'Hurricane Sandy: The next climate wake-up call?'

[LakeEffectKing]

 

It was the first such track in the historic record. You don't need a satellite to tell you that.

 

http://www.ldeo.columbia.edu/~sobel/Papers/hall_sobel_grl_submitted.pdf

 With or without any potential AGW influences, the timing on the ULL and Sandy had to be extremely precise for such a track.

I remember in the 1995 there was a 'cane approaching the MA area, and for awhile, models were indicating a similar sharp left hand turn into the MA...(was it Felix?? I know it had been a cat 4 at one time..) but the timing fell apart and we were left with a stall (close call!!) and exit stage right....Then of course there was Hazel of '54 and Isabel with "unique" tracks. I'm sure there are other mid latitude interactions that were unique as was...just not near millions of people...

[forkyfork]

none of those storms had a blocking pattern as extreme as sandy's

[bluewave]

 

 With or without any potential AGW influences, the timing on the ULL and Sandy had to be extremely precise for such a track.

I remember in the 1995 there was a 'cane approaching the MA area, and for awhile, models were indicating a similar sharp left hand turn into the MA...(was it Felix?? I know it had been a cat 4 at one time..) but the timing fell apart and we were left with a stall (close call!!) and exit stage right....Then of course there was Hazel of '54 and Isabel with "unique" tracks. I'm sure there are other mid latitude interactions that were unique as was...just not near millions of people...

 

Yeah, that's what made this such a rare meteorological occurrence. Storms like Isabel, Hazel and the 1933 Hurricane were already

on a NW trajectory when they made Landfall over the Mid-Atlantic. 

[forkyfork]

Yeah, that's what made this such a rare meteorological occurrence. Storms like Isabel, Hazel and the 1933 Hurricane were already

on a NW trajectory when they made Landfall over the Mid-Atlantic.

the blocking pattern allowed for lots of wiggle room. it was anything but a thread the needle event

[SN_Lover]

can you show us a similar storm from the past to prove that?

 

storms and their landfall locations

 

 

Sandy was not that unusual. Donna and Hazel were stronger with respect to SLP. When Donna and Hazel hit America was not as modernized, therefore damage was not so great. a.      Sandy’s maximum rainfall was not unusual. Hurricane Agnes maximum rainfall was 6.17 in more than Hurricane Sandy. It is not unprecedented for hurricanes to have as high of rain, but it’s not as common. All the other hurricanes has rainfall averaged around 7 inches. Sandy was experiencing shear along its track. Other landfilling hurricanes have the same special pattern such as Agnes, Gerda, Gloria, and Bob. This is common with the trough position in relation to climatological hurricanes impacting the NE. Sandy’s precipitation impact was severe because the sheer vector was long the track. This caused precipitation to fall mainly to the south of the track. If the sheer was across the track the precipitation will be distributed evenly on both sides of the track. This would be caused by the precipitation falling in the NE and NW quadrant of the hurricane.  Sandy’s storm surge was not unprecedented, but unusual. Sandy’s storm surge is second highest amongst 7 storms in the list.The special extent of sandy was not unusual. Carl and Great New England had relatively the same special structure. This only difference is that the world was more modernized and Sandy’s storm surge impacted a higher population than the previous hurricanes. Sandy’s storm surge impact was severe. Sandy impacted major cities that had very high population densities. The great New England hurricane had storm surge that was higher, but struck at an earlier time.  All the other hurricanes had lower storm surges and the hurricanes were not angled in such a way to impact high population densities that much

[bluewave]

the blocking pattern allowed for lots of wiggle room. it was anything but a thread the needle event

 

It was a remarkable combination of the record blocking being timed with the favorable MJO phase and 

hurricane development leading to the historic phase.

 

 

 

 

[ORH_wxman]

 

http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2013/08/21/researcher-defends-work-linking-arctic-warming-and-extreme-weather/

Comments on Barnes 2013: Revisiting the evidence linking Arctic amplification to extreme weather in midlatitudes. GRL. by J.A Francis

 

I am pleased that Dr. Barnes, a respected and talented atmospheric dynamicist, has taken an interest in the topic of linkages between the rapidly changing Arctic and the large-scale circulation. The emerging influence of Arctic amplification (AA) on mid-latitude weather patterns is complex, and her expertise will help resolve some fundamental dynamical questions that are relevant to understanding mechanisms driving these linkages as the Arctic continues to warm faster than elsewhere.

