Hurricanes and Climate Change: Huge Dangers, Huge Unknowns

By: Dr. Jeff Masters , 9:57 AM GMT on August 05, 2013

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Hurricane Sandy's enormous $65 billion price tag put that great storm in third place for the most expensive weather-related disaster in U.S. (and world) history, and six of the ten most expensive U.S. weather-related disasters since 1980 have been hurricanes. Thus, how the strongest hurricanes may be affected due a changing climate is a topic of critical concern. Since hurricanes are heat engines that extract heat energy from the oceans to power themselves, hurricane scientists are confident that the very strongest storms will get stronger by the end of the century, when Earth's land and ocean temperatures are expected to warm 2 - 3°C, to levels unmatched since the Eemian Era, 115,000 years ago. Computer modeling work consistently indicates that greenhouse warming will cause the globally averaged intensity of tropical cyclones to shift towards stronger storms, with intensity increases of 2–11% by 2100. But hurricanes are fussy creations, and are sensitive to wind shear and dry air. Although the strongest storms should get stronger when "perfect storm" conditions are present, these "perfect storm" conditions may become less frequent in the future, due to the presence of higher wind shear, altered atmospheric circulation patterns, or more dry air at mid levels of the atmosphere. Indeed, the climate models used to formulate the 2007 IPCC report suggested that we might see the strongest hurricanes getting stronger, but a decrease in the total number of hurricanes in the Atlantic (and worldwide) later this century. However, the latest set of models used to formulate the 2013 IPCC report left open the possibility that we might see in increase in the total number of hurricanes, and and increase in their intensity. Given the conflicting model results, we really don't know how global warming will affect the number of hurricanes and their intensity, but we run the risk of making one of humanity's greatest scourges worse.


Figure 1. The list of most expensive U.S. weather-related disasters since 1980 is dominated by hurricanes.

Climate models and hurricane frequency
The database we have on historical hurricanes does not extend far enough into the past and is not of high enough quality to make many judgements on how human-caused climate change may be affecting these great storms. A landmark 2010 review paper, "Tropical Cyclones and Climate Change", authored by ten top hurricane scientists concluded that the U.S. has not seen any long-term increase in landfalling tropical storms and hurricanes, and that "it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes" (tropical cyclone is the generic term which encompasses tropical depressions, tropical storms, hurricanes, and typhoons.) Based in part on modeling studies using climate models run for the 2007 IPCC report, the scientists concluded that "it is likely that global mean tropical cyclone frequency will either decrease or remain unchanged owing to greenhouse warming." For example, one of the modeling studies the review paper quoted, Knutson et al. (2008), "Simulated reduction in Atlantic hurricane frequency under twenty-first-century warming conditions", projected a decrease in Atlantic tropical storms by 27% and hurricanes by 18% by the end of the century. An important reason that their model predicted these decreases was due to a predicted increase in wind shear. As I explain in my wind shear tutorial, a large change of wind speed with height over a hurricane creates a shearing force that tends to tear the storm apart. The amount of wind shear is critical in determining whether a hurricane can form or survive.

But a July 2013 study by MIT's Dr. Kerry Emanuel, "Downscaling CMIP5 climate models shows increased tropical cyclone activity over the 21st century", challenged this result. Dr. Emanuel argued that tropical cyclones are likely to become both stronger and more frequent as the climate continues to warm. This increase is most likely to occur in Western North Pacific, with smaller increases in the Atlantic. Dr. Emanuel took output from six newer higher-resolution climate models used to formulate the 2013 IPCC report, and used the output to drive a high-resolution hurricane model. The simulations found that the global frequency of tropical cyclones would increase by 11% to 40% by 2100, with intensity increases as well. The combined effects produced a global increase in Category 3 and stronger hurricanes of 40%. The behavior of these strongest hurricanes is critical, since they do most of the damage we observe. Over the past century, Category 3 - 5 hurricanes accounted for 85% of US hurricane damage, despite representing only 24% of U.S. landfalling storms. Category 4 and 5 hurricanes made up only 6% of all U.S. landfalls, but accounted for 48% of all U.S. damage (if normalized to account for increases in U.S. population and wealth, see Pielke et al., 2008.)


