La Niña is here

By: Dr. Jeff Masters , 1:16 PM GMT on July 15, 2010

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The equatorial Eastern Pacific Ocean continues to cool, and we have now crossed the threshold into La Niña conditions. Sea surface temperatures (SSTs) over the tropical Eastern Pacific in the area 5°N - 5°S, 120°W - 170°W, also called the "Niña 3.4 region", fell to 0.8°C below average by July 12, according to NOAA.. The Australian Bureau of Meteorology put this number at 0.7°C below average (as of July 11.) Since La Niña conditions are defined as occurring when this number reaches 0.5°C below average, we are well into the territory of a weak La Niña event. La Niña conditions must be present for several months before this will be officially classified as a La Niña event, but it is highly likely that a full-fledged La Niña event lasting at least eight months has arrived. We started out the year with a strong El Niño, so it may seem surprising that we have transitioned La Niña so quickly, However, historically, about 35 - 40% of El Niño events are followed by a La Niña within the same year. Given current trends, I expect the current La Niña to cross the threshold needed to be defined as "moderate" strength--temperatures at least 1.0°C below average in the equatorial Eastern Pacific--by September.


Figure 1. Progression of El Niño to La Niña over the past year, as measured by SSTs in the the tropical Eastern Pacific in the area 5°N - 5°S, 120°W - 170°W, also called the "Niña 3.4 region". Image credit: NOAA Climate Prediction Center.

The implications
It is well-known that both the number and intensity of hurricanes in the Atlantic tend to increase during La Niña events. However, as I discussed in a post last month, since 1995, neutral years (when neither an El Niño or La Niña are present) have had Atlantic hurricane activity equal to La Niña years. The last time we had a strong El Niño event followed by a La Niña event in the same year, in 1998, we had a Atlantic hurricane season 40% above average in activity, with 14 named storms, 10 hurricanes, and 3 intense hurricanes. The season was relatively late-starting, with only one named storm occurring before August 20. I'm thinking this year's season may be similar, though four or more intense hurricanes are a good bet due to the record warm SSTs.

Both El Niño and La Niña events have major impacts on regional and global weather patterns. For the remainder of July and August, we can expect La Niña to bring cloudier and wetter than average conditions to the Caribbean, but weather patterns over North America should not see much impact (Figure 2.) Globally, La Niña conditions tend to cause a net cooling of surface temperatures. Thus, while the past twelve month period has been the warmest globally since record keeping began in 1880, it is unlikely that the calendar year of 2010 will set the record for warmest year ever.



Figure 2. Typical regional weather anomalies observed during June - August when La Niña conditions are present. The Caribbean tends to be cloudier and wetter than average, but there is typically little change to temperature and precipitation patterns over North America. Image credit: NOAA Climate Prediction Center.

The tropics are quiet
There are no threat areas to discuss in the Tropical Atlantic today, and none of the reliable computer models is calling for tropical cyclone development over the next seven days.

Next post
I'll have a new post on Friday.

Jeff Masters

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I would say that the National Hurricane Center would up it to 20%.

However, Convection is pretty much not there at all, so I'd imagine they keep it at 10%
Member Since: July 6, 2010 Posts: 113 Comments: 31862
Quoting Floodman:


So, by my experience, the troll is calling someone else a troll? No offense meant if it isn't true, but that's some funny!
it just keeps gettin better and better :)
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Quoting StSimonsIslandGAGuy:
I'll say NHC keeps development at 10% since it is still devoid of convection.



However, if convection starts during the night and it can keep it during the day tomorrow, then orange is likely.



Think about it, if they classified TD2, they could classify this.. but they wont LOL... 10% on the next TWO until convection forms.
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944. IKE
Quoting KEEPEROFTHEGATE:
evening
looks like it time for some empty space


A lot of it. Please admin.
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Quoting tkeith:
give that man a cigar...


So, by my experience, the troll is calling someone else a troll? No offense meant if it isn't true, but that's some funny!
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Quoting MississippiWx:


USM School of Polymers, Hattiesburg, MS
USM-TRRG:

Current Temp: 101.6F
Heat Index: 113F
Dew Point: 73F


Double yuck.
Member Since: July 6, 2010 Posts: 113 Comments: 31862
Daily near death experience: Tornado cell went right over my house a few minutes ago in E Hillsborough County. Lost computer for a while.
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Quoting Floodman:
Wait a minute...isn;t there a mrsalagranny?
give that man a cigar...
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Wait a minute...isn't there a mrsalagranny?
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evening
looks like it time for some empty space
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Quoting MississippiWx:


USM School of Polymers, Hattiesburg, MS
USM-TRRG:

Current Temp: 101.6F
Heat Index: 113F
Dew Point: 73F


Now see, THAT'S hot!
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:
Fort Worth, Meacham International Airport
Lat: 32.83 Lon: -97.35 Elev: 687
Last Update on Jul 15, 4:53 pm CDT


Fair

97 °F
(36 °C) Humidity: 43 %
Wind Speed: S 12 G 17 MPH
Barometer: 29.95" (1013.2 mb)
Dewpoint: 71 °F (22 °C)
Heat Index: 105 °F (41 °C)

Visibility: 10.00 mi

MAKE IT GO AWAY!!!




USM School of Polymers, Hattiesburg, MS
USM-TRRG:

Current Temp: 101.6F
Heat Index: 113F
Dew Point: 73F
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10% at 8
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Quoting TropicalAnalystwx13:
Fort Worth, Meacham International Airport
Lat: 32.83 Lon: -97.35 Elev: 687
Last Update on Jul 15, 4:53 pm CDT


Fair

97 °F
(36 °C) Humidity: 43 %
Wind Speed: S 12 G 17 MPH
Barometer: 29.95" (1013.2 mb)
Dewpoint: 71 °F (22 °C)
Heat Index: 105 °F (41 °C)

Visibility: 10.00 mi

MAKE IT GO AWAY!!!




