2012-2013 WINTER FORECAST

        Autumn has come to a close. The leaves have long since fallen off the trees, and the air has lost its warmth. Soon, solar winter will commence beginning on December 21st. As winter moves in, cold air and snowstorms will soon begin to threaten the region. However, memories of a classic Northeast winter seem somewhat distant. It has been over one year since the last widespread major snowstorm struck the Northeast back in October of 2011. The winter that followed ushered in the 4th warmest and 3rd most snowless winter in United States history. It was as if winter just never arrived to portions of the country. Following last year’s “non-winter” millions are left wondering if we will see a repeat this year. Well, folks, after months of extensive research and analysis, I can confidently state that the upcoming winter  of 2012-2013 will feature a pattern immensely different from that of last year; a pattern that favors above-average snowfall and below average throughout portions of the Northeast. This year’s winter of 2012-2013 will feature more frequent storms, and heavier snowfall in comparison to last.

        While there are many factors contributing into this season’s forecast, the first thing I take into consideration when attempting to accurately predict any given winter is the current phase of ENSO (El Niño Southern Oscillation). This winter, I am predicting “ENSO-Neutral” (ONI  +.3) conditions for the winter of 2012-2013. This means that sea surface temperatures across the equilateral Pacific are not at a departure great enough to be defined as either La Niña (ONI -.5 or less) or El Niño (ONI+.5 or greater). During the winter of 2012-2013, I am predicting ENSO-Neural conditions leaning towards a weak El Niño (ONI value of +.3). 

        The current state of ENSO has a significant impact on our winter here in the Northeast. Historically, ENSO-Neural winters leaning towards a weak El Niño favor above average snowfall to the portions of the Northeast; specifically, the heavily populated I-95 corridor from Washington, D.C. to Boston, MA. This year is no exception. In the east, an active southern jet stream (associated with ENSO-Neural/Weak El Niño winters) may occasionally phase with the northern jet stream, producing substantial winter storms along the eastern portion of the nation.

         However, the current state of ENSO is not the only factor contributing into the 2012-2013 Winter Forecast. While the current state of ENSO (El Niño Southern Oscillation) plays a fundamental role on our global (and local) weather pattern; a similar climatic variable located in the northern Pacific Ocean known as the Pacific Decadal Oscillation or in short the “PDO” can have just as much of an impact on our winter pattern. The PDO is similar to ENSO as they are both large scale oceanic variables, that dictate convection and jet stream positioning across portions of the world. The PDO has two phases: The first phase, known as the “warm phase” is characterized by cooler-than-normal sea surface temperatures across the northeastern Pacific; historically supporting warmer-than-normal sea surface temperatures across the equilateral Pacific (a phenomenon known as “El Niño”). The second phase (known as the “cool” phase) is characterized by warmer-than-normal sea surface temperatures across the northwestern Pacific. This is historically supportive of a La Niña (cooler-than-normal sea surface temperatures across the equilateral pacific). In years past, the current phase of ENSO has agreed with the PDO. However, this year is particularly unusual.
Since the summer of 2010, the PDO has been in a “cool phase”. This is one of the reasons we experienced a moderate to strong La Niña during the winter of 2010-2011, and yet another La Niña during the winter of 2011-2012. The PDO reached strongly negative values, further intensifying La Niña in the equatorial Pacific. 

        While the PDO is gradually trending towards positive values, it is still negative. This is one of the main reasons a full-fledged El Niño failed to develop this year. While the atmosphere over the equatorial Pacific is in favor of an El Niño, the current cool phase of the PDO favors cooler-than-normal sea surface temperatures across the equatorial pacific (closer to La Niña). Looking back in history, when the PDO and ENSO disagree, the PDO typically overwhelms the current phase of ENSO. This is something that has become present this year, resulting in the current “ENSO-Neutral” conditions expected to persist into the winter months. 

  While the current phases of the PDO & ENSO have an immense influence on our winter pattern, they are not the only elements that determine out winter pattern; located in the Northern Atlantic is a climatic variable known as the Northern Atlantic Oscillation or “NAO”. While virtually unpredictable past a week, The NAO is perhaps the most prominent element when predicting any given winter. 

There are two phases of the NAO; the positive phase, and the negative phase. During the positive phase, low pressure centered around Iceland strengthens, coinciding with strengthening high pressure centered around the Azores Islands. The stronger the systems in these areas, the more positive the NAO becomes. Throughout the positive phase, the Jet-Stream retreats to the North, allowing warmer air to advance farther north, impacting the Northeast with well-above average temperatures. Historically, large-scale east coast storms are far less common during positive phases of the NAO. 

