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AMO,PDO,ENSO,QBO,NAD,AO,PNA. What the Hell does it all mean?

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AMO,PDO,ENSO,QBO,NAD,AO,PNA. What the Hell does it all mean?






Yes, each one of those little acronyms have something to do with how cold, how hot, how many storms, and ect we will get during the upcoming Winter Season.

These factors derive from both the Oceans and the Atmosphere and they both have a major role in determining weather patterns across the world. One of the big misconceptions out there in the world of the internets is what effects the lack of, or presents of El-Nino', and what it means to the pattern in the South. You hear people comment about the lack of El-Nino' coming on as predicted, the colder and wetter forecast are a bust for this year. That is all hog wash if you ask me. There are way to many other factors that play a much more important role in determining these factors. Lets go over a few...

The entire equation begins in the oceans.

ENSO: El Niño–Southern Oscillation

ENSO is a quasiperiodic climate pattern, not a storm, that occurs across the tropical Pacific Ocean roughly every five years. The Southern Oscillation refers to variations in the temperature of the surface of the tropical eastern Pacific Ocean (warming and cooling known as El Niño and La Niña respectively) and in air surface pressure in the tropical western Pacific. The two variations are coupled: the warm oceanic phase, El Niño, accompanies high air surface pressure in the western Pacific, while the cold phase, La Niña, accompanies low air surface pressure in the western Pacific. Mechanisms that cause the oscillation are currently not completely understood, (as in many things with science ) and remain under study.



The extremes of this climate pattern's oscillations, El Niño and La Niña, cause extreme weather (such as floods and droughts) in many regions of the world. Developing countries dependent upon agriculture and fishing, particularly those bordering the Pacific Ocean, are the most affected. In popular usage, the El Niño–Southern Oscillation is often called just "El Niño". El Niño is Spanish for "the little boy" and refers to the Christ child, because periodic warming in the Pacific near South America is usually noticed around Christmas.



Current analysis.

While we saw a brief bump in the warming and we continue to see some subsurface warm water it most likely will not be enough to push us into what I believe a significant enough weak el nino to see the classic weak el nino effects on the pattern. When you look back there arent many years that had a multiyear nina event that went warm neutral without going into full blown weak el nino territory. That leaves one to wonder, will we be able to push to near the 1.0 point or does this year buck the trend. Personally I beleive we max out in the .5-.7 range possibly sneaking up to .8.

PDO: The Pacific Decadal Oscillation

The Pacific Decadal Oscillation (PDO) is a pattern of Pacific climate variability that shifts phases on at least inter-decadal time scale, usually about 20 to 30 years. The PDO is detected as warm or cool surface waters in the Pacific Ocean, north of 20° N. During a "warm", or "positive", phase, the west Pacific becomes cool and part of the eastern ocean warms; during a "cool" or "negative" phase, the opposite pattern occurs.





IPO or ID; Interdecadal Pacific oscillation


The interdecadal Pacific oscillation (IPO or ID) display similar sea-surface temperature (SST) and sea-level pressure (SLP) patterns, with a cycle of 15–30 years, but affects both the north and south Pacific. In the tropical Pacific, maximum SST anomalies are found away from the equator. This is quite different from the quasi-decadal oscillation (QDO) with a period of 8-to-12 years and maximum SST anomalies straddling the equator, thus resembling the ENSO.

Current Analysis;

After seeing a record negative PDO September we saw the PDO rebound quite a bit during the month of October, however it continues to remain negative and out of phase with ENSO which is a negative factor for building/sustaining a nino. Given that these PDO warming bumps are quite common in the grander scheme I doubt that we will see a monthly positive PDO for DJF though we may sustain closer to normal before starting to fall off again as we head toward spring. The negative anomalies in the GOA certainly is one that will favor seeing more troughing in this area through the winter, while the current ridge in the aleutians may warm the SST's and create an aleutian high.

AMO: Atlantic multidecadal oscillation

The Atlantic Multidecadal Oscillation (AMO) is a mode of variability occurring in the North Atlantic Ocean and which has its principal expression in the sea surface temperature (SST) field. While there is some support for this mode in models and in historical observations, controversy exists with regard to its amplitude, and in particular, the attribution of sea surface temperature change to natural or anthropogenic causes, especially in tropical Atlantic areas important for hurricane development.



Analysis;

Warm. Not really a lot we can say here, its in the sae warm phase we have been in since we started looking at weather on the internet. That said the warm SST anomalies are certainly a positive and one that is found in many -NAO years. I would like to see a little more cold water near NF, however, given the passage of Sandy and the Noreaster that followed, we may have seen these areas cool.

From the skies above, ATMOSPHERIC

MJO: The Madden-Julian oscillation

The Madden–Julian oscillation (MJO) is the largest element of the intraseasonal (30–90 days) variability in the tropical atmosphere. It is a large-scale coupling between atmospheric circulation and tropical deep convection. Rather than being a standing pattern (like ENSO) it is a traveling pattern, propagating eastwards at approximately 4 to 8 m/s, through the atmosphere above the warm parts of the Indian and Pacific oceans. This overall circulation pattern manifests itself in various ways, most clearly as anomalous rainfall.

