A record quiet start to the 2010 Northern Hemisphere tropical cyclone season

By: Dr. Jeff Masters , 3:42 PM GMT on August 12, 2010

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The remnants of Tropical Depression Five have re-organized this morning, and the storm is pounding Southeast Louisiana with heavy rains. Radar imagery out of New Orleans shows that the remains of TD 5 have have formed some respectable low-level spiral bands that have brought heavy rains in excess of five inches in some areas. However, with the circulation center now moving over land, not much further development can occur.


Figure 1. Morning radar image of TD Five's remains.

Why so quiet in the Atlantic?
The Tropical Atlantic is quiet, and there are no threat areas to discuss today. The Invest 93 system we were tracking has been destroyed by dry air and wind shear. There are a couple of long-range threats suggested by some of the models--the GFS model predicts a tropical depression could form off the coast of Mississippi six days from now, and the NOGAPS model thinks something could get going in the Gulf of Mexico's Bay of Campeche seven days from now. Neither of these possibilities are worthy of concern at present. Overall, it's been a surprisingly quiet August, considering the pre-season predictions of a hyperactive season. According the National Hurricane Center, this hurricane season has been exactly average so far. There have been three named storms and one hurricane as of August 12. The average date of formation of the third named storm is August 13. One hurricane typically forms by August 10. One reason for this year's inactivity may be an unusual number of upper-level low pressure systems that have paraded across the tropical Atlantic. These lows, also called Tropical Upper Tropospheric Trough (TUTT) lows, tend to bring high wind shear that inhibits tropical cyclone formation. The other major factor appears to be that vertical instability has been unusually low in the Atlantic over the past month. Instability is measured as the difference in temperature between the surface and the top of the troposphere (the highest altitude that thunderstorm tops can penetrate to.) If the surface is very warm and the top of the troposphere is cold, an unstable atmosphere results, which helps to enhance thunderstorm updrafts and promote hurricane development. Since SSTs in the Atlantic are at record highs, enhancing instability, something else must be going on. Dry air can act to reduce instability, and it appears that an unusually dry atmosphere over the Atlantic this month is responsible for the lack of instability.


Figure 2. Vertical instability (in °C) over the Caribbean (left) and tropical Atlantic between the Lesser Antilles Islands and coast of Africa (right) in 2010. Normal instability is the black line, and this year's instability levels are in blue. The atmosphere became much more stable than normal in both regions at the end of July. This lack of instability also extends to the Gulf of Mexico and North Atlantic Ocean between Europe and North America, as well as the Western Pacific east of the Philippines, and the South Indian Ocean. Image credit: NOAA/CIRA.

A record quiet start to the 2010 tropical cyclone season in the Northern Hemisphere
What is really odd about this year, though, is the lack of tropical cyclone activity across the entire Northern Hemisphere. Usually, if one ocean basin is experiencing a quiet season, one of the other ocean basins is going bonkers. That is not the case this year. Over in the Eastern Pacific, there have been five named storms and two hurricanes. The average is seven named storms and four hurricanes for this point in the season. This year's quiet season is not too surprising, since there is a moderate La Niña event underway, and La Niña conditions usually supresses Eastern Pacific hurricane activity. But over in the Western Pacific, which usually generates more tropical cyclones than any ocean basin on Earth, it has been a near-record quiet season. Just four named storms have occurred in the West Pacific this year, and the average for this date is eleven. Only one typhoon season has had fewer named storms this late in the season--1998, with just three. The total number of named storms in the Northern Hemisphere thus far this year is fifteen, which is the fewest since reliable records began in 1948. Second place belongs to 1983 and 1957, with eighteen named storms. According to an email I received from NOAA hurricane researcher Gabe Vecchi, the lack of tropical cyclones so far this year in the Northern Hemisphere is between a 1-in-80 and 1-in-100 year event.

