Super Typhoon Haiyan's Intensification and Unusually Warm Sub-Surface Waters

By: Dr. Jeff Masters , 6:25 PM GMT on November 13, 2013

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A remarkable warming of the sub-surface Pacific waters east of the Philippines in recent decades, due to a shift in atmospheric circulation patterns and ocean currents that began in the early 1990s, could be responsible for the rapid intensification of Super Typhoon Haiyan. Hurricanes are heat engines, which means they take heat energy out of the ocean, and convert it to kinetic energy in the form of wind. It's well-known that tropical cyclones need surface water temperatures of at least 26.5°C (80°F) to maintain themselves, and that the warmer the water, and the deeper the warm water is, the stronger the storm can get. Deep warm water is important, since as a tropical cyclone tracks over the ocean, it stirs up cooler water from the depths, potentially reducing the intensity of the storm. When both Hurricane Katrina and Hurricane Rita exploded into Category 5 hurricanes as they crossed over a warm eddy in the Gulf of Mexico with a lot of deep, warm water, the concept of the total heat energy available to fuel a hurricane--the Tropical Cyclone Heat Potential (TCHP)--became one that gained wide recognition. The Pacific Ocean east of the Philippines has the largest area of deep, warm water of anywhere on Earth, and these waters have historically fueled the highest incidence of Category 5 storms of anywhere on the planet. Super Typhoon Haiyan tracked over surface waters that were of near-average warmth, 29.5 - 30.5°C (85 - 87°F.) However, the waters at a depth of 100 meters (328 feet) beneath Haiyan during its rapid intensification phase were a huge 3°C above average, according to Professor I-I Lin of the Department of Atmospheric Science at the National Taiwan University. An analysis by the Japan Meteorological Agency for October showed ocean temperatures 4 - 5°C (7 - 9°F) above average during October (Figure 1). This analysis was from a model. When looking at actual measurements made by the Argo float data in early November, the temperatures in the layer 100 meters below the surface under Haiyan were about 3°C above average, not 4 - 5°C, according to Dr. Lin. As the typhoon stirred this unusually warm water to the surface, the storm was likely able to feed off the heat, allowing Haiyan to intensify into one of the strongest tropical cyclones ever observed.


Figure 1. Modeled departure of temperature from average at a depth of 100 meters in the West Pacific Ocean during October 2013, compared to a 1986 - 2008 average. The track and intensity of Super Typhoon Haiyan are overlaid. Haiyan passed directly over large areas of sub-surface water that were much above average in temperature, which likely contributed to the storm's explosive deepening. While this model showed 4 - 5°C departures from average in October, the actual values were closer to 3°C in early November, according to Argo float data. Image credit: Japan Meteorological Agency.

Why was there such unusually warm sub-surface water?
The sub-surface waters east of the Philippines have warmed dramatically over the past twenty years. According to Pun et al. (2013), "Recent increase in high tropical cyclone heat potential area in the Western North Pacific Ocean", the depth to where ocean temperatures of at least 26°C (79°F) penetrates has increased by 17% since the early 1990s, and the Tropical Cyclone Heat Potential has increased by 13%. The warm-up is due to an increase in the surface winds blowing across the region--the trade winds--which have caused a southward migration and strengthening of the North Equatorial Current (NEC) and the North Equatorial Counter Current (NECC). The strong trade winds have pushed a large amount of water up against the east coast of the Philippines in the past twenty years, resulting in a rate of sea level rise of 10 mm per year--more than triple the global average of 3.1 mm/yr (Figure 2.) This extra sea level rise contributed to the storm surge damage from Super Typhoon Haiyan. Sea level rise data from Legaspi in the Eastern Philippines shows a rise of about 305 mm (12 inches) since 1949. For comparison, global average sea level rose 7.5" (190 mm) since 1901. Part of the rise along the eastern Philippine coast is from tectonic processes--the subsidence of the Philippine plate under the Eurasian plate--but most of it is due to the stronger trade winds piling up warm water along the coast, and the fact that warmer waters expand, raising sea level.


