1ST
ISSUED OCT 31 privately... RELEASED ON THE
WEB SITE NOV 15
This forecast has been delayed a bit because of the impending move from my current location to Near Leesburg VA at the end of NOV 2006. Clients get it first... then the web site and the general public but with the move well something was going to delayed. Pull up a Hot cup of Tea and some cake.
Text that is in RED BOLD has been so designated because it contains KEY ideas.
Throughout this forecast you will see the acronym "CF" used. The two letters "CF" stands for "Consensus Forecast" which is term that I use to describe the general view or a summary of what most PWSIP (private weather service Information Services) and / or NWS forecasters are saying. The CF is very important in determining how the seasonal trade in Energy and Agriculture markets will unfold as well the operational side of the weather biz. For example… State DOTs will often significantly lower their Salt and Sand purchases if the CF is for a Mild winter in their areas. The CF often consists of
a) the CPC (Climate Prediction Center) …whose
forecast carry a lot of weight...
b) large well known Private Weather Service Information Provider (PWSIPs) and
c) some well known Energy/ Ag forecasters.
REVIEW of SUMMER 2006
After careful consideration I have come to the conclusion that
the WxRisk Summer forecast of 2006 was arguably the best seasonal forecast I had
ever issued on this web site over the past six or seven years. And quite
frankly from what I've seen from every else's forecasts... it appears that my
Summer 2006 forecast was best one out there. Period.
Without going into a lot a detail because I simply don't wish to... suffice to
say my Summer forecast has generated quite a bit of reaction and business from
the various Energy and Ag markets.. trading houses and traders ... which makes
me happy.
In my Summer 2006 forecast ...which again you can see at this
LINK... I argued that the
weak La Nino was collapsing in May and therefore we would not see a drought over the WCB
that the drought would be confined to the Plains and eastern Rockies regions
that the collapse of the La Nina would have significant impact on the 2006 hurricane season
The vastly different phase of the QBO from 2005 meant that we are going to have a significantly different hurricane season for 2006
that overall Hurricane activity would be much lower than what the consensus forecast was calling for
the overall pattern did
not support significant hurricane activity along the East Coast but rather
several near misses.
| JET STREAM | TEMPS | RAIN | ACTUAL TEMPS |
ACTUAL RAIN |
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| JUNE |
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| JULY |
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| AUG |
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THE BOTTOM LINE
******* There will be a MID WINTER UPDATE JAN 15*****
The winter of 2006 --07 is going to be colder and snowier than expected by the CF (consensus Forecast) over the Midwest and Northeast. However at this time I can see no reason to forecast a colder and / or snowier winter than Normal for most areas. In other words I am making a distinction that there is separate or NEW category to be considered from the usual MUCH ABOVE NORMAL... ABOVE NORMAL ...NORMAL BELOW NORMAL and MUCH BELOW NORMAL. Since this web site is aimed at assisting Individual Ag and Energy traders.... Trading forms / houses and Meteorologists as well as non trading Businesses... I have developed this distinction. There is a BIG differences between the climatological NORM values of 1971-2000 which the assessment of Below or Above precipitation / temperatures are made versus what is a expected.
With the announcement of the El Niño event by the Climate Prediction Center early this Autumn... they have blindly assumed... as have many private weather forecasters that we are going to see another mild winter over most over the CONUS. Thus the bias for this winter from the Consensus forecasts is for a milder than normal and less now than Normal winter as well. Likewise there appears to be a consensus for a fairly dry winter over the Pacific Northwest and a normal winter for the West Coast. The developing drought conditions over the eastern Rockies and central / Lower Plains will continue throughout the winter and if anything worse and can had a significant impact on the winter wheat crop as well as affecting the overall Jet stream pattern for much of the nation. The analog season is the winters of 1986-87 followed by 1971-72 and 1966-67.
BACKGROUND
Given the recent successes that I've had in seasonal forecasting over the past few years some may hold the viewpoint that I have simply "lucked out" because I've generally gone against the consensus forecasts and by taking a generally contrary position to what the consensus has been over the past few seasons I had been the beneficiary almost as a matter of default. Well you can think that if you want to but if that is the case I suggest you stop reading right now because any sort need a meteorological explanation or reasoning which I am going to put forth really would just be considered to be a smokescreen if you held this view. I not a big fan of "consensus forecasting" ( CF) and while I have nothing against consensus forecasting per se I think to a large degree it is overrated. It is for this reason that my e-mail's have a signature on them which reads ...."When everybody's thinking the same someone isn't thinking..". a phrase from George S Patton.
If you are energy / Nat Gas trader then you know
how important this upcoming seasonal forecast is going to be. Because all the
hype and hysteria around the anticipation of 2006 hurricane season one no
well-known energy trading house in Connecticut ended up taking the long position
with regard to natural gas and as a result when the hurricane season collapsed
so did their financial position and they were forced into bankruptcy.
That is how important seasonal forecasting has become over the last few years
and I hope this gives you an idea how much money and power is involved in this
endeavor. It is one thing to make the same hurricane or when to forecast year
after year for excitable weather hobbyist and weenies but is quite another to
get the forecast accurate with tens of millions if not hundreds of millions of
dollars at stake. Indeed the Connecticut trading Aramath took its position on
natural gas going to this hurricane season because they did listen to the folks
at CPC EARTHSAT AccuWeather Weather 2000 and all these other private forecasters
which seem to be in race to forecast the most Armageddon like scenario and get
the most media coverage.