Figure 2. Projected changes in tropical cyclone track density during the 2006-2100 period compared to the 1950-2005 period, using output from six climate models included in the 2013 IPCC report. The global frequency of tropical cyclones is predicted to increase by 11% to 40%, with the largest changes occurring in the Northwest Pacific off the coast of Japan. Smaller increases are predicted for the Atlantic and near Australia. Image credit: Kerry Emanuel, "Downscaling CMIP5 climate models shows increased tropical cyclone activity over the 21st century", Proceedings of the National Academy of Sciences, July 8, 2013, doi: 10.1073/pnas.1301293110.

However, a study by Knutson et al. (2013), using the same latest-generation climate models as used by Emanuel (2013), but using the output from the models to drive a different high-resolution hurricane model, found a 20% decrease in Atlantic tropical storms and hurricanes by 2100. Two other 2013 studies by Villarini et al. and Camargo, also using output from the 2013 IPCC models, found essentially no change in Atlantic tropical cyclones. The reason for the differences, lies, in part, with how much global warming is assumed in the studies. Dr. Emanuel's study, which found an increase in tropical cyclone activity, assumed a worst-case warming situation (RCP 8.5), following the "business as usual" emissions path humanity is currently on. The Knutson et al. study, which found a decrease of 20% in Atlantic tropical cyclones, used a scenario (RCP 4.5) where it was assumed humans will wise up and cause about half of the worst-case greenhouse warming. The study found found "marginally significant" increases in Atlantic Category 4 and 5 hurricanes of 39% - 45% by 2100. These dramatically different results give credence to Dr. Emanuel statement at the end of his paper, "the response of tropical cyclones to projected climate change will remain uncertain for some time to come." The 2013 IPCC report also emphasized the high amount of uncertainty in how climate change might affect hurricanes, stating that there was "low confidence" that we have observed any increases in intense tropical cyclones due to human causes. However, since the 1970s, it is virtually certain (99 - 100% chance) that the frequency and intensity of hurricanes and tropical storms in the North Atlantic has increased, and there is medium confidence that a reduction in small air pollution particles (aerosols) over the North Atlantic caused part of this effect. The report's forecast for the future stated that it is "more likely than not" (50 - 100% chance) that human-caused climate change will cause a substantial increase in intense tropical cyclones in some ocean basins by 2100, with the Western North Pacific and Atlantic being at particular risk. Also, there will likely (66 - 100% chance) be an increase in both global mean tropical cyclone maximum wind speed and rain rates by 2100, and more likely than not (50 - 100% chance) that the increase in the most intense tropical cyclones will be larger than 10% in some basins.


Figure 3. Expected change in Atlantic Category 4 and 5 hurricanes per decade expected by the year 2100, according to Knutson et al. (2013), "Dynamical Downscaling Projections of 21st Century Atlantic Hurricane Activity: CMIP3 and CMIP5 Model-based Scenarios." This research used the latest generation of climate models from the 2013 IPCC report, and found "marginally significant" increases in Atlantic Category 4 and 5 hurricanes of 39% - 45% by 2100.

Commentary
Hurricane damages are currently doubling every ten years without the effect of climate change, according to Pielke et al., 2008. This is primarily due to the increasing population along the coast and increased wealth of the population. The authors theorize that the Great Miami Hurricane of 1926, a Category 4 monster that made a direct hit on Miami Beach, would have caused about $150 billion in damage had it hit in 2005. Thus, by 2015, the same hurricane would do $300 billion in damage, and $600 billion by 2025. This is without considering the impact that accelerating sea level rise will have on storm surge damages. Global sea level rise over the past decade has been about double what it was in the 20th century, and the rate of sea level rise is expected to increase further in the coming decades. Storm surge does the majority of damage in major hurricanes, and storm surges riding on top of higher sea levels are going to do a lot more damage in the coming decades. If we toss in the (controversial) increases in Category 3 and stronger storms like Dr. Emanuel suggests may occur, the hurricane damage math gets very impressive. We can also add onto that the relatively non-controversial increase in tropical cyclone rainfall of 20% expected by 2100, which will sharply increase damages due to fresh water river flooding. It is controversial whether or not we are already be seeing an increase in heavy precipitation events associated with tropical cyclones in the U.S., though. The total number of daily rainfall events exceeding 2" associated with tropical cyclones in the Southeast U.S. on a century time scale has not changed significantly, according to Groisman et al., 2004. But a 2010 study by Kunkel et al., "Recent increases in U.S. heavy precipitation associated with tropical cyclones", found that the number of Southeast U.S. tropical cyclone heavy precipitation events, defined as 1-in-5-year events, more than doubled between 1994 - 2008, compared to the long-term average from 1895 - 2008.