During the negative phase, low pressure centered around Iceland weakens significantly, and moves over Greenland, while high pressure centered around the Azores weakens. Positive heights build near Greenland as a result of higher atmospheric pressures; and in consequence, the jet stream dips far to the South. Consequently, cold Arctic air is forced down upon the eastern portion of the United States. According to history, it is far more likely for large-scale Nor’easters, and on occasion blizzards to develop and slam the northeastern portion of the United States with heavy snowfall during a negative NAO. 

Among the leading causes for last year’s unusually warm and non-stormy winter was an exceptionally stubborn positive NAO coalesced with a negative PNA pattern. This supported ridging in the East, in addition to a “zonal Pacific-flow” that setup across the nation. This allowed warm, pacific air to invade the country. The cold air needed to spawn snowstorms remained locked away in the Arctic. 

This year, a very different pattern has setup; one much more supportive of a negative NAO pattern. Taking a look at the Atlantic Ocean sea surface temperature anomalies centered around Newfoundland, you can see a pattern immensely different from last year shaping up; something similar to that of the winters of 2009-2010 & 2010-2011. Sea surface temperatures are running much above average south of Greenland, extending down towards Newfoundland, and the far southern waters of Nova Scotia. This is a patten very supportive of a negative NAO. A similar setup occurred back during the winter of 2010-2009 and 2010-2011, resulting in much above average snowfall for portions of the Northeast. Meanwhile, off to the South, in an area extending from the shorelines of the United States mid-Atlantic region, to the shores of the UK and Spain, there is an area of below average sea surface temperatures developing. This is a potential signal that an active storm track may develop, and shift further to the South, in a similar fashion to that of 2009-2010. While I do not expect a pattern nearly as extreme as the winter of 2009-2010, there are a few similarities showing up. Needless to say, there are strong signals coming out of the Atlantic ocean that this winter may feature a primarily negative NAO.

Taking recent trends into consideration, I am predicting a predominately negative NAO for the winter of 2012-2013. This will support the occasional development of strong coastal storms, or “Nor’easters” along the East coast; potentially producing above-average snowfall for portions of the Northeast. In addition to the potential for above average precipitation, there is a heightened risk for below-average temperatures across the eastern portion of the nation.  

Another major component contributing to the 2012-2013 winter pattern is the Arctic Oscillation or “AO”. The AO is yet another climatic variable- or “fluctuation” with two phases. Like the NAO, the AO plays a large role in dictating the wintertime storm track, as well as regulating the amount of cold air that pours down upon the east coast. There are two phases of the AO: the positive phase, and the negative phase.
Throughout the duration of the negative phase, high pressure builds in over the Arctic, forcing the jet stream and Polar Vortex to the south, and with it, cold Arctic air. The more negative the AO, the greater the influence cold Arctic air has on the midwestern and eastern portion of the nation. Very cold and stormy conditions historically accompany negative AO patterns in these regions of the country during the wintertime months. 

Meanwhile, during the positive phase, low pressure builds in the Arctic, forcing the jet stream and Polar Vortex to move far to the north, trapping Arctic air up in higher latitudes. Positive phases of the AO result in above-average temperatures across the continental United States, as a zonal pacific flow sets up, carrying warm, pacific air across the continental United States
In similar configuration to that of the NAO, the AO is virtually impossible to predict no further than 1.5-2 weeks out at a time. However, there is one, specific signal that may help us figure out what phase will be dominant during the winter months. During January of 2013, NASA is expecting us to reach a “Solar Maximum”. This signifies that sunspot activity will peak this winter. Recent research by NASA and NOAA has pointed towards the idea that during the minimum of the 11-year sunspot cycle, rapid drops in UV light can trigger a strongly negative AO pattern. Evidence of this can be found in the solar minimum that took place during the winters of 2009 continuing through 2010. During this period, the AO remained obstinately negative, resulting in brutal cold throughout Europe and the United States. 

Based off of this research, one could conceive that there is an increased risk of a positive AO pattern this winter. However, recent trends of the AO point towards a predominately negative pattern this winter. Based off of the research, I am predicting the winter to start out with a negative AO, lasting into late January with occasional, however infrequent fluctuations towards positive; then as we move into the later portions of winter, the AO will tend do fluctuate, and not stick to any one phase. This will result in the increased risk for below-average temperatures across the Midwest and northeast, in addition to the increased risk of storminess. 

