11/30/12

Support For Cold Winter In The East Grows


Take a look at this interesting article on Judah Cohen's Winter Outlook based on Siberian Snow Cover. I remember when this study came out a few years back and I mentioned it in one of my Outlooks. His Outlook for the East matches well with my Winter Outlook and accompanying analogues this winter that strongly suggest below normal temperatures also across Southeast Lower Michigan.

Meet Judah Cohen. Director of seasonal forecasting for Atmospheric and Environmental Research (AER), a Verisk Analytics company, Cohen has earned fame in the weather community for developing cutting edge techniques for issuing winter outlooks which show tremendous promise.

In short, Cohen relates the amount of snow cover and its rate of advance in Siberia in October to temperatures during winter in North America. The more snow in Siberia and the faster it increases he suggests, the colder it’s likely to be in the eastern U.S. This October, snow came down fast and furious in Siberia and, thus, Cohen is bullish about a harsh winter for the eastern U.S.

Rest of article here. 

Set of data numbered with Eurasian snow cover and subsequent winters in the US. Note #2, if you take this data and projections verbatim; we were doomed with a cold winter!






Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian




11/28/12

So; What Do The Analogues Say For December?

As mentioned when previewing my Winter Outlook for the Winter of 2012-13; I intended to do more subsequent work or as I put it "new formats for the up-coming winter"

In the 15 years or so in using specified analogues I researched; more often than not they were helpful in projecting the season outlook. While last winter was a bust; in many of the preceding winters before last winters; the analogues helped in projecting temperatures, snow and overall trends during the winter. This was more the case when there was a decided preference on a certain weather element such a temperature or snowfall being above, below or normal. Will it happen this winter; I certainly hope so but in any event, there are variables to consider.

One of the most important things to consider is timing and subsequent trend in the Outlooks. A good example of that was stated in my Outlook this go around. When mentioning the trend seen in the past in these analogue winters, the trend was for the "first part of the winter to be harder or harsher".  Explaining this further; it has been my observation that winters (both temperatures and snowfall) generally unfold in four main ways and two less often ways. 1- First half the worst 2-Second half the worst 3-Early and later winter the worst with break mid winter or 4-Early and late winter relatively tranquil and mild but mid winter rough. The two that are less often are; 1-A rough and cold winter throughout 2- A tranquil and mild winter throughout. It is unusual to get wave after wave of cold or mild air throughout the winter though of course; it does happen. A good example of a recent mild winter was just last winter when the temperatures averaged well above normal and placed the region in at the sixth warmest winter on record at Detroit; fifth warmest at Flint and third warmest at Saginaw. All three cities placed in the top 20 warmest months for December, January and February. The winter of 2001-2002 was similar and I commented I thought last winter was very similar to that of 2001-02. As it turned out; the Winter of 2011-12 placed close to 2001-02 for mild winters along with the strong El Nino winter of 1997-98.

In regard to the above mentioned trends of winter; very rarely do you see these trends distributed nice and neatly in each winter month. On the other side of the coin; trends usually don't come all wrapped up nicely in individual monthly sequences; whether it be colder, warmer; snowier or snow-less than average. Many, many times prevailing trends of the month tend to overlap before or after the month. Meteorological oscillation patterns tend to prevail in a two to three week dominance. Therefore; when we look at composites for monthly sequences during the analogue years they a reflecting only the anomaly for the particular month not the dominant trend. For an example; the first three weeks in December could average below normal but the last week well above normal and thus; wiping out the dominant temperature trend of the month. While at the NWS and writing the Monthly Climatological Summary for Detroit and Flint (which included Saginaw), I saw this conflicting problem many times. I therefore, developed the "headline trend" of the month, which at times, could be completely opposite of the statistical figures.  As an example; say the average temperature departure for December was +1.7 degrees. On just that alone; you'd think it had been a relatively mild December. However; digging deeper you find out that the first three weeks of the month averaged below normal and just the last week or so, well above. Therefore the "dominant trend of the month" was actually below normal but was eliminated when the monthly statistical temperature calculated; averaged above. Actually; this happens fairly regularly and I felt it should be addressed simply for the reason that it is more accurate for climate/public purposes and to a lesser extent, the public tends to better remember the dominant trend of the month.