Figure 2. Trend in sea level from satellite altimeter measurements in 1993 - 2010. Black lines are the Sea Surface Height (SSH) in cm from Rio et al. (2009.) Image credit: Qiu, B., and S. Chen, 2012, "Multidecadal sea level and gyre circulation variability in the northwestern tropical Pacific Ocean", Journal of Physical Oceanography 42.1 (2012): 193-206.

Why have the trade winds sped up?
The surface trade winds in the equatorial Pacific are part of the Walker Circulation--a pattern of rising and sinking air along the Equator that the El Nino/La Nina cycle influences. A strong Walker circulation means there is lower pressure over Indonesia, which pulls in more air at the surface along the Equator from the east, increasing the easterly trade winds. As these trade winds strengthen, they pull surface ocean waters away from South America, allowing cold water to upwell to the surface. This is a La Niña-like situation, which takes heat energy out of the atmosphere, putting it into the ocean, keeping global surface temperatures cooler than they would otherwise be. A weakened Walker circulation is the reverse, resulting in weaker trade winds, and a more El Niño-like situation with higher global surface temperatures. As long as the stronger Walker circulation that has been in place since the early 1990s holds, global surface temperatures should stay cooler than they otherwise would be, prolonging the slow-down in global surface warming that has received much attention this year. There may also be a greater chance of super typhoons and higher storm surges affecting the Philippines, due to the warmer sub-surface waters and re-arranged ocean currents. A 2013 paper by L’Heureux et al. notes that the climate models predict that the Walker circulation should weaken (a more El Niño-like situation)--the reverse of what has been observed the past twenty years. The researchers took the observed pressure patterns over the Pacific in recent decades and removed the atmospheric response to the El Niño/La Niña cycle. The resulting pattern they found showed a steady strengthening of the Walker circulation, in concert with global rising temperatures. So, are we seeing a failure of the climate models? Or is the recent speed-up of the Walker circulation a decades-long temporary "speed bump" in the climate system? Time will tell. It is worth pointing out that a just-released paper by British and Canadian researchers shows that the global surface temperature rise of the past 15 years has been greatly underestimated. As discussed at realclimate.org, "The reason is the data gaps in the weather station network, especially in the Arctic. If you fill these data gaps using satellite measurements, the warming trend is more than doubled in the widely-used HadCRUT4 data, and the much-discussed “warming pause” has virtually disappeared."

I appeared on PBS Newshour last night to discuss the linkages between stronger tropical cyclones and climate change, video here.

References
L’Heureux, Michelle L., Sukyoung Lee, and Bradfield Lyon, 2013, "Recent multidecadal strengthening of the Walker circulation across the tropical Pacific", Nature Climate Change 3.6 (2013): 571-576.

Pun, Iam‐Fei, I‐I. Lin, and Min‐Hui Lo, 2013, "Recent increase in high tropical cyclone heat potential area in the Western North Pacific Ocean", Geophysical Research Letters (2013).

Qiu, B., and S. Chen, 2012, "Multidecadal sea level and gyre circulation variability in the northwestern tropical Pacific Ocean", Journal of Physical Oceanography 42.1 (2012): 193-206.

Jeff Masters

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Quoting 334. Bluestorm5:


We're supposed to drop to 15 degrees tonight.
We had a few spotty teens around..That is near record low around here for mid Nov...
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Quoting 332. TropicalAnalystwx13:
It's so cold right now.

26F/-3C outside.


Come north to mild Baltimore!

What's the earliest it's been in the teens there? Could it get into the teens tonight?

Hmmm. The earliest it has been in the teens in Wilmington NC was 16 on November 26, 1950.
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Quoting 332. TropicalAnalystwx13:
It's so cold right now.

26F/-3C outside.