So, what is causing this quiet tropical cyclone season? One possibility is that since Northern Hemisphere land areas have heated up to record temperatures this summer, this has created strong rising motion over the continents. This rising motion must be compensated by strong sinking motion over the adjacent oceans in order to conserve mass. Sinking air causes drying and an increase in stability. Another possibility is that the unusual jet stream configuration that is responsible for the Russia heat wave and record flooding in Pakistan is also bringing dry, stable air to the Northern Hemisphere's tropical cyclone breeding grounds. It is also possible that climate change is causing the reduction in tropical cyclone activity, for a variety of complex reasons. Computer simulations of a future warmer climate generally show a reduction in global number of tropical cyclones (though the strongest storms get stronger), and it is possible we are seeing a preview of that future climate. Or, this year's quietness may simply be natural variability. It will be interesting to see when the Russian heat wave breaks if vertical instability over the Atlantic increases back to normal levels. Current forecasts from the GFS and ECMWF models project the Russian heat wave to break late next week.

Moscow's air remains clear; coolest temperatures in two weeks
Moscow's winds remained favorable for keeping smoke away from the city today, and temperatures "cooled" to at Moscow's Domodedovo airport to 33°C (91°F)--the lowest maximum temperature since a high of 32°C (90°F) was recorded on July 30. Moscow's airport has reached a maximum temperature of 30°C (86°F) or higher for 35 consecutive days now (at Moscow's official observing site, the Moscow Observatory, this string is 30 days.) Moscow's average high temperature for August 12 is 20°C (68°F). Moscow's high temperatures have averaged 15°C (27°F) above average so far this August--a truly extraordinary anomaly for a country so famous for its notorious cold weather. The latest forecast for Moscow calls for high temperatures of 30 - 33°C (86 - 91°F) Thursday through Monday. This is still 23°F above normal, but will be a welcome change from the extreme heat of the past two weeks. Long range forecasts from the ECMWF and GFS models continue to suggest that a series of troughs of low pressure will begin to attack the ridge of high pressure anchored over Russia beginning on Wednesday, bringing cooler temperatures just 5°C (8°F) above average to Russia late next week. By ten days from now, the ECMWF model shows a strong trough of low pressure over Moscow, and a end to the Great Russian Heat Wave of 2010.

Next update
I'll have an update Friday morning.

Jeff Masters

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Since the tropics are quiet (as of now)figure I ask a preparation question. My old standby portable TV will not receive the new digital signals. I bought a portable digital set, but could not get signals in my house and had to take it back. Has anybody found a good sensitive portable TV that would be useful during a hurricane (low power consumption would be good)?
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Quoting CyclonicVoyage:


And the 2 weeks of speculation, yeee haww :-/
It's yee-haa! The other one doesn't sound right.
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1336. pottery
Quoting kmanislander:


I have had a great year with my tree. I have to give them away !!

I'll swap you 2, for a shower of rain..
Member Since: October 24, 2005 Posts: 0 Comments: 23105
Quoting CybrTeddy:


I ignore everything past 192 hours or so. But the GFS develops it only a day or so after it emerges the coast. Late-Wednesday.


It could happen but I don't think the atmosphere will "switch on" that quickly. It would take a significant shift of all the key elements in the next 4 days to allow for development come Wednesday next week. Is the atmosphere likely to moisten up,will the ULLs disappear overnight and will upper level instability set in ??.

Not that quickly IMO
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1334. scott39
Quoting mrsalagranny:
Hey Scott39 did u listen to Channel 10 News just a secod ago? He said that a low pressure system would be sitting on us Monday.
I didnt hear that, but I saw channel 15 at 5pm, and he said the models are showing it loop back to us. What it does after that is still up in the air.
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Quoting CybrTeddy:


I ignore everything past 192 hours or so. But the GFS develops it only a day or so after it emerges the coast. Late-Wednesday.


And the 2 weeks of speculation, yeee haww :-/
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1331. pottery
Quoting SLU:


Any more thunderstorms again today?