The MJO is characterized by an eastward progression of large regions of both enhanced and suppressed tropical rainfall, observed mainly over the Indian Ocean and Pacific Ocean. The anomalous rainfall is usually first evident over the western Indian Ocean, and remains evident as it propagates over the very warm ocean waters of the western and central tropical Pacific. This pattern of tropical rainfall then generally becomes nondescript as it moves over the cooler ocean waters of the eastern Pacific (except over the region of warmer water off the west coast of Central America) but occasionally reappears at low amplitude over the tropical Atlantic and higher amplitude over the Indian Ocean. The wet phase of enhanced convection and precipitation is followed by a dry phase where thunderstorm activity is suppressed. Each cycle lasts approximately 30–60 days. Because of this pattern, The MJO is also known as the 30–60 day oscillation, 30–60 day wave, or intraseasonal oscillation. While we all think as MJO as strictly and tool to forecast the enhanced Tropical Cyclone activity, it has is place in what may occur during the non-tropical seasons also.




Analysis;

While I do think its fairly difficult to predict the MJO, in the extended I am a firm believer that the MJO can be used to predict the long term pattern if we are in a stable MJO circuit. That said, I think we will be able to get more help from the MJO this year given the warm neutral enso conditions not being a detriment to any approaching kelvin waves. So basically watch the MJO forecasts and see where we are.

QBO; Quasi-biennial oscillation

Yet another Oscillation. duh The quasi-biennial oscillation (QBO) is a quasi-periodic oscillation of the equatorial zonal wind between easterlies and westerlies in the tropical stratosphere with a mean period of 28 to 29 months. The alternating wind regimes develop at the top of the lower stratosphere and propagate downwards at about 1 km (0.6 mi) per month until they are dissipated at the tropical tropopause. Downward motion of the easterlies is usually more irregular than that of the westerlies. The amplitude of the easterly phase is about twice as strong as that of the westerly phase. At the top of the vertical QBO domain, easterlies dominate, while at the bottom, westerlies are more likely to be found.

Analysis;

I am and have always believe the QBO does at least have some effect on the overall level of blocking ( we will talk more about this ) that we see across the Northern Hemisphere. With the QBO strongly negative now and near its peak the weakening over the winter we should see patterns that are ripe to set up with blocking, not dissimilar to what we have seen the entire fall.

NAO: North Atlantic Oscillation

The North Atlantic Oscillation (NAO) is a climatic phenomenon in the North Atlantic Ocean of fluctuations in the difference of atmospheric pressure at sea level between the Icelandic low and the Azores high. Through east-west oscillation motions of the Icelandic low and the Azores high, it controls the strength and direction of westerly winds and storm tracks across the North Atlantic. It is part of the Arctic oscillation, and varies over time with no particular periodicity.

The NAO is the dominant mode of winter climate variability in the North Atlantic region ranging from central North America to Europe and much into Northern Asia. The NAO is a large scale seesaw in atmospheric mass between the subtropical high and the polar low. The corresponding index varies from year to year, but also exhibits a tendency to remain in one phase for intervals lasting several years.

Westerly winds blowing across the Atlantic bring moist air into Europe. In years when westerlies are strong, summers are cool, winters are mild and rain is frequent. If westerlies are suppressed, the temperature is more extreme in summer and winter leading to heatwaves, deep freezes and reduced rainfall.

A permanent low-pressure system over Iceland (the Icelandic Low) and a permanent high-pressure system over the Azores (the Azores High) control the direction and strength of westerly winds into Europe. The relative strengths and positions of these systems vary from year to year and this variation is known as the NAO. A large difference in the pressure at the two stations (a high index year, denoted NAO+) leads to increased westerlies and, consequently, cool summers and mild and wet winters in Central Europe and its Atlantic facade. In contrast, if the index is low (NAO-), westerlies are suppressed, these areas suffer cold winters and storms track southerly toward the Mediterranean Sea. This brings increased storm activity and rainfall to southern Europe and North Africa.

Especially during the months of November to April, the NAO is responsible for much of the variability of weather in the North Atlantic region, affecting wind speed and wind direction changes, changes in temperature and moisture distribution and the intensity, number and track of storms.

Although having a less direct influence than for Western Europe, the NAO is also believed to have an impact on the weather over much of eastern North America. During the winter, when the index is high (NAO+), the Icelandic low draws a stronger south-westerly circulation over the eastern half of the North American continent which prevents Arctic air from plunging southward. In combination with the El Niño, this effect can produce significantly warmer winters over the northeastern United States and southeastern Canada. Conversely, when the NAO index is low (NAO-), the eastern seaboard and southeastern United States can incur winter cold outbreaks more than the norm with associated snowstorms and sub-freezing conditions to visit us here in Florida, in summer, a strong NAO- is thought to contribute to a weakened jet stream that normally pulls zonal systems into the Atlantic Basin, thus contributing to heat waves.

Positive Phase



Negative Phase



Analysis;

As stated above I do like the fact the QBO is negative and rising. A negative QBO has in general supported a -AO/NAO couplet through most analogs. This combined with the decadal trend of a -NAO, warm SST's around Greenland and what looks to be an upcoming PV split. I, along with many other Mets, believe we are heading into a steady negative phase of the NAO for the Winter.

As you can see, compared to last year, the NAO has been negative





AO: The Arctic oscillation

The Arctic oscillation (AO) or Northern Annular Mode/Northern Hemisphere Annular Mode (NAM) is an index (which varies over time with no particular periodicity) of the dominant pattern of non-seasonal sea-level pressure variations north of 20N latitude, and it is characterized by pressure anomalies of one sign in the Arctic with the opposite anomalies centered about 37–45N.[1] The AO is believed by climatologists to be causally related to, and thus partially predictive of, weather patterns in locations many thousands of miles away, including many of the major population centers of Europe and North America.