We're supposed to drop to 15 degrees tonight.
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Quoting 325. KoritheMan:


I wouldn't call that "lucky" at all; fast-moving tropical cyclones frequently carry damaging winds well inland, and frictional convergence at the coast could theoretically maximize the winds at the landfall point, especially in gusts.
Haiyan was a monster so bad, that no matter how fast or slow it was moving, there would have been catastrophic damage. However, it could be argued that if she was moving at 8 to 10 mph, the damage from flooding possibly may have killed more people .
Member Since: September 27, 2007 Posts: 1 Comments: 20493
It's so cold right now.

26F/-3C outside.
Member Since: July 6, 2010 Posts: 113 Comments: 31438
For that matter I bet there was a pressure gradient at least as strong as Hattie's in Dade County when Hurricane Andrew made landfall.
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330. beell
Quoting 320. hydrus:
She was haulin..24 mph I heard.


Heard that also. Would not seem to matter too much if "Departure of temperature from average at a depth of 100 meters in the West Pacific Ocean" was 4-5°C above average at that speed.

Not in any one spot long enough?

I did consider that if sub-surface water at 100 m was 4-5°C above average it would be somwhat warmer above that level.

Signed,
Curious
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Quoting 327. HuracanTaino:
For us in Puerto Rico was kind of weird to face a Western Caribean Hurricane,a week before Thanks giviing, quite an experience, could happen again, anytime...!
I bet it was weird..Kinda like us gettin hit by a tornado from the east..it jus dont happen.
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Quoting 324. sar2401:

Look at his CV and education. He's never had a real job in his life and has a Master of Arts in Global Environmental Policy (whatever that is) and is writing about a subject (typhoons) that, as far as I can tell, he has absolutely no training. You should read some of his other blogs. I'm ashamed to say this feeder at the public trough still lives in my hometown, Cleveland, where poverty is rampant, and there are lots of public funds available for over educated losers like this to write about problems and offer no workable solutions, since he's never had to work. Talk about welfare....
What a troubled world we live in.
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Quoting GTstormChaserCaleb:
14 years ago Wrong-Way Lenny formed in the SW Caribbean Sea.



11 PM Saturday Nov. 3.



The blog would be crazy busy tonight if we had something like a Lenny.
For us in Puerto Rico was kind of weird to face a Western Caribean Hurricane,a week before Thanks giviing, quite an experience, could happen again, anytime...!
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Durring Hurricane Hattie's landfall at Belize there was a pressure differential of 1.53" over 20 miles with 28.70" at Stanley Field and 27.17" reported 20 miles SE. So Haiyan could have still been a Cat 5 when it passed Tacloban.

The PDF is from the Department of Defense and must be downloaded to be viewed.
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Quoting 321. Chicklit:

that was the lucky part.
unfortunately Yolanda was also throwing off about 190 mile per hour winds as she sped by with her massive bulk


I wouldn't call that "lucky" at all; fast-moving tropical cyclones frequently carry damaging winds well inland, and frictional convergence at the coast could theoretically maximize the winds at the landfall point, especially in gusts.
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Quoting Chucktown:
More "knee jerk" reaction on Haiyan

Link

Look at his CV and education. He's never had a real job in his life and has a Master of Arts in Global Environmental Policy (whatever that is) and is writing about a subject (typhoons) that, as far as I can tell, he has absolutely no training. You should read some of his other blogs. I'm ashamed to say this feeder at the public trough still lives in my hometown, Cleveland, where poverty is rampant, and there are lots of public funds available for over educated losers like this to write about problems and offer no workable solutions, since he's never had to work. Talk about welfare....
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Quoting 320. hydrus:
She was haulin..24 mph I heard.
Sadly, Haiyan moving that fast is part of reason why it's 195 mph or maybe even 200 mph peak sustained on the north-northeastern side of storm.
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Quoting 321. Chicklit:

that was the lucky part.
unfortunately Yolanda was also throwing off about 190 mile per hour winds as she sped by with her massive bulk
One may ascertain also that if the typhoon is moving at 24 miles per her that winds on the northern quadrant may have been higher than what they already wer...which is a scery thought.
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Quoting 320. hydrus:
She was haulin..24 mph I heard.