You seem to live very close to me...it's North Texas in July son, MAN UP! Wait til August!
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Quoting TropicalAnalystwx13:
Fort Worth, Meacham International Airport
Lat: 32.83 Lon: -97.35 Elev: 687
Last Update on Jul 15, 4:53 pm CDT


Fair

97 °F
(36 °C) Humidity: 43 %
Wind Speed: S 12 G 17 MPH
Barometer: 29.95" (1013.2 mb)
Dewpoint: 71 °F (22 °C)
Heat Index: 105 °F (41 °C)

Visibility: 10.00 mi

MAKE IT GO AWAY!!!






i make it hoter for you
Member Since: Posts: Comments:
Fort Worth, Meacham International Airport
Lat: 32.83 Lon: -97.35 Elev: 687
Last Update on Jul 15, 4:53 pm CDT


Fair

97 °F
(36 °C) Humidity: 43 %
Wind Speed: S 12 G 17 MPH
Barometer: 29.95" (1013.2 mb)
Dewpoint: 71 °F (22 °C)
Heat Index: 105 °F (41 °C)

Visibility: 10.00 mi

MAKE IT GO AWAY!!!


Member Since: July 6, 2010 Posts: 113 Comments: 31862
Quoting primadonnagirl:
I WILL leave seaon

this season is over

i bet MR.YELLOW

is gone by 8pm

there is nothing out there

wind too strong

too much dust

the fat lady has sung

this season is over


not to add to ms primadonna but hey she did say the Fat Lady has sung, so she must be the fat lady. LOL just had to say it.
It's really nice that the tropics are quite.

Sheri
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SURVEY SAYS!

that sounded just like Richard Dawson..

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O and BTW I'm a lurker, not a troll.
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Quoting WFOR:
Miami, did you not hear me, I HAD SAID, THAT WAS NOT DIRECTED TOWARDS YOU, ALRIGHT? Besides, why does that freak you out? get it straight, OK? My reference was towards anotehr ''Robert'', whom of which, I will not reveal his identity, geeze. Case close, -_-.


anotehr.......c'mon man!
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Quoting MiamiHurricanes09:
D. 20%.

Same here.
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920. xcool
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Quoting TropicalAnalystwx13:


A. No Circle(s)
B. Near 0%
C. 10%
D. 20%
E. 30%
F. Over 30%


Ike is awarded the forecaster of the day trophy. He predicted this would happen.
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918. xcool
C
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Quoting tkeith:
keep your fingers crossed the pressure holds...


indeeeed!!
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Quoting TropicalAnalystwx13:


A. No Circle(s)
B. Near 0%
C. 10%
D. 20%
E. 30%
F. Over 30%


10%
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GOM spill has been capped!!! ... now the HARD work begins.

yep...
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Quoting TropicalAnalystwx13:


A. No Circle(s)
B. Near 0%
C. 10%
D. 20%
E. 30%
F. Over 30%
D. 20%.
Member Since: September 2, 2009 Posts: 130 Comments: 21099
Quoting DestinJeff:
Ike, I know you may be waiting for this so I will ask it for you...

What will the AOI percentage be from NHC at the next TWO?

SURVEY SAYS!
20% for me.
Member Since: September 2, 2009 Posts: 130 Comments: 21099
Quoting DestinJeff:
Ike, I know you may be waiting for this so I will ask it for you...

What will the AOI percentage be from NHC at the next TWO?

SURVEY SAYS!


A. No Circle(s)
B. Near 0%
C. 10%
D. 20%
E. 30%
F. Over 30%
Member Since: July 6, 2010 Posts: 113 Comments: 31862
Quoting MississippiWx:



LOL!!
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Quoting brla61:
Thanks tkeith.. having technical difficulties due to lack of sleep..lol
keep your fingers crossed the pressure holds...
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Quoting WeatherNerdPR:

primadonnagirl just got POOFED!


poofed and reported
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Skook you must be my next door neighbor, i live east of plant city and just reported to my daughter same storm. came up fast.
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907. IKE
Quoting primadonnagirl:
sorry, but i must leave

this season is so slow

can't handle this, so boring

like bye everyone

enjoy
your crow

caw caw


You got that right.....poof!
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Quoting primadonnagirl:
I WILL leave seaon

this season is over

i bet MR.YELLOW

is gone by 8pm

there is nothing out there

wind too strong

too much dust

the fat lady has sung

this season is over


This is the best time for a 'cane.
South of Jamaica and off coast of Africa for starters...
GOM spill has been capped!!! ... now the HARD work begins.
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905. HadesGodWyvern (Mod)
I can't grasp the true form of that rick roll..
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Thanks tkeith.. having technical difficulties due to lack of sleep..lol
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901. HadesGodWyvern (Mod)
ZCZC 875
WTPQ20 BABJ 152100
SUBJECTIVE FORECAST
TY CONSON 1002 (1002) INITIAL TIME 152100 UTC
00HR 17.0N 111.6E 975HPA 33M/S (65 knots)

30KTS 250KM
50KTS 60KM
P12HR WNW 20KM/H
NNNN
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Thanks so much for responding. I thought I was on ignore. I may have misundertood bu I thought that the post said that cap would have to be removed ifa storm came. thanks
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Quoting StormW:


Poofage!

primadonnagirl just got POOFED!
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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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