Results 101 to 125 of 231
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09-17-2010, 09:58 PM #101
Vail?
Area Monthly Seasonal Seasons
Strongly favored by La Nina
Big Mountain, Mont. 6,700 -30.5%
Castle Mt., Alb. 5,700 -33.3%
Sunshine Village, Alb. 7,028 -23.5% -55.6% 40
Mt. Hood Meadows, Ore. 5,400 -19.5% -55.8% 21
Jackson Hole, Wyo. 8,250 -20.7% -50.9% 43
Mt. Baker, Wash. 4,300 -20.7% -50.7% 20
Mt. Rainier Paradise, Wash. 5,420 -25.3% -49.9% 44
Silver Star, B. C. 5,200 -24.2% -48.9% 18
Fernie Snow Valley, B. C. 5,400 -17.1% -48.9% 21
Mt. Fidelity (Selkirks), B. C. 6,150 -20.1% -47.5% 41
Whistler Base, B. C. 2,200 -24.9% -46.1% 39
Bridger Bowl, Mont. 7,100 -23.1%
Schweitzer, Idaho 4,700 -23.4%
Teton Pass, Wyo. 8,000 -21.3%
Snoqualmie Pass, Wash. 3,000 -19.1%
Mildly favored by La Nina
Steamboat, Colo. 9,200 -18.5% -41.3% 27
Smuggler's Notch, Vt. 1,600 -17.8% -40.5% 18
Lake Louise, Alb. 6,700 -17.7% -38.5% 41
Cannon Mt., N. H. 1,800 -16.6% -31.0% 34
Mt. Bachelor, Ore. 6,350 -18.4% -30.2% 37
Tod Mt. (Sun Peaks), B. C. 6,100 -17.1%
Mt. Norquay, Alb. 5,350 -16.3% -32.7% 20
Jay Peak, Vt. 3,000 -16.6% -34.8% 29
Stevens Pass, Wash. 4,061 -16.4%
Loon, N. H. 2,000 -16.4%
Mt. St. Anne, Que. 2,000 -15.7%
Stowe, Vt. 3,950 -14.7% -31.6% 44
Crater Lake (Mt. Bailey), Ore. 6,800 -15.3% -31.0% 44
Big White, B. C. 6,200 -12.0% -31.3% 25
Grand Targhee, Wyo. 8,200 -14.1% -29.4% 34
Spencer's Creek, Australia 5,903 -25.8% 53
For Washington and Oregon I selected the Mt. Rainier (purple line) and Crater Lake (yellow line) National Park data because it was complete for all 44 years. Mt. Rainier is close to Crystal Mt. ski area, and Crater Lake is close to Mt. Bailey snowcat skiing and a couple of hours drive from Mt. Bachelor ski area. Jackson Hole (orange line) and Sunshine Village (light blue line) are good representative ski areas for the Northern Rockies of the U.S. and Canada respectively.
Results are quite consistent for these 4 areas in the strong La Nina seasons. All 4 areas are at least average in the top 7 La Nina years except for Sunshine at 94% in 1974-75. In the 2 highest years 1973-74 and 1970-71, 3 of the 4 selected areas were over 130% of normal snowfall. And in the 5th highest 1998-99, 3 of the 4 areas were over 140%.
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09-20-2010, 05:42 PM #102
i seem to remember getting more snow than "mildly favored" targhee the last nina year. muwhahahhahhaha =)
"I think people resist freedom because they're afraid of the unknown. But it's ironic....That unknown was once very well known. It's where our souls belong....The only solution is to confront them--confront yourself--with the greatest fear imaginable. Expose yourself to your deepest fear. After that, fear has no power, and fear of freedom shrinks and vanishes. You are free." -Jim Morrison
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10-04-2010, 07:54 PM #103
edit - nevermind, found some specifics/guesses on Montana
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Expected La Niña impacts during September-November 2010 include suppressed convection over the central tropical Pacific Ocean, and enhanced convection over Indonesia. The transition into the Northern Hemisphere Fall means that La Niña will begin to exert an increasing influence on the weather and climate of the United States. These impacts include an enhanced chance of above-average precipitation in the Pacific Northwest, and below-average precipitation in the Southwest and in portions of the middle and lower Mississippi Valley and Tennessee Valley. Also, La Niña can contribute to increased Atlantic hurricane activity by decreasing the vertical wind shear over the Caribbean Sea and tropical Atlantic Ocean (see the August 5th update of the NOAA Atlantic Seasonal Hurricane Outlook), and to suppressed hurricane activity across the central and eastern tropical North Pacific.