Figure 4. Time series of the 15-year running average (plotted at the end point of the 15-yr blocks) of a Tropical Cyclone Heavy Precipitation Index (red) and 15-year running average of U.S. landfalling hurricanes (blue). Note that there has been no long-term increase in U.S. landfalling hurricanes, but there has been a sharp increase in extreme rainfall events associated with landfalling tropical cyclones--the kind of rainfall events most likely to cause damaging flooding. Image credit: Kunkel et al. (2010), "Recent increases in U.S. heavy precipitation associated with tropical cyclones", Geophysical Research Letters.

It is essential that we limit coastal development in vulnerable coastal areas, particularly along barrier islands, to reduce some of the astronomical price tags hurricanes are going to be causing in the future. Adoption and enforcement of strict building standards is also a must, as well as more reforms to the government's National Flood Insurance Program (NFIP), which subsidizes development in high-risk coastal regions that private insurers won't touch. NFIP is now $25 - 30 billion in the red, thanks to Hurricane Katrina and Hurricane Sandy. Reform of NFIP is already underway. In 2012, before Sandy hit, Congress passed the Biggert-Waters Flood Insurance Reform Act, which requires people with NFIP policies to pay large premium increases of about 25% per year over the next five years. Naturally, this move has caused major controversy.

References
Camargo, S., (2013), "Global and regional aspects of tropical cyclone activity in the CMIP5 models," J. Climate.

Emanuel, K.A., 2013, "Downscaling CMIP5 climate models shows increased tropical cyclone activity over the 21st century", PNAS, July 8, 2013, doi: 10.1073/pnas.1301293110

Groisman, Pavel Ya, et al., "Contemporary changes of the hydrological cycle over the contiguous United States: Trends derived from in situ observations," Journal of Hydrometeorology 5.1 (2004): 64-85.

Knutson et al., 2010, "Tropical Cyclones and Climate Change", Nature Geoscience 3, 157 - 163, Published online: 21 February 2010 | doi:10.1038/ngeo779

Knutson et al., 2013, Dynamical Downscaling Projections of 21st Century Atlantic Hurricane Activity: CMIP3 and CMIP5 Model-based Scenarios, Journal of Climate 2013 ; e-View
doi: http://dx.doi.org/10.1175/JCLI-D-12-00539.1

Pielke, R.A, et al., 2008, "Normalized Hurricane Damage in the United States: 1900 - 2005," Natural Hazards Review, DOI:10.1061/ASCE1527-6988(2008)9:1(29)

Villarini, G, and G.A. Vecchi, 2012, "Twenty-first-century projections of North Atlantic tropical storms from CMIP5 models," Nature Clim. Change 2:604–607.

Related posts
Global warming and the frequency of intense Atlantic hurricanes: model results, my 2010 blog post.

Climate Central's analysis of the new 2013 Kerry Emanuel paper.

Goodbye, Miami: Jeff Goodell's sobering 2013 article in Rolling Stone on the challenges Miami faces due to sea level rise and hurricanes.


What the official climate assessments say about climate change and hurricanes
The 2013 IPCC report gives “low confidence”--a 20% chance--that we have observed a human-caused increase in intense hurricanes in some parts of the world. This is a reduction in odds from the 2007 report, which said that it was more likely than not (greater than 50% chance.) The IPCC likely took note of a landmark 2010 review paper, "Tropical Cyclones and Climate Change", authored by ten top hurricane scientists, which concluded that the U.S. had not seen any long-term increase in landfalling tropical storms and hurricanes, and that "it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes." The 2013 IPCC report predicts that there is a greater than 50% chance (more likely than not) that we will see a human-caused increase in intense hurricanes by 2100 in some regions; this is also a reduction from the 2007 report, which said this would be likely (66% chance or higher.)