In correlation to the NAO and AO, is the Pacific North American or “PNA” in short. The PNA is a climatic variable; fluctuating in-between two phases; positive and negative. This variable has a large impact on the North American wintertime pattern. During the positive phase, high pressure centered around the Rocky Mountains strengthens  simultaneously with low pressure centered around the Aleutian Islands. This creates a large ridge across the eastern Pacific extending into the western United States. In response to the western ridge, an amplified trough develops in the East, resulting in cold and stormy conditions.
In contrast, during the negative phase of the PNA, essentially the exact opposite pattern sets in. High pressure centered over the Rocky Mountains weakens, as high pressure centered around the northern Gulf Coast strengthens. This creates a trough in the West, associated with cold and stormy conditions; while to the east, a large ridge of high pressure forms resulting in warm, and relatively dry conditions. On occasion, a negative PNA can form a stubborn “southeast ridge” continually pumping warmth into the eastern seaboard for an extended period of time.  During the winter of 2011-2012, A predominately negative PNA pattern unfolded, and as a consequence, a stubborn southeast ridge formed. This, along with a few other factors greatly contributed to the exceptionally warm fall and winter of 2011-2012.

The PNA is strongly influenced by ENSO (El Niño Southern Oscillation). The positive phase of the PNA is historically more common during an El Niño, while the negative phase tends to be more prevalent during La Niña episodes. Based off of recent trends, and the fact that we will be experiencing ENSO-Neutral conditions during the winter of 2012-2013, I am predicting a relatively balanced PNA pattern this year, possibly leaning towards the positive phase. The PNA will oscillate from one phase to another throughout the winter, resulting in periods of cold and stormy weather for both the east, and west coasts of the United States.

Snow cover over Siberia is also a significant component in figuring out the winter forecast. Recently, research has tied above-average snow cover over eastern Siberia to below average temperatures, and increased snow cover over North America. This is evident upon closer examination of the past three years. During the cold and snowy winters of 2009-2010 and 2010-2011, snow cover over Siberia averaged out much above average during the fall and winter months. Consequently, there was a stronger presence of cold air over North America. 

Meanwhile, during the exceptionally warm winter of 2011-2012, snow cover over Siberia averaged out below normal. In the same ways above average snow cover effected North America during the winters of 2009-2010 and 2010-2011; below average Siberian snowfall served to aggrandize an already exceptionally warm winter throughout the continental United States.

        However, this year, snow cover over Siberia is painting a very different picture. When comparing this year’s snow cover an anomaly to that of last year, the two are almost polar-opposites. During the fall months of 2011, snow cover over eastern Siberia was about 25-56% below normal. In contrast, when taking a look at this past fall season’s Siberian snow cover anomaly, there is about 61-100% above normal snow cover over eastern and southern Siberia. Historically, this is supportive of a stronger presence of cold and snowy conditions across the United States during the winter of 2012-2013. 

I expect the climatic variables discussed above to have a tremendous impact on this year’s winter pattern.
        Based off of my research, I am predicting the winter of 2012-2013 to feature a much colder and stormier pattern throughout the Midwest, East, Mid-Atlantic and Southern Northeast regions of the United States. Meanwhile, the Southwest and southern plains regions of the United States are expected to experience a relatively warm, and potentially dry winter.  Extensive research has gone into the maps you see in this forecast. Using analogue years of similar ONI (Oceanic Nino Index) values & patterns, current 30 to 90 day temperature anomalies, climate forecasting models, climatic variable trends, and much more; I have crunched in the numbers, and what I have found is the following. I will begin with the Precipitation Outlook issued for late December, January, February continuing through the first week of March. 

In the forecast, I am calling for a large area from Arkansas, through the Tennessee & Ohio Valley, and up through northeastern seaboard to receive above-average precipitation this winter. This is  a result of an active southern jet stream associated with ENSO-Neutral years learning towards a weak El Niño. Above-normal precipitation is historically more common in these places during ENSO-Neutral years; as a more active subtropical jet stream tends to set up, supplying major storms with copious amounts of moisture. This particular characteristic has been present during the fall of 2012; as major storms (such as Hurricane Sandy, our early November snowstorm, and recently, the December 19th-21st midwest blizzard) were supplied with an abundant source of moisture coming out of the subtropical jet stream. This aided to intensify these storms, and enhance precipitation across affected areas. 

This winter, I expect an active storm track in the East. This is a consequence of a predominantly negative NAO & AO coalesced with a positive to neutral PNA. On occasion, this pattern will support the development of large-scale winter storms along the coast known as “Nor’easters’. These storms are notorious for slamming the east coast with tremendous amounts of snow, occasionally slamming the big cities of the Northeast, shutting transportation down for days. While I do not expect a pattern as active as past winters of 2009-2010 and 2010-2011, there will likely be sporadic storms and cold in the Mid-Atlantic & Northeast similar to the active winters of the past. Overall, I expect at 2-4 major coastal storms or “Nor’easters” to impact the Northeast & Northern Mid-Atlantic during the winter of 2012-2013. 