Analogue Temperature/Precipitation Composites 

When looking at temperature or precipitation composites for the month, we are looking at the anomaly for the month; meaning whether the month averaged above, below or at/near the statistical "normal" used. This normal used also becomes important because what normal you use can have a notable difference on the outcome. I have been a long-time critic of our /NWS/ 30 year normal process since it is so narrow and short termed regimented. I feel at least a 50 year normal would serve the public better and also would be at least; a little more accurate. However; when looking at alternating cycles of ENSO, NAO, PDO etc etc, a climatologically more inclusive 80 or even 100 year normal is optimal. It has been proven that many of those oscillations follow a gradual 35-45 year cycle from below to above; and then another 35-45 years to below again. Therefore; a complete cycle or "wave length" would take an estimated 80 years or so. Therefore; an all inclusive normal in regards to include the complete wave length of many of these oscillations should be at least 80 years. And ironically; close to the a person's average life time expectancy - also a plus for the public and to use it. It becomes more relevant to the public as they age and relate past climate trends to current. Using 30 year normals would be more relevant for studying more recent trend changes with scientists. Also; like the present, the normals would be revolving or updated every ten years. Therefore; as of 2012, the normals used for temperatures, precipitation and snowfall would come from the years of 1930-2010. Then in 2020-21, the new normals would come from 1940-2020. Ok, ok, ok..enough on my climatological normals soapbox! What do the analogues show for the month of December?

December 2012
                                                                                             Map-1

Temperature Anomaly Composites



                                                                                                                    Map-2


 
The composites show a colder than normal December on average in the past when using our analogue winters. Remember above when I mentioned the anomaly (departure) is of course, relative to the normal used. Note; the subtle moderating effect (about a degree or so, depending on location) the longer term average has on the anomalies. Basically meaning; our normals now (1980-2010) in map-1 are warmer than the 105 year normals (1895-2000) displayed in map-2. There were some cold, a few brutally, December temperature averages in that lot; 1976 - 21.5...1985 - 22.2...1989 - 18.0 and 2000 - 19.3. Thus, the anomaly is skewed down somewhat and remember in the past I've said the anomaly (departure) sign is more important than the numerical value. Therefore; basically the analogues are portraying a below normal temperature month with December colder than "normal". This also feeds into the thinking that the first half of the season in the past was the harsher.


Precipitation Anomaly Composites


In the past Decembers; the general precipitation for December averaged around normal. If the temperatures verify colder than normal and precipitation is near normal, that would set us up for at least normal to possibly above snowfall. Hmmm...we've certainly been hard pressed to see any decent snows around here lately; so THAT would be a change. The precipitation pattern intimates a subtle storm track around the Gulf states and up into the eastern Ohio Valley/eastern Lakes Region and another in the Plains; through the Upper Midwest and Upper Great Lakes. Another possible track would be up around the Gulf states; then up the East Coast with most of the precipitation well inland.

500 MB Mean Height Composite



500 MB Mean Anomaly Composite


No doubt about what the analogues (mean 500 MB Jet and anomaly) blatantly suggest for the upper flow; ridge in the west and trough in the east. Is this for the whole month? If you read the first part of this blog; you should know the answer. NO! What the analogues are suggesting to me anyway; is that this was the main pattern in many of the previous analogue December's and again; may be our dominant or most notable pattern this December. We shall see!

Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian













11/22/12

Though a Record or Near Record Warm Thanksgiving Today; Take a Look at a Record Cold Wave That Engulfed The Region at This Time and Refuses to Budge From The Record Books Back in 1880!