The May 2014 United States National Climate Assessment found that “The intensity, frequency, and duration of North Atlantic hurricanes, as well as the frequency of the strongest (Category 4 and 5) hurricanes, have all increased since the early 1980s. The relative contributions of human and natural causes to these increases are still uncertain. Hurricane-associated storm intensity and rainfall rates are projected to increase as the climate continues to warm.”

Jeff Masters

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Quoting 138. GTstormChaserCaleb:
That is the empirical model which is based on climatology and if things were to propagate in a perfect manner. I was told to use the GFS or Euro MJO forecast.



GT, is that GOM potential home-grown? Or is it a long-tracker?
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The TPW (click to enlarge). The upwelling at Pottery's doorsteps (or the Caribbean) looks a bit suspicious...
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Quoting 162. gator23:


I feel it got kicked off with Chantal


Only difference was that she dissipated before hitting land.
Member Since: July 27, 2013 Posts: 0 Comments: 501
Quoting 161. Jedkins01:
Let's hope the climate models are wrong, that doesn't bode well for us coastal Floridians, add that to sea level rise and yikes :/


Except for Central America, it doesn't look good for anybody! And outside of creating State or National parks, you can forget about stopping people from moving towards the coast, money goes where money wants.
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Quoting 159. mitchelace5:


What about in the Atlantic?
The MJO travels East. It will get to the Atlantic after the Caribbean.
Member Since: August 2, 2011 Posts: 0 Comments: 2044
"GIL HAS BEEN MAINTAINING ENOUGH DEEP CONVECTION OVER THE PAST 6-12
HOURS TO RESET THE REMNANT LOW CLOCK BACK TO ZERO..."

Lol, James.
Member Since: July 6, 2010 Posts: 113 Comments: 32277

Next wave of thunderstorm attacks is developing in France (near Lyon). Will it reach me tonight? I'm sitting somewhere in the upper right section of the animation, lol. BBL.


Details see discusson on estofex.org
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Quoting 67. StormTrackerScott:


That is one impressive wave over C Africa! Could that kick off the Cape Verde season? Well time will tell.


I feel it got kicked off with Chantal
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Let's hope the climate models are wrong, that doesn't bode well for us coastal Floridians, add that to sea level rise and yikes :/
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Don't forget to Box or Wheel your Trifecta

and yes all you master's snobs...this is all about the tropics

box ....refers to heberts box...

wheel of course is the spin of a tropical system...

and trifecta...is the cycle of a tropical system....from td....to tropical storm......to hurricane
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Quoting 157. unknowncomic:
When it hits there switch in activity may go on.


What about in the Atlantic?
Member Since: July 27, 2013 Posts: 0 Comments: 501
Quoting 155. ricderr:
MP....give me my crystal ball back......i need to know who will win in the 7th at sunland park today


Don't forget to Box or Wheel your Trifecta
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Quoting 151. GTstormChaserCaleb:
No orange is downward motion and green is upward motion. May in fact get a system in the Western Caribbean, GOM, or BOC before we see development in the far eastern Atlantic.
When it hits there switch in activity may go on.
Member Since: August 2, 2011 Posts: 0 Comments: 2044
Quoting 151. GTstormChaserCaleb:
No orange is downward motion and green is upward motion. May in fact get a system in the Western Caribbean, GOM, or BOC before we see development in the far eastern Atlantic.

Got it. re-reads post 134 *facepalm*...
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MP....give me my crystal ball back......i need to know who will win in the 7th at sunland park today
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Quoting 138. GTstormChaserCaleb:
That is the empirical model which is based on climatology and if things were to propagate in a perfect manner. I was told to use the GFS or Euro MJO forecast.

Big boost in moisture in Africa Aug 18th.
Member Since: August 2, 2011 Posts: 0 Comments: 2044
Quoting 143. GTstormChaserCaleb:
Not a strong one, but in octants 1 & 8, the Atlantic is 8 right?