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Western Montana's warm fall expected to turn into cold, wet winter
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Found this OB article that talks about the 96-97 La Nina - http://www.outsidebozeman.com/magazi...&articleID=315
La Nina in Montana
One hundred and ten years after the record-breaking, tough winter of 1886-’87, Montana experienced its last “real” winter, and the weather occurrence known as La Nina may be the culprit in both cases.
The winter of 1996-97 also broke records, with heavy snowfalls that left skiers and snowboarders salivating, but also brought some bone-chilling temperatures: on Christmas morning, the temperature hovered around zero in Bozeman, and two feet of fresh snow buried cars and made streets impassable. When spring finally rolled around, flooding made Albertson’s parking lot a lake and N. Rouse a rolling stream. Many local rivers set new high water records, like the Yellowstone, which rose nearly three feet above flood stage, cresting a quarter-inch below 11 feet and making the river a half-mile wide in many Park County stretches for days. Hardcore kayakers and rafters were delighted, but property owners weren’t.
Blame it on La Nina, the term scientists use to describe a cooling trend in the waters of the southern Pacific Ocean which affects weather worldwide. La Nina and its opposite sister, El Nino, which causes a warming of the southern ocean waters, began to be studied by scientists studying weather patterns in the 1980s. According to researchers, weather changes during La Nina seasons usually occur during the transition between fall and winter, essentially during the holiday season, from Thanksgiving through New Year’s Day. During all the La Nina seasons researched, temperatures went from well above average to normal or below during the transition, accompanied by above-normal precipitation.
Coincidentally, the harsh winter of 1886-’87 is also the first scientifically recorded (using available data) La Nina episode, although the native peoples of Chile, Bolivia, and Peru have observed and remembered La Nina and El Nino occurrences for centuries. The winter of 1996-97 was the last time La Nina played with the weather and brought real winter to Montana. What does this winter hold for us?
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10-07-2010, 11:38 AM #104
EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
7 October 2010
ENSO Alert System Status: La Niña Advisory
Synopsis: La Niña is expected to last at least into the Northern Hemisphere spring 2011.
La Niña continued during September 2010 as reflected by the large expanse of below-average sea surface temperatures (SSTs) across most of the equatorial Pacific Ocean (Fig. 1). All weekly Niño SST index values were between –1.3°C and –1.8°C at the end of the month (Fig. 2). In addition, the subsurface heat content (average temperatures in the upper 300m of the ocean, Fig. 3) remained below-average, reflecting a shallower-than-average thermocline in the central and eastern Pacific (Fig. 4). Convection remained enhanced over Indonesia and suppressed over the western and central equatorial Pacific (Fig. 5). This pattern was linked to a continuation of enhanced low-level easterly trade winds and anomalous upper-level westerly winds over the western and central equatorial Pacific. Collectively, these oceanic and atmospheric anomalies reflect the ongoing La Niña.
Consistent with nearly all of the forecast models (Fig. 6), La Niña is expected to last at least into the Northern Hemisphere spring 2011. Just over half of the models, as well as the dynamical and statistical averages, predict La Niña to become a strong episode (defined by a 3-month average Niño-3.4 index of –1.5°C or colder) by the November-January season before beginning to weaken. Even though the rate of anomalous cooling temporarily abated during September, this model outcome is favored due to the historical tendency for La Niña to strengthen as winter approaches.
Likely La Niña impacts during October-December 2010 include suppressed convection over the central tropical Pacific Ocean, and enhanced convection over Indonesia. The transition into the Northern Hemisphere fall means that La Niña will begin to exert an increasing influence on the weather and climate of the United States. Expected U.S. impacts include an enhanced chance of above-average precipitation in the Pacific Northwest, and below-average precipitation across the southern tier of the country. Also, La Niña can contribute to increased Atlantic hurricane activity by decreasing the vertical wind shear over the Caribbean Sea and tropical Atlantic Ocean (see the August 5th update of the NOAA Atlantic Seasonal Hurricane Outlook). Conversely, La Niña is associated with suppressed hurricane activity across the central and eastern tropical North Pacific.