Record November Cold Wave Holds Steadfast For Well Over a Century
                      
Nothing in Southeast Michigan ’s record books has anything close to the record cold wave that occurred so early in the cold season than way back in the late 19th century in November 1880, or 132 years ago! The bitter cold surges blasted Southeast Lower Michigan from the 18th to the 23rd from the Arctic region and engulfed much of the country. The Arctic chill came down in the form of two impressively strong Arctic high pressure systems (see maps below) for mid winter, let alone mid November. 
 
Below is the record chart for that period that contains both the record low maximums and record lows that occurred during the November cold wave which left six days of records that have not been touched since! The three degree reading on the 21st and zero on the 22nd have yet to be superseded by colder temperatures in the entire month of November. A zero (or below) record low does not appear in Detroit ’s record lows for another 10 days when a -2 was recorded on December 2nd, 1976!    

  

Again, not only is the cold impressive but that both the record low maximums and the record lows have not been breached since this cold wave. The six days of record breaking cold remains intact since 1880!  So what caused this bone-chilling cold so early in the season, what did the weather maps (or best representation of) look like so far back? Let’s take a look at copies of the archaic weather map records from Nov 18-23, 1880 which shows the couple of mammoth Arctic high pressure systems that affected much of the during the period.  





As of 7AM - Thu  Nov 18th  Note the first big chunk of cold dense air is well reflected by the exceptionally high pressure for November (not to mention over the southern states) in eastern Oklahoma of 30.78" /1042.MB/  (just at the bottom edge of our map).  This massive Arctic high made its way south out of the Northern Plains and as a result, temperatures across much of the region were in the single digits and teens.



As of 11PM - Nov 19th   By late Friday night, a new surge of Arctic air is beginning to show its face here as a new low pressure trough enters the Upper Midwest and Great Lakes Region. Note, temperatures haven’t had a chance to recover much from the first bitter cold blast!

 

As of 11PM - Nov 20th   The second surge of fresh Arctic air continues advancing across the Great Lakes and Ohio Valley as general high pressure holds over the southern states.



As of 11PM - Nov 21st   A second, duplicate strong high pressure appears on our map, once again by way of the Northern Plains and expands south and east into into the Upper Mississippi Valley and Great Lakes. Low pressure troughing holds sway over the relatively warmer waters of the Great Lakes (estimates of water temperatures in the mid 30s to mid 40s). Temperatures have plummeted below zero already in the Upper Mississippi Valley by late Sunday night.



 As of 11PM - Nov 22nd   A huge bitter cold high pressure lies spralled across the Ohio Valley and Great Lakes with a central pressure of 30.85" /1045 MB/! The public continues to be greated by record cold as the Thanksgiving work week commenced across the nation. The 30.85" was a record high pressure at the time (and may be yet) for Cincinnati, Ohio. Besides our own,  numerous other record lows were attained with the passage of these Arctic highs.



As of 11PM - Nov 23rd  The large high pressure moves ever so slowly east with the central high pressure now over the mid Atlantic States.

Evidently this was not the first notable November cold snap that engulfed the region so early in the weather record days. The following was taken from the 1880 Monthly Weather Review:  
"The passage of of this area was marked by minimum temperatures for the Lakes region, the Atlantic States,  the Ohio, Upper Mississippi and Lower Missouri valleys. They occurred from seven to eight days earlier in the month than the remarkably low temperatures of 1875. The most notable temperatures observed at the Signal Service Stations were Washington, 12.5;  Philadelphia, 10;  St. Louis and Louisville, 8;  Pittsburgh, 4;  Buffalo, 3;  Chicago, 1;  Erie, Detroit, Sandusky, Grand Haven and Des Moines, 0;  Champaign, -3;  Alpena, -4;  Columbus, Indianapolis, Keokuk and Milwaukee, -5;  Port Huron, -6;  Marquette, -9."
 
As mentioned, all the Detroit records remain intact 132 years later in 2012 and I wonder how many others are still around at other offices? 

 Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian

11/25/2012 Update - First Measurable Snow Of The Season Possible Tuesday After Flirting With Record Territory For Warm Thanksgivings!

11/25/2012-Quick Update on snow potential Tuesday;

Snow lovers; I'm sorry to say the system that had the potential to bring us snow will stay well south and east of Southeast Michigan. The main reason is energy from the northern stream is now unanimously projected to be flatter and weaker with the better sampling of the atmosphere over the Pacific and northern Canada the past couple days. What phasing of the jet streams that does occur will be weaker and occur further south and east of our region. In fact; all projections the next week or so are rather benign and somewhat boring with no notable storms expected to affect the region.
-----------------------------------------------------------------------------------------------------------------
Original 11/22/2012

On this beautiful, sun filled warm Thanksgiving Day...the last thing "some" people want to hear about is snow. ;-)  As temperatures make a run into the lower to possibly mid 60s; keep in mind the record high for the 22nd at Detroit is 69 way back in 1913! However...if you just look at all previous Thanksgiving Days (and granted the date moves around because of the nature of the Turkey beast); the record high for Detroit for all Thanksgivings is 65 set back on 11/26/1986. At Flint the record warmest Thanksgiving is 61 on 11/30/1933; while in Saginaw, the warmest Thanksgiving was back on 11/26/1908 and again on the same date; 11/26 but in 1914 when both Thanksgivings the mercury rose to 64. There is the chance that one or all will challenge their respective warmest Turkey Day temperature this afternoon; particularly Flint. Again; this would NOT be the record for the date (Detroit-69, Flint-65, Saginaw 66); though Flint and Saginaw may come close to those records too. For other fun filled facts for Thanksgiving Days; visit the NWS in White Lake.

Ok back to next week;
As mentioned at the end of my Winter Outlook; something may be brewing for the last week of November. Well that depends on what extended model you believe. Our GFS model has been intimating that a low pressure system will form over the Midwest Monday night and track northeast through the northern Ohio Valley Tuesday. This puts Southeast Lower Michigan on the north side of the system in the colder air and the likelihood for out first general snow. Albeit; scatted locations may have seen a couple tenths due to snow showers this cold season, most have not. Since the models have been all over the board with the system's track and depth; I'm leery of calling for any "certainty" on this system at this time. Besides that; it's still relatively early in the season and with temperatures in the 30s, even under the best scenario (for snow) with this system; an inch or two on grassy surfaces would suffice. I say "best" because there is the risk she'll miss us all together and track far enough south and we get nothing or just a little melting snow or rain/snow. Here's the latest projection for the system from the GFS that far out:



In any event; I'll update on the "possible" system as the time approaches. Have a fun and safe Thanksgiving on this beautiful warm day!

Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian

11/13/12

Weak El Nino This Winter? Much Ado About Nothing; Winter 2012-13 Outlook - Parts 1 - 3



Winter 2012-13 Outlook For Southeast Lower Michigan
Part - 1

After last winter's outlook fiasco; I must say I and nearly all who put together an outlook last season (at least that I saw), scampered away with their tails between their legs. Yes indeed, the Winter of 2011-12 left many a meteorologist and winter weather enthusiast crushed with repeated dashed hopes of basically, winter weather! Early in the game (in fact at climatologically, winters open) I theorized that we were in for a troublesome forecastable winter.  Later in the winter; in my mid winter update 1/22/12, I discussed the relevance between the winter weather that had occurred up to that point and those exact same issues.  