Even the AG traders are facing a problem going to this season since many
prominent forecasters in the month of April and May 2006 forecast at the Plains
drought to expand over a good portion of the Midwest. Of course that did not
happened ( because of the El Niño event developed instead) and the corn and
soybean prices never really recovered until the wet Autumn developed in
September & October 2006.
KEY ASPECTS OF THE COMING WINTER
FORECAST MAPS
| JET STREAM | TEMPS | PRECIP | |
| DEC 2006 |
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| JAN 2007 |
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| FEB 2007 |
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HOW THIS FORECAST WAS PREPARED
We have entered a new stage and weather forecasting over the last several years. While academically the interest has been in mesoscale features... the business concern as the climate continues to appear to become more unstable has been in 30-day and seasonal forecasting. There are several different techniques that meteorologists use in making a seasonal forecasts.
Among these various methods is the use all for "ANALOGS"... the SSTA-- sea surface temperature anomalies in the Pacific and Atlantic oceans... and seasonal indices and patterns (such as the PDO in the QBO and NAO features) new climate forecasting models.
THE USE OF ANALOGS
Many (but not all) forecasters use "Analogs" to help
make a seasonal or monthly forecast. In weather forecasting the use of analog is
an attempt to understand the seasonal forecast period
based (in past) upon similarities between a particular set of parameters. The idea is by searching for similarities
with other years or seasons it gives a forecaster
some clues as to how the monthly or seasonal forecast
may develop. .
For example one may consider the fact that most US winters
during strong El Nino years bring warm and dry conditions to
the Upper Plains and Midwest and rather wet and
cool conditions to the Deep South and changeable conditions in the Northeast.
Or a forecaster may look at say the past 6 months... 12 months... or 18 months
worth of temperature and precipitation data over a certain section
of the country and use those similarities to the current situation to assist
them in making the monthly or seasonal forecast.
Done the correct way the Analog method has validity to it. But the key
thing to keep in mind is that when you are choosing a analog year you must
choose one which matches the current set of conditions.
For example to simply assumed that all El Nino events
produce ONLY one set of conditions in the winter months
is of course folly. Some of the most severe winters in the
last 100 years have been El Nino winters and likewise.... some of the most Mild
winters in the last 100 years have also been El Nino winters.
On the other hand some forecasters hold the view that analogs are not very helpful since weather records are incomplete or not sufficient enough to be considered as complete data source. For most locations temperature and precipitation data only extends back 100 or 130 years and accurate Upper Air maps only go back 70 years at best . That argument is Valid. Thus ANY seasonal forecast using analogs that is based on ONE parameter is a very risky and has a high degrees of failure built within the forecast.
One way of getting around this is to use several factors parameters and cross matching the analogs to look for common ground.
AUTUMN PATTERN 2006 SO FAR...
The Autumn pattern so far has been one that has features a
LOT of major Low pressure areas developing over portions of the Midwest and
again on the East Coast. As of mid-November there had already been at least for
major or significant low pressure areas moving to the Midwest with the 5th
significant low pressure area for the Midwest now underway. Likewise over the
East Coast there been several significant coastal storms including the one in
early October and again the weekend of November 10-12 and NOV 4-5.
The months of September 2006 and October 2006 with the first two consecutive
cold months seen over the eastern half of the US since 2004. It has been argued
that temperature patterns can run in long-term cycles and indeed if one were to
graph mean temperatures over key cities over the CONUS over the past 100 years
we would see clusters of years where temperatures would tend to run Normal...
Above Normal or Below Normal.
On the other hand we have seen very warm and dry conditions over the central and
Lower Plains for much of the Autumn. There are two reasons for this. First the
overall pattern featuring a trough in the northeastern Pacific and then one over
the New England states or the Northwest Atlantic does support some sort of Mean
Ridge over the middle portions of the CONUS. Second is the developing drought
over the central and Lower Plains which tends to reinforce the existing Ridge of
High-pressure in the Jet stream over the Lower Plains because of the overall
pattern.
Also we can briefly talk about the collapse of
the 2006 Hurricane season. But I'll do that more so in the session about the
QBO... and what it means if anything for the Winter.
THE EL NINO / STATUS FOR THIS WINTER ...
Although there is little doubt that the El Nino events are somewhat is over hyped... the fact of the matter is that El Nino and La Nina events are major players and MUST be considered in any attempt to make a seasonal forecast. The technical name for the El Nino and La Nina event is ENSO. The warm water events ....popularly called El Nino can also be referred to as warm ENSO.... while the cold water events .... La Nina .... is referred to as cold ENSO events.
This map (fig 1)refers to the area of the world where ENSO events ( El Nino / la Nina) occur. There are two agencies within the US that have the official responsibility to monitor the ENSO region -- CDC ( climate Diagnostic Center) and CPC (climate Prediction center). The ENSO region consists of several sectors .... ENSO 1+2 ( 1.2) ENSO 3 ENSO 4 and ENSO 3.4. Officially an El Nino or La Nina event is declared when the SSTA (sea surface temperature anomalies) have reached a certain level for a 5 month time period over the ENSO region known as 3.4 .
figure 1
By committing to such a forecast so early in the season some forecasters
have missed the very critical point that the SSTA in the ENSO regions 3.4 have
NOT risen at all in the past 4 weeks . This is very much like a problem we had
with all the hurricane season forecasts that what issued back in May and June of
2006 which were disastrously long and far too high. Those hurricane forecasts
were based upon certain conditions existing in the atmosphere or that the La
Nina event would continue. It is hoped that after the lessons of the 2006
hurricane forecasts BUSTs .... some of these seasonal forecast would not repeat
the same mistake.
The fact that the El Nino has not warmed and is some sort of weak steady state
weak ... really puts a crimp into those forecasters were counting on moderate El
Niño conditions to develop during the heart of the winter. Unless there is a
sudden and dramatic change in the SSTA in ENSO region 3.4 the odds are very
strong that we are not going to see either a moderate or strong El Niño this
winter
WEAK vs MODERATE/ STRONG EL NINO EVENTs
These next four images will clearly show differing impacts between a weak El Niño and a moderate or strong one with respect to temperatures and precipitation. As you can clearly see there is a very strong correlation between a weak El Niño event and colder than normal temperatures over much of the central and especially eastern US. Taking a look at the precipitation patterns we see that in the period of OCT- NOV- DEC there is a strong bias of Much Below Normal rainfall over the lower Plains during the weak El Niño event that is not their during a moderate or strong El Niño. Not surprisingly the drought they have been having over the lower Plains strongly matches the warm El Niño scenario with regard to rainfall
| TEMPERATURES | PRECIPITATION | ||
| OCT- NOV- DEC | JAN FEB MAR | OCT- NOV- DEC | JAN FEB MAR |
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These next two charts clearly show where the current El
Nino event is with respect to other previous events since the 1950s. This first
link shows you a chart comparing the current SSTA in ENSO region 3.4 the last 14
El Nino events and as you can see the current event is definitely in the weaker
category or weaker group of all 14 El Niño events.
This next map shows you a more reasonable and closer look
of the MEI of weak El Niño events since the early 1950s with respect to how this
current event matches up. You can see that the closest overall match appears to
be the 1963- 64 weak El Nino event... but all these events on this
chart .... were significantly colder and
snowier than normal winters for Much of the central and
eastern CONUS.... except for 1951-52
It is important to keep in mind 2 salient
points regarding this El Niño event. First we have never seen a El Niño event
develop in the month of August. Not once as is ever happened. Second ... last
winter... 2005-06 featured a weak La Nina event. If take a look at the history
of the El Niño events in the Winter which have occurred after a weak La Nina the
previous Winter we find a very significant fact in the database.
Which is this... Most of the El Nino events that have occurred after a WEAK La
Nina the previous Winter has NOT reached Moderate El Nino criteria for more a
than a few weeks. Let's take a look at this in a bit more detail. This chart
shows is the CPC 3 month mean SSTA for the region of ENSO 3.4. I have
highlighted in purple the five cases where we have seen a weak La Nina in a
winter season that was then followed by SOME sort of El Nino event the very next
Winter. They are
We can discard the 2001 event because after the weak La Nina died off the SSTA
in ENSO 3.4 stayed flat the Winter of 2001-02.
1957 began with a weak La Nina that quickly moved into weak El Nino in the
SPRING then reached moderate levels of +1.2c and +1.5c in the 1957-58 winter.
However the 1957-58 El Nino is not a great analog match for this season because
that El Nino began in the Spring of 1957.
1963 is as close to a perfect match as one can possibly have. After the weak La
Nina died off in the spring of 1963 SSTA remained a neutral until the Autumn
then only rose to +1.0C in ENSO 3.4... which is exactly the pattern we are
seeing what these current El Niño.
1968 ... is also a good match to the current event... the El Nino reached +1.3c
briefly in January of 1969 then began to weaken.
1986... is also a decent match for the current event. However the cold water in
ENSO 3.4 in the Jan and FEB of 1986 was not really strong enough to be
officially declared a La Nina
KEY POINT THE BEST 3 MATCHES WHICH MATCH THE CURRENT EL NINO IN THE ENSO 3.4 REGION are 1963.... 1968...1986... then 1957
ENSO FORECAST FROM VARIOUS CLIMATE MODELS
This next table provides some information as to how strong the El Niño event names become during the winter. FIGURE 1 is a breakdown the18 Member CFS climate model used at CPC ... which is run every few days
As you can see there is a general consensus among these
ensembles members of the CFS model that the warm SSTAs in ENSO region 3.4 will
reach a peak of 1.25 to near +1.50 degrees sometime in middle or late January or
perhaps very early February.... and then begin to the climate pretty steady pace
Figure 2 and three are the ENSO 3.4 region forecasts from
the ECMWF centre in downtown Europe...
with Fig 2 based on September 1 and FIG 3 based on October 1. He may importance
of these two images shows that he knew right of the European climate model shows
a very sharp drop-off in the SSTA in ENSO 3.4 region in the 2nd half of the
winter.
And lastly we can see figure #4 which is a collection of 19 various climate
models that forecasters can consider regarding the ENSO region 3.4. Looking at
this image we can see that almost all the models show a significant drop-off in
the second half of the winter with the warm SSTAs in this region and only 1
model briefly reaches +1.5C with the vast majority of the data showing a
borderline WEAK/ MODERATE event.
This next table actually is a breakdown of all those individual models that we
see here and I have highlighted or summarized like these forecast models are
showing... and began only a 5 of the 19 models show SSTA in ENSO 3.4 reaching
and HOLDING Moderate level.
| TABLE 1 | |||
CMB'S ENSO FORECAST |
ECMWF ENSO 3.4 Forecast | IRI CLIMATE
MODEL FORECAST 19 FORECAST MODELS |
|
| REGION 3.4 | SEPT 1 | OCT 1 | EARLY OCT |
 1 |
 2 |
 3 |
4will |
DETAILED BREAK DOWN OF ALL 19 IRI CLIMATE MODELS USED IN FIG 4
| Seasons (2006-2007) | ||||||||||
| Model | OND | NDJ | DJF | JFM | FMA | MAM | AMJ | MJJ | JJA | COMMENTS |
| Dynamical models | ||||||||||
| NASA GMAO model | 1.2 | 1.3 | 1.3 | 1.2 | 1.1 | 1 | 0.9 | 0.8 | 0.6 | Moderate |
| NCEP Coupled Fcst Sys model | 1 | 1.2 | 1.4 | 1.5 | 1.4 | 1.2 | 1 | 1 | Moderate | |
| Japan Met. Agency model | 0.6 | 0.6 | 0.5 | 0.4 | 0.3 | weak | ||||
| Scripps Inst. HCM | 0.9 | 0.9 | 0.9 | 0.8 | 0.7 | 0.5 | 0.3 | 0.2 | 0.1 | weak |
| Lamont-Doherty model | 0.9 | 1 | 1.1 | 1.1 | 1.1 | 1.1 | 1.1 | 1.1 | 1 | weak/ Mod |
| POAMA (Austr) model | 0.5 | 0.7 | 0.8 | 0.9 | 0.9 | 0.9 | 0.9 | weak | ||
| ECMWF model | 1.1 | 1.1 | 1.1 | weak/ Mod | ||||||
| UKMO model | 1.4 | 1.4 | 1.4 | Moderate | ||||||
| SNU (Korea) model | 0.9 | 0.9 | 0.9 | 0.9 | 0.8 | 0.8 | 0.7 | 0.6 | 0.5 | weak |
| ESSIC Intermed. Coupled model | 0.5 | 0.6 | 0.6 | 0.5 | 0.5 | 0.5 | 0.5 | 0.6 | 0.7 | weak |
| ECHAM/MOM | 1.2 | 1.3 | 1.3 | 1.2 | 0.9 | Moderate falls off to weak late in winter | ||||
| COLA ANOM | 1.3 | 1.3 | 1.2 | 0.9 | 0.6 | 0.4 | 0.2 | 0.2 | 0.1 | Moderate falls off to weak late in winter |
| Average, dynamical models | 0.9 | 1 | 1 | 0.9 | 0.8 | 0.8 | 0.7 | 0.6 | 0.5 | WEAK |
| Statistical models | ||||||||||
| NCEP/CPC Markov model | 0.9 | 1 | 1 | 0.9 | 0.8 | 0.7 | 0.6 | 0.6 | 0.5 | weak |
| NOAA/CDC Linear Inverse | 0.8 | 0.7 | 0.7 | 0.7 | 0.6 | 0.5 | 0.4 | 0.3 | 0.3 | weak |
| NCEP/CPC Constructed Analog | 0.8 | 0.7 | 0.6 | 0.4 | 0.3 | 0.3 | 0.3 | 0.4 | 0.4 | weak |
| NCEP/CPC Can Cor Anal | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | weak |
| Landsea/Knaff CLIPER | 1 | 0.9 | 0.9 | 0.8 | 0.7 | 0.7 | 0.6 | 0.5 | 0.4 | weak |
| Univ. BC Neural Network | 1.1 | 1.4 | 1.4 | 1.5 | 1.6 | 1.4 | 1.2 | 1 | 0.9 | MODERATE |
| FSU Regression | 1.2 | 1.2 | 1.2 | 1 | 0.8 | 0.5 | 0.3 | 0 | -0.2 | Moderate falls off to weak late in winter |
| TDC - UCLA | 1.3 | 1.3 | 1.1 | 0.9 | 0.6 | 0.5 | 0.4 | 0.3 | 0.3 | Moderate falls off to weak late in winter |
| Average, statistical models | 0.9 | 1 | 0.9 | 0.8 | 0.7 | 0.6 | 0.6 | 0.5 | 0.4 | WEAK |
| Average, all models | 0.9 | 1 | 1 | 0.9 | 0.8 | 0.7 | 0.6 | 0.5 | 0.4 | WEAK |
The folks over at CDC
- Climate Diagnostic Center have developed a
More complete way of measuring ENSO
events .... be it a El Nino or La Nina event. The
MEI or Multivariate ENSO Index (MEI) measure
all El Nino and La Nina events
on six main observed variables over the tropical Pacific. (
sea-level pressure... zonal surface winds...
meridian surface winds.... sea surface temperature...
surface air temperature... and total cloudiness as a fraction of the sky
FULL DETAIL and a better overall image of
ALL the MEI data since 1950 can be
seen here
http://www.cdc.noaa.gov/people/klaus.wolter/MEI/
However for ease of comprehension I have created this table of MEI values from January to November 2006. what I am searching for here is NOT a exact numerical Value match but the overall trend .
2006 MEI VALUES FROM JAN TO NOV 6 |
|||||||||
| JAN | FEB | MARCH | APRIL | MAY | JUNE | JULY | AUG | SEPT | OCT |
| -.382 | -0.417 | -0.554 | -0.594 | -.014 | +.481 | +.643 | +.750 | +0.892 | +1.027 |
Note the MEI values were moderately NEGATIVE in the Winter and Spring (hence the weak La Nina)... then rose to NEUTRAL and steadily But NOT rapidly rose into weak El Nino levels in JULY AUG SEPT. The OCT 2006 value is right on the border between WEAK and MODERATE El Nino...
Here are the 4 analog years that closet match with what we have seen with this CURRENT MEI . Over on the far right columns I have made a few comments for your consideration
| 1957 | -.983 |
-0.426 | +0.88 | +.388 | +.886 | +.755 | +0.958 | +1.104 | +1.138 | +1.091 | +1.111 | +1.19 | So-So... MEI rose to above +1.0 in AUG 1957 |
| 1963 | -.748 | -.893 | -.684 | -.784 | -434 | -.081 | +.372 | +.651 | +.44 | +892 | +.934 | +.703 | PERFECT MATCH |
| 1986 | -0.304 | -0.225 | +0.040 | -0.103 | +.318 | +.311 | +.387 | +0.713 | +1.093 | +1.012 | +.856 | +1.186 | 2ND BEST ... ROSE TO +1.012 in OCT 1986 matching the OCT 2006 value |
| 2002 | -.111 | -0.147 | -0.81 | +.414 | +.882 | +0.853 | +0.567 | +0.864 | +0.806 | +0.914 | +.987 | +1.151 | Good match |
KEY POINT THE BEST 3 MATCHES to MEI OF 2006 .... 1963 1986 and 2002
THE
HURRICANE OF 2006 --
DOES IT MEAN ANYTHING FOR THE WINTER OF
2006-07?
You know what's really interesting? Last year when we had
that super active hurricane season there were an awful lot of private
forecasters out there ranting and raving about how the 2005 Hurricane season was
somehow connected atmospherically to what the upcoming Winter might hold for the
eastern half of CONUS. Now that we have had a sub active hurricane
season... suddenly there are not a lot of people talking about the hurricane
connection and what it might or might not mean for the winter.
Isn't that curious?
Since there is not a lot of speculation about what the 2006 hurricane season
might mean for this coming Winter across the CONUS... I won't
spend a lot of time on this aspect of the forecast. However it one point I do
want to make is that there is significant research out there which shows
SOME correlation between Hurricane activity over the
southeast US and what that means or implies for the following winter.
You see the problem was that last year these private forecasters that were
banging the drum about Winter of 2005-06 took that
research and misused it. Instead of using the actual research which does lend
some support to the idea that active hurricane season over the southeast US has
implications for the overall pattern in the following winter... they took this
data and asserted that ANY sort of above normal activity in the Gulf Mexico has
implications for the overall Winter pattern. That of course is 100% BS...
However IF the goal was to get an awful lot Media attention and get
yourself on CNBC while Natural gas and Heating oil prices rise.... then that
strategy was successful .
Again keeping in mind the original research... we have seen some Hurricane
seasons where there has been decent a cluster of over the
Southeast CONUS and the following Winters have been
significant. The hurricane season of 1995 which featured a lot of activity
in the tropics but saw numerous Tropical
Cyclones constantly turned away from the East Coast ....because the mean trough
position was located over the East Coast in the autumn of 1995. Likewise we
sought awful lot of activity into Florida and the Southeast states in 2004 in
the winter of 2004 --05 with reactive as well.
This year while we have not see a lot of activity... they were three of
the 9 named storms that developed in eastern Gulf OR off the FL coast that
passes through a very close Florida and /or parallel the Southeast US coast...
ALBERTO BERYL and ERNESTO. There also several Tropical Cyclones which were
turned out to see in the central portions of Atlantic. First let me show
why this idea is crap and then why it was done.
Again keeping in mind that it is my goal to convey information without
getting bogged down in Too much detail...
The NAO or North Atlantic Oscillation is one of the major modes of variability
of the Northern Hemisphere atmosphere. It is particularly important in winter,
when it exerts a strong control on the climate of the Northern Hemisphere. There
are several manifestations of the NAO. Basically without getting to technical
DNA always for us to a particular jet stream configuration which exists over the
regions of the Northern Hemisphere from eastern or northeastern Canada to
Greenland and over towards Iceland and Northwest Europe.
Sometimes you'll hear the phrase 'High Latitude blocking'
and if this is occurring over eastern Canada or Greenland for example
this phrase might be referring to a negative phase of the NAO.
Arguably the most difficult aspect of any WINTER forecast for the central and
eastern half of the CONUS is trying to predict or figure out what he and Io is
going to be doing this winter... what percentage of the time will this critical
feature be in the NEGATIVE phase ( colder and stormy pattern for the central and
eastern US as well as se Canada) or POSITIVE PHASE (milder and less stormy).
SOME LINKS FOR THOSE WHO WISH TO KNOW MORE
http://www.cru.uea.ac.uk/~timo/projpages/nao_update.htmis
http://www.met.rdg.ac.uk/cag/NAO/index.htmlgas
This image is the latest sea surface temperature anomaly map for the entire world which comes from the Unisys web site... and it shows some very interesting things.
To begin there is a noticeable area of very warm SSTAs
located east of the Newfoundland in the Northwest Atlantic which stretches up
into the Davis Straits and east over towards the Northeast Atlantic. This pool
of very warm water has been there since the Summer but back then this pool of
very warm water was located significantly further south. In addition we can see
some more temperatures that are actually below normal off the Southeast coast of
the CONUS and sea surface temperatures are between Iceland and Greenland.
Research has shown that this sort of sea surface temperature anomaly
configuration ( in the weather biz this is called the North Atlantic SSTA
tripole) is supportive of a sustained negative phase of the NAO. This is not by
any means a guarantee but there is some correlation between sea surface
temperature configuration like the ones we currently have in the North Atlantic
and fairly long intervals of the NAO staying in the negative.
In addition as I mentioned about with the drought pattern over the Plains states
.... the location of the Ridge over the Plains supports the mean trough position
over the East Coast which in turn does favor some sort of positive height
anomaly over the Northwest Atlantic and /or Greenland.
If we look at the longer-term trend will see that the NAO has been in the
negative phase for the most part since late July early August with only a few
brief intervals where the NAO went positive.
Keep in mind there are a lot of government and private forecasts which attempt
to predict me and we'll phase for either a portion of the winter or for the
season as a whole. Most of their forecast have not as bad but wretchedly so in
this may explain why so many of the last few went to forecast had been so bad
across North America.
For example the British issue a "experimental" NAO forecast every Autumn for the
following winter. As you can see from this chart... provided by the UKMO... they
have been making these NAO forecasts for many years. The problem is that the
British NAO seasonal forecast has really really wrong for many years. In fact I
cannot recall the last time the British have gotten the NAO phase even remotely
correct over the last 10 years.
Looking at the last several years of this chart since
2000... if the British went out of their way to intentionally forecast the WRONG
phase of the NAO they could not do a better job!!! Of course that Is not what
they are trying to do and they should be applauded for making an effort. However
in my opinion by putting out NAO forecasts which well SUCK... a lot of private
forecasters refer to the well-known British NAO forecast as is
some sort of reliable piece of data when as you can see from this chart the
British NAO is absolutely worthless.
WXRISK VIEW: While many
see the SSTA set up for
the Atlantic Ocean as NOT ideal for
sustained intervals of the negative
phase of the NAO I see some promise. Many
forecasters assume that there can only be one particular manifestation of the
negative phase of the NAO... which is called the Greenland Block. However
sometimes you can get a
-NAO manifestation that shows up as a blocking pattern over the Davis
Straits... or northeastern Canada or northern Québec.
Indeed we saw that several times during the months of September and October. And
the strong pools of very warm SSTA in and around the Davis Straits and of the
coast of southeastern Canada strongly supports the idea of a westward positioned
blocking pattern developing over northern Québec or the Davis Straits from time
to time this winter. I do not see a " ideal" SSTA
configuration at this time although it would not take much to change the
Atlantic SSTAs into a pattern that would favor sustained -NAO.
Over the last 10 years there has been a significant amount of research done on a climate pattern that is called the PDO in the weather biz. The PDO or "Pacific Decadal Oscillation" a long-lived climate pattern that exists over the northern Pacific Ocean.
The PDO involves the location and intensity of large pools of warm and /or cold Seas Surface Temperature anomalies (SSTAs) in the central and eastern areas of the Northern Pacific. Why is this important? Again research has shown that large areas of warm and cold water pools called SSTA couplets STRONGLY affect the Jet stream pattern and the positions of Ridges and troughs within the Jet Stream over the Pacific and western North America.
This is diagram shows you the Two phases of the PDO... the BLUE color represents very cold SSTA... the Green cool SSTA.... the RED color very warm SSTA and the Yellow warm SSTA.
The map below explains HOW and why the PDO affects the pattern across North America. Click on the Maps to see the Full size. As you can see when the PDO is in the Positive or WARM phase... the warm sea surface temperature anomalies along the West Coast North America strongly supports a ridge developing over the western portions of the continent and locking this Ridge in place. Of course if you have a Ridge over the West Coast then downstream you have to have a trough.... (for every action there is the equal opposite reaction)... which in this case is over the eastern third of the US. This pattern is known as the +PNA and it is the classic signature for a cold weather pattern. The arctic air masses from the Arctic regions and northern Canada follow the Jet stream down into this trough which results in sustained intervals of below row temperatures cold water. On the West Coast the Ridge of High-pressure means clear skies very little storminess and Above normal temperatures.
However the opposite is true what we had a negative or cold phase of the PDO. In this case the warm water is located out in the Central Pacific Ocean and cold water develops along the West Coast North America. This results in the jet stream developing a trough along the West coast... and of course downstream a Ridge develops over the eastern half the US. This sort of pattern results in a very cold and stormy West Coast with areas such as a Seattle and Portland saying snowstorms in the very strong cases out of the negative phase PDO... and the central and eastern US saying below normal precipitation and above mobile temperatures.
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The correlation between the temperature patterns across North America and PDO phase is very strong and it's very hard to ignore.
The PDO also has some impact on El Nino / La Nina events. While the PDO and ENSO events have similar climate "fingerprints"... they have very different behaviors in time. For example a phase of the PDO can persist for 20-to-30 years while typical ENSO events persisted for 6 to 18 months. Within that 20-30 year PDO cycle one phase is more favored than the other. For example when the PDO is in the "Negative Phase" most of the time the PDO will run in the Negative pattern with just a few instances of PDO developing a Positive Phase... and vice versa. In additions the PDO directly affects the ability of the El Nino or La Nina event to reach the STRONG category. When the PDO is in a negative phase the El Nino event trend to be weaker while La Nina events are stronger. On the other when when the PDO is in the Positive or warm phase the El Nino events tend to be longer lasting and stronger while La Nina event s are weaker
Again if we take a
look at the latest SSTA map
we see large areas of cold water located off the Baja California coast and
SSTA that close to neutral or slightly below normal over much of the Northeast
Pacific-- off the West coast of Canada -- and north of Hawaii.
In fact in the northern Pacific the only areas of really large bodies of warm
water exist in and around Japan. The overall sea surface
temperature pattern or configuration is clearly indicative of a negative phase
PDO ( hereafter called a -PDO). However it is not a
strongly negative phase like we saw last year which means that it's possible
during the middle or second half the winter the PDO phase could change... from
negative to positive. In order for something like that to occur... they would
have to be a significant increase in areas of warm either over the Central
Pacific that moves eastward or developing over the Eastern Pacific near the
North American coast. Began at this time there does not appear to be anything
indicating that might be the case but because we are dealing with a weak -PDO
phase such a change could occur in the second half of the winter.
Again keep in mind that -PDO means a constant stream of Pacific Energy
bombarding the West Coast and it also restricts the ability of cold air pour
southward from Western Central Canada into the central and eastern portions of
the CONUS. However since this -PDO is a weak one ... there is a high probability
that the Pacific Jet stream will split into two branches on the West Coast. This
sort of split in the jet stream pattern is an indicator that forecasters look
for that the pattern is about to become stormy.
http://www.atmos.ucla.edu/~cwhung/qbo.html
http://strat-www.met.fu-berlin.de/products/cdrom/html/section5.html
http://ugamp.nerc.ac.uk/hot/ajh/qbo.htm
The quasi-biennial oscillation (QBO) is a Band of High level zonal winds found over the Equatorial at very high altitudes ( even above the Jet Stream). It is a very well known periodic oscillation in atmosphere. The has been a lot of research done over the last 10 years that shows the QBO has significant impact of overall climate patterns ... as well as Winter Weather patterns as well as the Hurricane season. The period of the QBO "oscillation" is about (a little over) two years. The QBO has two "phases" with occur within the 1 Oscillation cycle-- the Easterly or NEGATIVE phase and the WESTERLY or Positive phase. Within the meteorological community the QBO is used heavily by SOME as a key ingredient to figuring out what the Winter pattern across North America might be... while other forecasters dont think its all that relevant.
In my opinion However much of the discussion is mis-directed towards How and why the QBO is important For example it has been asserted that during the Winter season....the Eastern half of the US is often cold and snowier than Normal when the QBO is in Westerly or Positive phase while others have asserted that the Easterly or Negative Phase is better for colder and snowier Eastern US winters.
This LINK has the QBO data going back to 1948. It is my position that the QBO index is NOT a indices that directly relates to the overall pattern per se ...be it Winter... Spring...Summer or Autumn. The reason why I think the QBO is important is that it tell us what the Pacific Jet is going to be doing over the central and eastern Pacific. Good weather forecasters should be willing to tell you that if you get the West coast of North America wrong ... you get EVERYTHING else-- the Rockies to the Plains to the Midwest to the Deep South and East coast wrong as well. Perhaps this explains why there are often so many snow and cold forecasts for the eastern US out there that are so often wrong or over hyped.
It is My contention that a East or Negative Phase of the QBO as we go into the Winter months correlates to a more active and stronger Pacific Jet stream... which means more rains and storminess for the Pacific NW and West coast and a Ridge over the SE or East coast.
A QBO value that is strongly positive as we go into the Winter months ...say above +10.0 or higher almost always implies a lack of cold air build up in Canada and a Milder winter for the CONUS .
A QBO value that is near zero as we go into the Winter months --- say from +5.0 to -5.0 implies a Pacific Jet that is weak and favorable for all sorts of large scale pattern shifts and changes -- called pattern amplification and de-amplification ( lots of storms and blocking patterns) .
Here are the current QBO values for 2005.
2006 QBO VALUES FROM JAN TO OCT |
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| JAN | FEB | MARCH | APRIL | MAY | JUNE | JULY | AUG | SEPT | OCT |
| -18.83 | -11.24 | -0.38 | +5.00 | +10.36 | +11.47 | +10.75 | +9.10 | +10.20 | +10.86 |
The KEY point to consider is that IF the
current QBO Phase stays strongly positive into the winter in any probabilities
all saying significant cold air outbreaks or a colder than normal overall
pattern would be significantly reduced. If on the other hand the QBO phase drops
towards neutral then the overall pattern becomes much more promising for
significant winter weather over much of the nation as well as the chances for
more significant cold air outbreaks.
If you scan all the QB0 data and you look for QBO events which were
strongly negative... reached NEUTRAL ... then PEAKED ... and
dropped back to NEUTRAL ... you can plot how long it takes for the
positive phase of the QBO to run its course. That
cycle takes anywhere from 10 to 16 months.
1994-95 had a QBO that was at one strong negative-- minus 25.00 or lower. Once
the QBO
reached Neutral with QBO took 12 months to reach the Peak Positive value then
drop back to Neutral.
On 1996-7 the QBO was a strongly negative one -- that dropped to -25.00 or
lower. Once the QBO reached Neutral... it took 11 months to reach its peak then
back to Neutral.
1984-85 the QBO was a strongly negative one -- that dropped to -25.00 or lower.
Once the QBO reached Neutral... it took 16 months to reach its peak then back to
Neutral.
The current QBO phase became neutral in March 2006... it
is now in its 9th month ( November 2006). It is probable that some point in the
winter or specially the second half the winter the QBO will rapidly
breakdown with which neutral. This again leads support to the overall idea that
the second half the winter was going to be significantly worse than the first
portion of winter 2006 --07.