AO Warm



AO Cool



However, the correlation between sharply negative Arctic Oscillations and excessive winter cold and snow in regions vulnerable in that way to these negative AOs should not be overstated. It is by no means a simple, one-to-one equivalence. An extreme Arctic Oscillation does not necessarily mean extreme weather will occur. For example, since 1950, eight out of the 10 coldest Januarys in New York did not coincide with the 10 lowest January AO values. And the fourth warmest January there since 1950 coincided with one of those 10 most negative AOs.[8] So, although many climatologists believe that the Arctic Oscillation affects the probability of certain weather events occurring in certain places, the heightened chance of a phenomenon by no means assures it, nor does the lessened likelihood exclude it. Further, the precise value of the AO index only imperfectly reflects the severity of the weather associated with it.




PNA: Pacific/North American Pattern

The Pacific/North American Pattern, or PNA, describes the variation of atmospheric circulation patterns over the Pacific Ocean and North America. Like other atmospheric circulations, the PNA has the most impact on climate variables during the winter. There are two phases of the PNA, a positive phase and a negative phase. The positive phase usually relates to El Niño and the negative phase to La Niña, however there is a weak connection between the PNA and ENSO.



During the positive phase of the PNA, ( shown above )the Aleutian low in the Gulf of Alaska strengthens and the high pressure ridge over the Rocky Mountains also strengthens. This is similar to the strong phase of the North Atlantic Oscillation and increases the pressure gradient between the two centers of circulation. This causes an increase in wind speed which steers more storms into the Pacific Northwest.

The positive phase of the PNA leads to above average temperatures in the western United States. These above-average temperatures are because of the upper-level ridge over the Rocky Mountains. (Recall that surface high pressure areas are located within ridges and are accompanied by sinking air and clear skies.) This ridge is stronger than under normal conditions, increasing the temperatures at the surface and preventing the development of thunderstorms over the mountains which could provide rainfall or snow. The winds off the Pacific are pushed northward because the ridge is blocking the air from continuing the normal track from the west. When this happens, the southwestern United States sometimes experiences drought conditions with decreased precipitation totals due to the blocked flow.

Also during the positive phase of the PNA, deepening troughs of low pressure exists over the Northern Pacific Ocean and the Southeastern United States. These troughs help bring colder air down farther into the South from the northern latitudes, increasing the winter storm activity for these regions. This helps cause below average temperatures across the south-central and southeastern US and above average precipitation in these areas as well. The deepening trough over the eastern US shifts the jet stream and the storm tracks farther south. This causes below average precipitation to fall throughout the Ohio Valley and the Mississippi Valley down into the northern part of the southeastern states.

The Pacific/North American Pattern involves changes in atmospheric pressure between the Aleutian Low and the high pressure over the Rocky Mountains.



The negative phase of the PNA ( above) is essentially the reverse pattern of the positive phase. The upper-level ridge over the Rocky Mountains becomes weaker than normal during the negative phase corresponding to cooler than normal air. The Aleutian low also weakens, reducing the pressure gradient between the two circulation centers. This results in below average temperatures across the western US. Above normal precipitation is also likely for the western United States as winds off of the Pacific Ocean will bring storms farther south into this region.

Over the eastern United States, the upper-level trough is weaker than normal and warmer temperatures persist throughout this area. This shifts the jet stream and storm tracks northward into the Ohio Valley and the Mississippi Valley. This creates areas with above average precipitation in these valleys. Warm air masses from the Gulf of Mexico now have the potential to move farther north and cause temperatures to be above average in the states surrounding the Gulf. Above average precipitation will also be a factor in the northeastern United States with these below average temperatures. Florida and the southern parts of the southeast US, however, will be experiencing a dry spell during a negative phase in the winter months, accompanied with warm temperatures.

All in all I expect the PNA to remain negative through the winter given the -PDO, GOA cold anomalies and cold water down the west coast. That said, this can be counteracted by the MJO. As the MJO orbits through favorable PNA phases we may see 1-2 week periods of +PNA conditions and potentially cross polar flow given the higher than normal potential for AO polar blocking. This was my thinking a few weeks ago when I was talking about it was going to get cold then go through a warm spell and then deep arctic cold heads South bound.

Ok what does this all mean. There is so much information to absorb. And one thing to note, back in the day, I hayed this teleconnection stuff. Guess I was more into woman and booze. ( But at least I did not sell myself for a quick 10 bucks like some on here ) lmao

When all things are thrown into the mix, this is what many feel that will be the end result.







Just keep in mind, the atmospheric warming in one part of the world effects the building of a blocking high over another part of the world, like Greenland. When there is blocking over Greenland, as was the case when Sandy was heading North, thing happen in the Eastern half of the County. Blocking is a contributor to huge East Coast snowstorms in three ways. First, blocking brings the cold air. Second, it helps to lower pressure off the Southeast coast to allow storms to form. Finally, it slows the eastward progression of storms, helping them to slow down, strengthen and dump heavier snow. Sandy gave us a preview of what can happen off the East Coast if we get phasing to take place. This is something we lacked last year.



Here is one video that shows some of the variables. Kinda a poor presentation at times but over all, describes and connects every thing together.



Stratospheric warming looks have begun, which should mean a tanking Arctic Oscillation and a possible deep freeze in December/January via the mid Atlantic and southeast!

This was from a couple weeks ago.



In response to the Stratospheric warming, the AO is responding and the GFS ensembles are showimg the high lat blocking in the AO and NAO regions! This in turn sends a deep trough over the SE US..Fun Times like occurred in 2009/10



I do have to admit, the models ( GFS and EURO ) have been junk as to consistency, and can not be trusted in the long term. But, the indexes we discussed above are very real and the outcome of what we are seeing has to be considered.