On the doorstep of the new winter at hand, already there are conflicting signals about El Nino that was "supposed" to develop this fall into early winter. Granted, it was likely to be weak anyway but to me; it's really was much ado about nothing. Therefore; I will go forward with the assumption that La Nada, or a Neutral ENSO phase (with Pacific SST 3-month average temperatures in area 3.4  between -0.5 and 0.5) is in the can for this winter. With that premise in mind; generally other winter producing elements will definitely overrule the ENSO phase and thus it's importance is negligible. I've always felt the ENSO phase, unless moderate to strong, is of lesser importance than many make it out to be, especially over the eastern half of the nation. More often than not; ENSO should be down on the list of important winter influencing factors for Southeast Lower Michigan and the Great Lakes, as a whole. We'll only use it as a "square one" or beginning of this discussion. (Note; interestingly upon just checking the CPC's ENSO page; they have just "discontinued" El Nino watch, so I guess we are on the same page, anyway). 


Studying the latest actual data from the Pacific SST's show the following;



Note; the determining area 3.4 showed a slight decrease in the above normal anomalies since September, while area 4 showed a bit warmer results. In addition; in areas 1 and 2, the SST anomalies just are hovering around normal. This is suggesting if there is any El Nino, it is/would be a west based El Nino  meaning any above normal SST's will continue to reside mainly over the western and possibly central areas of the Pacific (in areas 3 and 4  and  we'll get back to its importance later in the actual winter forecast section of my Outlook).

                                                                   Areas of SST's


As stated, the beginnings of the earlier predicted El Nino have certainly sputtered in the latest analysis and  most recent model projections; which are now converging on basically aa Neutral Winter. The CFSv2 model's most recent projection (as of 11/12) reveals the following:



This obviously shows one of the main reasons why CPC discontinued the "El Nino Watch"; simply because latest model projections say there isn't going to be one or at least not during this winter. Humorously; if anything besides a Neutral pattern, the CFSv2 model even intimates it may cool enough for possibly another weak La Nina by Spring 2013. Ah the models; got-a- love em! At this time, however, the general consensus of all the models shows a downsloping toward the Neutral phase as well but with less sloping downward for the winter than the CFSv2 above.





Longer term, the ENSO cycle is evident on the graph below. The sine-wave cyclical nature of the ENSO index is apparent from the sketched-in cycle I drew. Note; La Nina years dominated from the late 1940s into the mid 1970s; then mainly El Nino years took over from the late 1970s into the mid 2000s. Recently; the cycle has been shifting to the La Nina dominant phase again.




Typical upper air patterns seen during Enso-Neutral years since 1961 are displayed below and while this pattern may very well dominate this winter; these Neutral years do not take timing (meaning; the sequence of events leading up to the Neutral conditions) into consideration. Therefore; not all of these Neutral years are analogue years to this winter simply because they were Neutral.



Part -2

Influencing Factors for the Winter 2012-13

NAO/AO
In addition; probably THE most important element in this winter's forecast and its subsequent success (especially its temperature forecast) is the dominant phase of the North Atlantic Oscillation /NAO/ along with the Arctic Oscillation /AO/ phase. As seen in the climate history chart below; whether the prevailing and projected NAO/AO is positive, neutral or negative can certainly help determine the winter's temperature and lesser extent; snowfall outcome. As an example; just with the projected Neutral (or La Nada) pattern alone, reveals the array of possibilities (highlighted) is somewhat variable. As I stated several times in the past "with a Neutral ENSO, we are totally at the mercy of the NAO/AO along with other meteorological winter influencing variables." Keeping this in mind brings the likelihood of more volatile temperatures and weather under these conditions!



Predicting the NAO/AO still remains one most elusive "nuts to crack" in the meteorological world. Even out for a week or two can be a challenge. The web site I generally go to for the prediction of the NAO/AO is at the Climate Prediction Center /CPC/ found here. An interesting experimental web site I found in projecting the NAO, AO, PNA and SST's for three months while researching for the Winter Outlook is a web site run out of University at Albany/SUNY, Albany, NY. It is done by an industrious young graduate student there named Kyle MacRitchie.  I'm still relatively new to the site but the predictions are based on current ensemble forecast data that is projected out for three months. Remember; the projection takes information from daily ensemble data so; like the ensemble data, the projections further out are subject to change, sometimes daily. Kyle also includes an "esemble variance line" projection. This shows where the esemble data is too variable for somewhat; reliable projections. He also includes his definition of the NAO/AO/PNA/SST's projections. As an example; the latest run of the NAO/AO and PNA out for three months on November 17th, 2012 shows the following:




As one can see; while the NAO projection is variable in the general sine-wave pattern, the AO has been projected (and again, as of the Nov 17th data) to be generally negative. We'll keep watch on the data through the winter for long range projections occasionally along with updates, in upcoming blogs. One thing is interesting to note, at least at this time; is the pronounced negative AO projection throughout the winter (I'm sure that will change however, at least somewhat in the succeeding days and weeks).

Snow Cover
Other theories and ideas that influence the winter somewhat over the central and eastern US is the snow cover over the northern hemisphere mid-late fall. Extensive snow cover forming October into November would tend to help "refrigerate" the cold air masses originating over Siberia and the Polar region that moved south across Canada into the states. Maps of the snow cover have been available for several years now and a "norm" has been established since 1995. The snow cover this autumn "up north" has been quite extensive to the north and northwest (see map below as of Nov 5th; note the comparison to average, in green).


From Rutgers University Snow Lab:
Across North America, snow cover extent for October 2012 was above average. Canada had much above average snow cover during the month, while the contiguous U.S. experienced below-average snow cover. The North American snow cover extent was 696,000 square km (269,000 square miles) above the long-term average of 8.1 million square km (3.1 million square miles). For the continent, above-average snow cover was observed across the Canadian Rockies and Prairies, while the U.S. Rockies and much of Alaska experienced below-average snow cover.

The Pacific Decadal Oscillation
The Pacific Decadal Oscillation (PDO) is the long-term ocean fluctuation of the Pacific Ocean. The PDO waxes and wanes approximately every 20 to 30 years. The graph below shows the cyclical nature of the PDO (like the ENSO) with its warm and cool phases. Most scientists think we have just entered the cool phase (see below: PDO Cycle -red arrow- during mid 2000s). The cool phase is characterized by a cool wedge of lower than normal sea-surface heights/ocean temperatures in the eastern Pacific and a warm horseshoe pattern of higher than normal sea-surface heights connecting the north. The last time the PDO trended into the negative phase was also in the early 1950s, lasting into the mid 1970s. There is good evidence by the ENSO chart (above) that during the cooler phase, La Nina’s tend to be more commonplace and last longer.

                                                                            
                                                                           PDO Cycle
The cool water anomaly below shows the lingering effect of the year old La Niña back in April 2008. The much broader area of cooler than normal water temperatures off the coast of North America from Alaska (top center) to the equator is the classic feature of the cool phase of the Pacific Decadal Oscillation /PDO/ talked about, above. The cooler waters wrap in a horseshoe shape around a core of warmer than normal water temperatures. (In the warm phase, the pattern is reversed - Image is courtesy of NASA)


                                                                             April 2008


While we are assuming mainly Neutral phase for ENSO this winter; I would be remiss if I didn't discuss where El Nino conditions do prevail (highest above normal SST's) out in the Pacific and what influence that has on the States. Referring back to part-1 of my Winter outlook, I discussed where the warmest of waters where located; out over the western Pacific. The departure map below give an idea of how west based El Nino's affect the US.



Part - 3

The Analogues

My earliest of Winter Outlooks were predicated on the analogue years I decided upon by researching basically, hemispheric conditions were of a similar nature to the upcoming winter. Interestingly; local conditions also mimicked some of the years but not always with more precedence given to the similar "preseasons". In this particular Winter 2012-13 set of analogues; the winters followed a similar sequence of events (though timing may vary a bit) that were recently observed over the Eastern Pacific during the past few seasons. La Nina prevailed during the previous winter, spring and into the summer. The second half of the year saw a gradual return to Neutral conditions such as seen this fall. While data this fall did show a trend toward a weak El Nino, a prevailing weak El Nino for the upcoming winter was discounted for reasons discussed above.