that was the lucky part.
unfortunately Yolanda was also throwing off about 190 mile per hour winds as she sped by with her massive bulk
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Quoting 309. beell:


Did anybody quiz Doc M today on the fast forward speed of Haiyan WRT to tapping the deep heat? I realize it was a powerful storm and upwelling would be above-average anyway. Curious.
She was haulin..24 mph I heard.
Member Since: September 27, 2007 Posts: 1 Comments: 20493

Toronto Pearson Int'l Airport
Date: 10:00 PM EST Wednesday 13 November 2013
Condition:Cloudy
Pressure:30.1 inches
Tendency:falling
Visibility:15 miles
Temperature:35.6°F
Dewpoint:16.3°F
Humidity:45%
Wind:SW 19 gust 31 mph
Member Since: July 15, 2006 Posts: 169 Comments: 53296
Quoting 290. StormTrackerScott:


Not surprised as this next blast of cold air means business.



18 degrees in Western NC? And I thought last night and tonight was cold enough...
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Australia sets new temperature records for September 2013 and hottest 12 month period

Submitted by takver on Mon, 10/07/2013 - 7:27am


Submitted by takver on Mon, 10/07/2013 - 7:27am
in Original News Australia Impacts Science Australia temperatures
Australia: 2013 Hottest September on record
Australia: 2013 Hottest September on record
Even though the global land surface temperatures have appeared to plateau since 1998 - a global hiatus - other measurements show global warming has continued with continued warming of the oceans, sea level rise, melting of Arctic sea ice, continued retreat of mountain glaciers. 2000 to 2010 was also the hottest decade on record.

Significantly, Australia has broken many temperature records this year with the extreme January heatwave and Angry Summer, sizzling warming into late Autumn, a relatively warm Winter, and now the hottest September on record averaged across Australia, and the hottest 12 months on record. Australia is also on track for the hottest calendar year this year.

The Bureau of Meteorology issued a Special Climate Statement updated on 13 October: Exceptionally warm late winter/early spring with unusually persistent warm conditions over the last 12 months (PDF). You can read the Climate Council analysis on this statement: ’OFF THE CHARTS – Record breaking September Heat and Climate Change’.

The BOM statement said:

Averaged over Australia, monthly maximum temperatures were 3.41 °C above average for September and monthly minimum temperatures 2.09 °C above average, combining to a monthly mean temperature 2.75 °C above average.

All of these have set new September records for Australia, with the monthly mean temperature more than a degree above the previous record. The monthly maximum and mean temperatures have also set Australian records for the largest positive temperature anomaly observed in any month. (The previous records are respectively, 3.16 °C above average in August 2009, and 2.66 °C above average in April 2005).

Some key facts from the BOM statement regarding mean temperature records for Australia from the last 12 months:

Australia’s warmest month on record (January)
Australia’s warmest September on record
Australia’s largest positive monthly anomaly on record (September)
Australia’s warmest summer on record (December 2012 to February 2013)
Australia’s warmest January to September period on record
Australia’s warmest 12-month period on record (broken twice, for the periods ending August and September)



Indeed, Australia’s warmest period on record for all periods 1 to 18 months long ending September 2013
Two significant daily maximum temperature records were also set this year: Australia’s hottest summer day on record (7 January) and Australia’s warmest winter day on record (31 August)

Rob Gell read from the BOM statement at the AMOS meeting discussing the latest IPCC report and asked the science panel about the significance of these new records.
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Quoting 311. txjac:


Thanks for the tip on reading about early weather.
Pffft, pop, guzzle...
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Quoting 310. Dakster:
Hydrus - Possible, but remember that the heat just provides the potential energy. So if the storm wasn't able to use the extra heat it would not have been any stronger.

Look at the 2013 ATLANTIC season for examples of having enough heat to form/strenghten a storm, but yet, nothing happened.
I understand completley Dakster. Even if the wawa was 210 degrees fahrenheit, if there was 72.5 knots of vertical shear, or a Hadley Cell slammin down on top of ole steamy, ther be no strenthenen..just ribbing ya :)
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Quoting 312. beell:


I guess I'm not-but there should be 60 knots of shear over northern AR on Sunday. A multitude of wind damage reports with the front looks likely.