What perplexes me, however, is that her intent in interpreting the new results in Barnes (2013) seems less than objective and is a direct attempt to disprove the work presented in Francis and Vavrus (2012; hereafter FV12). A very different interpretation of the results could be made. While her overarching conclusion is that the connections between AA and mid-latitude extreme weather are unfounded, I see a great deal of support for our results in her new work. For example:

Figure 2 presents time series of wave amplitudes (or extents) measured using two methods: one similar to ours and an alternative based on seasonal latitude differences. In all cases the trends are positive, suggesting an increase in amplitude during fall and summer, albeit only some of the trends are statistically significant. Because AA has emerged from the noise of natural variability only in the last 15 year or so, it is not surprising that its influence would not drive 30-year trends in a statistically significant way. Note that her new method does exhibit significant trends. This supports FV12.

My interpretation of the results in her Figure 3 is that in the ranges of 500 hPa heights that typically occur in mid-latitudes during summer (5.6 to 5.8 km) and autumn (5.5 to 5.7 km), the wave amplitudes are increasing from the early to the later part of the record. This, once again, supports FV12. She claims that because warming is shifting a particular height contour northward, it is incorrect to conclude that wave amplitudes are increasing. In fact, it is this northward shift – in particular the larger shift in high latitudes where warming is greatest – that we hypothesized would be a factor causing the waves to elongate.

Figure 4 presents measures of wave phase speed. While FV12 did not present wave speeds, we speculated that larger amplitude waves should have slower wave speeds. Her measure of phase speed for waves at 500 hPa slows with time, supporting our speculation. She then measures speeds at the 250 hPa level and finds no change in speed. This much higher level is near the tropopause, often above the jet stream, and can be affected by dynamics of the stratosphere. The stratosphere is cooling with increasing greenhouse gases, leading to very different dynamical changes. Why did she choose to analyze this level? My only guess is to deliberately cast doubt on FV12.

The mechanisms linking Arctic amplification with large-scale circulation patterns are clearly not simple and we still have much to learn. These new results provide additional insight into those linkages, but it appears that the interpretation of these results in Barnes (2013) was conducted with a particular intent. I welcome and appreciate Dr. Barnes’ contribution to the community’s efforts to understand the effects of AA on large-scale circulation changes, but perhaps a more balanced approach to interpreting the results could be applied going forward.

 

 

 

 

 

 

It will be interesting to see if Francis gets a peer reviewed rebuttal. So far, that is not the case.

[Ginx snewx]

http://www.pnas.org/content/110/38/15211

Yea good link(would be nice if they could model correctly day 7 forward though)

 

Superstorm Sandy ravaged the eastern seaboard of the United States, costing a great number of lives and billions of dollars in damage. Whether events like Sandy will become more frequent as anthropogenic greenhouse gases continue to increase remains an open and complex question. Here we consider whether the persistent large-scale atmospheric patterns that steered Sandy onto the coast will become more frequent in the coming decades. Using the Coupled Model Intercomparison Project, phase 5 multimodel ensemble, we demonstrate that climate models consistently project a decrease in the frequency and persistence of the westward flow that led to Sandy’s unprecedented track, implying that future atmospheric conditions are less likely than at present to propel storms westward into the coast.

[Ginx snewx]

none of those storms had a blocking pattern as extreme as sandy's

again if not for the coinciding timing with a super tide this all is a basic non issue, you end up with Cat 1 gusts and some coastal flooding. The ULL capture has as much to do with this as blocking. Can't say ULL capture is unprecedented. 