Last edited by emcf30 on Sun Nov 25, 2012 9:39 am; edited 1 time in total

emcf30

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AMO,PDO,ENSO,QBO,NAD,AO,PNA. What the Hell does it all mean? :: Comments

Post on Fri Nov 23, 2012 10:37 am by gomexwx

It means everything has cycles....and there is no Global Warming:) that was fun.

Last edited by gomexwx on Sat Nov 24, 2012 7:25 am; edited 1 time in total

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Post on Fri Nov 23, 2012 11:37 am by sangria

WOW !! Great blog, e !! Thanks for all the effort, you put into it......I'll have to read this one, several times......just to absorb, a bit of it!!

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Post on Fri Nov 23, 2012 11:45 am by StAugustineFL

"( But at least I did not sell myself for a quick 10 bucks like some on here )"

finger lmao

Thanks E. Too much for me to absorb at once but well done sir.

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Post on Fri Nov 23, 2012 12:27 pm by StAugustineFL

sangria wrote:WOW !! Great blog, e !! Thanks for all the effort, you put into it......I'll have to read this one, several times......just to absorb, a bit of it!!

It's been 50 minutes since your post. How many times have you read so far san? bart mooning

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Post on Fri Nov 23, 2012 12:28 pm by emcf30

StAugustineFL wrote:"( But at least I did not sell myself for a quick 10 bucks like some on here )"

finger lmao

Thanks E. Too much for me to absorb at once but well done sir.


I see you caught that. Was making sure you read the blog. LOL

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Post on Fri Nov 23, 2012 12:40 pm by emcf30

WARNING LANGUAGE.

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Post on Fri Nov 23, 2012 1:06 pm by sangria

StAugustineFL wrote:
sangria wrote:WOW !! Great blog, e !! Thanks for all the effort, you put into it......I'll have to read this one, several times......just to absorb, a bit of it!!

It's been 50 minutes since your post. How many times have you read so far san? bart mooning

One and a half ........ finger

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Post on Fri Nov 23, 2012 7:16 pm by emcf30

GFS NOA Forecast. In the Negative





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Post on Fri Nov 23, 2012 9:55 pm by StAugustineFL

That's a substantial negative on the GFS E. To my eye things look relatively quiet for another week model wise before the NAO really dips. I'm curious to see what the first week of December brings.

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Post on Sat Nov 24, 2012 7:26 am by gomexwx

We know who the dips are.....

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Post on Sat Nov 24, 2012 12:53 pm by emcf30

One of the final pieces to the puzzle is falling into places now. Finally, the emergence of a solid +PNA will be of great importance to break this western trough poised to set up over the next week. With all this mess going on in the Pacific, nothing will go on, as far as storms in the East.



This, along with the -NAO all bets are off. With the blocking pattern projected to stay strong during this period.



The middle of December continues to be interesting. Must be something to do with Global Warming. The CO2 as really got everything screwed up.

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Post on Sat Nov 24, 2012 12:57 pm by emcf30

Interesting. CLICK to animate;
http://collaboration.cmc.ec.gc.ca/cmc/cmdn/pcpn_type/pcpn_type_gem_reg.html

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Post on Sat Nov 24, 2012 1:08 pm by emcf30

Looks like NYC in for some snow....

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Post on Sat Nov 24, 2012 2:54 pm by StAugustineFL

E, the -NAO has backed off (for today). It's headed weak negative after a brief dip. Honestly I get a little frustrated with all these "forecasts" from the CPC. Shizz changes direction like a fart in the wind.



The snowfall map you posted is on par with my thoughts in chat this morning.

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Post on Sun Nov 25, 2012 8:41 am by emcf30

Just for comparison..here is the current CPC AO ensemble forecast graph (Top) compared to this same time 2009 (Bottom)



Many Mets, believe the atmospheric conditions setting up is very very similar to the 2009 - 2010 winter. Now, you might ask why the Winter of 09-10 was so bad for Many across the globe. During the winter of 2009-2010 a rare combination of known factors (as we are seeing setting up now) in earth’s climate variability systems -- the Arctic Oscillation and North Atlantic Oscillation in the Atlantic. El Nino, the Pacific Decadal Oscillation and Pacific/North American Pattern in the Pacific and the Indian Ocean Dipole -- influenced the Northern Hemisphere winter from North America, across Europe to eastern Eurasia - as far east as Mongolia, China and Korea.



This has been a highly unusual northern hemisphere winter; extremely cold and snowy in some regions, stormy in others - yet Canada had its warmest winter on record, parts of the the Arctic and tropical sea temperatures were unusually warm. Now, to be fair, this year wee will NOT see a strong El-Nino' event as back in 2009-2010. Not even close.



According to Accuweather, 22 storms passed over the USA's east coast region in the 2009-2010 winter; drenching it with 30-40 (76-101cm) inches of precipitation [snow and rain]. The average is 20-25 (20-63 cm) inches. These rains, combined with a saturated ground and previous snow-melt, produced widespread and historic flooding. This was immediately followed by an abnormal heatwave; with over 100 records for high temperature at this time of year broken over the USA's Midwest and north-east. Source.

Storms also impacted the north-west USA during March. In the Midwest and Southern Plains several storms crossed the region (it was also tornado & severe weather season by then), and in late March 2010, a great snowstorm crossed eastern Oklahoma, western Arkansas and north eastern Texas. Texas had its second snowiest winter on record.

For the USA it was the coldest winter in 25 years. Various cities and areas of the USA saw this winter become one of their top five snowiest &/or coldest winters since their records began. For a few States and cities the 2009/2010 winter took the top spot for snowfall or cold.