Best bet is to always consider/consult professional guidance.
;-)


Ok.

*In the background* MOM!!! I need help!

:D
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Quoting 307. txag91met:

I left The Weather Channel just before this...
You are from the 80,s weather channel.?
Member Since: September 27, 2007 Posts: 1 Comments: 20493
312. beell
Quoting 308. wxchaser97:

So the NSSL isn't going to be predicting a record outbreak this weekend?


I guess I'm not-but there should be 60 knots of shear over northern southern AR on Sunday. A multitude of wind damage reports with the front looks likely.

Best bet is to always consider/consult professional guidance.
;-)
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311. txjac
Quoting 305. Pallis:
Actually our current civilization has been created by a slow warming trend for the last 12,000 years or so, and has survived some serious cold spells that killed plenty when there were not so many people. A Chronological Listing of Early Weather Events by James A. Marusek, is a good place to start for a slightly broader view of more than a few decades. A recent cold snap was in the 20's and 30's. Funny thing about that one is there are still a few people alive that can tell you first hand how friggin miserable it was, especially when they actually had to walk to school with holes in their shoes. That was during the great depression.


Thanks for the tip on reading about early weather.
Member Since: April 24, 2010 Posts: 1 Comments: 2454
Hydrus - Possible, but remember that the heat just provides the potential energy. So if the storm wasn't able to use the extra heat it would not have been any stronger.

Look at the 2013 ATLANTIC season for examples of having enough heat to form/strenghten a storm, but yet, nothing happened.
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309. beell
Quoting 304. hydrus:

I can help but ask myself if Haiyan tracked 50 miles south across that hot patch of water rather than the 85 degree stuff would it have been even stronger?


Did anybody quiz Doc M today on the fast forward speed of Haiyan WRT to tapping the deep heat? I realize it was a powerful storm and upwelling would be above-average anyway. Curious.
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Quoting 300. beell:


Heck, it could all change 3 model runs from now.

The more insolation we can get on Sunday, the greater the chance for discrete. But some elevated convection on Saturday and some upglide over the retreating cool surface air may hinder that process.

So the NSSL isn't going to be predicting a record outbreak this weekend?
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Quoting 271. GTstormChaserCaleb:
14 years ago Wrong-Way Lenny formed in the SW Caribbean Sea.



11 PM Saturday Nov. 3.



The blog would be crazy busy tonight if we had something like a Lenny.

I left The Weather Channel just before this...
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Quoting 302. beell:


Don't make me come up there...
:)
lmao..
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Quoting 261. Xyrus2000:


No, "any warming now is a good thing" is a complete load of bovine excrement. We have built our entire civilization on a relatively stable climate, and ANY threat to that stability should be viewed a lot of concern.

Many companies and government agencies, including the DoD take climate change and it's impacts very seriously. A couple of severe extended droughts in a few key areas is enough to cause global instability. We've already had a small taste of that when Russia shut down it's food exports as a result of the severe drought and fires from a couple years backs.

Considering ice ages and warm periods are induced by as a little as a 2C differential and that often these rapid changes resulted in extinction events counteracts you statement. Sudden changes, regardless of direction, is detrimental to the species existing at that time.

C
Actually our current civilization has been created by a slow warming trend for the last 12,000 years or so, and has survived some serious cold spells that killed plenty when there were not so many people. A Chronological Listing of Early Weather Events by James A. Marusek, is a good place to start for a slightly broader view of more than a few decades. A recent cold snap was in the 20's and 30's. Funny thing about that one is there are still a few people alive that can tell you first hand how friggin miserable it was, especially when they actually had to walk to school with holes in their shoes. That was during the great depression.
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I can help but ask myself if Haiyan tracked 50 miles south across that hot patch of water rather than the 85 degree stuff would it have been even stronger?
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Expedite Share.
ROLL INFO

ReliefWEB
PHILIPPINES Humanitarian Response


All Groups,Teams should not deploy to Tacloban unless they are completely self sufficient.

