WINTER SEASON 2015/16: ENTERING SOLAR MINIMUM

The emerging sleep of-the-Sun, with only three (3) identified sunspots visible on the solar disk as of 
November 25, 2015.  

Originally prepared: November 23, 2015 (Facebook timeline-post) 

I would like to talk about El Niño, that has made significant headlines in the media. El Niño "The Boy", which is an unusual warming of Pacific sea surface temperature (SST) anomalies, is NOT basin wide through the equatorial Pacific Ocean. In fact close observation shows there is NO comparison to the 1997/98 super El Niño, as this particular event is *Central-to-West-based and NOT basin wide or East-based. This means the warming of SST anomalies over the Pacific is concentrated from the International Dateline, points east to the *Central / North American continent.

A *Central-to-West-based El Niño will in-fact encourage an energized sub-tropical jet-stream but ridging (above normal heights) over western North America due to the area of above normal SST's concentrated through the eastern Pacific, that will tend to encourage troughing (below normal heights) over eastern North America.

What is the foundation of the 2015/16 Winter season?

1. Solar Minimum / High Latitude Blocking - it's very important to consider that we are now entering a solar minimum following the 9-11 year sunspot cycle. The Sun has been averaging 20 daily events or less (in-terms of sunspot activity on the solar disk) since November 7, 2014, and is currently at 15 daily events as of November 20, 2015. Through the majority of absent New England Winter's of the 1990's, the Sun was averaging 40-100 daily events, * sending a moderate to high frequency of ultraviolet (UV) rays at-the-Earth. The higher frequency of ultraviolet (UV) rays acts to deplete ozone and in-return allows for pronounced cooling of the pole's stratosphere, with the Polar Vortex (PV) almost never splitting to influence middle latitudes of-the-Earth. Strongly taking into consideration current solar activity, lends hand to the highly cyclical 9-11 year (Schwabe) sunspot cycle, that we are indeed entering a solar minimum. The emerging sleep of-the-Sun will soon encourage pronounced warming of the pole's stratosphere due to increased ozone, * as this warming pushes down through the * stratosphere and troposphere, the PV will in-turn react and SPLIT, the pole will moderate. As the split PV drops south in-latitude, a reaction-to-action, ejecting the Arctic Oscillation (AO) / North Atlantic Oscillation (NAO) into a pronounced negative phase. This will be the said driver of the 500-millibar Height Pattern over the Northern Hemisphere during the coming 2015/16 Winter season, NOT El Niño.

2. El Niño - the above said factors will tend to encourage an unusually stronger than normal or *enhanced* sub-tropical jet-stream, that will as-a-result of location, be a high moisture source to interact with the Polar jet-stream. This will be, an enhancer, encouraging a moderate to strong probability of Nor'easters.

When will this change influence New England?

While we have experienced a gradual step-down since mid November, there are key signals that will indicate CHANGE. 
A strong low pressure system tracking through the eastern Great Lakes region, producing rainfall in New England, around the week of November 29th may be the mechanism that encourages a significant pattern change. 
Therefore, December 5-12th is the time period of high volatility.

* Corrected information on sudden stratospheric warming & the current state of El Niño.

FINAL THOUGHTS ON THE 2014/15 WINTER SEASON!

Originally prepared: January 14-15, 2015 (Facebook timeline-post) 
A further in-depth look at the 2014/15 Winter Season! Well, changes are... and certainly have occurred. The image below (although-not-current) depicts - MAJOR - changes that have occurred with the 500-millibar Height Pattern over North America (and the Northern Hemisphere as-a-whole). What has happened? The most noteworthy change from December is-with-the Polar Vortex (PV), itself. The polar vortex is an intense (cold) upper-level low pressure system that originates over the Arctic / North Pole, and this-is-where the PV stayed for most of December. However, through poleward stratospheric changes "warming"... the PV SPLIT into two (2) separate lobes and dropped south, with one lobe falling over North America, and the other over Eurasia. Through these changes, the pole moderates... as "Blocking High Pressure" becomes established across northern latitudes (i.e. Arctic Oscillation "AO" becomes increasingly negative), ejecting the upper-level low pressure system from the Gulf of Alaska & replacing-it with intensifying High Pressure (notice the greenish shade toward the Gulf of Alaska on-the-image, indicating moderating anomalies, which is a significant change from December). It's very IMPORTANT to understand that during most of-the-classic old fashioned winter's experienced in New England during the 1950's, 60's, & 70's the PV almost always split... if this doesn't take place, you end-up with a longwave weather pattern similar to-that-of December 2014, "progressive", which was experienced through most-of-the absent winter's of-the-1990's! Now that the PV has split, what will happen? The 500-millibar Height Pattern is-open to configure itself to repeat the 1950's, 60's, & 70's all-over-again... and will attempt to do just that on-or-about January 21st, before this time frame there will be a temporary moderation... indicating CHANGE. What does this mean? We have now certainly experienced the "cold" but have yet to combine that with true snowstorms (Nor'easters)... on-or-about this date (1/21) is when all-the-elements have the potential to-come-together (i.e. North Atlantic Oscillation "NAO" also becomes negative), thus "blocking" / lifting the jet-stream up along the U.S. Eastern seaboard, promoting East coast cyclogenesis. This change will make run at balancing the December blowtorch, as January 2015 should average "at least" 1-2° below normal in-temperature, however beyond this... with the exception of a brief mild spell around the second week-of-February, both February & March 2015 have a strong probability of averaging below normal in-temperature, considering the above-said-factors. In closing, the Winter Season of 2014/15 has strong potential of averaging slightly below normal in-temperature overall, with above normal snowfall through much-of-New England. What is average snowfall? For example: ADAMS / NORTH ADAMS - 78.1" average annual snowfall. Winter 2014/15: potential 100.0"+ for-the-season as-a-whole. BOSTON - around 43.0" average annual snowfall. Winter 2014/15: potential 50.0"+ for-the-season as-a-whole.