The overall continental USA temperature anomaly was minus 1.771 C; which makes February 2010 the coldest for the continental USA since February 1979. An unusually negative Arctic Oscillation caused 'blocking' areas of high pressure that diverted the paths of the Jet Streams, this allowed cold polar air to spill southwards over the U.S.A.



Now, let me sound like Dr. M. for a few moments. But instead of harping on the record warm lets talk about record cold.

Both the south and south-east regions of the USA experienced their seventh coldest February on record. Meanwhile, warmer-than-average temperatures ( opps, I lied ) dominated the extreme north-west and north-east climate.
For Louisiana it was its fifth coldest February. Alabama, Georgia and Texas each had their sixth coldest. It was the seventh coldest February in Arkansas, while both Mississippi and South Carolina experienced their eighth coldest. Source: NOAA.
For Houston, Texas, the winter of 2009 - 2010 was one of the coldest in the area since record keeping began.

The cold Arctic air reached us here in Florida; in early January 2010 we suffered unaccustomed cold and frosts.



This was later followed by the cold air mixing with air coming from the Gulf of Mexico, caused by El Nino in the Pacific, carrying moisture that resulted in snow and ice coating Florida's roadways and fields.

Both the months of January 2010 and February 2010 were the 6th coldest on record for Tampa (Florida) since records began in 1890. (December was around normal.) For Miami Beach (Florida) it was the coldest winter on record.

Florida overall had its fourth coldest February. The first 3 months of 2010 were the coldest ever reported in Miami Beach, Naples, and West Palm Beach, and was among the coldest winters ever for Ft. Lauderdale and Miami. El Nino conditions also resulted in the coldest March on record in Miami Beach; second coldest in West Palm Beach. It also remained wet over much of Florida.

For the period of December, January & February it was the coldest three-month stretch ever recorded for Florida overall; its coldest winter on record. Source: Here and Here.

Late December 2009 saw a snowstorm that brought up to 20 inches (50 cm) of snow across America's eastern seaboard. See also Wikipedia: North American Blizzard of 2009.
February saw three major snowstorms over north-eastern parts of the USA; originating from storms coming from the tropical Pacific, bringing moisture-rich air over the USA to meet the cold air pushed down from the Arctic. This clash of airstreams generated major snowfalls.

The first was named Snowmageddon (Feb 4th-7th) by the media



Snowmageddon was followed a few days later (Feb 9th-11th) by another great snow-storm across the eastern USA. This was dubbed variously 'Snowmageddon 2', 'Snoverkill', 'Snowapocalypse' & Snowtorious B.I.G! by sections of the media.



Yet another very heavy snowfall occurred in the last week of February (23rd-28th). Named Snowicane by one weather service, this brought protests of 'Enough of these bad puns' from a snow (and hype) weary public.



February was Washington DC's second-snowiest month on record, with 32.1 inches. In contrast, in March it had no measurable snow, and set a record by having no freezing days at all.

This year's snowfall in both Kansas City (Kanas) and Tulsa (Oklahoma) gave them both one of their top five snowiest winters. For Texas it was the second snowiest winters ever (including the March totals), only half-an-inch short of the record; if it snows again in April a new record could be set.



Rainfall totals on Monday 29th March 2010 surpassed 2 inches (5 cm); from North Carolina to Massachusetts, with amounts nearing 4 inches in spots. Over a dozen daily rainfall records fell in this area on this day. Extensive flooding resulted. These rains were almost immediately followed by much warmer weather across the north-east, with temperatures reaching 80 degrees F (27 degrees C) on the Easter weekend. See also: Here.

The Pacific north-west also had wild March weather, that brought heavy rains (snow at high elevations) and strong winds.

As March 2010 ended, violent storms had swept across much of the USA, bringing strong winds, low temperatures, heavy rains and snowfalls; it was also the annual severe weather season.

Warmth and high temperatures (27 degrees C + (80 degrees F) then appeared at the end of March 2010. Many towns across the US plains set records for high temperatures in a March. On March 30th in Denver, temperatures peaked at 27.2 degrees C (81 degrees F). Chicago had its warmest April 1st since 1946, temperatures reached 83 degrees F (28 degrees C). The seasonal spring battle to banish winter was underway.

Overall the USA averaged warmer-than-normal conditions in March 2010. Warmer in the north, colder in the south.

It was the warmest January-March period for Maine, Vermont and New Hampshire. By contrast, the three-month stretch was the coldest ever for Florida, the second coldest for Louisiana, and the third coldest for Mississippi and Alabama.

The March temperature averaged across the contiguous United States was 44.4 degrees F, which is 1.9 degrees F above the long-term average.

However, the 2009-2010 winter was highly unusual in that some northern regions of continental north America remained relatively snow-free and warm, during its coldest months; whilst regions further south were colder and received heavy snowfalls.

At the same time as Snowmageddon, Vancouver - host city of the 2010 Winter Olympics - was trucking snow up to its ski-slopes, as its warmest winter on record threatened to leave the ski-runs snow free.
For Coeur d’Alene (Idaho) and Spokane (Washington State), 2010 will go down in the records books as the least snowiest for both locations. Minnesota had a snowless March for the first time in 130 years of records. Syracuse (NYS) had the lowest amount of snow for any March since 1951.

Much of the north of the continent was notably warmer and less snowy than in the south, Canada in particular. Some U.S. forecasters named this 'The upside-down winter' with lots of snow in some places where it usually doesn't fall and relatively little in some where it usually does.

Canada actually had its WARMEST, driest winter (Dec, Jan & Feb) on record! (Source: Environment Canada.)