Again this afternoon.
Typical "back-in-times" wet-season weather.
Everything is nice, except the MUD!!!
Member Since: October 24, 2005 Posts: 0 Comments: 23105
Quoting firecane:
isn't that like kind of like having braille on the drive thru ATM's?
Oh my God. I never thought of that. lolol
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1329. robj144
Quoting Tazmanian:
whats new with the mode runs tonight


Are there subsets of model runs (maybe different initial data) called modes? You always refer to modes.
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possibly the hurricane season is being delayed; it will be interesting to see how long the season lasts in comparison to the last few years.
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1327. xcool
scott39 .yup ruff
Member Since: September 26, 2009 Posts: 2 Comments: 15603
Hey Scott39 did u listen to Channel 10 News just a secod ago? He said that a low pressure system would be sitting on us Monday.
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I still use thumbtacks on the tracking chart.This blog is fun though.
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Yes, clwstmchasr, 2004 was almost surreal in Florida. Always remember a poor old guy that was close to the place were 3 of the storms almost crossed saying "Boy I a am getting really tired of having to clean-up". We were very lucky in the Tampa Bay area. Curiously enough two friends at work fled Charlie to Orlando and got to experience a hurricane first hand.
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Quoting kmanislander:


From my memory of the posts earlier today everyone was focusing on systems all the way to next weekend which is over 200 hours out. The system referred to does not exit the West coast of Africa until next Tuesday.

Bit of a stretch IMO


I ignore everything past 192 hours or so. But the GFS develops it only a day or so after it emerges the coast. Late-Wednesday.
Member Since: July 8, 2005 Posts: 259 Comments: 23015
1322. pottery
Quoting AstroHurricane001:


I only began to track global SSTs last December. So I don't have any other years to compare it to. But I did post a comment on the blog prior to the quake about how the rapid fluctuations occurred on the very spot that the 1960 earthquake occurred, and another later comment about how the moon was full during the February 27 earthquake, and also that there had been a recent conjunction of the full moon and Mars and that this conjunction was directly overhead the Haiti earthquake zone on the night before the earthquake in Chile at local midnight or something like that.

Well, it would be fun to put all that together in a blog or something.
Would like to see it.
Member Since: October 24, 2005 Posts: 0 Comments: 23105
Quoting pottery:
Last week I cut the top 12 feet off my breadfruit tree.
It barely survived the dry-season, and lost all it's leaves. The top section died.
Giving it one more year.
Not a single fruit this year....


I have had a great year with my tree. I have to give them away !!
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Which way is the moisture from what was TD 5 supposed to move? It hasn't moved much today, but I thought it was supposed to go in a northeast direction when it did/does. Is that still correct?
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1319. SLU
Quoting pottery:
Hi, SLU !


Any more thunderstorms again today?
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Quoting clwstmchasr:


The GFS takes a huge CV hurricane out to the middle of the Atlantic.


Moderate to Strong La Nina's tend to favor an easterly placed high profile. Looking at things though, taking day by day, things are surely different.
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1317. pottery
Quoting jrweatherman:


And if the models were pointing at the U.S. most people would agree with them? But since it shows a fish they say the models are struggling.

Classic!
Member Since: October 24, 2005 Posts: 0 Comments: 23105
Quoting jrweatherman:


And if the models were pointing at the U.S. most people would agree with them? But since it shows a fish they say the models are struggling.


I don't know about others but I am a model sceptic regardless of where they point to.
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1315. HadesGodWyvern (Mod)
Japan Meteorological Agency

EXTRATROPICAL LOW, FORMER DIANMU (T1004)
43.0ºN 151.0ºE - 998 hPa

Low Position
===================
Sea East of Japan moving east northeast at 35 knots
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Quoting xcool:
xxxtd5 is alive alive lol
You hangin in there xcool?
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Quoting pottery:

Have you (or anyone) noted a similiar ocean phenomenon there, and no quake in the past?
Interesting....


I only began to track global SSTs last December. So I don't have any other years to compare it to. But I did post a comment on the blog prior to the quake about how the rapid fluctuations occurred on the very spot that the 1960 earthquake occurred, and another later comment about how the moon was full during the February 27 earthquake, and also that there had been a recent conjunction of the full moon and Mars and that this conjunction was directly overhead the Haiti earthquake zone on the night before the earthquake in Chile at local midnight or something like that.
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Quoting MiamiHurricanes09:
Not 250 hours out, more like 144 hours out. The GFS, CMC, and ECMWF all develop it into a tropical cyclone.

G'night everyone!


From my memory of the posts earlier today everyone was focusing on systems all the way to next weekend which is over 200 hours out. The system referred to does not exit the West coast of Africa until next Tuesday.