As for a QBO analog... let me emphasize that we are not looking for an exact
match with respect to the numerical values per se but the overall QBO trend.
What I am looking for is a analog to this particular pattern... a QBO that was
very strongly negative ( -25.00 or lower) last winter... that became neutral by
March 2006... that rose to +10 or higher in May 2006 and held close to +10 since
then.
| JAN | FEB | MARCH | APRIL | MAY | JUNE | JULY | AUG | SEPT | OCT | NOV | DEC | ||
| 1957-58 | -20.06 | -17.24 | -14.02 | -9.27 | -5.91 | -2.30 | +3.15 | +7.07 | +10.09 | +11.69 | +10.71 | +8.30 | NOT a good match Summer 1959 to Summer 2006 |
| 1957-58 | -13.05 |
-11.58 | -6.98 | -2.01 | +1.80 | +3.21 | +4.05 | +6.30 | +8.36 | +10.46 | +10.11 | +7.35 | NOT a good match Summer 1957 to Summer 2006 |
| 1966-67 | -21.90 | -17.14 | -11.07 | -2.33 | +2.16 | +5.42 | +7.47 | +7.63 | +9.23 | +11.00 | +11.74 | +13.26 | too strong going into winter of 1966-67 when compared to 2006-07 |
| 1971-72 | -10.67 | -3.67 | +0.91 | +3.75 | +6.77 | +8.28 | +8.8 | +8.34 | +8.95 | +8.47 | +8.47 | +9.10 | BEST ... note the Plateau of Pos value between +8 and +9 all summer and Autumn 1971 ... similar to Summer Autumn 2006 |
| 1975-76 | -16..0 | -15.39 | -13.04 | -5.12 | +1.18 | +4.47 | +7.41 | +9.06 | +10.25 | +10.65 | +11.27 | +10.95 | Good match... note the Plateau of Pos value between +10 and +11 Autumn 1975 |
KEY POINT THE BEST 3 MATCHES to QBO OF 2006 .... year 1971 1966 and 1975
SNOW COVER NORTH AMERICA
Snow cover is one of those nebulous qualities
that forecasters look at in the months of October & November in Canada. The
Premise is that when you have early or heavy snow cover over a good portion of
Canada there is a tendency to build colder and longer lasting arctic air masses
which can then plunge into various portions all of the CONUS during the Winter
months.
There is data which shows a very strong
correlation especially east of the Mississippi River to mean temperatures during
December January and February and snow cover in Canada. When the snow
cover in OCT and NOV is above Normal Temperatures East of the Mississippi river
tend to run Below or Much below normal.... and when snow cover in the months of
October November is Below normal in Canada temperatures east of the Mississippi
river tend to run milder than Normal.
That being said simply having early and/or heavy snow cover in the months of
October and November over Canada does not necessarily mean that you are going to
have a cold and/or Snowy Winter over the central and eastern US. It
just increases the chances that such a scenario COULD happen... the tendency to
produce colder and longer lasting air masses is there. However if one were to
look at the data from the Autumn of 1977 snow cover was below normal in Canada
during the months of October November and yet that turned out to be one of the
cold winters on record. On the other hand there was above normal snow cover in
the months of October November 1978 in Canada and we had a very cold and stormy
winter that followed in the lower 48 states.
The only thing can be said with any degree of certainty in my opinion regarding
snow cover is that if you have October and November with below normal snow cover
the odds are increased that you will have significantly LESS cold air outbreaks
plunging into the CONUS. For example the super warm winter of 2001 --02 saw much
below normal snow cover in October and November over Canada. The implication
here is that when the cold air masses formed and moved south they rapidly
modified as they came southward due to lack a snow cover in southern Canada
during the heart of the 2001-02 winter.
To be certain we got off to a very weak start with snow cover over Canada in
October 2006. The data does show that snow cover for Canada was below normal but
we did see significant increases in the snow cover as the month came to a close.
We can see that clearly here...
and the differences in snow cover from the first
week October when compared to the last days of October are quite impressive.
This increased snow cover continues through
mid-November right up to the US Canada border. The snow
cover build up in Siberia is Impressive -- Much
above Normal there.
Now typically what happens with Moderate or strong El Niño
pattern is that the large Upper Low develops over Alaska near the Bering Sea...
and from this position the strong jet stream comes around the Upper Low and
slams into Western Canada. This ends up destroying the snow cover in Western
Canada as well as preventing any sort of cross Polar flow developing from
Siberia into North America. This is just one of the ways (but a overlooked way)
that a strong or moderate El Niño ends up affecting the overall pattern North
America
However with a weak El Niño the entire pattern gets displaced. The vortex that
in a strong / moderate El Niño is over the Bering Sea often gets displaced to
the east in a weak El Niño... and is often found in the northeastern Gulf of
Alaska near the West Canada Coast. When this pattern occurs Western
portions of Canada and the Pacific Northwest see a lot of precipitation... but
much of it falls as snow since the very deep Vortex is located on the western
Canadian Coast and that brings in some very cold air masses. In addition the
weak El Niño position ends up increasing snow cover over much of Canada even
while it provides a mild conditions for much of the CONUS.
Thus when the Jet stream decides to split into two branches the cold air is
located very close to the US Canada border and the Arctic outbreaks can occur
with a lot more frequency.
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