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10-07-2010, 01:22 PM #105Registered User
- Join Date
- Dec 2008
- Posts
- 824
Data suggests that 96/97 was a neutral year, though. http://www.cpc.ncep.noaa.gov/product...nsoyears.shtml
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10-17-2010, 08:23 AM #106
Thats cuz "mildly favored" is calculated off an ideal "average" of 500 inches. Ergo a mere 20% increase in pow days for the season is a +100 inches and gets you to the magic 600 inches, hardly a mild season by anyone's standards. But we all know that a strong Nino can short the Ghee with a relatively lame season of 275-400 inches. What the term "mildly favored" totally fails to convey is the potential difference between a strong Nino and Nina at the Ghee - the difference between 300 and 600 inches. Last season is an interesting example. It was a mediocre season(downright lame in Jackson) as the weak Nino fizzled out in Jan/Feb but when the ocean temps began the cooling period starting in March, the season suddenly blew up with two prolonged spring storm cycles bringing in 10 feet and afterwards we also saw the wettest May on record in east Idaho.
Targhee got 630 inches on the ridgetop in 07/08(Nina) and struggled to make 350 in 06/07(Nino) but the guy who put together these stats prefers to see the effects of the cycle as mild at the Ghee. Obviously, an armchair analyst who doesn't actually ski here year in and out. There is nothing "mild" about the difference between a frustrating, forgetable season and 600+ inches, one of the best seasons you'll ever have in your lifetime.Last edited by neckdeep; 10-24-2010 at 10:45 AM.
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11-03-2010, 09:35 AM #107
So this is actually from a commodity trading newsletter. Obviously temps are more important to them but there is some interesting Ocean Temp. Info cited suggesting the severity of this La Nina. I don't know if anyone has access to the full "Browning" news report he is citing
“Browning” is one of the better, long term weather
forecasting reports we read on a consistent basis, and
the latest edition has our attention for Ms. Garriss writes
of weather in football game terms noting that this winter
we may see
"a potential pile on. Three enormous weather
patterns are surrounding North America. All
three cause cold winter weather. Expect to be
flattened."
Ms. Garriss notes that the La Nina in the Pacific Ocean
has taken the ocean temperatures there down quite
sharply. As she says
"Temperatures between 0.5°C – 1.0°C (0.9° -
1.8°F) below normal are considered a “weak”
La Nina. When the chill is more than 1.0°C
(1.8°F) below normal, the event is “moderate.”
Now temperatures range from 1.4°C (2.5°F)
below normal in the central Pacific around Fiji
to 2.0°C (3.6°F) off the coast of Peru."
She notes further that although the temperatures in the
central Pacific are holding steady at the current rather
archly low levels, they are continuing to fall in the
eastern Pacific off the coast of S. America. She also
notes that it is not just cool water temperatures that she
finds worrisome. There are other global weather effects
in place that serve to make the current La Nina material
and worrisome. We will try to detail those effects in the
days ahead, but she summarizes her findings with the
following rather ominous statement:
"If all of these are combined, then the current
La Nina is the strongest in over 70 years. It is
almost as intense as the La Nina in the winters
of 1955-1956. It is currently almost two
standard deviations below normal and most
models expect the phenomenon to intensify
over the next three months."
This mostly speaks to temperatures, so I don't know what this means about the important things (like precipitation) but seems somewhat relevant.I wear crocs for the style, not the comfort.
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11-03-2010, 10:01 AM #108
The high levels of precip in the favored areas come from the way in which the prevalent storm track off the NW Pacific sets up when the ocean is cold. We are hoping to see the storm track held in the "pinapple express" pattern for prolonged storm cycles rather than the big ridge/deep trough pattern more common with an El Nino. Visualize it as the difference between having a hose sprayed directly at you or sprayed back and forth across you. You are gonna get wetter with the hose pointed directly at you. You are also going to see some monster lift closing wind events and brutally subzero days that can burn your face. La Nina opens the door to some huge frigid air masses from Siberia. The map in Freak's post (on this page) shows the interplay between the pinapple express and Siberian airmass.