THOUGHTS ON THE 2013/14 WINTER SEASON!

NASA Solar Activity as of November 19, 2013

 Solar Activity, while mentioned by few professionals concerning Winter Outlooks... is one-of-the most important factors shaping this upcoming Winter season, it is what I call the foundation. The above image of the solar disk from NASA on November 19, 2013, shows 4-active sunspot regions in-general (circled-in-black) on the sun. The sunspot region toward the center of the solar disk, is most active... however all circled sunspot regions have-to-be-watched. Of note, during a Solar Minimum, the solar disk would be virtually free of sunspot activity... as we head toward 2016, the above image will be less-of-a-factor. Sunspots have a direct relation to High Latitude Blocking episodes, due to the entrapment of heat through UV Rays... promoting increased ozone formation. The more active the sun, the more of a driver it is... influencing the Earth's stratosphere (poleward), where pronounced cooling occurs. Therefore, the orientation of the jet-stream keeps the heart of the Polar Vortex (PV) at the North Pole...
encouraging an overall progressive pattern (with short-lived shots of cold air) in middle latitudes with a highly Positive Phase of the Arctic Oscillation (AO) and 
North Atlantic Oscillation (NAO). As a result, the weather pattern experienced in middle latitudes, is an overall milder, dryer pattern... which is a signature of increased solar activity, especially during a Solar Maximum.

AO GEFS Index Forecast  -  November 19, 2013

Looking at the Arctic Oscillation (AO) Global Ensemble Forecast System (GEFS) forecast, shows true signs of solar influence. Within the area circled-in-red, the AO Index has been averaging around  +3.0 Standard Deviation (SD) above normal-mean... from extreme late October to mid-November. During this time period there was also a  pronounced resurgence in sunspot activity, which is clearly observed with this classic +AO signature.

SWPC Solar Cycle Progression as of November 4, 2013

Viewers of this site understood that a Solar Maximum was experienced during 2011/12 & 2001/02... following the 9-11 year Schwabe Cycle, which averages to be exactly every 10.66 years that a solar maximum is observed. However, following this cycle also hints at a resurgence of solar activity about 2 years after the actual observed maximum... this occurred in 2003/04 (which highly influenced that Winter season) now were 2 years after the maximum again, with another resurgence in sunspot activity. In posts I published during the 2012/13 Winter Season, I wrote about a return to the classic old-fashioned New England Winter's (as experienced throughout most of the 1960's & 70's) from 2016 through 2020. I stated this with a strong understanding that this period will be the start of a Solar Minimum (which will strongly encourage High Latitude Blocking episodes due to a non-active solar influence), following the Schwabe Cycle. But, there is also another important factor to strongly consider...
on January 4, 2008 we entered Solar Cycle 24. While Solar Cycle 23 was highly active in-terms of sunspot activity, especially before the observed minimum in 2006 (as seen on the SWPC image above), Solar Cycle 24 has paled in-comparison. This is a highly important factor, that will also have a significant influence over the next decade+... considering that the actual solar cycle is about 22 years long.

My thoughts for the 2013/14 Winter Season: Due to a resurgence in solar activity, it's critical in how active the sun remains. However, I will clearly state that seeing the actual Solar Maximum was observed in 2011/12... I certainly believe that it won't be as mild as that Winter. In fact, if you follow the Schwabe Cycle closely... this resurgence in active sunspots should be short-lived. Taking this strongly into consideration, I feel the potential is strong for established High Latitude Blocking episodes from January through March. December is critical, but will more than likely be a period of transition... as the current solar activity will be less of a factor on the overall 500-millibar Height Pattern.

Now that I presented the foundation, I am going to link to NY NJ PA Weather for the finer details on the Winter Forecast for 2013/2014... which is the best seasonal outlook I have ever read.