[Jonger]

Yea good link(would be nice if they could model correctly day 7 forward though)

 

Superstorm Sandy ravaged the eastern seaboard of the United States, costing a great number of lives and billions of dollars in damage. Whether events like Sandy will become more frequent as anthropogenic greenhouse gases continue to increase remains an open and complex question. Here we consider whether the persistent large-scale atmospheric patterns that steered Sandy onto the coast will become more frequent in the coming decades. Using the Coupled Model Intercomparison Project, phase 5 multimodel ensemble, we demonstrate that climate models consistently project a decrease in the frequency and persistence of the westward flow that led to Sandy’s unprecedented track, implying that future atmospheric conditions are less likely than at present to propel storms westward into the coast.

 

Meaning the next one should appear in 100 years, or Sandy-like definitions will continue to be applied more liberally to achieve the shock value.

[CoastalWx]

Yea good link(would be nice if they could model correctly day 7 forward though)

 

Superstorm Sandy ravaged the eastern seaboard of the United States, costing a great number of lives and billions of dollars in damage. Whether events like Sandy will become more frequent as anthropogenic greenhouse gases continue to increase remains an open and complex question. Here we consider whether the persistent large-scale atmospheric patterns that steered Sandy onto the coast will become more frequent in the coming decades. Using the Coupled Model Intercomparison Project, phase 5 multimodel ensemble, we demonstrate that climate models consistently project a decrease in the frequency and persistence of the westward flow that led to Sandy’s unprecedented track, implying that future atmospheric conditions are less likely than at present to propel storms westward into the coast.

 

The point is that a thread the needle event and AGW probably aren't the best to link together. There appears to be both sides of the argument between Barnes and Francis.

[skierinvermont]

The numerous posts debating whether Sandy was unprecedented (Jonger, Ginxy, mp184qcr) are irrelevant. Whether Sandy was unprecedented or not is a pointless question. The important question was whether Sandy and storms like it are/will be made more common by AGW. 

 

Yes, I agree there is evidence on both sides, although the weight of evidence currently seems to fall on the side of extreme -NAOs becoming more common, which would likely mean more storms being steered west into the coast.

 

 

Also, looking through the record of the last 100 years, it doesn't appear that any storm took such an extreme left hook. 

 

 

Also, as I said before I don't think a regional increase in hurricane frequency is very important if the globe witnesses no change overall. But it could be of interest to people that live in the northeast. 

[LakeEffectKing]

none of those storms had a blocking pattern as extreme as sandy's

True, but there have been many canes that encountered such blocking...moved wnw-ward then captured....but they were a few hundred miles east over open ocean.  Blocking isn't a new phenomena when dealing with hurricanes.  The strength of the ULL, independent of the blocking, is what drove this wnw-ward...the blocking at that latitude most likely would have provided a stall, or a drift westward.....the ULL, both it's steering currents, and dynamical forcing, is what accelerated this westward.

 

Was this a rare meteorological setup/event?  Of course.  The rest of the discussion for this one event regarding anything other than meteorology is, relatively speaking, insignificant speculation. 

[blizzard1024]

Sandy was a tropical storm/minimal hurricane when it made landfall. It got captured by an upper level low

that developed below a blocking high in the north atlantic. Blocking highs have been occurring regularly for thousands and

thousands and thousands of years. The 1960s saw a lot of blocking up there in a globally cool period. The Little

ice age was postulated to have a lot of blocking highs in the N Atlantic which made for terribly cold winters in England. 

To insinuate somehow that a warming climate causes blocking high is tenuous at best. In the late 1990s climate scientists

were saying that AGW was leading to a stronger PV because of cooling in the stratosphere which leads

to more positive NAO/AO patterns. That was, of course ,after an unprecedented period of positive NAO/AO

patterns. Now we are seeing a drop in the NAO/AO and more blocking and, low and behold,  AGW is

supposedly related to this.  Agnes was trapped in an upper level low pattern and tracked westward

too in 1972.... again a cool period globally. Why are scientists wasting their time on this. AGW

will not make the weather more extreme...less temp gradients between the poles and the tropics

(arctic amplification) means weaker baroclinic storms. This is basic meteorology 101. The only possible

thing that Sandy might have been affected by AGW is the 7 inch rise in sea level if you assume

ALL the rise is from AGW. I don't believe this is the case because the sea levels have been rising

since the end of the little ice age. 