That's correct.
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Quoting 149. ricderr:
And who says we can't predict 7 days out......


now when you can FORECAST 7 days out....give me a call....well actually...you won't have time...because noaa and such will be calling you....

most on here are predictors....funny thing is...they're usually more accurate than forecasters for the simple reason...predictors base theirs on the conclusions of everyone else as forecasters make their own conclusions on the data provided


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Quoting 147. DrMickey:

So based on this forecast, the MJO is at its peak in the Carribean today.
No orange is downward motion and green is upward motion. May in fact get a system in the Western Caribbean, GOM, or BOC before we see development in the far eastern Atlantic.
Member Since: June 30, 2013 Posts: 12 Comments: 8436
Quoting 114. opal92nwf:
Well that's not good for where I live in the FL Panhandle

I so disagree with this.... We will always have a chance of a Cat4 - Cat5 in the Atlantic, GOM and or E Pacific on any given Hurricane Season Year.... I just don't think that The GOM will produce more Cat4-Cat5s than the Atlantic....Now I understand that some years (05) are not normal, but how many storms were not counted before Technology was even around????? Now this is just "My" opinion and how I see this.... I do believe this is a cycle and not GW...

Taco :o)
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And who says we can't predict 7 days out......


now when you can FORECAST 7 days out....give me a call....well actually...you won't have time...because noaa and such will be calling you....

most on here are predictors....funny thing is...they're usually more accurate than forecasters for the simple reason...predictors base theirs on the conclusions of everyone else as forecasters make their own conclusions on the data provided
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Quoting 144. Bluestorm5:
That make sense and explain why EPAC is active right now. I didn't know about this model. Where did you find it?
Link...scroll down and you will see Global Forecast System right next to the Empirical Wave Propagation.
Member Since: June 30, 2013 Posts: 12 Comments: 8436
Quoting 138. GTstormChaserCaleb:
That is the empirical model which is based on climatology and if things were to propagate in a perfect manner. I was told to use the GFS or Euro MJO forecast.


So based on this forecast, the MJO is at its peak in the Carribean today.
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TROPICAL DEPRESSION GIL DISCUSSION NUMBER 25
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072013
800 AM PDT MON AUG 05 2013

GIL HAS BEEN MAINTAINING ENOUGH DEEP CONVECTION OVER THE PAST 6-12
HOURS TO RESET THE REMNANT LOW CLOCK BACK TO ZERO...AND A PAIR OF
ASCAT PASSES AROUND 07Z SUGGEST THAT THE SYSTEM STILL HAS WINDS OF
25-30 KT. THE ASCAT PASSES WERE ALSO HELPFUL IN ESTABLISHING THE
CENTER POSITION AND INITIAL MOTION...NOW ESTIMATED AT 250/7...AND
SUGGEST THAT THE CENTER IS WELL EMBEDDED IN THE CONVECTION.

ALTHOUGH THE ENVIRONMENTAL THERMODYNAMICS ARE NOT CONDUCIVE TO
STRENGTHENING...EASTERLY SHEAR IS NOT PROHIBITIVE AND THE
UNDERLYING SSTS OF 27C COULD SUPPORT INTERMITTENT CONVECTION OVER
THE NEXT FEW DAYS. MOST OF THE DYNAMICAL GUIDANCE SUGGESTS A
ROUGHLY STEADY STATE FOR GIL DURING THE FORECAST PERIOD...AND THE
SHIPS AND LGEM SHOW THE SYSTEM ULTIMATELY REGAINING TROPICAL STORM
STATUS. WITH CONVECTION CURRENTLY ACTIVE...THE OFFICIAL FORECAST
DELAYS DEGENERATION TO A REMNANT LOW UNTIL TOMORROW.

THE LATEST TRACK FORECAST ASSUMES A LITTLE MORE INTERACTION WITH A
MID-LEVEL TROUGH AFTER ABOUT 36 HOURS...AS SHOWN BY MOST OF THE
CURRENT DYNAMICAL GUIDANCE...AND IS A LITTLE SLOWER AND TO THE
NORTH OF THE PREVIOUS FORECAST. BASED ON THE CURRENT PROJECTION...
GIL WILL MOVE INTO THE CENTRAL PACIFIC HURRICANE CENTER AREA OF
RESPONSIBILITY FOR THE 06/09Z ADVISORY PACKAGE.