For the big cities along the heavily populated I-95 corridor from Washington, D.C. to Boston, MA; I am predicting 33-50% above normal snowfall, with a slight (33%) risk of below average temperatures. 

For the interior portions of the Northeast, I am predicting closer to normal precipitation, with the risk of slightly below average precipitation around the great lake snow belts in western New York state. This is repercussion of below-normal lake effect snows this winter, and a storm track closer to the coast.

Across the southern ”Gulf coast” region of the nation from Texas to Florida, historical trends point towards a drier than normal winter; as the storm track will likely be to the north of this region for the majority of winter. However, with an active subtropical jet stream setting up this winter, there is potential for a few major rainstorms, or developing coastal storms to impact this region with heavy precipitation during the winter of 2012-2013.

Meanwhile, out in the midwestern portion of the nation, I am forecasting significantly below average precipitation. As a repercussion; a severe drought that started back in 2011 throughout portions of the Midwest will likely be aggravated by below-average precipitation during the winter of 2012-2013. 

Further to the northwest, specifically in The Pacific Northwest, an active storm track throughout late December into January should lead to above average precipitation here, with heavy mountain snows. The same is true for portions of southern and coastal California including the mountainous regions of southern California as well. Numerous disturbances sliding down the coast will move onshore in southern California this winter; resulting in above average precipitation in this region of the country. 

Furthermore, I have created a Temperature Outlook issued for late December, January, February continuing through the first week of March. 

        

        I will begin with the Northeast, where I am forecasting a wide spectrum of departures from normal this winter. In the northern tier of the Northeast and eastern portion of Canada from Boston to the north, continuing on through all of Northern New England, Atlantic Canada a large portion of Quèbec, and northern and eastern Ontario, I am forecasting above average temperatures.

This can be attributed to a strong presence of blocking over the Hudson Bay & Greenland expected to setup this winter. As a result of the blocking, above average temperatures will extend down through the regions listed above.

Consequently, blocking in the northern Atlantic as characterized by a negative NAO will assist to bring below average tempters to a large portion of the nation this winter. I am predicting a large area extending from North Dakota, through the northern midwest, the Ohio & Tennessee Valleys, into the Mid Atlantic region to receive below average temperatures this winter. Occasional invasions of Arctic air throughout this portion of the country will also help to bring down the average temperature below normal, as I am forecasting arctic air to have a much stronger presence throughout this particular portion of the country in comparison to last year. 

Meanwhile, out over the western portion of the nation, there is a high likelihood of above average temperatures during the winter of 2012-2013. Extensive research completed in order to put this forecast is in strong agreement that this particular region of the country will experience  warmer-than normal temperatures this winter. High pressure will have a significant influence out west this winter; as associated with a predominately positive PNA expected to setup throughout portions of the winter season. Ramifications of the predicted PNA include a stubborn ridge forming over the West, resulting in above-average temperatures throughout the region. 

Overall, Arctic air will have a greater presence in portions of the United States this year I comparison to last. This will lead to increased storminess in the East, and the risk for below average temperatures throughout a large portion of the nation. 

In conclusion, the winter of 2012-2013 will feature a pattern remarkably dissimilar from that of the previous winter of 2011-2012. This winter, a pattern will develop that favors above-average snowfall and below average temperatures throughout a large portion of the region and correspondingly, nation as a whole. After months of extensive research, I can confidently say that the winter of 2012-2013 will feature more frequent storms, and heavier snowfall in comparison to the last. 

Thank You for reading The Official 2012-2013 Winter Forecast written and published by Sam Ebby of Northeast Weather. For the very latest on winter storms set to affect the Northeast this winter, be sure to stay tuned to Northeast Weather as I will work to bring you all the latest. Thank You again for reading; Have a wonderful holiday, and winter season! 

-Sam Ebby of Northeast Weather 

The Official 2012 Fall Forecast & Hints into Winter

THE OFFICIAL 2012 FALL FORECAST

By Sam Ebby of Northeast Weather

Setpember 27th, 2012  

As summer fades to autumn, we are reminded that winter lies right around the corner. Much can be said about any season’s winter during the Fall Season. Atmospheric patterns tend to spill over into the winter from autumn. Last year’s Fall season proved to be quite diverse in nature. A historic “freak” paralyzing snowstorm struck the Northeast in late October, only to be followed by an unseasonably warm November across the Northeast and much of the Nation. November of 2011 was the 11th warmest November of all time. These conditions, to the disappointment of many, spilled over into the Winter. This year, the planet is in a completely different atmospheric pattern; one dominated by a weak El Niño. This is essentially the opposite of the Moderate La Niña that we experienced last year. The 2012 Fall season will develop an entirely different pattern than that of last year, potentially leading us into a far snowier winter this year in comparison to last.

