012. Image credit: NOAA/GSFC.


Figure 2. Predicted storm surge at Sandy Hook, NJ, for Winter Storm Athena, from the experimental Extratropical Storm Surge model, run by NOAA’s Meteorological Development Laboratory. This model used winds from this morning’s 6Z (1 am EDT) run of the GFS model. The peak storm surge (yellowish-brown line) is predicted to be 3.4′, occurring Wednesday evening. High tide (green line) occurs near 1 pm Wednesday afternoon, resulting in a peak storm tide of approximately 7.2′ around 1 pm Wednesday (black line). For comparison, Sandy delivered a 8.6′ storm surge to Sandy Hook before their tide gauge failed, with the storm tide reaching 13.2′ above MLLW (Mean Lower Low Water.)

The decision to name Athena
The Weather Channel announced in October that they would begin naming winter storms this year, in an effort to aid in raising awareness and reduce the risks the public faces. One of the main criteria for naming a storm is its impact on populated areas; the meteorology of the storm may not get it named, if the storm doesn’t affect a populated area. If Hurricane Sandy had not devastated the region of coast being affected by today’s Winter Storm Athena, it may not have gotten a name. With so many people still under recovery efforts even well inland, the combination of heavy, wet snow and wind prompted the decision to name Athena. The models have been trending towards more cold air getting pulled into this system, so it is possible Athena could drop heavier snows than currently advertised. The National Weather Service will not be referring to today’s Nor’easter as “Athena”. They put out this internal directive: “The NWS does not use named winter storms in our products. Please refrain from using the term Athena in any of our products.”

Here are the peak wind gusts from Athena as of 11 am EST on Wednesday, November 7, 2012:

Jeff Masters

from:    http://www.wunderground.com/blog/JeffMasters/article.html

First Sandy, and Now, A Nor-easter

A moderate-strength Nor’easter on Wednesday looking increasingly likely

Published: 7:38 PM GMT on November 03, 2012

Storm-weary U.S. residents pounded by Superstorm Sandy may have a new storm to contend with on Wednesday: an early-season Nor’easter is expected to impact the mid-Atlantic and New England with strong winds and heavy rain. Our two top models, the European (ECMWF) and GFS (run by the U.S. National Weather Service), are now in agreement on both the track and intensity of the storm. The storm will move off the coast of South Carolina/Georgia on Tuesday evening. Once over the warm waters off the coast, the low will intensify, spreading heavy rains of 2 – 3″ over coastal North Carolina on Tuesday night and Wednesday morning. The storm will accelerate to the north-northeast on Wednesday and pull in cold air from Canada, intensifying into a medium-strength Nor’easter with a central pressure of 984 mb by Wednesday evening. The European model, which did an exemplary job forecasting Hurricane Sandy, is slower, predicting the Nor’easter’s highest winds will begin affecting New Jersey on Wednesday night. The GFS model is about 12 hours faster, predicting the strongest winds will arrive on Wednesday morning. A 12-hour period of strong winds of 40 – 45 mph will likely affect the coast from Maryland to Massachusetts, accompanied by a swath of 2 – 3″ of rain. The heaviest rains will likely fall over Eastern Massachusetts and Rhode Island. The storm also has the potential to bring more than a foot of snow to mountain areas of New England. The storm is still four days away, and four-day forecasts of the path and intensity of Nor’easters usually have large errors. Nevertheless, residents and relief workers in the region hit by Sandy should anticipate the possibility of the arrival on Wednesday of a moderate-strength Nor’easter with heavy rain, accompanied by high winds capable of driving a 1 – 2 foot storm surge with battering waves. The surge and waves will potentially cause moderate to severe erosion on New Jersey coast, where Hurricane Sandy pulverized the protective beach dunes.


Figure 1. Predicted wind speed for Thursday morning, November 8, 2012, from the ECMWF model (left) and predicted wind speed for 2 pm EST on Wednesday, November 7, from the GFS model (right). Both models runs were done beginning at 12Z (8 am EDT) on November 3, 2012. Winds tropical storm-force (39+ mph) are predicted to extend from coastal Virginia to Massachusetts. The GFS model brings the Nor’easter to a point off the New Jersey coast about 12 hours faster than the ECMWF model.