The Tetons have all ready had one pinapple express storm (last weekend) and picked up an astounding 3.5 inches of water in a 3ft dump. Too much of a good thing? I'm concerned that if the ocean gets extremely cold, the storm track could migrate up into Canada and leave the Tetons/Wasatch dry for awhile in midwinter.Last edited by neckdeep; 11-03-2010 at 10:14 AM.
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11-04-2010, 12:21 AM #109
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11-04-2010, 07:02 PM #110
EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
4 November 2010
ENSO Alert System Status: La Niña Advisory
Synopsis: La Niña is expected to last at least into the Northern Hemisphere spring 2011.
La Niña continued during October 2010, as indicated by below-average sea surface temperatures (SSTs) across most of the equatorial Pacific Ocean (Fig. 1). The weekly Niño SST index values remained nearly unchanged, and were all –1.4°C at the end of the month (Fig. 2). The subsurface heat content (average temperatures in the upper 300m of the ocean, Fig. 3) also changed little during October, and remained well below-average in association with a shallower-than-average thermocline across the central and eastern Pacific (Fig. 4). Convection remained enhanced over Indonesia and suppressed over the western and central equatorial Pacific (Fig. 5). This pattern was linked to a continuation of enhanced low-level easterly trade winds and anomalous upper-level westerly winds over the western and central equatorial Pacific. Collectively, these oceanic and atmospheric anomalies reflect the ongoing La Niña.
Consistent with nearly all ENSO forecast models (Fig. 6), La Niña is expected to last at least into the Northern Hemisphere spring 2011. A large majority of models also predict La Niña to become a strong episode (defined by a 3-month average Niño-3.4 index of –1.5°C or colder) by the November-January season before gradually weakening. A few of the models, including the NCEP Climate Forecast System (CFS), suggest that La Niña could persist into the Northern Hemisphere summer 2011. However, no particular outcome is favored beyond the Northern Hemisphere spring due to large model disagreement and lower model skill during the period.
Likely La Niña impacts during November 2010-January 2011 include suppressed convection over the central tropical Pacific Ocean, and enhanced convection over Indonesia. Expected impacts in the United States include an enhanced chance of above-average precipitation in the Pacific Northwest, Northern Rockies (along with a concomitant increase in snowfall), and Ohio Valley, while below-average precipitation is most likely across the south-central and southeastern states. An increased chance of below-average temperatures is predicted for coastal and near-coastal regions of the northern West Coast, and a higher possibility of above-average temperatures is expected for much of the southern and central U.S. (see 3-month seasonal outlook released on October 21st, 2010).
This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA’s National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Forecasts for the evolution of El Niño/La Niña are updated monthly in the Forecast Forum section of CPC's Climate Diagnostics Bulletin. The next ENSO Diagnostics Discussion is scheduled for 9 December 2010. To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: ncep.list.enso-update@noaa.gov.
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12-06-2010, 03:52 PM #111
has there been any updates?
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12-09-2010, 07:38 PM #112
It just came out today:
EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
9 December 2010
ENSO Alert System Status: La Niña Advisory
Synopsis: La Niña is expected to last at least into the Northern Hemisphere spring 2011.
During November 2010, the ongoing La Niña was reflected by below-average sea surface temperatures (SSTs) across the equatorial Pacific Ocean (Fig. 1). For the second straight month, only small changes were evident in the Niño SST indices, which ranged from –1.3°C to –1.7°C at the end of the month (Fig. 2). The subsurface oceanic heat content (average temperatures in the upper 300m of the ocean, Fig. 3) also remained well below-average in association with a shallower-than-average thermocline across the central and eastern equatorial Pacific (Fig. 4). Convection remained enhanced over Indonesia and suppressed over the western and central equatorial Pacific (Fig. 5). Enhanced low-level easterly trade winds and anomalous upper-level westerly winds continued over the equatorial Pacific. Collectively, these oceanic and atmospheric anomalies reflect a moderate-to-strong La Niña.
Consistent with nearly all ENSO forecast models (Fig. 6), La Niña is expected to peak during November-January and to continue into the Northern Hemisphere spring 2011. Thereafter, the fate of La Niña is more uncertain. The majority of forecast models and all of the multi-model combinations (thicker lines) indicate a return to ENSO-neutral conditions during the Northern Hemisphere spring and early summer. However, a smaller number of models, including the NCEP Climate Forecast System, suggest that La Niña could persist into the summer. Historically, there are more multi-year La Niña episodes than El Niño episodes, but other than support from a few model runs, there is no consensus for a multi-year La Niña at this time. Consequently, La Niña is anticipated to continue into the Northern Hemisphere spring, with no particular outcome favored thereafter.
Likely La Niña impacts during December 2010-February 2011 include suppressed convection over the central tropical Pacific Ocean, and enhanced convection over Indonesia. Impacts in the United States include an enhanced chance of above-average precipitation in the Pacific Northwest, Northern Rockies (along with a concomitant increase in snowfall), Great Lakes, and Ohio Valley. Below-average precipitation is most likely across the southern states, extending into the Mid-Atlantic region. An increased chance of below-average temperatures is predicted for the northernmost western and central states, and a higher possibility of above-average temperatures is forecast for much of the southern and central U.S. (see 3-month seasonal outlook released on November 18th, 2010).
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01-04-2011, 07:48 AM #113
Latest EL Nino Spanish for the Nino/Southern Oscillation forecast
Damn. I saw the January pics and got all excited, thinking there was that much snow somewhere only a week ago.
Then I realized it was 2010 now...and those pictures were a year old.
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01-07-2011, 12:42 AM #114
EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
6 January 2011
ENSO Alert System Status: La Niña Advisory
Synopsis: La Niña is expected to continue well into the Northern Hemisphere spring 2011.
A moderate-to-strong La Niña continued during December 2010 as reflected by well below-average sea surface temperatures (SSTs) across the equatorial Pacific Ocean (Fig. 1). All of the Niño indices were –1.5°C at the end of December, except for the easternmost Niño-1+2 region (Fig. 2). The subsurface oceanic heat content (average temperatures in the upper 300m of the ocean, Fig. 3) continued to reflect a large reservoir of below-average temperatures at depth in the central and eastern equatorial Pacific (Fig. 4). Convection remained enhanced over Indonesia and suppressed over the western and central equatorial Pacific (Fig. 5). Also, enhanced low-level easterly trade winds and anomalous upper-level westerly winds continued over the equatorial Pacific. Collectively, these oceanic and atmospheric anomalies reflect the ongoing La Niña.
The current ENSO model forecasts have not changed significantly compared to last month (Fig. 6). La Niña is currently near its peak and is expected to persist into the Northern Hemisphere spring 2011 at a lesser intensity. Thereafter, there remains considerable uncertainty as to whether La Niña will last into the Northern Hemisphere summer (as suggested by the NCEP CFS and a few other models), or whether there will be a transition to ENSO-neutral conditions (as suggested by the CPC CON and a majority of the other models).
Likely La Niña impacts during January-March 2011 include suppressed convection over the west-central tropical Pacific Ocean, and enhanced convection over Indonesia. Impacts in the United States include an enhanced chance of above-average precipitation in the Pacific Northwest, Northern Rockies (along with a concomitant increase in snowfall), Great Lakes, and Ohio Valley. Below-average precipitation is favored across the southwestern and southeastern states. An increased chance of below-average temperatures is predicted for much of the West Coast and northern tier of states (excluding New England), and a higher possibility of above-average temperatures is forecast for much of the southern and central U.S. (see 3-month seasonal outlook released on December 16th, 2010). While seasonal temperature and precipitation patterns in the U.S. are strongly influenced by La Niña, these signals can be modified by other factors, such as the Arctic Oscillation (AO)/ North Atlantic Oscillation (NAO).
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02-10-2011, 10:35 PM #115
EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
10 February 2011
ENSO Alert System Status: La Niña Advisory
Synopsis: ENSO-Neutral or La Niña conditions are equally likely during May-June 2011
La Niña persisted during January 2011 as reflected by well below-average sea surface
temperatures (SSTs) across much of the equatorial Pacific Ocean (Fig. 1). However, some weakening
was evident in certain atmospheric and oceanic anomalies, in part due to Madden-Julian Oscillation
activity. Most Niño indices were between –1°C and –1.5°C at the end of January, with the easternmost
Niño-1+2 region returning to near-average (Fig. 2). A lessening of the negative subsurface oceanic heat
content anomalies (average temperatures in the upper 300m of the ocean, Fig. 3) was observed mostly in
association with an eastward shift in the above-average temperatures at depth in the central equatorial
Pacific (Fig. 4). Convection remained enhanced over Indonesia and suppressed over the western and
central equatorial Pacific (Fig. 5). Also over the western and central equatorial Pacific, the anomalous
low-level easterly and upper-level westerly winds decreased in magnitude. Collectively, these oceanic
and atmospheric anomalies reflect an ongoing, mature La Niña that has begun to weaken.