While there are many contributing factors into this seasons forecast, among the most influential is the current phase of ENSO (El Niño Southern Oscillation). As of September 24th, 2012, A weak El Niño is expected to develop, and remain present throughout the Winter months. El Niño is characterized by unusually warm sea surface temperatures in the equilateral Pacific ocean, or an ONI (Oceanic Nino Index) value of +0.5 or greater. During the Fall months of a weak El Niño, the southern branch of the Jet Stream historically becomes very active; producing large rainstorms that primarily impact the southeast and occasionally the Mid Atlantic/Northeast. This is something I expect to become existent during this year’s Fall Season. In addition to the chance for above average precipitation, A weak El Niño historically bring slightly above-average temperatures during the autumn months of September, October and November.

However, the current phase of ENSO is not the only factor contributing to the fall season’s forecast. There are three other prominent factors that dictate our climate here in the Northeast and across the world. The N.A.O or (the Northern Atlantic Oscillation), being the first. The NAO is a climactic fluctuation, located in the Northern Atlantic Ocean. There are two phases of the NAO: the positive phase, and the negative phase. During the positive phase, low pressure centered around Iceland and high pressure centered around the Azores Islands intensify. The stronger the systems in these areas, the more positive the NAO becomes. Throughout the positive phase, the Jet-Stream retreats to the north, allowing warmer air to move farther north, having an impact on the Northeast with well-above average temperatures. Historically, large-scale storms are less common during positive phases of the NAO.

During the negative phase, low pressure centered around Iceland weakens significantly, and moves over Greenland, while the Azores high weakens. This creates a “blocking” effect, forcing the Jet stream to dip far to the  South, allowing cold Arctic air to drop down onto the Eastern United States. This periodically allows large-scale Nor’easters to move up the eastern seaboard, and cause heavy rain and/or snow during the fall and winter months. While it is nearly impossible to predict the NAO for an entire season, let alone four weeks, I can tell you this: I have noted recent trends are beginning to  point towards a more negative NAO this fall season in comparison to last year. This would allow large-scale storms like Nor’easters to strengthen and move up the eastern seaboard in greater frequency than last autumn. Unlike last year’s fall season, when the NAO stayed positive for the majority of the fall and winter seasons, resulting in an unusually warm fall, with very few Nor’easters. This was a pattern followed us into winter. While I cannot eliminate this scenario, it is far less likely to occur once again this year.

  The second major factor or “teleconnection” contributing to the fall season’s forecast is the A.O or (Arctic Oscillation). The AO, like the NAO has two phases, and tends to fluctuate a great deal.  When in it’s negative phase, High pressure builds in over the arctic, forcing the Jet Stream south, and with it, cold arctic air. During the Positive phase of the AO, low pressure builds in the arctic, trapping Arctic air up in higher latitudes, while a zonal flow tends to develop across the United states, spreading warm Pacific air across the nation. Along with the NAO, the AO is virtually impossible to predict no further than 1.5 - 2 weeks out at a time. Recent trends suggest that for the most part, we are in a primarily positive phase. However, this can change dramatically over the course of a few weeks.

  The Third major contributing factor is the P.N.A or (Pacific/North American). The PNA like the AO and NAO, has two phases, and is a variable. The Pacific/North American can have a large Impact on the National weather pattern during the fall and winter seasons. During the PNA’s positive phase, high pressure centered around the Rocky Mountains strengthens, while low pressure centered around the Aleutian Islands does the same . This creates a large ridge across the eastern Pacific extending into the western United States. In response to the western ridge, a trough develops in the east.

  The negative phase of the PNA is essentially the exact opposite. High pressure centered over the Rocky Mountains weakens, as high pressure centered over the northern Gulf Coast strengthens. This creates a trough in the West, and a large ridge in the East. On occasion, a negative PNA can form a stubborn “southeast ridge” continuously pumping warmth into the eastern seaboard for an extended period of time. This was something that was very persistent last year, and greatly contributed to the exceptionally warm fall and winter of 2011-2012. However, this year I do not see a southeast ridge developing and persisting for as long as it did last year. As far as the PNA goes, I am forecasting it to fluctuate often, wondering in between positive phases, and negative phases. Neither phase more dominant than the other. However, this will likely change as we head into winter.