       WINTER 2012-13 ANALOGUES




Local Comparisons/Results:

TEMPERATURES:

Clearly, the trend seen in this year’s analogue winters is the dominance of below normal temperatures. Taking recent past seasons into account; it is thought the coldest of winters are too cold for our recent trend and longer term winter trend. Another trend seen during the winters may prove helpful is that there tended to be a notable period of below normal temperatures with many of the seasons showing this more likely to occur during the first half of the winter (or first half of the cold season of mid Nov-mid Mar). Many (but not all) of they analogues did reflect a harsher first half of the winter as a trend. After taking into account all the data contained in this research and displayed here, a somerwhat colder winter seems likely. Also, considering the Neutral conditions expected; this leaves the door open for variances in temperatures with wide swings.


SNOWFALLS:

Season snowfall ranges of the winters tended to be closer to normal (or a bit above  when averaged across the region). The most notable trend in the snow and precipitation this go around also happens during the first half of the winter; when snowier conditions (total snowfall thru mid winter) are projected. Though I did not post Flint and Saginaw analogues at this time; central and northern areas of Southeast Lower Michigan seemed to have the better chance of at least normal snow; while areas further south over extreme Southeast Lower Michigan (basically south of a Detroit – Ann Arbor line) showed normal to below snowfall.  Of course, this is highly dependent on storm tracks and speaking of...

UPPER WIND PATTERNS/ STORM TRACKS






The upper wind pattern averaged for all analogues is a cold one for the Northeast quarter of the country.  This not surprising since there were only two "mild" winters in the study. I used a composite of the jet streams for the analogue Winters of 1951-52 and on for the storm tracks (see map above); being they were the most pronounced however; all winters indicated a similar trend.  

The dominant upper wind jet streams this winter are projected by the analogues and also have been seen in recent fall patterns; a predominant split flow with the Arctic/Polar jet  from Canada and the sub-tropical jet in the south, both are displayed in the warm colors on the above map storm track map. These two distinctive jet streams will dominant this winter and phase. Most winter see these tracks more or less during the winter but it is their dominance that makes or breaks a snowy winter.  The most dominant of the storm tracks expected this winter are (numbered in order of precedence):


 1- Alberta Clippers bore by the northern Pacific jet and/or the Polar/Arctic jet which will usher in polar or arctic air originating from western Canada or the Arctic.

2- Two other storm tracks will be induced by later phasing of jets over the Ohio valley or up the East Coast. This pattern has already been active this fall. The storm track up the East Coast was noted more in the Neutral winters than La Nina’s especially with a negative NAO when troughing more prevalent in the eastern half of the country.  It is these two tracks which bear watching to see if strong arctic pushes of air keep more snow to the south of the region.

3- The Southern Plains/ Texas Low which we be bore over that region by phasing of the Arctic/Polar jet  from Canada and the sub-tropical jet in the south.

Composites for the Winter Analogues




The composites of the analogue winters show a broad area of below normal readings over the north-central part of the country; east across the Lakes/Ohio Valley into the Northeast. With the upper wind pattern from those winters, this isn't at all surprising. Note in the precipitation composite, the distinct "below normal-normal precipitation" region north/south over the Ohio Valley. This intimates a storm track up through the Ohio Valley just west of the Appalachians. It's also interesting to note that the East Coast averaged a bit drier, I say "averaged" that dry region could be misleading as some years may too have been wetter. What it does say is that more often than not; a storm track was in the vicinity of the Ohio Valley to the Northeast. If this bears out again; where she places will have a definite affect on our precipitation and snowfall; at least from the southern tracks.

Solar Cycles in Analogue Years

Ever since writing my Outlooks back in the mid 1990's; I've been a supporter of more research on solar cycles influence on the earths climate and even shorter term patterns. Many article have been written on researching this same topic. Scientists studying climate change are interested in understanding the effects of variations in the total and spectral solar irradiance on Earth and its climate. More and more evidence has been published on the solar cycle and its direct affect on earth's climate. One such fascinating study was done by NCAR  back on 2009 on the effects of the 11 year solar cycle and ENSO.