FORECAST POSITIONS AND MAX WINDS

INIT 05/1500Z 13.4N 138.6W 25 KT 30 MPH
12H 06/0000Z 13.0N 139.6W 25 KT 30 MPH
24H 06/1200Z 12.6N 140.9W 25 KT 30 MPH
36H 07/0000Z 12.5N 142.4W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 07/1200Z 12.5N 144.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 08/1200Z 13.0N 147.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 09/1200Z 13.5N 151.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 10/1200Z 14.0N 155.0W 20 KT 25 MPH...POST-TROP/REMNT LOW

$$
FORECASTER FRANKLIN

Member Since: April 29, 2009 Posts: 75 Comments: 14332

Anyone feel like they are about to check into this resort as the season ramps up very soon.
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Quoting 138. GTstormChaserCaleb:
That is the empirical model which is based on climatology and if things were to propagate in a perfect manner. I was told to use the GFS or Euro MJO forecast.

That make sense and explain why EPAC is active right now. I didn't know about this model. Where did you find it?
Member Since: August 1, 2011 Posts: 28 Comments: 8030
Not a strong one, but in octants 1 & 8, the Atlantic is 8 right?

Member Since: June 30, 2013 Posts: 12 Comments: 8436
Katrina 2005:

Your US Dollar Conversion:

Monday, 5 August 2013

The deflator index for 2013 is 106.2 and for 2005 it is 91.991 (US Dollar Implicit Price Deflators for Gross Domestic Product 1929-2013, 2009=100, BEA). It follows that, with numbers rounded to two decimals:

149,000,000,000.00 US Dollars of 2013 are worth 129,064,585,628.32 US Dollars of 2005.

USD GDP Deflator <---

Wow...in just 8 years $129B goes to $149B..insane

Let's do Andrew 1992:


Your US Dollar Conversion:

Monday, 5 August 2013

The deflator index for 2013 is 106.2 and for 1992 it is 70.644 (US Dollar Implicit Price Deflators for Gross Domestic Product 1929-2013, 2009=100, BEA). It follows that, with numbers rounded to two decimals:

45,000,000,000.00 US Dollars of 2013 are worth 29,933,897,975.60 US Dollars of 1992.

wow..now Sandy 2012:

Your US Dollar Conversion:

Monday, 5 August 2013

The deflator index for 2013 is 106.2 and for 2012 it is 105.002 (US Dollar Implicit Price Deflators for Gross Domestic Product 1929-2013, 2009=100, BEA). It follows that, with numbers rounded to two decimals:

65,000,000,000.00 US Dollars of 2013 are worth 64,266,762,002.97 US Dollars of 2012.

WHEW! Look at that! In less than a year! Who figured weather could play a lesson in economics.

USD GDP Deflator
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TROPICAL STORM HENRIETTE DISCUSSION NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL EP082013
800 AM PDT MON AUG 05 2013

SATELLITE IMAGES INDICATE THAT THE OVERALL ORGANIZATION OF THE
TROPICAL CYCLONE HAS IMPROVED THIS MORNING. A BAND OF DEEP
CONVECTION NOW WRAPS AROUND THE SOUTH AND EAST PORTIONS
OF THE CIRCULATION AND BASED ON THE IMPROVED ORGANIZATION...
THE INITIAL INTENSITY IS RAISED TO 50 KT...A CONSENSUS
OF SUBJECTIVE AND OBJECTIVE DVORAK ESTIMATES.

HENRIETTE IS MOVING SLOWLY WESTWARD OR 270/4 KT. THE RIDGE TO THE
NORTH OF THE CYCLONE IS FORECAST TO CONTINUE WEAKENING IN RESPONSE
TO A MID- TO UPPER-LEVEL TROUGH THAT IS DEEPENING WELL WEST OF THE
COAST OF THE WESTERN UNITED STATES. THIS SHOULD CAUSE HENRIETTE TO
TURN WEST-NORTHWESTWARD LATER TODAY AND REMAIN ON THIS GENERAL
HEADING FOR THE NEXT 2 TO 3 DAYS. THE TRACK GUIDANCE ENVELOPE HAS
SHIFTED NORTHWARD THROUGH 48 HOURS. THE OFFICIAL FORECAST HAS
BEEN ADJUSTED IN THAT DIRECTION AND NOW LIES ON THE SOUTHERN EDGE OF
THE GUIDANCE ENVELOPE. AFTER 72 HOURS...THE TROUGH IS FORECAST
TO LIFT OUT WITH THE RIDGE BUILDING WESTWARD ONCE AGAIN. AS A
RESULT...HENRIETTE SHOULD TURN WESTWARD AND STAY ON THAT GENERAL
HEADING DURING THE 3- TO 5-DAY TIME PERIOD.