Nearly all of the ENSO model forecasts weaken La Niña in the coming months (Fig. 6). A
majority of the models predict a return to ENSO-neutral conditions by May-June-July 2011, although
some models persist a weaker La Niña into the Northern Hemisphere summer 2011. Recent trends in the
observations and models do not offer many hints on which outcome is more likely. Also, model skill is
historically at a minimum during the Northern Hemisphere spring (the “spring barrier”). Therefore La
Niña is expected to weaken during the next several months, with ENSO-neutral or La Niña conditions
equally likely during May-June 2011.
Expected La Niña impacts during February-April 2011 include suppressed convection over the
west-central tropical Pacific Ocean, and enhanced convection over Indonesia. Potential impacts in the
United States include an enhanced chance of above-average precipitation in the Northern Rockies and
western regions of the Northern Plains (along with a concomitant increase in snowfall), Great Lakes, and
Ohio Valley. Below-average precipitation is favored across much of the southern states. An increased
chance of below-average temperatures is predicted for much of the West Coast and northern tier of states
(excluding New England), and a higher possibility of above-average temperatures is forecast for much of
the southern and central U.S. (see 3-month seasonal outlook released on January 20th, 2011).
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03-11-2011, 07:32 PM #116
EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
10 March 2011
ENSO Alert System Status: La Niña Advisory
Synopsis: ENSO-neutral conditions are expected by June 2011.
La Niña continued to weaken during February 2011 as reflected by the reduced strength of the negative surface and near-surface temperature anomalies across much of the equatorial Pacific Ocean (Figs. 1 and 4). The Niño indices were between –0.5°C and –1.3°C at the end of February (Fig. 2). Subsurface oceanic heat content anomalies (average temperatures in the upper 300m of the ocean, Fig. 3) returned to near zero in response to the eastward progression of a strong oceanic Kelvin wave, which has weakened the negative temperature anomalies at depth in the central and eastern equatorial Pacific (Fig. 4). La Niña continued to be most evident in the atmospheric circulation over the equatorial Pacific, although at lesser intensity. Convection remained enhanced over much of Indonesia and suppressed over the western and central equatorial Pacific (Fig. 5). Also, anomalous low-level easterly and upper-level westerly winds have persisted in this region. However, a reduction in the strength of the anomalous low-level cross-equatorial flow, and associated oceanic upwelling, over the eastern Pacific contributed to anomalous SST warming in that region. Collectively, these oceanic and atmospheric anomalies reflect a weakening La Niña.
In concurrence with the observed evolution, nearly all of the ENSO models predict La Niña to weaken further in the coming months (Fig. 6). While the majority of models predict a return to ENSO-neutral by May-June-July 2011 (three month average in the Nino-3.4 index between –0.5°C and +0.5°C), there continues to be large uncertainty in the status of ENSO through the Northern Hemisphere summer and fall. Due to both model and observed trends, there is increasing confidence in ENSO-neutral conditions by June 2011. However, model forecasts issued in the spring typically have minimum skill (the “spring barrier”), which results in low confidence forecasts for summer and beyond.
La Niña will continue to have global impacts even as the episode weakens through the Northern Hemisphere Spring. Expected La Niña impacts during March-May 2011 include suppressed convection over the west-central tropical Pacific Ocean, and enhanced convection over Indonesia. Potential impacts in the United States include an enhanced chance of below-average precipitation across much of the southern states and the Central Rockies and Central Plains. An increased chance of below-average temperatures is predicted for much of the West Coast and across the northern tier of states (excluding New England). A higher possibility of above-average temperatures is favored for much of the southern half of the contiguous U.S. (see 3-month seasonal outlook released on February 17th, 2011).
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04-14-2011, 11:49 PM #117
EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
7 April 2011
ENSO Alert System Status: La Niña Advisory
Synopsis: A transition to ENSO-neutral conditions is expected by June 2011.
La Niña weakened for the third consecutive month, as reflected by increasing surface and subsurface ocean temperatures across the equatorial Pacific Ocean. All four Niño indices ranged between –0.3°C and –0.8°C at the end of March 2011 (Fig. 1). Subsurface oceanic heat content anomalies (average temperatures in the upper 300m of the ocean, Fig. 2) became weakly positive in response to the continued eastward progression of a strong oceanic Kelvin wave, which has begun to shoal in the eastern Pacific (Fig. 3). However, the basin wide extent of negative SST anomalies remained considerable throughout the month (Fig. 4). Also, La Niña impacts on the atmospheric circulation remained strong over the tropical and subtropical Pacific. Convection remained enhanced over much of Indonesia and suppressed over the western and central equatorial Pacific (Fig. 5). Also, anomalous low-level easterly and upper-level westerly winds have persisted in this region. Collectively, these oceanic and atmospheric anomalies reflect a weakening La Niña, but with ongoing global impacts.
Nearly all of the ENSO models predict La Niña to continue weakening in the coming months, and the majority of models indicate a return to ENSO-neutral by May-June-July 2011 (three month average in the Nino-3.4 index between –0.5°C and +0.5°C; Fig. 6). While there is confidence in ENSO-neutral conditions by June 2011, the forecasts for the late summer and beyond remain highly uncertain. At this time, all of the multi-model forecasts (shown by the thick lines) suggest ENSO-neutral conditions will persist from June through the rest of the year. However, the spread of individual model forecasts and overall model skill at these lead times leaves the door open for either El Niño or La Niña conditions by the end of 2011.
La Niña will continue to have global impacts even as the episode weakens through the Northern Hemisphere spring. Expected La Niña impacts during April-June 2011 include suppressed convection over the west-central tropical Pacific Ocean, and enhanced convection over Indonesia. Potential impacts in the United States include an enhanced chance for below-average precipitation across much of the South, while above-average precipitation is favored for the northern Plains. An increased chance of below-average temperatures is predicted across the northern tier of the country (excluding New England). A higher possibility of above-average temperatures is favored for much of the southern half of the contiguous U.S. (see 3-month seasonal outlook released on March 17th, 2011).
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07-10-2011, 09:46 AM #118
Grabbed from latest ENSO discussion:
Forecasts from a majority of the ENSO models, indicate ENSO-neutral will continue into the Northern Hemisphere fall 2011 (three-month average in the Nino-3.4 index between –0.5°C and +0.5°C; Fig. 6). However, over the last couple of weeks, forecasts created by the NCEP Climate Forecast System (CFS) have begun to indicate the re-emergence of La Niña during Northern Hemisphere fall 2011 (Fig. 7). Combined with the recent weakening of the positive subsurface ocean anomalies and the lingering La Niña state of the atmosphere, the possibility of a return to La Niña during the Northern Hemisphere fall 2011 has increased over the past month. However, ENSO-neutral remains most likely into the Northern Hemisphere fall 2011, with most models and all multi-model forecasts (shown by the thick lines) predicting ENSO-neutral to continue through early 2012
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07-19-2011, 06:57 AM #119
Nina mixed with neutral...will Jackson see there inches go OVER 9000? only time will tell
<3 weather
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08-04-2011, 11:04 PM #120
EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
4 August 2011
ENSO Alert System Status: La Niña Watch
Synopsis: ENSO-neutral is expected to continue into the Northern Hemisphere fall 2011, with ENSO-neutral or La Niña equally likely thereafter.
During July 2011, ENSO-neutral was reflected in the overall pattern of small sea surface temperature (SST) anomalies across the equatorial Pacific Ocean (Fig. 1). All of the latest weekly Niño index values were generally near average (Fig. 2), ranging from –0.2°C (Niño-3.4) to 0.5°C (Niño-1+2). However, the subsurface oceanic heat content anomaly (average temperature anomalies in the upper 300m of the ocean, Fig. 3) continued to weaken and is currently near zero, which reflects the strengthening of the below-average temperatures at depth in the east-central Pacific Ocean (Fig. 4). The atmospheric circulation anomalies were more variable during the past month, but the monthly means still reflect aspects of La Niña. For example, convection continued to be enhanced over eastern Indonesia and Papua New Guinea, and generally suppressed over the central equatorial Pacific, mainly south of the equator (Fig. 5). Also, anomalous low-level easterly and upper-level westerly winds persisted over the central tropical Pacific. Thus, while tropical Pacific oceanic anomalies indicate ENSO-neutral, the atmospheric patterns continue to reflect La Niña-like conditions.
The majority of ENSO models, and all multi-model average forecasts (indicated by thicker lines, Fig. 6), indicate ENSO-neutral will continue into the Northern Hemisphere fall 2011 (three-month average in the Nino-3.4 index between –0.5°C and +0.5°C). Beyond the early fall, the forecasts are less certain with half of the models persisting ENSO-neutral conditions continuously through early 2012. Along with a few other models, the latest runs from the NCEP Climate Forecast System (CFS) models predict La Niña to re-develop during the fall (Fig. 7). This forecast is also supported by the ongoing La Niña-like tropical atmosphere, subsurface temperature trends, and the historical tendency for significant wintertime La Niña episodes to be followed by relatively weaker La Niña episodes the following winter. Therefore, ENSO-neutral is expected to continue into the Northern Hemisphere fall 2011, with ENSO-neutral or La Niña equally likely thereafter.
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08-04-2011, 11:47 PM #121
Sounds favorable.
I form the light, and create darkness: I make peace, and create evil: I the LORD do all these things. -אלוהים אדירים
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09-08-2011, 08:56 AM #122
EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
8 September 2011
ENSO Alert System Status: La Niña Advisory
Synopsis: La Niña conditions have returned and are expected to gradually strengthen and continue into the Northern Hemisphere winter 2011-12.
La Niña conditions returned in August 2011 due to the strengthening of negative sea surface temperature (SST) anomalies across the eastern half of the equatorial Pacific Ocean (Fig. 1). With the exception of the far westernmost Niño-4 region, all of the latest weekly Niño index values were –0.5°C or less (Fig. 2). Also supporting the return of La Niña conditions was the strengthening of the below-average subsurface oceanic heat content anomaly (average temperature anomalies in the upper 300m of the ocean, Fig. 3), in response to increased upwelling and further shoaling of the thermocline across the eastern Pacific Ocean (Fig. 4). The atmospheric circulation over the tropical Pacific continued to exhibit La Niña characteristics, but remained weaker and less canonical than the wintertime atmospheric patterns. For example, convection continued to be suppressed near the Date Line, but remained south of the equator, while convection was only weakly enhanced near Papua New Guinea (Fig. 5). In addition, anomalous low-level easterly and upper-level westerly winds persisted over the central tropical Pacific. Collectively, these oceanic and atmospheric patterns reflect the return of La Niña conditions.
Over the last several months many models have predicted increasingly negative SST anomalies in the Nino-3.4 region during the upcoming Northern Hemisphere fall and winter. However, the majority of models continue to predict ENSO-neutral conditions for this period (Fig. 6). The NCEP Climate Forecast System (CFS) has performed quite well over the past several months (Fig. 7) capturing the recent decrease in SST anomalies. The better model performance, combined with the historical tendency for significant La Nina episodes (as in 2010-11) to be followed by relatively weaker La Niña episodes, leads to increased confidence that La Niña will persist into the winter. While it is not yet clear what the ultimate strength of this La Niña will be, La Niña conditions have returned and are expected to gradually strengthen and continue into the Northern Hemisphere winter 2011-12.
Across the contiguous United States, temperature and precipitation impacts associated with La Niña are expected to remain weak during the remainder of the Northern Hemisphere summer and early fall, and to generally strengthen during the late fall and winter. During September-November 2011, there is evidence that La Niña favors an increased chance of above-average temperatures across the mid-section of the country, and an increased chance of above-average precipitation across the Pacific Northwest (see 3-month seasonal outlook released on 18 August 2011).
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09-08-2011, 06:40 PM #123I form the light, and create darkness: I make peace, and create evil: I the LORD do all these things. -אלוהים אדירים
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09-10-2011, 05:42 AM #124
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09-10-2011, 11:18 AM #125
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