From the article:

"The research may pave the way toward predictions of temperature and precipitation patterns at certain times during the approximately 11-year solar cycle. These results are striking in that they point to a scientifically feasible series of events that link the 11-year solar cycle with ENSO"
                                                           
In my analogue study; one of many items I look at is the past winter analogue seasons and attending solar cycle and correlate with our upcoming Neutral 2012-13 season and current placing in the solar cycle.






































All years highlighted in light blue are "close" to our current time (red x); disregarding the lowest and highest years gives us 1904-05, 1976-77 as the closest analogue winters, solar cycle speaking. The winter's of 1956-57 and 1985-86 are a close second. Taking this one step further; all those winters were on the up cycle like our present winter.

Both winters of 1904-05 and 1976-77 were cold, brutal winters. The Winter temperature average of 1904-05 was 20.5; while the Winter of 1976-77 was even worse at 19.8. Many of us lived through the Winter of '76-77 and do remember it vividly. The Winter's of 1956-57 was one of two "mild" winters with an average temperature of 28.9; while the winter of 1985-86 was again colder with an average of 23.6! So; out of the four closest analogue winter's; three out of four were cold and below normal. Before we get too carried away, solar cycles are most likely to have the least affect on our winter weather! With climate change so much in the news and importance; I would surmise studies will continue to go on as to their short term affects on weather. Therefore; this section is added for interest sake only and to me anyway, it is interesting. 






































       Summarizing:

























Temperatures
Look for temperatures during the winter to average below normal /-3.0 to -0.5/ compared to the 30 year /1981-2010/ normals. While the trend of our winter analogues show mainly significantly below normal; it is felt the coldest of analogues are too cold and thus skewing the average down. However, at the same time, some of the cold outbreaks seen this winter may rival some of the outbreaks seen in recent winters and thus; a colder than average winter is likely. Considering the Neutral conditions expected; this leaves the door open for variances in temperatures with wide swings.

The biggest caveat will be of course, the phase of the NAO/AO and where that ridge and trough dominants during the winter! If the ridge moves inland too much and continues to cross the country like it has for so many months; I'm in trouble. I'm banking on the mother-lode of cold (upper low in Canada) to help squelch the ridge.
I must say; it is hard to go below normal after what happened last year but the evidence for at least normal to below temperatures is compelling. More often than not; my analogues have held me in "good stead" as the British say (to be of great use and benefit to someone) so on with the show!


      Snowfall and Rainfall:

Snowfall and rainfall ranges in the Winter analogues for 2012-13 are a little closer to normal over extreme Southeast Lower Michigan (when compared to many other years I've done). Therefore, while snowfalls last season were predominantly below to well below normal; this winter indications suggest the best snows will be closer to normal (within 5 inches of). Indications are the best snows will fall  across the northern areas of the regionor from Detroit’s northern suburbs across Flint and Port Huron and on into the Saginaw Valley and Thumb Region. Near normal to below snow is expected south of a line from Ann Arbor to Detroit. The analogue winters are strongly hinting toward a two-tier snowfall pattern this winter with the heaviest amounts to the north along with an average chance for mixed precipitation the entire region. It will be interesting to see if these particulars bear out. (See more in: Storm Tracks)




Some Winter Dates:

Winter Begins early on:  December 21st,  2012 @  612 AM EST
Christmas:   Tuesday December 25th2012
Holiday Cold  Full Moon:   Friday December 28th, 2012 @521 AM EST
New Years:  Tuesday January 1st 2013
Ground Hogs Day:   Saturday February 2nd, 2013
Valentine’s Day:  Thursday February 14th, 2013













Next :

Active weather brewing for the last week of November?  

Look for the details late this week. Have a Happy Thanksgiving!






































Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian