WINTER  FORECAST   -- 15  NOV  2004  

2004-05  WINTER FORECAST MAPS

2ND  HALF     WINTER  FORECAST...  click   HERE

TECHNICAL  STUFF

review of 2003-2004   Winter   Forecast:   VERY    SUCCESSFUL...

Within the confines  of  the   seasonal   weekly  and    sometimes even daily   weather     forecasting...  the standard  for   succcess or   failure   is  set  by  "consensus forecast" ( hereafter   referred to as CF).   The  CF   is term that I use   to describe  the general view or summary of what most PWSIP  (private weather  service  Information Services)      and / or   NWS forecasters are saying.      From  the week 2 forecast   Range   to   the  seasonal   foroecasts  the  CF    is set  by  CPC    ( Climate  Prediction Center).     Thus the CF is very important in determining how the seasonal trade in Energy and Agriculture markets will view  he   overall season  as well the  How the operational Meteorologist will    view the   season.   For example… State DOTs will often significantly lower their Salt and Sand purchases if the CF is for a Mild winter in their area.      The CF often consists of  a) the CPC    foecast   (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  that are  not part of a   PWSIP.  

The  Wxrisk.com  2003-04 Winter forecast   was  a   major success and was  again    clearly  superior  to the    the  general or Consensus Forecasts.   In  October  and November of   2003   there seemed to have been an early consensus that a repeat of the impressive winter of 2002 -- 2003 would occur across  much of the central and eastern U.S.   However by the time November 2003 rolled around most of the skilled private weather services information providers (PWSIPs)  that do not have to engage in hype to get media play had committed to their clients a forecast that did not feature a repeat of the previous historic Eastern US winter. To see  forecast maps  for  Winter   2003-04 Click Here.    

Although   the    monthly   forecast maps  were   only Mariginally   successful   I  did  predict  several   key  features

• A period of  Intense   cold  for   Mid  January 

• A    supressed  or  Southern    storm track

• Increased    precip  over the   Pacific NW and  Rokcies for the 1st time  in   several   winters.

• For more importantly however   was the development of a significant feature which dominated all of North America to the late Autumn 2003 and the  Winter 2003-04.  This  feature  was    completely  missed by all of my competitors  -- both  with   CPC  and  other  well known  PWSIPs.   I first detected the   development of  the Powerful Pacific Jet stream in   early OCT of 2003.    

• The only question was whether the Pacific jet was going to be a dominating feature for the winter. What  was surprising to me is that so many forecasters messed this feature.   There  were   two   strong   reasons  which led me to forecast a strong Pacific jet dominating the weather patterns across North America last winter.   First were the sea surface temperature anomaly patterns   (SSTA)    in the central eastern Pacific Ocean which clearly supported a mean trough position located along West coast of North America... and the strongly negative readings from the QBO index.    Some forecasters had anticipated that the extremely native values in the QBO index we saw in the cool wet summer of 2003 would rapidly decrease and move towards zero mark by late December or early January2004.    (The idea was that IF the QBO could switch phases from the storng EAST opahse to a neutral or West phase in late DEC 2003 or early January 2004 the second half of the winter might turn into a cold and snowy one for the Midwest and Northeast US).     However
  in October and November of 2003 the QBO index remained very strongly in the native values and showed no signs of rapidly decreasing and moving towards a neutral value.    This pretty much killed  the idea of a change in the phase of the QBO and the strongly indicated to me that Pacific Jet was going to be dominant all winter.       Paranthetically this might comes as a shock to some but not every seasonal index in the world is related to ONLY the Northeast US and snowfall.

Click HERE    for a  Brief  REVIEW  OF LAST WINTER  FORECASTS   FROM   OTHER   PWSIPs

CPC    WINTER  FORECASTS   FROM  LAST WINTER...   2003-04

REVIEW   of WINTER  2003-2004

On a  nationwide level   the    Winter of  2003-04  was   nearly  prefect   ordinary winter..   but  as with all generalizations     once  they become so general   the  are generally useless.    For  example hidden in the  fact  the   Winter of  2003-04 placed  68th   with regard to temps..   is the   2 periods of bitter cold for  New England   that occurred.   In addition   DEC 2003  was  WARM over the entire western US   but  fairly  wet.  And  FEB 2004    -- as the data clearly  shows-- the  storm   track was indeed  supressed  to the south  much like we  saw  with the   winter of  1979 -80...   with  temps    from   CALIF to    VA   running Below   Normal     and  precip  well Above  Normal.

	CLIMATE  DIVISONS TEMPS	CLIMATE  DIVISIONS PRECIP	REGIONS   TEMPS	STATE   TEMPS	STATES   PRECIP	500 MB PATTERNS	% OF SNOW TO  NORMAL
DEC   2003
JAN    2004
FEB   2004
ACTUAL  SNOWFALL   FOR THE  SEASON		%  SNOWFALL   COMPARED TO NORMAL		NEW  ENGLAND   COLD		NC    HEAVY SNOW

 Once again in this winter forecast that there will be a midwinter review which occurs sometime after the New Year. The science of seasonal weather forecasting  is half science and half art. The mistake that many forecasters make    (in my opinion)   regarding seasonal forecast is NOT  so much attempting to make the accurate seasonal forecast and then having it bust.   The problem is in not following up on their forecast... seeing how the pattern is or is not developing and failing to issues any changes to  the forecast.

A classic case of this was  my Summer forecast for 2003.   My original Summer forecast ( issued Mid May ) was for a hot dry Summer across the Plains and the Midwest and  cool wet one for the East coast.  This idea was   based on a moderate La Nina developing  in the El Nino regions... and since there is a strong correlation between moderate La Nina and hot dry summers in the Plains and Midwest.... that forecast was fairly reasonable.   Moreover going into the month of MAY 2003 the data clearly showed a moderate La Nina event was building as the sea surface temperatures cooled significantly off of South America.

However the cold sea surface temperatures reversed itself and rapidly warmed during the month of June -- which of course is a month after I issued my summer forecast. The collapse of the developing La Nina effect is due the the - PDO which is a long-term weather phenomenon in the Pacific ocean that  enhances or inhibited the development of El Nino and La Nina events.  Thus on the basis of the   collapse  in the La Nina  in JUNE... I  updated   the Summer forecast right before the July 4th weekend--- which can be seen on the Web site.    In my opinion it is really quite pointless  to issue   the seasonal forecast  MONTHS before the season  under consideration actually begins    and  then issue NO updates.

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 part)   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 the current situation to assist them in making the monthly or seasonal forecast.

Done the correct way the Analog method has validity to it.   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.  Some forecasters  and   weather hobbyists   hold  the view   that analogs  are   not very helpful since  weather  records are incomplete or not sufficient enough to be considered as an indicator of what the upcoming seasons might hold.      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   does have   some merit   and  basing a  seasonal  forecast on ONE   parameter is   very risky  and has a high degrees of failure.     The problem for  seasonal forecasters    is that  we  have  SOME   data on SOME    useful  seasonal  Paramaters... but not enough  to be used with confidence.  

One way of getting around this is to use several factors parameters and cross matching the analogs to look for common ground.

Just   like   the  last several  seasonal    forecasts   I will use these   parameters and in this order of  importance

1. ENSO

2. SOI

3. MEI  

4. QBO  

5. CLIMATE MODELS  

6. SEASONAL  PATTERN    

7. CANADIAN SNOW COVER

THE   STATUS   OF  THE   CURRENT  EL NINO THIS WINTER ?...

The first parameter that I will consider will be the Sea Surface Temperature Anomalies (SSTA) in the ENSO regions. (Warm ENSO are called El Nino... cold ENSO are called La Nina). For the purpose of clarification I have presented  the   Official map   from CPC   that is used  to show the   ENSO  regions  broken down into  4 areas.      Officially  an El Nino or La Nina event is "declared"   when the SSTA have reached a certain Temperature criteria   for a 3 month time period.  El Nino events   begin    and   are centered  in  the various   regions.   Usually  the   very strong El Nino  events     develop   in  ENSO  region 1+2  and spread   or  build  west  towards the  Dateline.    This was  the  case   in the supert intense   El Nino   events of  1982-83   1987-88 and   1997-98.

However  some   El Nino events     developed in  ENSO  region  4  ( the furthest West)   or   ENSO region 3...  and  spread    east towards Peru. In almost every case   these  El Nino events   have either been Moderate  weak  events.  We saw this in 2002-03... 1977-78... and in the   1960s as well.

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.   Until  fairly  recently    whenever their was a   El Nino event  declared the   CPC  (climate prediction center)   winter  forecast    was  ALWAYS the  same  regardless  of   how storng the  El Nino was  or  what  region  the   El Nino  was centered in:  "Cool and wet"   over  the Southern US  from  California   to  NC  and    "Warm and Dry"   from Montana to  Massachuseets.      Indeed  the    CPC winter  forecast from forecast  from   2002-03   depicted   exactly those    conditions   (  that a  moderate to strong El Nino would develop and flood  the central  & eastern US  with mild air).   Instead the El Nino of  2002-03 collapsed in early January 2003   and    the winter turned ot to be    exceptionally stormy and  fairly  cold for much of the Midwest and Northeast.      

Likewise in the Spring of 2003 the development of a La Nina led many forecasters (myself included)  to make  a    "Hotter than Normal and  Drier than Normal"   Summer forecast for the central Plains and portions of the Midwest.    Instead the La Nina collapsed in June and the wet cool pattern held.

It should therefore be obvious and self-evident that a seasonal forecast which is premised on the idea that the   current  El Nino  is   subject to change.   Over the last 8 weeks  the  SSTA  in ENSO  region 3.4    which   held steady   from early    JULY 2004  to    OCT 2004   (between   +0.7C  and  +0.9C)  have started to warm slowly over the last    few weeks to  +1.2 degrees C .  This  qualifies as a weak   El Nino event  BUT   does not  meet the criteria  for   a moderate   one.  

LINK FOR    RAW  DATA  IS HERE

CMB'S  ENSO    REGION 3.4 FORECAST		ECMWF   ENSO  3.4     Forecast
NOV  10

All the data  shows  that  the  current     trend  in   the  weak  El Nino  in region   3.4   is  going to  continue through the winter.  It is still possible that     the  El Nino might reach  the   criteria for Moderate status   at some point but   this is    uncertain and if it were to happen.... the  Moderate  intensity    would not last   more  than a few weeks. . Thus I  come to our first critical assessment of this forecast. Based upon what I am seeing right now... my forecast is going to be heavily based upon the idea of a weak El Nino developing in the second half the Winter into the Spring and therefore the analogs which I am be considering have to be based on that.

There are several sources that one can use to figure out which historical period might be considered as they analog. Below I have reproduced the well known Table that shows El Nino / La Nina years from the Climate Prediction Center that gives a general overview of the last 50 years by 3 month intervals.  http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.html    Warm    ENSO (or  El NINO)  regions 3.4  Quarters are in RED and
cold SSTA in  region  3.4 ( or  La Nina)    quarters are in  BLUE   based on a threshold of +/- 0.5^oC for the Oceanic Niño Index (ONI) .

I have  highlighted these  events in  GRAY...   and  the   current  event   YELLOW.   Since   there is NO data  that shows   the current  El Nino   that is at   criteria    for  "Moderate"   or   :Strong"      AND   since    there is no data shows that  the    Current  El Nino is building to  Moderate or   Strong..    only    weak  El Nino  events  are   being considered.   For   example   the   Strong   El Nino event of  1965 -66  is  NOT  considered  becasue   the   SSTA    in  Region  3.4   was    far too strong   when compared to the   current   El Nino.     This  gives us  8  possible analogs  to consider...   1951-52   1957-58...  1963 -64...   1977-78...   1986-87... 1991-92...  1994-95...  and   2002 -03