Highlights

An estimated 11.5 million people are affected by Typhoon Haiyan; 544,600 people remain displaced. Trucks and fuel are urgently needed to deliver aid. Debris and logistics continue to severely constrain the delivery of humanitarian assistance.

The Emergency Relief Coordinator visited the most affected areas of Tacloban City to take stock of the humanitarian situation. Transporting and distributing food, emergency shelter material, hygiene kits, body bags and establishing a family tracing service are urgently needed in Tacloban for the next days. The Haiyan Action Plan, launched on 12 November, is 13 per cent funded ($38 million).

See full OCHA Sitrep #7.
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302. beell
Quoting 301. hydrus:
The LLJ is at 851 mb,s not 850...


Don't make me come up there...
:)
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Quoting 295. beell:


What he meant was the cold air undercuts the convection. Overtakes the storms from behind in a sense. I think. The surface low will be way up over Iowa with a pre-frontal trough extending SSW across AR and the ARKLATX.

In addition the 850 mb LLJ will veer pretty quick (a strong westerly component) and shunt the moisture east into much less instability and even farther away from the better dynamics as the surface and mid-level system lift quickly out towards the Upper Great Lakes.



Probably enough surface convergence along the pre-frontal trough to provide enough lift to fire off a few short-lived discrete supercells and some strong storms with the front with a unidirectional wind profile (parrallel to the boundary).



The LLJ is at 851 mb,s not 850...
Member Since: September 27, 2007 Posts: 1 Comments: 20493
300. beell
Quoting 297. KoritheMan:


I have no idea why I was presuming the surface low to be that far south. Do you realize how deep of much of a southern extension the trough would have if that were the case? lol

My bad. But still, we had the same general idea. :)


Heck, it could all change 3 model runs from now.

The more insolation we can get on Sunday, the greater the chance for discrete. But some elevated convection on Saturday and some upglide over the retreating cool surface air may hinder that process.
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Quoting 288. Astrometeor:


I have no idea what that is, but it looks delicious.


Tiramisu is an awesome cake layered with cream and flavored with coffee and chocolate.
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It did not reach freezing in Baltimore's inner city last night. But it was close!
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Quoting 295. beell:


What he meant was the cold air undercuts the convection. Overtakes the storms from behind in a sense. I think. The surface low will be way up over Iowa with a pre-frontal trough extending SSW across AR and the ARKLATX.

In addition the 850 mb LLJ will veer pretty quick (a strong westerly component) and shunt the moisture east into much less instability and even farther away from the better dynamics as the surface and mid-level system lift quickly out towards the Upper Great Lakes.



Probably enough surface convergence along the pre-frontal trough to provide enough lift to fire off a few short-lived discrete supercells and some strong storms with the front with a unidirectional wind profile (parrallel to the boundary).



I have no idea why I was presuming the surface low to be that far south. Do you realize how much of a southern extension the trough would have if that were the case? lol

My bad. But still, we had the same general idea. :)
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Quoting 239. TropicalAnalystwx13:

There's no inherent pressure range for a Category 5. In the database, the pressure for past storms ranges from a questionable 972 millibars (Ethel '60) to an insane 882 millibars (Wilma '05). It's likely that Haiyan had a crazy pressure gradient, though the idea of this being a sub-900mb system by the point of landfall (in Leyte) would probably not be accurate given the measurements they observed. It's very possible it was sub-900mb as it hit Guiuan, however.




Furthermore, the strongest winds are often found right up until the point of entering the eye. I would think that the pressure gradient with a tropical cyclone with that kind of wind power would have a significant pressure difference within the eyewall over a very short distance. After all, we are talking a 190 to 195 mph tropical cyclone, there is going to be a ridiculous pressure gradient in the inner core.

Just being in a different part of Tacloban could mean a a completely different pressure reading. If the report has been several miles south, I think it would have read much lower.
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295. beell
Quoting 287. KoritheMan:


Remember what Ryan (1900) said about cold air overrunning the surface low? The SPC is going along with that now, too:

BEFORE THE COLD INTRUSION CUTS OFF MOISTURE RETURN FROM THE GULF OF
MEXICO
...A WINDOW OF OPPORTUNITY DOES APPEAR TO EXIST FOR THE
DEVELOPMENT OF A CORRIDOR OF SUBSTANTIVE BOUNDARY LAYER
DESTABILIZATION...IN THE PRESENCE OF STRONG DEEP LAYER SHEAR AND
MID/UPPER FORCING FOR ASCENT...SUPPORTIVE OF THE RISK FOR SEVERE
STORMS.

Yeah. :/


What he meant was the cold air undercuts the convection. Overtakes the storms from behind in a sense. I think. The surface low will be way up over Iowa with a pre-frontal trough extending SSW across AR and the ARKLATX.

In addition the 850 mb LLJ will veer pretty quick (a strong westerly component) and shunt the moisture east into much less instability and even farther away from the better dynamics as the surface and mid-level system lift quickly out towards the Upper Great Lakes.



Probably enough surface convergence along the pre-frontal trough to provide enough lift to fire off a few short-lived discrete supercells and some strong storms with the front with a unidirectional wind profile (parrallel to the boundary).



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Quoting 288. Astrometeor:


I have no idea what that is, but it looks delicious.
I make the best..Mascarpone cheese, best coffee liquor, real cocoa and ladyfingers..its tha bom.
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Quoting 291. KEEPEROFTHEGATE:
its November its time
yep..Seems like every fall I loose a tree...
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Looking more and more stormy on Friday across C & N FL

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Quoting 281. GTstormChaserCaleb:
Severe weather coming?



its November its time
Member Since: July 15, 2006 Posts: 169 Comments: 53296
Quoting 287. KoritheMan:


Remember what Ryan (1900) said about cold air overrunning the surface low? The SPC is going along with that now, too:

BEFORE THE COLD INTRUSION CUTS OFF MOISTURE RETURN FROM THE GULF OF
MEXICO
...A WINDOW OF OPPORTUNITY DOES APPEAR TO EXIST FOR THE
DEVELOPMENT OF A CORRIDOR OF SUBSTANTIVE BOUNDARY LAYER
DESTABILIZATION...IN THE PRESENCE OF STRONG DEEP LAYER SHEAR AND
MID/UPPER FORCING FOR ASCENT...SUPPORTIVE OF THE RISK FOR SEVERE
STORMS.

Yeah. :/


Not surprised as this next blast of cold air means business.

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Quoting 270. Climate175:
Pattern shift in December will allow for more cold air to come down and if we get a southern storm ride up the east coast bring us some snows if the timing is perfect.
Dec 10-20 seems the most reasonable time frame. Dec 5 could also bean interesting player for first snow date bu we will have to see.


Dec 5 has already verified as first snow date in DC four times in the thirteen years of the 21's century. Coincidence but remarkable anyway.
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Quoting 284. GTstormChaserCaleb:
I'll bring tiramisu ;)



I have no idea what that is, but it looks delicious.
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Quoting 286. StormTrackerScott:


Wind dynamics are there but no cape or not much that is.


Remember what Ryan (1900) said about cold air overrunning the surface low? The SPC is going along with that now, too:

BEFORE THE COLD INTRUSION CUTS OFF MOISTURE RETURN FROM THE GULF OF
MEXICO
...A WINDOW OF OPPORTUNITY DOES APPEAR TO EXIST FOR THE
DEVELOPMENT OF A CORRIDOR OF SUBSTANTIVE BOUNDARY LAYER
DESTABILIZATION...IN THE PRESENCE OF STRONG DEEP LAYER SHEAR AND
MID/UPPER FORCING FOR ASCENT...SUPPORTIVE OF THE RISK FOR SEVERE
STORMS.

Yeah. :/
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Quoting 281. GTstormChaserCaleb:
Severe weather coming?





Wind dynamics are there but no cape or not much that is.
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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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