January 2010 in Vancouver (Canada) was the warmest since record keeping began in 1937. Not a good omen for the Winter Olympics held there in February 2010; unseasonal warm, wet weather continued throughout February. (Typically, an El Nino event brings warmer than average temperatures to Vancouver, and cooler than average conditions to Florida.)

In Toronto, Canada's biggest city, the temperature departure for the winter was nearly 2 degrees F above normal. Montreal was warmer than usual by more than 6 degrees F.

Temperatures 8 degrees F to 12 degrees F above normal spread over wide swathes of Yukon, Northwest Territories, Nunavut, British Columbia and Manitoba and the sprawling vastness of Labrador and Quebec, where half of the province's twelve largest cities experienced their warmest or second warmest January on record. This warmth extended as far south as Newfoundland and New Brunswick. Canada had its second-warmest January on record (since 2003).

Hell, I could go on and on and on. The point being, look at the projected effect of winter this year and compare them to 2009-10.



Just sayin

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Post on Sun Nov 25, 2012 9:01 am by emcf30

North Atlantic blocking will occur this week and should bring below average temps first to western Europe (UK, western France, Spain) then the cold will spread east into central and eastern Europe during the first week of DEC. Could even have some wintery weather across the UK and parts of northern Europe during the upcoming cold snap... it's likely the North Atlantic remains blocked into the second week of DEC... the forecast of the AO index continues to plunge in the coming days as well...could be lots of interesting weather upcoming across the northern hemisphere as the tropospheric polar vortex (jet stream) weakens... it would also appear we're starting the onset of stratospheric warming and a disruption of the stratospheric polar vortex, however, it's also likely the impacts of a SSW event won't be felt at the surface for several weeks down the road...



And the split is showing signs of occurring.



Complete stratospheric vortex split by D7 look at the massive warm anomalies at 70mb over Asia. If this were to happen, watch for the Polar Express, And I ain't talking about the train heading to the North Pole.

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Post on Sun Nov 25, 2012 9:14 am by scouter534

Thanks E for your effort, very informative.

2009-10 was also the great iguana kill off, lots and lots froze to death. Fingers crossed. lmao lmao

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Post on Sun Nov 25, 2012 9:23 am by emcf30

scouter534 wrote:Thanks E for your effort, very informative.

2009-10 was also the great iguana kill off, lots and lots froze to death. Fingers crossed. lmao lmao

That is one way of handling your iguana problem. LMAO

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Post on Sun Nov 25, 2012 9:43 am by emcf30

SNOW TORNADO

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Post on Mon Nov 26, 2012 5:38 am by emcf30

Well, the November Forecast were a bust.

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Post on Mon Nov 26, 2012 5:44 am by emcf30

Now, here is what they are saying about December.

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Post on Mon Nov 26, 2012 5:49 am by emcf30

Here is what the GFS says about the Fantasy Storms



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Post on Wed Nov 28, 2012 7:02 am by emcf30

GFS Continues with a crazy cold shot.



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Post on Wed Nov 28, 2012 7:03 am by emcf30

Could be a fantasy, or not!

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Post on Wed Nov 28, 2012 1:10 pm by sangria

Hey e....has the forecasted cold, shifted west, more?

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Post on Thu Nov 29, 2012 5:19 am by emcf30

Could you imagine

Overnight. Snow. Steady temperature around 17. Wind chill values as low as -10. Windy, with a south southwest wind around 45 mph, with gusts as high as 65 mph. Chance of precipitation is 90%. Total nighttime snow accumulation of 8 to 12 inches possible.

Thursday Snow. High near 19. Wind chill values as low as -18. Windy, with a south southwest wind 75 to 85 mph, with gusts as high as 115 mph. Chance of precipitation is 100%. New snow accumulation of 33 to 39 inches possible.

Thursday Night Snow. The snow could be heavy at times. Low around 16. Wind chill values as low as -13. Windy, with a south southwest wind 90 to 95 mph increasing to 100 to 105 mph in the evening. Winds could gust as high as 115 mph. Chance of precipitation is 100%. New snow accumulation of 37 to 43 inches possible.

Friday Snow. High near 18. Wind chill values as low as -14. Windy, with a south southwest wind 85 to 95 mph decreasing to 75 to 85 mph in the morning. Winds could gust as high as 115 mph. Chance of precipitation is 100%. New snow accumulation of 23 to 29 inches possible.

Friday Night Snow. Low around 14. Windy, with a south southwest wind around 75 mph, with gusts as high as 115 mph. Chance of precipitation is 100%. New snow accumulation of 21 to 27 inches possible.

Saturday Snow. High near 19. Windy. Chance of precipitation is 100%. New snow accumulation of 21 to 27 inches possible.
Saturday Night Snow. The snow could be heavy at times. Low around 17. Windy. Chance of precipitation is 100%. New snow accumulation of 27 to 33 inches possible.

Could you imagine receiving 200 inches of snow in 3 days

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Post on Sat Dec 08, 2012 6:16 am by emcf30

After all this talk about the different factors that determine our weather the dots look to be finally connecting together for some type of pattern change that has been anticipated after the current warm trend. To start out with, one really would have to begin to look at the Aleutians and Bering Straights for the first signs of change given the pattern we have been in.

The ridging once over the Aleutians and Bering Straight retrogrades west. This has been in place for the past few months. At the same time, the Pacific storms breaks cyclonically northward. Ridging over the eastern Pacific gets pumped up into the Gulf of Alaska, with an intensifying polar jet streak pushing north into the Yukon.





Infact, the Bering Sea ridge is already going POOF.



This is the catalyst for change. What happens after that? A classic anticyclonic system will pound into into British Columbia. This will result in a 170kt+ northerly jet diving into the Pacific Northwest.