[tacoman25]

Sandy was a tropical storm/minimal hurricane when it made landfall. It got captured by an upper level low

that developed below a blocking high in the north atlantic. Blocking highs have been occurring regularly for thousands and

thousands and thousands of years. The 1960s saw a lot of blocking up there in a globally cool period. The Little

ice age was postulated to have a lot of blocking highs in the N Atlantic which made for terribly cold winters in England. 

To insinuate somehow that a warming climate causes blocking high is tenuous at best. In the late 1990s climate scientists

were saying that AGW was leading to a stronger PV because of cooling in the stratosphere which leads

to more positive NAO/AO patterns. That was, of course ,after an unprecedented period of positive NAO/AO

patterns. Now we are seeing a drop in the NAO/AO and more blocking and, low and behold,  AGW is

supposedly related to this.  Agnes was trapped in an upper level low pattern and tracked westward

too in 1972.... again a cool period globally. Why are scientists wasting their time on this. AGW

will not make the weather more extreme...less temp gradients between the poles and the tropics

(arctic amplification) means weaker baroclinic storms. This is basic meteorology 101. The only possible

thing that Sandy might have been affected by AGW is the 7 inch rise in sea level if you assume

ALL the rise is from AGW. I don't believe this is the case because the sea levels have been rising

since the end of the little ice age. 

 

Bingo. It's funny how many people don't seem to understand that more often than not, science is scrambling to explain recent trends, and is not always adept at predicting future ones.

[f2tornado]

The only possible thing that Sandy might have been affected by AGW is the 7 inch rise in sea level if you assume

ALL the rise is from AGW. I don't believe this is the case because the sea levels have been rising since the end of the little ice age. 

 

The eastern and central United States is subsiding at 1 to 2 millimeter per year owing to post-glacial isostatic adjustment. This means the effective sea level rise in the area Sandy hit is 1 to 2 millimeter per year regardless of eustatic MSL rise from AGW. No amount of CO2 reduction is gonna fix that particular contribution to the problem.

[skierinvermont]

The eastern and central United States is subsiding at 1 to 2 millimeter per year owing to post-glacial isostatic adjustment. This means the effective sea level rise in the area Sandy hit is 1 to 2 millimeter per year regardless of eustatic MSL rise from AGW. No amount of CO2 reduction is gonna fix that particular contribution to the problem.

 

Indeed which is why total SLR at NYC is more like a foot with about 3/4s of that coming from AGW.

[WXheights]

 

Chances for super anomalous blocking, extra warm SST's, late season hurricane combo are likely higher than before

[Ed Lizard]

http://en.wikipedia.org/wiki/Snow_Hurricane_of_1804

[Ginx snewx]

Indeed which is why total SLR at NYC is more like a foot with about 3/4s of that coming from AGW.

Kings Point, New York

8516945The mean sea level trend is 2.35 mm/year with a 95% confidence interval of +/- 0.24 mm/year based on monthly mean sea level data from 1931 to 2006 which is equivalent to a change of 0.77 feet in 100 years

[tacoman25]

Blocking.png

 

Chances for super anomalous blocking, extra warm SST's, late season hurricane combo are likely higher than before

 

You have to wonder what the correlating factor is with that block days graph (how exactly is that defined, anyhow)? The trend was pretty much flat from the late 1960s to about 2000. AGW was certainly ongoing that whole time. It seems to coincide with the dramatic increase in Arctic temps seen around that time...makes sense. But what isn't clear is what exactly triggered the shift to more high latitude blocking and Arctic warmth in the early 2000s.

[chrisf97212]

Blocking.png

 

Chances for super anomalous blocking, extra warm SST's, late season hurricane combo are likely higher than before

What does the Y axis represent?  It can't be days per year

[f2tornado]

The graph suggests a decent falling trend from the start of the period to the early 80s. There is likely some natural oscillation modulating whatever AGW signal one wants to try and pick out.

[WXheights]

What does the Y axis represent?  It can't be days per year

 Total number of blockinmg days - if two occur simultaneously they are added up together i.e one in the Atlantic and other in the Pacific in one day thats why the 0-600