Figure 2. Forecast track error for four of our top models used to predict Hurricane Sandy. The GFS model performed the best for 1 – 3 day forecasts, but the European (ECMWF) model far out-performed all models at longer-range 4 – 5 day forecasts. This may be due to the fact the model was able to successfully predict the timing of the arrival of a trough of low pressure over the Eastern U.S. that acted to steer Sandy to the north and then northwest. Image credit: Morris Bender, NOAA/GFDL.

Charities mobilize for Sandy
Sandy’s death toll of 109 in the U.S. makes it the 25th deadliest hurricane in U.S. history, and the 2nd deadliest since 1972, when Hurricane Agnes killed 122 in the Northeast U.S. The main owners of The Weather Channel have agreed to match donations of up to $1 million to the American Red Cross, with all donations to benefit people in the hard-hit areas of the U.S. To have your donation matched, please visit www.redcross.org/sandy, or text SANDY to 90999. I also recommend my favorite disaster relief charity, Portlight.org. They are focusing their response efforts exclusively on the post-Sandy needs of people with disabilities.Check out the Portlight blog to see what they’re up to. Sandy’s greatest devastation occurred in Haiti, where rains of up to 20 inches in 24 hours unleashed rampaging flood waters that killed at least 54, left 200,000 homeless, wiped out thousand of acres of crops, and killed massive numbers of livestock. For impoverished families in Haiti still struggling to recover from the earthquake in 2010 and Hurricane Isaac in August, Sandy was devastating. These crops are the very essence of rural Haitian’s livelihoods, and there are fears widespread starvation will result. A disaster relief charity in Haiti that I’ve contributed to for many years, The Lambi Fund of Haiti, is seeking donations to help farmers purchase local seeds so that they can replant their crops in the wake of this latest terrible Haitian catastrophe.

I’ll have an update Monday, unless there’s some major change in the model forecasts for the coming Nor’easter.

from:    http://www.wunderground.com/blog/JeffMasters/article.html

The Toll Of Hurricane Sandy

Sandy by the numbers: trying to comprehend a stunning disaster

Published: 7:19 PM GMT on November 01, 2012

The immensity of the impact of Superstorm Sandy on the Eastern U.S. is difficult to comprehend, and the scenes of devastation coming from the impact zone are stunning and heart-wrenching. To help understand the extraordinary scale of this historic storm, I’ve put together a list of notable statistics from Sandy:

Death toll: 160 (88 in the U.S., 54 in Haiti, 11 in Cuba)

Damage estimates: $10 – $55 billion

Power outages: 8.5 million U.S. customers, 2nd most for a natural disaster behind the 1993 blizzard (10 million)

Maximum U.S. sustained winds: 69 mph at Westerly, RI

Peak U.S. wind gusts: 90 mph at Islip, NY and Tompkinsville, NJ

Maximum U.S. storm surge: 9.45′, Bergen Point, NJ 9:24 pm EDT October 29, 2012

Maximum U.S. Storm Tide: 14.60′, Bergen Point, NJ, 9:24 pm EDT October 29, 2012

Maximum wave height: 33.1′ at the buoy east of Cape Hatteras, NC (2nd highest: 32.5′ at the Entrance to New York Harbor)

Maximum U.S. rainfall: 12.55″, Easton, MD

Maximum snowfall: 36″, Richwood, WV

Minimum pressure: 945.5 mb, Atlantic City, NJ at 7:24 pm EST, October 29, 2012. This is the lowest pressure measured in the U.S., at any location north of Cape Hatteras, NC (previous record: 946 mb in the 1938 hurricane on Long Island, NY)

Destructive potential of storm surge: 5.8 on a scale of 0 to 6, highest of any hurricane observed since 1969. Previous record: 5.6 on a scale of 0 to 6, set during Hurricane Isabel of 2003.

Diameter of tropical storm-force winds at landfall: 945 miles

Diameter of ocean with 12′ seas at landfall: 1500 miles


Figure 1. The Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite acquired this image of Superstorm Sandy around 3:35 a.m. Eastern Daylight Time (7:35 Universal Time) on October 30. This image is from the “day-night band” on VIIRS, which detects light wavelengths from green to near-infrared. The full Moon lit up the tops of the clouds. Image credit: NASA.


Figure 2. Preliminary death and damage statistics for Sandy as compiled by Wikipedia on November 1, 2012.


Figure 3. Precipitation from Superstorm Sandy for the 7-day period ending at 8 am EDT Thursday, November 1, 2012. Image credit: NOAA/NWS/AHPS.


Figure 4. Top five weather-related power outages in the U.S.


Figure 5. Strong winds from Sandy blow snow in West Virginia on October 30, 2012. Image credit: Facebook/Cheryl Clay

Sandy’s snows
Several cities set records for snowiest October day on record during Sandy: Elkin, WV (7″, previous record, 4.6″ in 1917) and Bluefield (4.7″, previous record 3.2″ in 1993.) Heavy snows caused roof collapses in West Virginia, and snows of two feet or more fell in four states–West Virginia, Tennessee, Maryland, and Virginia. However, Sandy fell short of setting the all-time record for snowfall from a hurricane. The Vermont Journal estimated that the Snow Hurricane of 1804 dumped up to 4 feet of snow in Vermont.

36″ Richwood, WV
34″ Mount Leconte, TN
34″ Sevier, TN
33″ Clayton, WV
32″ Snowshoe, WV
29″ Quinwood, WV
28″ Frostburg, WV
28″ Davis, WV
28″ Huttonsville, WV
28″ Flat Top, WV
26″ Redhouse, MD
26″ Garret, MD
26″ Craigsville, WV
24″ Oakland, MD
24″ Alpine Lake, WV
24″ Nettie, WV
24″ Norton, VA
24″ Quinwood, WV
24″ Alexander, WV

Links
Impressive loop of 1-minute visible satellite imagery spanning 6 days of Sandy’s life.

A one-day time lapse video from a New York City webcam showing Sandy’s impact on the city. It’s eerie to see the city suddenly plunged into darkness.

First round of damage assessment aerial imagery collected by NOAA’s National Geodetic Survey on Oct. 31 along the New Jersey coast.


Figure 6. Flooding in Haiti from Hurricane Sandy. Image credit: The Lambi Fund of Haiti.

Charities mobilize for Sandy
The outpouring of charitable donations in the wake of the devastation wrought by Hurricane Sandy has been one of the bright spots in the gloomy aftermath of the storm. The main owners of The Weather Channel have agreed to match donations of up to $1 million to the American Red Cross, if you text SANDY to 90999 ($10). I also recommend my favorite disaster relief charity, Portlight.org. They are focusing their response efforts exclusively on the post-Sandy neeeds of people with disabilities.Check out the Portlight blog to see what they’re up to; donations are always needed.

Sandy’s greatest devastation occurred in Haiti, where rains of up to 20 inches in 24 hours unleashed rampaging flood waters that killed at least 54, left 200,000 homeless, wiped out thousand of acres of crops, and killed massive numbers of livestock. For impoverished families in Haiti still struggling to recover from the earthquake in 2010 and Hurricane Isaac in August, Sandy was devastating.  These crops are the very essence of rural Haitian’s livelihoods, and there are fears widespread starvation will result. A disaster relief charity in Haiti that I’ve contributed to for many years, The Lambi Fund of Haiti, is seeking donations to help farmers purchase local seeds so that they can replant their crops in the wake of this latest terrible Haitian catastrophe.

from:    http://www.wunderground.com/blog/JeffMasters/article.html

Dr. Jeff Masters on Sandy’s Trek IntoNew Jersey

Why did Hurricane Sandy take such an unusual track into New Jersey?

Published: 4:33 PM GMT on October 31, 2012

We’re used to seeing hurricane-battered beaches and flooded cities in Florida, North Carolina, and the Gulf Coast. But to see these images from the Jersey Shore and New York City in the wake of Hurricane Sandy is a shocking experience. New Jersey only rarely gets hit by hurricanes because it lies in a portion of the coast that doesn’t stick out much, and is too far north. How did this happen? How was a hurricane able to move from southeast to northwest at landfall, so far north, and so late in hurricane season? We expect hurricanes to move from east to west in the tropics, where the prevailing trade winds blow that direction. But the prevailing wind direction reverses at mid-latitudes, flowing predominately west-to-east, due to the spin of the Earth. Hurricanes that penetrate to about Florida’s latitude usually get caught up in these westerly winds, and are whisked northeastwards, out to sea. However, the jet stream, that powerful band of upper-atmosphere west-to-east flowing air, has many dips and bulges. These troughs of low pressure and ridges of high pressure allow winds at mid-latitudes to flow more to the north or to the south. Every so often, a trough in the jet stream bends back on itself when encountering a ridge of high pressure stuck in place ahead of it. These “negatively tilted” troughs have winds that flow from southeast to northwest. It is this sort of negatively tilted trough that sucked in Sandy and allowed the hurricane to take such an unusual path into New Jersey.


Figure 1. Inlet section of Atlantic City, N.J., after Hurricane Sandy. Image credit: 6 ABC Action News.

The 1903 Vagabond Hurricane
The only other hurricane to hit New Jersey since 1851 besides Sandy was the 1903 Category 1 Vagabond Hurricane. According to Wikipedia, the Vagabond Hurricane caused heavy damage along the New Jersey coast ($180 million in 2006 dollars.) The hurricane killed 57 people, and endangered the life of President Theodore Roosevelt, who was sailing on a yacht near Long Island, NY, when the hurricane hit. However, the Vagabond Hurricane hit in September, when the jet stream is typically weaker and farther to the north. It is quite extraordinary that Sandy was able to hit New Jersey in late October, when the jet stream is typically stronger and farther south, making recurvature to the northeast much more likely than in September.


Figure 2. The path of the 1903 Vagabond Hurricane, the only other hurricane to hit New Jersey since 1851.

The blocking ridge that steered Sandy into New Jersey
A strong ridge of high pressure parked itself over Greenland beginning on October 20, creating a “blocking ridge” that prevented the normal west-to-east flow of winds over Eastern North America. Think of the blocking ridge like a big truck parked over Greenland. Storms approaching from the west (like the fall low pressure system that moved across the U.S. from California to Pennsylvania last week) or from the south (Hurricane Sandy) were blocked from heading to the northeast. Caught in the equivalent of an atmospheric traffic jam, the two storms collided over the Northeast U.S., combined into one, and are now waiting for the truck parked over Greenland to move. The strength of the blocking ridge, as measured by the strength of the North Atlantic Oscillation (NAO), was quite high–about two standard deviations from average, something that occurs approximately 5% of the time. When the NAO is in a strong negative phase, we tend to have blocking ridges over Greenland.


Figure 3. Jet stream winds at a pressure of 300 mb on October 29, 2012, as Hurricane Sandy approached the coast of New Jersey. Note that the wind direction over New Jersey (black arrows) was from the southeast, due to a negatively tilted trough of low pressure over the Eastern U.S. caused by a strong blocking ridge of high pressure over Greenland. Image credit: NOAA/ESRL.

Arctic sea ice loss can cause blocking ridges
Blocking ridges occur naturally, but are uncommon over Greenland this time of year. According to NOAA’s Climate Prediction Center, blocking near the longitude of Greenland (50°W) only occurs about 2% of the time in the fall. These odds rise to about 6% in winter and spring. As I discussed in an April post, Arctic sea ice loss tied to unusual jet stream patterns, three studies published in the past year have found that the jet stream has been getting stuck in unusually strong blocking patterns in recent years. These studies found that the recent record decline in Arctic sea ice could be responsible, since this heats up the pole, altering the Equator-to-pole temperature difference, forcing the jet stream to slow down, meander, and get stuck in large loops. The 2012 Arctic sea ice melt season was extreme, with sea ice extent hitting a record lows. Could sea ice loss have contributed to the blocking ridge that steered Sandy into New Jersey? It is possible, but we will need to much more research on the subject before we make such a link, as the studies of sea ice loss on jet stream patterns are so new. The author of one of the new studies, Dr. Jennifer Francis of Rutgers, had this say in a recent post by Andy Revkin in his Dot Earth blog: “While it’s impossible to say how this scenario might have unfolded if sea-ice had been as extensive as it was in the 1980s, the situation at hand is completely consistent with what I’d expect to see happen more often as a result of unabated warming and especially the amplification of that warming in the Arctic.”

from:    http://www.wunderground.com/blog/JeffMasters/article.html

Destructive POtential of Hurricane Sandy

Hurricane Sandy pounding Jamaica, may hit U.S. this weekend; TS Tony forms

Published: 2:21 PM GMT on October 24, 2012

Hurricane warnings are flying for Jamaica and Eastern Cuba, as an intensifying Hurricane Sandy plows north-northeast at 13 mph towards landfall. The Hurricane Hunters are in the storm, and measured surface winds of hurricane strength–75 to 80 mph–in the storm’s northeast quadrant near 9:25 am EDT. Sandy’s pressure at the time of the 9:28 am center fix was 973 mb, and the temperature in the eye had warmed 2°C since the 7:48 am fix, a sign of strengthening. Intermittent rain squalls from Sandy have been affecting Jamaica since Monday night, and Kingston, Jamaica has picked up 2.12″ of rain from Sandy as of 9 am EDT. Winds in Jamaica have been below 20 mph as of 10 am EDT, but will start to rise quickly in the next few hours. The Hurricane Hunters found a large 55 mile-diameter eye that was open to the WNW this morning, and it is likely that Kingston will receive high winds of 55 – 65 mph from the western eyewall, which will cause considerable damage to Jamaica’s capital. The eastern tip of Jamaica will likely see the eye pass overhead, and will receive the strongest winds. The eye is beginning to appear on visible satellite loops, and Sandy is showing an increasing degree of organization as it closes in on Jamaica. Sandy is the tenth hurricane of the 2012 hurricane season, which is now tied for eighth place for most hurricanes in a year since record keeping began in 1851.


Figure 1. Morning microwave satellite image of Tropical Storm Sandy taken at 8:45 am EDT. The large 55-mile diameter eye was just south of Jamaica. Image credit: Navy Research Lab, Monterey.

Near-term forecast for Sandy
Wind shear is forecast to be in the moderate range and ocean temperatures will be a warm 28°C through Thursday morning, which will favor intensification. However, Sandy doesn’t have much time left over water before it encounters the high mountains of Jamaica this afternoon, which should interrupt the intensification process. The strongest Sandy is likely to be at landfall in Jamaica is a 90 mph Category 1 hurricanes. After encountering Jamaica, Sandy won’t have time to re-organize much before making landfall in Eastern Cuba near 10 pm EDT tonight, and the strongest the storm is likely to be then is a 90 mph Category 1. Passage over the rugged terrain of Cuba should weaken Sandy’s winds by 20 – 30 mph, and it will be difficult for the storm to regain all of that lost strength in the face of the high wind shear of 20 – 30 knots it will encounter Thursday and Friday. I expect that Sandy will be a 60 – 70 mph tropical storm as it traverses the Bahamas.


Figure 2. MODIS satellite image of Tropical Storm Sandy taken at 11:45 am EDT Tuesday, October 23, 2012. At the time, Sandy had top winds of 50 mph. Image credit: NASA.

Sandy: a potential billion-dollar storm for the mid-Atlantic and New England
On Friday, a very complicated meteorological situation unfolds, as Sandy interacts with a trough of low pressure approaching the U.S. East Coast and trough of low pressure over the Central Atlantic. The Central Atlantic trough may be strong enough to pull Sandy northeastwards, out to sea, as predicted by the official NHC forecast, and the 06Z GFS, 00Z UKMET, 00Z Canadian, and 06Z HWRF models (00Z is 8 pm EDT, and 06Z is 2 am EDT.) However, an alternative solution, shown by the 00Z ECMWF, 06Z GFDL, and 06Z NOGAPS models, is for Sandy to get caught up by the trough approaching the Eastern U.S., which will inject a large amount of energy into Sandy, converting it to a powerful subtropical storm that hits the mid-Atlantic or New England early next week with a central pressure below 960 mb and sustained winds of 60 – 70 mph. Such a storm would likely cause massive power outages and over a billion dollars in damage, as trees still in leaf take out power grids, and heavy rains and coastal storm surges create damaging flooding. The full moon is on Monday, which means astronomical tides will be at their peak for the month, increasing potential storm surge flooding. A similar meteorological situation occurred in October 1991, when Hurricane Grace became absorbed by a Nor’easter, becoming the so-called “Perfect Storm” that killed 13 people and did over $200 million in damage in the Northeast U.S.