  Overall, I do expect the weak El Niño to have a substantial impact on the nations pattern as we move towards winter. Extensive research  has been completed in order to create the maps you see in this forecast. Using analogue years of similar ONI values & patterns, current 30 to 90 day temperature anomalies, climate forecasting models, and much more, I have crunched in the numbers, and what I have found is the following. I will begin with the Temperature Outlook issued for September, October, November and into early December of 2012

In the forecast, I am calling for a good portion of the Northeast to experience slightly to moderately above average 

temperatures during the fall season of 2012. The probability of above average temperatures begins in Allentown, PA and extends north, throughout the rest of the Northeast. While to the South & west of Allentown, there are “Equal Chances” for both above, and below average temperatures. This is where I anticipate either “near normal” or a  less than 20% risk of either above of below average temperatures. Either departure is possible, however nothing significant. To the south, Starting in North Carolina, and extending throughout the Southeast and portions of  eastern Texas, I am forecasting below average temperatures. This is backed up by both history, and 30-Day and 90-Day trends. Negative temperature anomalies are beginning to develop in these areas. 

  Meanwhile, off to the Northwest, I am calling for among the greatest departure from normal to setup to the southwest of the Hudson Bay in Canada. Nearly every year with a similar pattern to that of this year has had above normal temperatures to the south of, or along the southwestern shores of the Hudson Bay. While off to the west, I am anticipating much of the west coast to experience below average temperatures. Especially along the western portions of California. In this area, I am forecasting a 60% chance of below average temperatures. Looking back in history, this idea is supported time and time again. Nearly every weak El Niño Fall, this area recorded below average temperatures. 

  Second, I have created a Precipitation Outlook issued for September, October, November and into early December of 2012. This year, I expect an active southern branch of the Jet Stream to produce large rainstorms across the Southeast & Gulf coasts. Periodically, if the conditions are right,  the southern branch may phase with the Northern branch, creating Nor'easters that move up the east coast. If we are to see a pattern favoring frequent Nor’easters over the course of the next 70 days, this may very likely carry over into Winter. However, at the same time, it is very possible that the Northern branch of the Jet Stream stays split, and rainstorms slide off the Southeastern coast instead of up the East Coast. As of now, I expect at least three Nor'easters to impact the Northeast this fall. My forecast calls for the heavily populated eastern I-95 section of the Northeast to receive slightly above average precipitation, while farther inland, the probability for normal if not below average precipitation increases. South of Philadelphia PA, the probability of above average precipitation increases significantly. This is a result of a moisture-rich active southern Jet Stream expected to fire up this Fall and early winter. During a typical weak El Niño fall, the Gulf  & Southeast coasts experience above average precipitation as a result of an active southern Jet Stream. Off to the Great Lakes & interior Northeast region, where a long stretch of below average precipitation is forecasted. This area typically receives less than normal amounts of precipitation during an weak El Niño Fall season.

As a result of El Niño, the Pacific Northwest is also expected to receive below average amounts of precipitation this Fall. Storms will be less frequent in the Washington/Oregon/Vancouver region of the Pacific Northwest.Most of the powerful Pacific storms that typically form during the fall and winter months, will track farther to the north, impacting central and northern British Columbia along with Alaska.

  Drought conditions in the south will likely see some relif. This year’s pattern favors a very wet season in the south. The wettest since the fall/winter season of 2009-2010. While I do not expect  the same pattern to setup, similar effects may be felt. 

In conclusion, expect a very different season this year in comparison to last. We must study the patterns that setup during the autumn season; as history has shown  they may very likely follow us into the winter season. I am forecasting a pattern immensely different from what we experienced last year; perhaps a pattern favoring heavier snowfall along the east coast in comparison to last year. This is an example of one of the many questions can only be answered by studying the nature of our global weather pattern during autumn.

Thank You for reading The Official 2012 Fall Forecast written and published by Sam Ebby of Northeast Weather. For more on the upcoming Winter of 2012-2013,  stay tuned to Northeast Weather over the next few weeks, as the Official 2012-2013 Winter Forecast is expected to be released in Mid/Late November.  Have a wonderful season! 