Bit of a stretch IMO
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1311. pottery
Hi, SLU !
Member Since: October 24, 2005 Posts: 0 Comments: 23105
1310. scott39
Quoting xcool:
xxxtd5 is alive alive lol
Its coming back around to get us again. LOL
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1309. robj144
Quoting Patrap:

A review of Saints vs Pats 2009 MNF game,when it counted..

LOL


What is this?! It's the past man. Let's see about this year... :)
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Quoting kmanislander:


The models are struggling big time this year. I wouldn't bet on anything they say, especially 250 hours out.


And if the models were pointing at the U.S. most people would agree with them? But since it shows a fish they say the models are struggling.
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1307. Drakoen
Quoting Tropicsweatherpr:


Drakoen, what does that graphic represent?


It shows the curvature vorticity at 700mb, the 700mb winds, and the stream function. The black lines oriented meridionally (north to south) indicate troughs and the red line represents the African Easterly Jet.
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1305. pottery
Quoting kmanislander:
On the subject of heat, the average temperature in Grand Cayman for June was 86F, 4 degrees above the long term average of 82F
Last week I cut the top 12 feet off my breadfruit tree.
It barely survived the dry-season, and lost all it's leaves. The top section died.
Giving it one more year.
Not a single fruit this year....
Member Since: October 24, 2005 Posts: 0 Comments: 23105
1304. scott39
Is there going to be an explosion of major hurricanes from the end of August until end of October? If im reading right all the ingredients are there except for moist air and to many ULL and TUTTS. And those unfavorable conditions are going to change soon. Im not so worried about how many storms will form, as I am of how dangerous the ones that do are!
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Quoting kmanislander:


The models are struggling big time this year. I wouldn't bet on anything they say, especially 250 hours out.
Not 250 hours out, more like 144 hours out. The GFS, CMC, and ECMWF all develop it into a tropical cyclone.

G'night everyone!
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1301. TxKeef
Quoting dsenecal2009:



Wouldn't worry about it. Most waves that pass over Nigeria have their identity stolen almost immediately.



Now THAT is funny.

XTD5 Must love LA.
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Quoting pottery:

4 degrees is a massive jump...


Indeed. Our electricity company tracks temperature anomalies.
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Quoting clwstmchasr:


The GFS takes a huge CV hurricane out to the middle of the Atlantic.


The models are struggling big time this year. I wouldn't bet on anything they say, especially 250 hours out.
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1298. pottery
Quoting kmanislander:
On the subject of heat, the average temperature in Grand Cayman for June was 86F, 4 degrees above the long term average of 82F

4 degrees is a massive jump...
Member Since: October 24, 2005 Posts: 0 Comments: 23105
Reading Klotzbach article Link , just had a weird moment of deja vu. I am sure some here have already commented on it, but 2004 also had an Alex, Bonnie and Danielle. But it had Charlie in between. That one almost got the Tampa Bay Area. Jim Cantore was stationed on the beach two miles from my house. If Charlie had hit the Tampa Bay Area, the results would have been horrific. Gives me the shivers.
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1295. SLU
Quoting CyclonicVoyage:


Unless something that isn't in the protocol continues to hamper the basin that is. Climate change is real folks, lol.

We're in the denial stage right now.


Let's hope it continues


Goodnight Pottery.


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Quoting stormhank:
Whats scary is the set up for more storms to threaten the coasts and not recurve..similiar it seems to 04 n 05 seasons


Not at the moment. Our first CV storm is going to be a fish - unlike 04 & 05.
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Due to the August jet stream pattern ending the dry heat wave in western Europe, floods continue in central Europe while Portugal fights fires. Link
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On the subject of heat, the average temperature in Grand Cayman for June was 86F, 4 degrees above the long term average of 82F
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1291. xcool
xxxtd5 is alive alive lol
Member Since: September 26, 2009 Posts: 2 Comments: 15603
1290. pottery
Quoting AstroHurricane001:


Of course, that was only an observed correlation and does not imply that either event caused the other one. But it's a potential theory to watch.

Have you (or anyone) noted a similiar ocean phenomenon there, and no quake in the past?
Interesting....
Member Since: October 24, 2005 Posts: 0 Comments: 23105
Forest fires in central Brazil. It's winter there. Link
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Thanks Patrap and scott......! Nothing like the information station here!
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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.