THE ENVIRONMENT AHEAD OF HENRIETTE APPEARS FAVORABLE FOR
STRENGTHENING DURING THE NEXT DAY OR SO. MODERATE EASTERLY SHEAR
THAT IS CURRENTLY OVER THE CYCLONE SHOULD DECREASE AS HENRIETTE
MOVES BENEATH AN UPPER-LEVEL RIDGE AXIS. DURING THAT TIME...THE
CYCLONE WILL BE OVER WARM WATERS...SO STEADY STRENGTHENING IS
ANTICIPATED. IN 36 TO 48 HOURS...HENRIETTE IS FORECAST TO CROSS
A TONGUE OF COOLER WATERS...WHICH IS LIKELY TO HALT THE
INTENSIFICATION PROCESS. THE SHEAR IS FORECAST TO REMAIN LIGHT
WHEN THE CYCLONE TURN WESTWARD IN ABOUT 3 DAYS...AND MOVES ALONG
THE 26 DEGREE CELSIUS ISOTHERM. THE COOLER WATERS AND A MORE
STABLE AIRMASS ARE LIKELY TO CAUSE GRADUAL WEAKENING...HOWEVER IF
HENRIETTE MOVES NORTH OF THE FORECAST TRACK IT COULD WEAKEN MUCH
FASTER THAN SHOWN BELOW. CONVERSELY...IF HENRIETTE IS SOUTH OF THE
FORECAST TRACK... THE RATE OF WEAKENING COULD BE SLOWER.



FORECAST POSITIONS AND MAX WINDS

INIT 05/1500Z 12.1N 128.2W 50 KT 60 MPH
12H 06/0000Z 12.6N 129.2W 60 KT 70 MPH
24H 06/1200Z 13.6N 130.7W 65 KT 75 MPH
36H 07/0000Z 14.7N 132.4W 75 KT 85 MPH
48H 07/1200Z 15.6N 134.1W 70 KT 80 MPH
72H 08/1200Z 16.9N 137.7W 65 KT 75 MPH
96H 09/1200Z 17.0N 141.5W 60 KT 70 MPH
120H 10/1200Z 17.0N 146.0W 50 KT 60 MPH

$$
FORECASTER BROWN
Member Since: April 29, 2009 Posts: 75 Comments: 14332
Quoting 135. Tropicsweatherpr:


Keeps pushing back in time as the forecast from two weeks ago was by early to mid August but now looks like late August to early September.
Yup... 2 weeks ago, it was supposed to arrive around August 20th. Now it's supposed to arrive first week of September. Of course people would say MJO is not that big of need during the peak of season, but it could boost it.
Member Since: August 1, 2011 Posts: 28 Comments: 8030
Quoting 111. GTstormChaserCaleb:
That's because you are looking at the short range models, need to look at the long range models. 3 of them show a system in the GOM.


Dude, I am both simultaneously looking forward to, and dreading your posts :P The one you posted yesterday w/ a system smack dab in the middle of the GOM quite honestly shocked me a bit, as I wasn't expecting it. But seriously, thanks for giving those of us on the Gulf an early heads up.
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Quoting 131. Bluestorm5:
We really don't need MJO during peak of season, but it's still a good boost to hurricane season. MJO is sure taking forever to travel toward Atlantic....

That is the empirical model which is based on climatology and if things were to propagate in a perfect manner. I was told to use the GFS or Euro MJO forecast.

Member Since: June 30, 2013 Posts: 12 Comments: 8436
Hmmmmm...
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New advisories have been issued on Gil and Henriette.
Gil
Henriette
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Quoting 131. Bluestorm5:
We really don't need MJO during peak of season, but it's still a good boost to hurricane season. MJO is sure taking forever to travel toward Atlantic....



Keeps pushing back in time as the forecast from two weeks ago was by early to mid August but now looks like late August to early September.
Member Since: April 29, 2009 Posts: 75 Comments: 14332
Quoting 133. 62901IL:

Is the green stuff the MJO or is that the yellow-orange stuff?
The mjo is the green the orange is sinking air.
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Quoting 131. Bluestorm5:
We really don't need MJO during peak of season, but it's still a good boost to hurricane season. MJO is sure taking forever to travel toward Atlantic....


Is the green stuff the MJO or is that the yellow-orange stuff?
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Quoting 41. Naga5000:


Sorry VR46L, the numbers are accurate and strict methodology is used to correct for bias. This paper on the methodology used might be interesting to you. Link

Before attacking the data, maybe 5 minutes of research to understand what the data is saying and to see how it is calculated is in order.


Naga - thanks for the link. Now that is not light reading. It's answered a lot of questions I've had in the past, though, as to how they actually calculate losses. The sheer complexity and variability as to the source of the losses, reporting losses, etc., always made me a bit skeptical as to how it could be done accurately. I knew there had to be a methodology used, but was not aware of it.

VR46L's point about 1992 losses compared to today ("...people in 1992 had the same goods and cost of living as today.. I don't think so , most people now have 1,000's of Dollars worth of electrical goods when back then people didn't have as many ..They would all go into the cost of a hurricane damage today..." was actually addressed in Dr. Masters' original post:

"Keep in mind that hurricane damages are currently doubling every ten years without the effect of climate change, according to Pielke et al., 2008. This is primarily due to the increasing population along the coast and increased wealth of the population."
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We really don't need MJO during peak of season, but it's still a good boost to hurricane season. MJO is sure taking forever to travel toward Atlantic....

Member Since: August 1, 2011 Posts: 28 Comments: 8030
Quoting 118. GTstormChaserCaleb:
GFS ensembles also showing it:



The CMC has a nice looking system off the SW Mexican coast:

Probably the first major of the epac unless Henriette does.
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Quoting 114. opal92nwf:
Well that's not good for where I live in the FL Panhandle


I live in the FL Peninsula, so I'm worse off than you, bro.
Member Since: July 27, 2013 Posts: 0 Comments: 501
Cold Neutral continues in the latest CPC update of 8/5/13.

Link

Member Since: April 29, 2009 Posts: 75 Comments: 14332
It appears that Gil is headed for the history books.
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Wow, slow blog eh?
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Hard to see but 3 systems, one over the Yucatan, another approaching Hawaii, and one developing in the WPAC:

Member Since: June 30, 2013 Posts: 12 Comments: 8436
Last 4 decades of global ACE from Dr. Ryan Maue's site:



http://policlimate.com/tropical/

Where is increase in powerful cyclones caused by AGW?
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Quoting 121. auburn:
The first American woman to walk in space has been tapped to be the new head of the National Oceanic and Atmospheric Administration (NOAA). President Barack Obama yesterday nominated Kathryn Sullivan, currently NOAA’s acting administrator, to fill the post vacated in February by marine scientist Jane Lubchenco.

YAY!
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Quoting 118. GTstormChaserCaleb:
GFS ensembles also showing it:



The CMC has a nice looking system off the SW Mexican coast:


Of course, the CMC is contstantly making cyclones.
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121. auburn (Mod)
The first American woman to walk in space has been tapped to be the new head of the National Oceanic and Atmospheric Administration (NOAA). President Barack Obama yesterday nominated Kathryn Sullivan, currently NOAA’s acting administrator, to fill the post vacated in February by marine scientist Jane Lubchenco.
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Quoting 109. GTstormChaserCaleb:
Good morning keeping an eye on the GOM in the long range:

Exp-FIM-8



Exp-FIM-7



GFS



Thank you, GT. I'll take hope any way I can get it.
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Thanks, Dr. Masters. That was a loaded blog post. Just the kind I like - this type of blog increases my level of understanding. The evolving understanding of scientists, complete with linked references, helps to clarify the factors influencing the uncertainty.

Question for anyone - Figure 4 from the original blog post shows a 'Time series of the 15-year running average (plotted at the end point of the 15-yr blocks) of a Tropical Cyclone Heavy Precipitation Index (red) and 15-year running average of U.S. landfalling hurricanes (blue)'. Anyone know why, if the graph is plotted at the end point of the 15-yr blocks, there are variations plotted within the 15-yr time periods? I've not seen this type of graph before, so I'm struggling a bit with it.

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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