Figure 3. The Wednesday morning 06Z (2 am EDT) run of the GFS model was done 20 times at lower resolution with slightly varying initial conditions of temperature, pressure, and moisture to generate an ensemble of forecast tracks for Sandy (pink lines). These forecasts show substantial uncertainty in Sandy’s path after Friday, with a minority of the forecasts taking Sandy to the northeast, out to sea, and the majority now predicting a landfall in the Northeast or mid-Atlantic states of the U.S. The white line shows the official GFS forecast, run at higher resolution.

When might Sandy arrive in the mid-Atlantic and New England?
The models vary significantly in their predictions of when Sandy might arrive along the U.S. coast. The 06Z NOGAPS model predicts Sandy’s heavy rains will arrive on North Carolina’s Outer Banks on Saturday, then spread into the mid-Atlantic and New England on Sunday. The 00Z ECMWF model predicts that Sandy’s rains won’t affect North Carolina until Sunday, with the storm making landfall in New Jersey on Monday night. The GFDL model is in-between these extremes, taking Sandy ashore in Delaware on Monday morning. The trough of low pressure that Sandy will be interacting with just moved ashore over the Western U.S. this morning, and got sampled by the 12Z (8 am EDT) set of land-based balloon-borne radiosondes for the first time. One of the reasons the models have been in such poor agreement on the long-term fate of Sandy is that the strength of this trough has not been very well known, since it has been over the ocean where we have limited data. Now that the trough is over land, it will be better sampled, and the next set of 12Z model runs, due out this afternoon between 2 pm – 4pm EDT, will hopefully begin to converge on a common solution. I’ll have an update this afternoon once the 12Z model runs are in.


Figure 4. Morning satellite image of Tropical Storm Tony.

Tropical Storm Tony forms in the middle Atlantic
Tropical Storm Tony formed Tuesday night in the middle Atlantic, becoming the nineteenth named storm of this very busy 2012 Atlantic hurricane season. Tony has a modest area of heavy thunderstorms, as seen on visible satellite images, but is battling dry air , wind shear, and ocean temperatures that have fallen below 26°C. Tony will not threaten any land areas, and will likely be dead by Thursday night.

Tony’s place in history
Tony is the Nineteenth named storm of the 2012 Atlantic hurricane season, tying this year with 1887, 1995, 2010, and 2011 for third busiest Atlantic season since the HURDAT historical data base began in 1851. With five more weeks left before the November 30 end of hurricane season, 2012 is likely to move into second place for most named storms before the year is out, as all six prior Atlantic hurricane seasons with nineteen or more named storms have had at least one named storm form after October 24. Here, then, is a list of the seven busiest Atlantic hurricane seasons on record:

2005 (28 named storms)
1933 (20 named storms, according to a new re-analysis)
2012 (19 named storms)
1887 (19 named storms)
2010 (19 named storms)
2011 (19 named storms)
1995 (19 named storms)

It’s pretty remarkable that we’ve now had three straight years with nineteen named storms in the Atlantic. But how many of these storms might not have been counted in the pre-satellite era (before 1960)? Here’s a list of weak and short-lived storms from 2010 – 2012 that stayed far out sea, and would likely have gone unnoticed in the pre-satellite era:

2012:
Tropical Storm Joyce
Tropical Storm Oscar
Tropical Storm Tony

2011:
Tropical Storm Jose
Tropical Storm Franklin

2010:
Tropical Storm Gaston

Even if we correct for the possible over-count of approximately two named storms per year during the 2010, 2011, and 2012 hurricane seasons, compared to the pre-satellite era, there is nothing in the HURDAT data base that compares to the type of activity we’ve seen the past three years. One likely contributor to the unusual string of active years is the fact hurricane season has gotten longer, perhaps due to warming ocean temperatures. I discussed in a 2008 blog post that Dr. Jim Kossin of the University of Wisconsin published a 2008 paper in Geophysical Research Letters titled, “Is the North Atlantic hurricane season getting longer?” He concluded that yes, there is a “apparent tendency toward more common early- and late-season storms that correlates with warming Sea Surface Temperature but the uncertainty in these relationships is high”.

Jeff Mastersfrom:    http://www.wunderground.com/blog/JeffMasters/article.html