So you know the trough and all that energy bottled up over Alaska and the Gulf? Well a lot of that comes pouring southeast on the wings of this jet into the northern Rockies, beginning this weekend.





Over the past few weeks the pattern has been dominated by a strong ridge configuration over the eastern CONUS. This ridge has allowed unseasonable warmth to take hold. Additionally, there has been a monster trough on the West Coast, as detailed above. What is interesting is this has happened during a negative AO period, but this set up has happened in the past. Guess it is because Global Cooling.

The GFS and EURO ensembles both support this continued dip in the AO, with the GFS ensembles taking it to very anomalous negative numbers next week. Statistically this would strongly favor a pattern change and indeed we have seen hints of this change on the GFS and EURO ensemble runs over the past week as well, however there has been little consistency or overlap in the two models until recent runs.

Ultimately I expect a strong system to form late next week over the plains and Midwest due to the deepening negative AO and warm anomalies building over the Arctic. This storm will be forced due to a frontal system surging into the lower 48. This system will likely spark a 500mb low over the 50/50 lat-long location. This is key, as it will allow the blocking near the poles to organize and build towards western Greenland, forcing the PV to weaken and setting up a possible favorable cold and snow pattern near the holidays.

This is the result one could expect with this sort of set up.

.

We can expect some nice pre frontal warm ups here at home over the next couple of days. With that, comes the chance of nasty weather. ( From accuweather ) Late this weekend into early next week, there is a possibility of a severe weather outbreak shifting eastward in parts of the Central and Eastern states Sunday into Tuesday. Cloud cover could limit the extent and severity of thunderstorms, perhaps preventing a large outbreak. However, there is the risk of localized severe weather centered over the lower Mississippi Valley.

The see-saw pattern with temperatures that began during the first weekend of December will continue over a large part of the nation into the second week of the month.

Whether or not severe thunderstorms ignite and the nature of the storms (tornadoes versus straight-line wind gusts) will depend largely on the track and strength of the storm emerging from the Rockies.

As of Saturday morning, it appears that the storm system will split into two parts. One will track toward the Great Lakes and the other will move across the South. It is the southern storm that brings the greatest potential for damaging wind gusts and perhaps a few tornadoes.




Then things cool off a bit. woohoo





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Post on Sat Dec 08, 2012 6:20 am by emcf30

LMAO. Guess admin changed A.G.W. to global cooling

Those Bastards and Beeeeatches

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Post on Sat Dec 08, 2012 7:42 am by StAugustineFL

Good work E man.

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Post on Wed Dec 12, 2012 4:57 am by emcf30

Ok, now that the time is getting closer to the storm that we have been talking about on and off for the past ten days is getting closer, let take a look at things.

As usual, this is going to be a battle of the models, American vs European. In the red corner, the GFS in bouncing back and forth from a warm system to freezing cold in the South while the blue corner, the Euro bring a nice shot of extremely cold air. This system will be very difficult to forecast and there's absolutely no reason to get entangled up in every single detail of every model run from the global models. But one thing that is for certain, someone will be playing hell with this one if the current model trends hold true.

As discussed in chat, you hardly ever see the upper level jet max @ 500mb look like this. 122 knots. That is a big Jason WOW



As far as teleconnection goes, the MJO is heading strong into phase 1 and the SOI way in the negative. This might encourage the system to stay more Southern. But one thing the models agree on, this ULL BOMBS out in the Northeast.





There has already been some interesting comments coming out of some of the local field offices in Tennessee.

DISCUSSION...MIDDLE TENNESSEE HAS FINALLY CLEARED OUT, ALTHOUGH
TEMPS REMAIN COOL WITH SURFACE RIDGE SITTING JUST TO OUR WEST.
LOOK FOR READINGS IN THE 20`S TONIGHT, WITH WARMER WEATHER ON THE
WAY STARTING TOMORROW AS THE UPPER TROUGH SWINGS THROUGH. RIDGE
SHOULD SLIDE EAST OF MIDDLE TENNESSEE WEDNESDAY NIGHT, WITH TEMPS
BACK IN THE 50`S ON THURSDAY. NEXT SURFACE SYSTEM WILL WORK ITS
WAY INTO THE MID STATE SATURDAY MORNING, WITH ISOLATED CONVECTION
POSSIBLE SATURDAY AFTERNOON, ALTHOUGH SPC DOES NOT HAVE ANY
CONVECTIVE OUTLOOKS FOR THE MID STATE WITH THIS SYSTEM. PERHAPS
SOME LEFTOVER SHOWERS SUNDAY MORNING BEFORE THE MOISTURE PULLS
OUT. SUBSEQUENT ACTIVE SYSTEM WILL BRING SHOWERS TO MIDDLE
TENNESSEE ON TUESDAY. IT IS POSSIBLE THAT AREAS EAST OF NASHVILLE
COULD SEE A RAIN/SNOW MIXTURE AFTER MIDNIGHT TUESDAY NIGHT.