New England NAO will continue to-be-updated through the Winter season.

WHAT IS THE NAO?

1.

The North Atlantic Oscillation (NAO) is part of an overall High-Latitude Atmospheric Blocking scheme, which oscillates between a North-South Center dipole of two anomalies. When the NAO is in a Negative Phase or North Centered, an intensifying High pressure anomaly center becomes established over the *southern-tip of Greenland... commonly referred to as the Greenland Block. Which in-return blocks, buckles the jet-stream (upper-air flow) from moving straight west to east... establishing a Meridional north to south flow. Sending air of polar origin south into middle latitudes of eastern North America & western Europe. *The Negative NAO influence is often noted as West-based or East-based, and although the overall -NAO loading-pattern effects New England with below to well below normal temperatures...where the blocking takes place in the North Atlantic is important. The West-based -NAO directly impacts New England & especially the Mid-Atlantic, as a result of the blocking high pressure anomaly center near or just off the southern-tip of Greenland. This pattern, teleconnecting with the Arctic Oscillation (AO) often produces text-book...                         

2.

Nor'easters. Due to a deep trough associated with an intense cold building High to the north, over Ontario, Canada ... that often becomes negatively-tilt as the downstream trough lifts-up along the U. S. Eastern Seaboard. 
For more information on Nor'easters, please visit... 

The East-based -NAO effects are less pronounced over New England & especially the Mid-Atlantic... due to the blocking High pressure anomaly to the east of Greenland. This pattern is still associated with below normal temperatures, however it usually does not teleconnect with the Arctic Oscillation... allowing it's influence to be short-lived. Also, with the High further east... the downstream trough is also further east, that is positively-tilt. In return, this significantly limits development along the U. S. Eastern Seaboard & promotes Miller Type B cyclogenesis that does develop... to move East-northeast from the East Coast.

3.

When an intensifying High pressure anomaly center builds off the southeastern 
United States coast or near Bermuda... commonly referred to as the 
Bermuda High,
the NAO is in a Positive Phase or South Centered. Unlike the Negative Phase, the Positive Phase enhances the westerlies... establishing a Zonal flow, or west to east orientation of the jet-stream, preventing buckling. Allowing for a pronounced south to southwest flow... at all levels of the atmosphere in middle latitudes.


Other major steering mechanism's of the
Northern Annular Mode (NAM), such as the
Arctic Oscillation (AO) strongly influence the NAO. When an intensifying High pressure anomaly center becomes established over the Arctic or 
North Pole, blocking the Polar jet-stream from moving straight west to east, expanding a developing Polar/Arctic Vortex southeast (over Hudson Bay, Ontario, Canada)... the
AO is in a Negative Phase or North Centered. Due to building heights in high northern latitudes of central & eastern North America... a Greenland Block often becomes established, producing a classic 
-AO / -NAO Couplet, fostering below to well below normal temperatures and strong potential of
Miller Type A cyclogenesis over central & eastern North America.
      
When an intensifying High pressure anomaly center builds over the U. S. Gulf Coast states or
Gulf of Mexico, encouraging a stronger than normal middle latitude & sub-tropical jet-stream, with above to well above normal temperatures over central & eastern North America... the AO is in a Positive Phase or
South Centered. As a result, High pressure also intensifies over the central Atlantic, encouraging establishment of a Bermuda High. Due to the highly influential AO, over NAO anomalies... it significantly influences the 
500-millibar Height Pattern over central and eastern North America.
 
Both the AO & NAO are part of the
Northern Hemisphere Teleconnection Longwave Pattern, and are observed through current trends & Indice Forecasts (of Operational Models & perspective Ensemble Members) from NOAA's -
NCEP Global Forecast System (GFS) and the
European Centre for Medium-range Weather Forecasts (ECMWF) in the
United Kingdom. Each Indice Forecast from it's perspective model measures the AO & NAO in-respect to normal-mean by an algebraic measure of variability, known as the
 Standard Deviation (SD)... defined by Wikipedia, the free online encyclopedia.

1. The first image above from NOAA's Climate Prediction Center (CPC) - demonstrates the NAO in a
classic Positive Phase.

2. The second image above from NOAA is of a March 2014 Nor'easter. 

3. The third image above of the
Trans-Atlantic continents - an area highly influenced by the
AO & NAO Teleconnection. 

4. The fourth image below from NOAA's Earth System Research Laboratory (Physical Sciences Division) & NCEP - demonstrates the NAO in a
classic Negative Phase.

4.

       

                 
In meteorological history the NAO was originally identified in 1924 by 
British Meteorologist Sir Gilbert Thomas Walker, with particular attention placed on sea-level pressure changes in the North Atlantic, as a result of Low pressure over Iceland and intensifying High pressure through the Azores.