-Sam Ebby of Northeast Weather

The 2012 Atlantic Hurricane Season Forecast:

June 1st marks the start of the 2012 Atlantic Hurricane Season. The season runs until November 30th.  This year, the 2012 Atlantic Hurricane Season will feature an average to slightly below average number of tropical cyclones. However, the overall threat for a Tropical cyclone to make landfall on the United States is greater than in years past. Water temperatures across the equilateral Pacific Ocean continue to warm, as we transition into El Nino from La Nina. Historically, this means less tropical cyclones in the Atlantic Ocean. Looking at the current Sea Surface Temperature anomalies, you can clearly see El Nino building in the equilateral Pacific, while sea surface temperatures across portions of the Atlantic Ocean are below average. This will hinder development of tropical cyclones in the open Atlantic, decreasing the overall number of Atlantic hurricanes. Meanwhile, in the Gulf of Mexico, sea surface temperatures are above average. This will contribute into making the Gulf of Mexico the place to watch for tropical cyclone development. This year, “homegrown” tropical systems will be more common, as conditions are favorable along the Southeastern & Gulf coasts for tropical cyclone development. Summer cold fronts moving across the country can provide moisture, lift and “spin” for tropical disturbances developing in the Gulf of Mexico. This creates a highly favorable environment for tropical cyclone development. Scenarios like this will likely be common off the coast of the Southeast United States & the Gulf of Mexico during the 2012 Atlantic Hurricane Season.  Another major factor contributing to the 2012 Atlantic Hurricane Season Forecast is the Bermuda ridge; the steering force behind most Atlantic tropical cyclones. The Bermuda ridge is a large subtropical area of high pressure typically centered around Bermuda. This ridge steers Atlantic cyclones towards the United States from Africa and the Western Atlantic Ocean. This year, I am anticipating this ridge, along with cooler than normal sea surface temperatures, to suppress tropical cyclone development in the Western Atlantic Ocean. However, placement of the Bermuda ridge this year will likely encourage tropical cyclones to track into the Southeastern United States & Gulf Coasts, making these areas higher at risk than in years past. Meanwhile, further up the coast along the Northeastern United States from Cape May, NJ up to Eastport, ME, the likelihood of a tropical cyclone to make landfall is slightly less than average. This is a result of the Polar jet stream dipping farther south than normal. Arctic high pressure centered around Greenland, and low pressure centered near the southern Hudson Bay will force the Polar jet stream south, reducing the risk of tropical cyclone landfall in the Northeast. However, not too far to the south, along the Mid Atlantic coastline, the risk for a tropical cyclone to make landfall is slightly greater than normal. This is a result of placement of the Bermuda ridge. Just as the Southeast United States is more prone to tropical cyclone landfall this year, so is the Mid Atlantic region. The Mid Atlantic United States coastline is not as high at risk as the Southeastern United States coastline. nonetheless, it is still possible that in mid August to early September, a tropical cyclone tracks into this region.      To conclude I would like to restate in further detail the areas along the United states coastline that are highest at risk for tropical cyclone landfall this year. These areas include: The entire Gulf Coast stretching from the Florida Keys all the way down to the Texas/Mexico border. In this area, I am anticipating tropical cyclone development to be slightly above average. July to September will be this regions most active months. The Southeastern United States is also at greater at risk for tropical cyclone landfall. This region extends from Wilmington, NC down to Miami, FL. In this area, I am anticipating tropical cyclone development to be average. June to September is anticipated to be the most active months for the region. The Mid-Atlantic region has a slightly higher than normal chance for tropical cyclone landfall this year. This area extends from Rehoboth Beach, DE down to the outer banks of North Carolina. In this area, I expect tropical cyclone development to be average to slightly below average. June to September will be the regions most active months. Planning ahead incase of a hurricane or tropical storm greatly reduces the risk of danger to yourself, and your family from these storms. Have an emergency hurricane plan set for you and your family. If you are aware that you live in an area prone to hurricanes and tropical storms, have a hurricane Kit ready, and learn evacuation routes and where emergency shelters are setup incase of an emergency. For more information on how to prepare in advance of a tropical cyclone, please visit this helpful site from the National Weather Service: http://www.nhc.noaa.gov/prepare/. Thank you for reading The Official 2012 Atlantic Hurricane Season Forecast written and published by Sam Ebby of Northeast Weather. Have a wonderful season, and remember to stay safe! 

- ©Sam Ebby of Northeast Weather 

FORECAST DISCUSSION, JANUARY 31ST, 2012 -
Today, Here in Philadelphia, PA the high temperature reached 61˚F. unseasonable warmth has taken over the vast majority of the east coast, and should continue Throughout Thursday. Wednesday, Looks like an area of (weak) low pressure will ride along the southern border of Maine, producing moderate-heavy snow from Rangeley, ME to Bangor, ME north. Some areas could receive 6-8”, While other areas such as Portland, will experience a rain/snow event, with little or no snow accumulation expected.
Thursday night, a shortwave will ride south of the area, potentially producing a brief period of sleet/rain/snow from D.C.-Philadelphia. No snow accumulations are expected with that system. Sunday, another area of low pressure should move into the area from the midwest. Current modeled guidance is very unreliable at the moment concerning this system, as currently, the storm is a weak wave of low pressure in the Northeastern Pacific. Wednesday’s 12z Model runs should have a better handle on the storm. NOAA is sending a winter weather flight into the storm to collect better data for the GFS. My current ideas go as this; A weakening area of low pressure moves east, and reforms along the coast, but remains too weak for any major accumulations if any at all across the Northeast. I will continue to watch this system over the coming days. But at the moment, it is not much of a threat.
SOI Values dropped again today, Dipping down into -6.21. SOI values have been consistently dropping since January 25th. From +46.03 to today's readings of -6.21. Lower SOI values = Less warmth across the Nation.
On another note, the MJO looks to go into Phase 7, and then potentially Phase 8. The MJO has ben stuck in phases 4, 5, & 6. These phases support much above normal temperatures across the Northeast, and that is what we have been seeing much of since December! This looks to change, into more favorable phases 7, 8 and potentially 1.
GFS 500mb Ensembles continue to show a -NAO & +PNA pattern setting up after the 8th of February. I do NOT expect any major winter storms to impact the I-95 corridor Until the 8th of February. From there on, conditions look much more favorable. As it looks now, i do expect a 2-3 week period of blocking to setup, and produce at least one major winter storm along the east coast. Looking at current modeled trends and history, it looks like this period f blocking will setup between the 8th of February and the 16th. Lets hope, because if the pattern we are in now holds, Expect more of the same. Warmth with translucent cold in the east, with quick hitting systems that put down mostly rain South of I-80.
Thats it for tonight Folks, As usual, i will update you all as details & advancements in the Forecast come about.
~
©Sam Ebby of Northeast Weather

Big change in the pattern coming as we head into February .... 

The PV has been stuck in the gulf of alaska since November, that looks to change dramatically. As the PV looks out move out of alaska and into Southeastern Canada. 

Along with the NAO. There has been virtually NO persistent  high-lattitude blocking over greenland since August! This too looks to change. the ECMWF shows a very negative NAO setting up around the 3rd of February. This is possible....As depicted in the picture, you can clearly see negative heights over greenland (showing a very +NAO) turn to more positive heights (this is  signature of a -NAO). Not only over greenland can you see a bug difference in the pattern, but look out over the Pacific. The EOP has been riding very positive recently. that looks to change, as you can clearly see positive heights turn negative. ( A Negative EOP is more favorable for east coast snowstorms). The biggest and perhaps most visible change to the pattern is the break-down of the alaskan vortex. Currently, there are vey negative heights over alaska, and this should continue into at least the first few days of February. Then, a massive change over to very positive heights as a -EPO * +PNA pattern setts in. A lot is still on the table, and this can change, but there are many more signals that point towards at least one major east coast snowstorm in February.The MJO (which has been in phases 5,4,6,) Looks to move out into phases 7,8,1 and potentially 2. These are much more favorable phases for a -NAO to setup, Resulting in more coastal storms. Not only that, but SOI Values continue to plummet, as of the past three days, SOI values have dropped from 46, to 21, to 7! an astonishing drop! (NOTE: Lower SOI Values = Less warmth across the United States.) 

FORECAST DISCUSSION - JANUARY 27th, 2012

Heavy rains, Winds & Heavy snows should be out of the region by Saturday. Most if not all of the rain that will fall has fallen in the I-95 corridor. Winds could gust as high as 40mph tonight across the Delaware Valley and portions of the I-95 corridor-West. 
NEXT WEEK: Things should remain generally warm across the region, with cold air up across the interior Northeast. Wednesday, looks damp and mild with a low passing to the north of the area. Then on friday, things could get interesting. The ECMWF model guidance wants to take a storm off the coast, with heavy snows to the N & W of I-95. While the GFS keeps the storms separate with generally mild air staying in place. The GFS shows marginal rains south of Hartford, with light-moderate snows to the north. At the moment, i am leaning towards the potential for a (weak) coastal system. High pressure should be to the north, pushing the storm offshore. If the NAO goes negative be next friday (which is possible, but unlikely) then we could very well see an east coast snowstorm. I don’t want to talk about who gets snow and how much, because both the GFS & ECMWF models are extremely unreliable in this time-range. Often, you see big storms 170-192 hours out, that virtually disappear days later. So for now, i will keep an eye on that potential system, but i do remain skeptical.
As we head into the long range (February 5th & Beyond) things are looking more favorable for an east coast snowstorm. I do see a time period between the 8th of February to the 16th or so of February where blocking could setup. If this does pan out, It does seem likely that at least one major east coast storm will hit the Big cities. It is possible that true winter could show itself for a few weeks with snow & cold taking over the eastern part of the country as we progress into February.

©Sam Ebby of Northeast Weather

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