LONG TERM (WEDNESDAY NIGHT THROUGH TUESDAY)...SURFACE HIGH PRESSURE
CENTERED OVER THE CENTRAL APPALACHIANS SLIDES SE TO THE OUTER BANKS
BY LATE FRIDAY. UPPER TROUGH MOVES EAST THROUGH THE AREA WEDNESDAY
NIGHT FOLLOWED BY RIDGING INTO THE EARLY WEEKEND. DRY CONDITIONS
INTO THE THE EARLY WEEKEND WITH TEMPERATURES RANGING JUST OUTSIDE
CLIMO. SHORT WAVE ENERGY EJECTING NE OUT OF THE SOUTHERN ROCKIES
DEVELOPS SURFACE LOW OVER KANSAS BY EARLY SATURDAY. THIS SYSTEM WILL
CONTINUE TO THE SOUTHERN GREAT LAKES BY LATE SUNDAY. WESTERLY
STEERING FLOW WILL DRIVE COLD FRONT AND ASSOCIATED SHOWER ACTIVITY
THROUGH THE TN VALLEY AND INTO THE SOUTHERN APPALACHIANS LATE
SATURDAY AND EARLY SUNDAY. LIGHT NW FLOW ACTIVITY POSSIBLE INTO
MONDAY. SIGNIFICANT LOW PRESSURE TAKING SHAPE ON TUESDAY. TRACK AND
TIMING REMAIN IN QUESTION BUT SNOW EVENT LIKELY WITH THIS SYSTEM


From James Spann; Both the GFS and the ECMWF are on board with a major cold core upper low swinging over Alabama Tuesday. We all know strange things can happen under a cold core; dynamic cooling can bring snow flakes when you don’t expect them. Low level thickness values here suggest just some cold rain at times for this part of Alabama Tuesday; any snow most likely would come over Tennessee. So, while things could change, for now it just doesn’t look like a snow look for Alabama on Tuesday.

Snow lovers tend to watch every model run this time of the year, going over the data with a fine toothed comb looking for the magical freezing line at 850 mb, and the 5400 meter 1000-500 mb thickness line (which can represent lines where it is “cold enough to snow”). The 12Z GFS shows a good snow look for North Alabama on December 22, followed by very cold air on through Christmas Day

I would prolly head to the mountains for this one.



Oh well we will see how it pans out. The 06Z runs are only out to 72 hour at the moment. Will be interesting to see what they show.




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Post on Wed Dec 12, 2012 5:00 am by emcf30

From Accuweather. I agree!


Snowy, Colder Pattern for U.S. Leading up to Christmas

AccuWeather.com long-range meteorologists are monitoring the
potential for a colder, snowier pattern across the Plains and the East
prior to Christmas.

Our forecast tools continue to show the potential for several storm
systems that could track from the South to the East from next week
through the holiday.

According to AccuWeather.com Chief Meteorologist Elliot Abrams,
"There could be one storm or three, but the truth is just as some people
may think there isn't going to be a white Christmas, we could have a storm develop right before the holiday to bring millions of people a nice surprise for the holiday."

Another reason that the pattern could turn snowy and colder is
because all signs point to a more active southern portion of the jet
stream or "storm track."

Generally systems coming out of the South have a high moisture
content and strengthen as they lift northward, which in turn, drives
cold air farther south.

According to AccuWeather.com Long-Range Meteorologist Joe Lundberg,
"The first big event comes out of the southern Rockies late on Friday
and Friday night, then cuts across the Plains and tracks through the
Great Lakes this weekend."
A track like this would almost certainly bring some snow to parts of
the Great Lakes over the weekend, but amounts and timing are still in
question.

Lundberg also states that as this system moves into the East on
Sunday and Sunday night, it could bring some snow to parts of New
England as well.

Another storm could affect parts of the South and the East during the
middle of next week with third system just before the holiday.

At any rate, even though there hasn't been a lot of snow so far this December, the signs of a snowier pattern are showing up.

AccuWeather.com meteorologists are confident that there will be
several opportunities for accumulating snow prior to Christmas from the
Plains to the East and that will make some folks happy who wish for a
white Christmas every year.

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Post on Wed Dec 12, 2012 6:37 am by emcf30

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0355 AM CST WED DEC 12 2012

VALID 151200Z - 201200Z

...DISCUSSION...
MEDIUM RANGE MODELS CONTINUE TO INDICATE STRONG WEST SOUTHWESTERLY
UPPER JET INTENSIFICATION ACROSS THE CENTRAL AND SOUTHERN TIER OF
THE U.S. BY THIS WEEKEND. THIS FEATURE IS THEN FORECAST TO
GRADUALLY PROPAGATE EAST NORTHEASTWARD INTO THE WESTERN ATLANTIC
...AS ANOTHER STRONG MID-LATITUDE JET NOSES INLAND OFF THE PACIFIC
...AND ACROSS THE U.S. THROUGH THE EARLY TO MIDDLE PART OF NEXT
WEEK. CONFIDENCE IS FAIRLY HIGH THAT VIGOROUS SHORT WAVE IMPULSES
ASSOCIATED WITH THESE FEATURES WILL CONTRIBUTE TO ONE OR MORE
INSTANCES OF STRONG SURFACE CYCLOGENESIS THAT COULD BECOME CAPABLE
OF SUPPORTING A SIGNIFICANT SEVERE WEATHER EVENT.
HOWEVER...THE
SPREAD AMONG THE VARIOUS MODELS AND MODEL ENSEMBLE DATA CONCERNING
THE TIMING AND DEVELOPMENT OF THESE FEATURES REMAINS MUCH TOO LARGE
TO CONFIDENTLY ASCERTAIN THE RISK FOR ONE OF THESE EVENTS...AND
GRAPHICALLY DELINEATE A REGIONAL SEVERE WEATHER AREA. IT DOES
SEEM...THOUGH...THAT GUIDANCE IS INCREASINGLY POINTING TOWARD A
ROUGH CORRIDOR ACROSS LOUISIANA/MISSISSIPPI/ ALABAMA AND
GEORGIA...INTO THE CAROLINAS...EITHER LATE THIS WEEKEND OR SOMETIME
DURING THE MIDDLE OF NEXT WEEK.

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