WINTER PREVIEW -- 22 OCT 2003
2003-04 WINTER FORECAST MAPS
|1. REVIEW OF WINTER 2002-03||2. USE of ANALOGS|
|3. Is there an El Nino Coming?||4. Current ENSO conditions|
|5. WXRISK ANALOGS||6. SOI|
|7. MEI||8. QBO|
|9. CLIMATE MODELS||10. AUTUMN SNOW COVER|
review of 2002-2003 Winter Forecast: MOSTLY SUCCESSFUL...
The Wxrisk.com 2002-03 Winter forecast was a major success and was easily superior to the the general or Consensus Forecasts (Hereafter called CF). Although my January forecast for 2003 flat out sucked... the forecast for December 2002 February 2003 and March 2003 was nearly Perfect. Within the confines of the private sector forecaster the standard for the CF which is set by CPC or the climate prediction Center. After potential clients are looking for an edge or a better forecast and if they get get a better forecast for free from CPC why pay for it? The term "consensus forecast" (CF) is term that I use to describe the general view or a summary of what most PWSIP (private weather service Information Services) / 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.
Last winter there was much talk of the developing El Nino in the equatorial regions of the Pacific ocean. Given the recent History of El Nino events in the 70s 80s and MUCH of the 90s... it seemed self evident that ANY talk of an El Nino automatically brings about certain pre-conceived notions about what the Summer and /or Winter season will be like. This can clearly see by CPC's terrible winter 2002 - 03 forecast. This map is a standard CPC "if it's an El Nino during the winter this is what the winter MUST be like...:" But as I (and some others) pointed out in OCT 2002 there were MANY indicators that showed the developing autumn El Nino was NOT going to bring about the same very mild winter MOST of the USA has seen in the El Nino events 70s 80s and 90s El Nino events.
Among those clues that the El Nino last winter was NOT going to bring about "typical" El Nino winter conditions in the CONUS were
WARM phase PDO which is Known for suppressing El Nino and La Nina events.... (which happened again in MAY 2003 when the PDO crushed the developing La Nina)
The Most active El Nino hurricane season EVER...
The 2nd greatest and deepest snow cover in OCT and NOV in Canada in the last 40+ years...
RECORD rainfall in OND along the east coast whereas the typical El Nino brings Drought to the east Coast...
REVIEW of WINTER
For locations East of the Mississippi River Winter 2002--03 ranged from seasonally cold to VERY cold while locations WEST of the Mississippi river saw a Warm DRY winter especially over the Upper Plains ands western Great Lakes. With respect to Snowfall... much of the East Coast saw a winter that placed in the top 10 to top 15 snowiest winter ever. January 2002 was the coldest month of the winter as the Jet stream surged well to the south... which forced the southern track tracks off the Southeast coast.
|WINTER 2002-03 TEMPERATURES||WINTER 2002-03 PRECIPITATION|
|CLIMATE DIVISIONS||CLIMATE DIVISIONS|
|STATE RANKING||STATE RANKING|
I have seen SEVERAL references made within various weather web sites discussions groups and some early winter forecasts that OCT 2003 is shaping up to be similar to OCTOBER 2002. Such statements are usually focused on the Sea Surface Temperature Anomalies patterns in various locations around the world .... OR the narrow view that is premised on the idea that OCT 2003 at " my house" is running similar to OCT 2002.
Such assertions are of course specious. As the 2 maps show OCT 2002 saw a large areas of temps below and Much below Normal over the Northern 1/3 of the Nation but especially over the Plains and WET conditions over the Lower Plains into the Southeast states and up the East coast. OCTOBER 2003 has featured days and days of Record or near record heat in the central and Upper Plains while the Lower Plains have been very dry. ( again NOTHING like OCT of 2002)) .
Once again in this winter forecast that there will be a late-season update for any changes which I think should be made... and of course there will be a midwinter review which occurs sometime after the New Year. The science of seasonal weather forecasting is half science and half arr. The mistake that 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 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 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 is Valid and ANY seasonal forecast using analogs that is based on ONE parameter is 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.
Just like the last several seasonal forecasts I will use these parameters and in this order of importance
CANADIAN SNOW COVER
IS THERE GOING TO BE AN EL NINO LATER 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 a map of the four different ENSO regions. Officially an El Nino or La Nina event is declared when the SSTA have reached a certain level for a 3 month time period. Usually for El Nino events ENSO region 3.4 are the critical regions.... while for La Nina events it is ENSO regions 1+2 .
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. As I stated earlier the official CPC (climate prediction center) forecast from last winter was heavily based upon the idea 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. Likewise in the Spring of 2003 the development of a La Nina led many forecasters (myself included) into making 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 there will NOT be an El Nino this winter is likely to fail (and badly) in the event that an El Nino event were to develop. Likewise a seasonal forecast which is based upon the idea of an El Nino developing only to see NO development ( or a delayed El Nino later in the Spring of 2004) is also a Winter forecast that just waiting to Bust. Indeed I have seen several forecasts from private weather services to the CPC to weather hobbyists insist back in early September that there is NO chance of a weak El Nino event developing. In fact the data over the last 30 days the data has turned decisively in my opinion towards the idea of a weak El Nino event developing.
CMB'S ENSO REGION 3.4 FORECAST
|ECMWF ENSO 3.4 Forecast||CMB ' FORECAST||SCRIPPS|
|OCT 14||SEPT||OCT||MID OCTOBER||SEPT 30 FORECAST|
As you can see from some of these recent forecasts from various sources... there has been a significant shift over the last 30 days regarding the development of a weak El Nino event during a second half of winter. 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.
Officially Sea Surface Temperature Anomalies 9SSTA) in all four regions are very close to neutral. However over the last 30 to 45 days there has been a slow increase in the warm water in the ENSO region 3. 4. The October reading of +0.8C is the warmest water in that region since last winter. Here are the official sea surface temperature anomalies for regions 1.2 and 3.4 based upon this LINK and this LINK
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. ( w= warm SSTA C= cold SSTA N = Neutral SSTA) http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.html As you can from the CPC table the ONLY periods that match the CURRENT ( December 2002 - October 2003) are the periods of 1958 1978 and to a lessor degree 1979. I have highlighted these periods in Blue and RED.
However a much comprehensive MONTHLY data base of all the ENSO regions -- both SSTs and SSTAs -- can be accessed at this site http://www.cpc.noaa.gov/data/indices/sstoi.indices.
|CURRENT ENSO SEAS SURFACE
TEMPERATURE ANOMALIES (SSTA)
The numbers are SSTs Anomalies in degrees Celsius from JAN 203 to OCT 2003 ;
RED = Negative Values BLUE = . POSITIVE values BLACK near Neutral
|ENSO 1+2 (off
JAN 2003 through OCT 2003
JAN 2003 through OCT 2003
|-0.13 -0.22 -0.50 -1.04 -1.78 -1.80
-1.00 -1.00 -0.90 -0.50
0.80 0.66 0.13 -0.39 -0.20
+0.30 +0.20 +0.30 +0.80
In ENSO regions 1.2 Sea surface
temperatures anomalies were fairly cold in the spring and summer 2003
(weak La Nina) then warmed in SEPT & OCT.
In ENSO region 3.4 sea surface temperature anomalies were rather warm
in January then dropped to neutral levels during the summer and are now warming again in
This is the pattern that we have to look for to see what IF any period in time matches the last 10 months.
The data at that link http://www.cpc.noaa.gov/data/indices/sstoi.indices.
shows that the only analogs that are
1968 1958 1960 1979 and 1969... the BIG 5 as I will call them.
YEARS - WHICH ONES ARE SIMILAR TO THE CURRENT SITUATION IN THE
ENSO REGIONS ?
1+2 (of .Americas)
|ENSO 3+4 EQ.PACIFIC
JANUARY to OCTOBER
THIS REGION IS MUCH MORE IMPORTANT FOR WINTER 2003-04
|1||1958||0.47 0.70 0.59 0.99
0.02 0.53 -0.26 0.25 0.05
|1.91 1.55 1.22 0.63 0.35
0.61 0.26 0.52 -0.51 0.11
|POOR match ENSO 1.2 as JAN -MAY 1958 was way too Positive early 1958; ENSO 3.4 closest match|
|2||1979||0.28 -0.34 -0.23
0.27 0.33 0.39 0.83 0.69
0.46 0.46 0.20 0.05
0.27 -0.24 -0.02 0.86 0.27
|BEST ALL AROUND MATCH IN BOTH REGIONS|
|3||1960||0.08 -0.33 -0.33 +0.74
-0.87 -0.84 -0.45 0.07 -0.69
|-0.03 -035 +0.24 0.15
-0.14 0.00 0.19 -0.01 -0.32
|CLOSE match in ENSO 1.2 ...
CLOSE 3.4 (JAN to JUNE 1960 in ENSO 3.4 was Much cooler than JAN -JUNE 2003
|4||1969||0.27 -0.50 0.40 0.96 1.63
1.28 0.39 0.19 0.21 0.88
1.12 0.84 0.49 0.81
0.60 0.20 0.63 0.63 0.85
|JAN to JUNE 1969 was to Positive
in ENSO 1.2 Much better in ENSO 3.4
|5||1968||-1.31 -1.26 -1.31 -1.38
-1.42 +0.72 -0.09 +0.39 0.25
|-0.63 -0.92 -0.60 -0.41 -0.57
+0.10 0.40 0.44 0.04 0.32
|Closest match in ENSO 1.2 POOR match ENSO 3.4 : Jan to May 68 was way too Negative|
SUMMARY: THE BEST 3 MATCHES ARE 1958 1960 and 1979... WHICH EQUATES TO THE WINTERS OF 1958-59 1979 -80 and 1960-61
HOWEVER a key indicator that helps forecasters understand the coming El Nino or La Nina and its intensity is called the SOI Index. This Link has a brief and basic review of the SOI and for ease of understanding please refer to this Link
The Southern Oscillation Index (SOI) is calculated from the monthly or seasonal fluctuations in the air pressure difference between Tahiti and Darwin. Sustained negative values of the SOI often indicate El Niņo episodes. These negative values are usually accompanied by sustained warming of the central and eastern tropical Pacific Ocean, a decrease in the strength of the Pacific Trade Winds, and a reduction in rainfall over eastern and northern Australia. The most recent strong El Niņo was in 1997/98. Positive values of the SOI are associated with stronger Pacific trade winds and warmer sea temperatures to the north of Australia, popularly known as a La Niņa episode. Waters in the central and eastern tropical Pacific Ocean become cooler during this time. Together these give an increased probability that eastern and northern Australia will be wetter than normal. The most recent strong La Niņa was in 1988/89; a moderate La Niņa event occurred in 1998/99, which weakened back to neutral conditions before reforming for a shorter period in 1999/2000. This last event finished in Autumn 2000.
For our purposes we shall use this LINK as the primary source to see what time periods IF ANY closely resemble the last 10 months of 2003. Generally since last winter the SOI has been Negative but for the most part at a "weak" value with a few brief surges in the SOI into -10 to -15 values. Note that there has only been 1 month in the last 12 with ANY positive values... a feeble +2.9 in JULY. As of OCT 20 the SOI value for OCT is -4.51 and it may end up close to -5.00.
ACTUAL SOI VALUES LAST 11 MONTHS
Looking through the data of SOI values back to 1900.... several time periods appear to have the SIMILAR VALUES AND SOI PATTERN that we have seen in the SOI over the last 11 Months ( NOV 2002 to OCT 2003). The periods that match up closest to the current SOI values of the last 11 months are
1957-58 which leads up to the winter of 1958-59...
1978-78 which leads up to the Winter of 1979-80
1968-69 which leads up to the Winter of 1969-70
1959 - 60 which leads up to a Winter of 60-61
Late in 1994 thru 1995 which leads up to 1995-96. However since late 1995 saw COLDER SSTA develop in ENSO 3.4 and SSTA are currently warming.... 95-96 is dismissed.
|1957||-11.9||-3.5||1958||-16.8||-6.9||-1.4||1.2||-8.2||0.2||2.2||7.8||-3.4||Leading to winter 58-59|
|1978||-2.0||-0.9||1979||-4.0||6.7||-3.0||-5.3||3.6||5.8||-8.2||-5.0||-1.9||Leading to winter 79-80|
|1959||11.1||8.2||1960||0.3||-2.2||5.6||7.8||5.2||-2.3||4.8||6.6||6.9||Leading to winter 60-61|
|1967||-4.0||-5.5||1968||4.1||9.6||-3.0||-3.0||14.7||12.3||7.4||0.1||-2.8||Leading to winter 68 - 69|
|1968||-3.4||2.1||1969||-13.5||-6.9||1.8||-8.8||-6.6||-0.6||-6.9||-4.4||-10.6||Leading to winter 69 -70|
|1994||-7.3||-11.6||1995||-4.0||-2.7||3.5||-16.2||-9.0||-1.5||4.2||0.8||3.2|| Leading to winter 95-96 BUT since
SSTA do not Match at all 95-96 is
WHAT IS THE MEI? ==========>> LINK
Dr. Klaus Wolter of the CDC (Climate Diagnostic Center) has developed a index called the MEI or Multivariate ENSO Index. The MEI is well known within the Meteorological Community. The problem with using just SSTA in ENSO regions 1.2 and 3.4 OR Just the SOI is that those values do not consider the El Nino / La Nina as a whole complex system. MEI measures six main observed variables over the tropical Pacific. (sea-level pressure, zonal and meridional components of the surface wind, sea surface temperature, surface air temperature and total cloudiness fraction of the sky ) .
Dr Wolter argues that the MEI is better for monitoring ENSO than the SOI or various SST indices because the MEI integrates more information than other indices, it reflects the nature of the coupled ocean-atmosphere system better than either component, and it is less vulnerable to occasional data glitches in the monthly update cycles.
The last 2 months has seen a BIG jump in the MEI for the autumn months and he acknowledges that we are getting close to El Nino threshold. Using the MEI data here ====>> http://www.cdc.noaa.gov/~kew/MEI/table.html
ACTUAL MEI VALUES LAST 10 MONTHS
Again carefully going through the table at the LINK provided above -- and I urge YOU to use the Links I have given above to go through the data and make sure that I A) have NOT Overlooked anything B) that I am accurate in my assessment -- and I can only find 3 years that match the CURRENT MEI over the last 10 months.
|1960 (NO match at all)||-0.29||-0.24||-0.09||-0.33||-0.35||-0.27||-0.31||-0.25||-0.51||-0.39|
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 oscillations in atmosphere. The has been a lot of reseach done over the last 10 years that shows the QBO has significant impact of overall climate patterns as well as Hurricane season and winter weather pattern. The period of the QBO oscillation is about (a little over) two years. The QBO has two "phases" with occur within the Oscillation cycle-- the Easterly or NEGATIVE phase and the WESTERLY or Positive phase. Within the forecast literature several prominent private forecasters have often cited the QBO as a key ingredient to figuring out what the winter pattern across North America might be. But alot of the discussion about How and why the QBO is important is rather speculative and fails to hold up to any scrutiny. For example it has been asserted that Winter the Eastern half of the US is often cold and snowier than Normal when the QBO is in Westerly or Positive phase while other 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. Going though the data it is easy to make specious assumptions. For example if one was to look at the QBO phases for colder and snowier than Normal eastern US winters... one might Notice that in the severe winter of 1977 - 78 the QBO was Positive or in the westerly Phase... as was the winter of 1978-78... but the active and snowy winter of 1962-63 had a strongly Negative / east QBO values.
I believe that I have detected a subtle but very important pattern in the QBO data that has been previously overlooked by Most (if not ALL) forecasters.
|WINTER WERE QBO WAS NEUTRAL or WEAKLY WEST / EAST ( +/- 4 to 8.00)||WINTERS WERE QBO SWITCHED FROM NEG TO POSITIVE VALUES IN DJF|
It appears that the timing of when the QBO changes from West / Positive Phase to East / Neg phase and the Intensity of the QBO can have significant impact on the winters across the Midwest and eastern US. In this table we can see that there are several prominent winters which occurred when the QBO phase was weakly (4.00 to 8.50) in the WEST / positive phase OR weakly in the EAST /Negative phase. The winters of the early 1950s saw a consistent easterly phase of the QBO which I think is suspect given the data that is available for researchers to look at . Those winters were not especially cold or snowy but were generally moderate across the Midwest and eastern US. However if we notice from the late 1950s (when the data became much more reliable) into the middle of the '60s there are several winters listed which had moderate QBO in the Positive / Westerly phase and those Winters are generally viewed as colder than normal and significantly snowier than normal for the Midwest and Eastern US.
Furthermore notice the gap between the winters from 1963-64 and 1977 78 -- there were NO winters where that saw weak East or West QBO phases that held through the winter. NONE. Except for the winter of 1969 1970 where the QBO phased changed in Mid winter ... all the winters from 1964-65 until 1976-77... had strong (9.00 or higher) East/Neg. QBO phases or strong West /Pos. QBO Phases. In that period of time MOST of those winter were MILD in the Midwest and eastern US.
Thus it is my assertion that when the QBO stays in the Weak Westerly OR Easterly phase for the ENTIRE winter... the winters in the eastern United States are often colder and snowier than normal. (2002-03 weakly negative 1995-96 weakly Neg. 1977-78 weakly positive... 1957-58 weakly positive)
Indeed looking at the data from the link posted above almost all winters which featured a QBO that was STRONGLY East or West were either not eventful winters for the Midwest and Northeast US OR had a suppressed pattern which favored storm tracks over the central Plains and Tennessee Valley and the lower mid-Atlantic or Southeast states.
As any good climotologist or whether hobbyist can tell you during the period from the late 1960s into the middle 1970s there are a series of very mild winters with a much below normal snowfall across large portions of the Midwest and eastern United States. In fact it was during this time when the snowless winter of 1972-73 occurred.... In fact that winter had a very strong easterly QB0 phase in December which rapidly turned around into the neutral status by February.
In the second column notice that there were several seasons where the positive phase of the QBO switched into the negative phase during the middle and second half of the winter --- 1955 -56 1964- 65 and 1969 1970. Those winters were considered to be moderate winters which featured some areas or periods that experienced SOME temperatures below normal but cannot qualify as particularly severe winters in either in the Midwest or the Northeast US. The two standouts are 1997-98 which was the year of the massive El Nino and 1960-61 which was one of the historically great winters in the eastern US.
CURRENT QBO STATUS
Trying to figure out what the QBO is going to be a very risky proposition and about as risky as trying to figure out what the phase of the NAO is going to predominate during the winter months. It is clear that the current negative phase of the QBO has reached its peak in the month of August and values have started to move back towards zero. However the question remains what the QBO will do during the winter months. One solution is to have the QBO stay Negative right into February / March 2004 .... And if this was the case than Analog year 1979 1980 would become the leading candidate.
Another scenario would have the QBO moving into the NEUTRAL or weak positive phase by early or Mid DEC with the QBO staying in the Weekly positive Phase for the winter... and as I have already shown this will significantly favor a cold and stormy winter over the Midwest & Eastern US.
The THIRD scenario has the QBO switching phase at a slower Place... with the phase change developing in January or the second half the winter... which incidentally is when IMO the weak EL NINO event will start to Kick in.
The climatology of the QBO change in phases is helpful here. The odds are heavily stacked against the QBO reaching Positive values By DEC... since 1953 the vast majority of the time the QBO after reaching its MAX Easterly value took 5 to 6 months to break into Positive values.
1954 east QBO took 7 months to reach positive values from its max Negative value
in AUG -14.53
1955-56 east QBO took 6 months to reach Positive values from its max Negative value in NOV -16.96
1959 east QBO took 6 months to reach Positive values from its max Negative value in June -20.06
1960-61 took 5 months to reach Positive values from its max Negative value in SEPT -16.01
1963 took 3 months to reach Positive values from its max Negative value in MAY -24.18
1966 took 4 months to reach Positive values from its max Negative value in -21.90 JAN
1968-69 took 7 months to reach Positive values from its max Negative value in -21.82 NOV
1970-71 took 4 months to reach Positive values from its max Negative value in-22.48 NOV
1972-3 took 5 months to reach Positive values from its max Negative value in-21.17 OCT
1974-75 took 6 months to reach Positive values from its max Negative value in -23.32 OCT
1977-78 took 6 months to reach Positive values from its max Negative value in-21.67 JUNE
1979-80 took 6 months to reach Positive values from its max Negative value in -23.32 OCT
1982 took 6 months to reach Positive values from its max Negative value in -16.67 MARCH
1984-85 took 6 months to reach Positive values from its max Negative value in -27.90 JULY
1987 took 3 months to reach Positive values from its max Negative value in-21.57 JUNE
1989-90 took 4 months to reach Positive values from its max Negative value in -21.30 MARCH
1992 took 5 months to reach Positive values from its max Negative value in-17.79 APRIL
1994 5 months to reach Positive values from its max Negative value in -28.65 JULY
1996-97 took 5 months to reach Positive values from its max Negative value in -26.02 AUG
1998-99 took 4 months to reach Positive values from its max Negative value in -24.70 AUG
1999-00 took 5 months to reach Positive values from its max Negative value in -24.45 JULY
Thus with the current East QBO having reached its maximum value in August it seems that IF we assume an average time of five or six months... than the phase shift would occur in January... NOT December . Of course there have been SOME instances where 3 or 4 month time period has shifted the QBO into the West phase so there is SOME Support for a faster turnaround. But as of this particular time the situation remains unclear and I can only use the climatology of the QBO to estimate when the changes going to be.
Thus my second critical assumption here is that the QBO is going to change phase in January. If the changes to WEST occurs in December and remains in the Weak Westerly phase through the winter than the odds of a significantly colder and stormy winter would be much higher for the Midwest &Northeast. Likewise is also possible that the QBO could stay strongly negative right into January which what I can favor the 1979 -- 80 winter pattern.
The climate models going into the winter 2003-04 are not looking nearly as promising as last years Climate Models. Last autumn the atmospheric general climate models or AGCM accurately forecasted a large area of below normal temperatures across much of the Midwest and the Northeast United States. That model picked up on the cold pattern in July 2002 and as we move closer to the winter the cold increased so that the last run of the AGCM before the winter-- November 2002 -- showed a very cold winter setting up for the eastern half of the US and Canada. For portions of the Upper Plains and the Midwest the AGCM Busted as the model depicted too much cold air too far to the west ... but in terms of the overall pattern and the intensity of the cold air in the eastern United States the autumn2002 AGCM get a very good job.
If we look at the last few runs of the AGCM for 2003
we see the exact opposite trend. The July and August AGCM showed large
areas of cold temperatures across the Midwest and Northeast and Southeastern Canada but as
we have move closer to the event the AGCM continues to show last last cold air. We can see
this by comparing the September AGCM to the October AGCM.
Thus if one were to make a Winter forecast based simply on the AGCM -- which would be really a stupid idea--- than the winter forecast would feature Much less cold and one would have to forecast a rather normal winter across most of the continental United States.
My experience shows however that the new long-range GSM has been doing a much better job with climate forecasting than the AGCM. The last several runs of the GSM shows a very cold pattern indeed for the central eastern US as well as eastern Canada during the winter months and a fairly strong ridge along West coast. At first glance it appears that this is a classic +PNA pattern... however the last few runs of the GSM continue to place the center of the cold air further and further south and deep in the trough over the eastern US to the point that it now poses a mean pattern which might take potential with the storms OFF the East coast of US and out to sea.
AUTUMN PATTERN 2003 SO FAR...
Recent research within the journal of climate has shown that the patterns which set up in October and November can often but not always the precursors to what the general winter pattern will be like in North America. Certainly this was true for the last few winters. For example last winter we saw a very active and cold October and November with several systems moving up East coast and that pattern continued right into the Winter of 2002-03. Likewise in the record warm winter of 2001 -- 02... there was a consistent zonal flow with no pattern amplification no cold outbreaks and very dry conditions throughout the month of October and November in the CONUS with no significant low-pressure areas developing anywhere in the Midwest or on East coast. Once again we saw that pattern continued into the winter months and we ended up with the record warm and dry winter. Another example of this idea generally working out he is the winter of 1995 1996 when again there were several systems that moved up East coast of United States during the autumn and that pattern continued to the winter.
In this regard is sometimes useful to look at the overall hurricane season and see what if any clues might be given by the pattern of the hurricane activity as well as what we are seeing so far halfway through autumn 2003. But one must be careful with this and NOT read too much into it.
The hurricane season of 2003 featured numerous Cape Verde systems - tropical ways and tropical depressions -- that failed to develop into significant Tropical Cyclones for the most part. There were two notable exceptions -- Hurricane Fabian and Hurricane Isabel. As the map shows most of the hurricane activity occurred in the Tropical and subtropical Atlantic which is why the Track of Isabel is such a standout. We can clearly see that MOST of the TC activity recurved to the East of the 65 degrees Longitude line.
In considering our analog years we can see that the season of 1960 and 1979 shows almost no similarity to the hurricane season that is now coming to a close. In the 1958 hurricane season we can see more of the recurvature that is similar to the 2003 hurricane season but by far away the Best match appears to be the hurricane season of 1969.
So far this season we have seen several attempts by the medium-range models to develop a large and powerful ridge on the West Coast and subsequently a rather deep and cold trough over the Eastern Half of the US. This has brought about comment from several meteorological sources as well as weather hobbyists that this AUTUMN (2003) is "just like last autumn" when of course that is utter nonsense. Only in the Northeast US are temperatures resembling anything close to what we saw in October 2002. The Plains states which in 2002 experience one of its coldest Octobers in the last 50 years has seen day after day of Much above temperatures in the 85 to 90 degree range. The snow cover is DRAMATICALLY LESS than OCT 2002..
In addition we have seen a very strong Pacific Jet stream develop that has bought in heavy rains and much-publicized flooding into far northwest Washington state as well as large portions of British Columbia. The development of the Pacific jet is going to be a problem for the first half the winter . Over the last 45 days we have seen system after system initially forecasted by the medium-range models to move to certain position or location.... Only to see that later model runs shift to the trough/ low or ridge further to east with subsequent model runs on a steady progression. For example in the last week of OCT 2003... there will be a major trough and surface Low developing over the Deep South and Midwest . Originally this is system was depicted by the medium-range models on the October 20-21 to form a closed off Low in the Upper levels of the atmosphere in MO or lower ILL. Instead we have seen a consistent shift with this major trough and surface Low so that it now looks like the system is going to form well to the East of the Mississippi River. In my opinion it is this shift towards the East which is going to be a problem with the Medium-range weather models all winter and is a common byproduct of having a active and strong Pacific jet stream.
AUTUMN SNOW COVER
IN N. AMERICA
Lastly there is the issue of Canadian snow cover. Sometimes the point about the Canadian snow cover gets overlooked... my experience has been that when Canadian snow cover is around the norm is not really a particular issue. However there are winter seasons where the Canadian snow cover has been significantly above or below normal and as a result the production and sustainability of the Arctic air masses becomes problematical.
To be sure there have been winter is where the snow cover into the Month of OCT has been below normal and still turn out to be colder than normal and snowier than normal winter and likewise there had been Months where the snow cover the month of October and Canada was Above normal and its turn out to be a WARM or mild Winter. Case to in point the winter of 2001-02 when the October snow cover was 17.9 which is very close to the Mean of 17.5 billion square KM. Or 1998 -99 when October snow cover was well above the mean at 18.9! However the general rule is that Autumn Months which are running Above normal in the snow cover in October and November generally have colder and snowier than normal winter's across the Midwest and Northeast.
Since the data for October and November is not yet in old I have to wait until the late-season update at the end of November before I can make a final the determination with regard to the Canadian snow cover issue. And because there are so many exceptions which prove the rule here I give this factor the least importance
NORTHERN HEMISPHERE SNOW AREA (Millions of Square KM) 12
J F M A M J J A S O N D MEAN
1973 45.0 45.8 39.2 30.9 19.9 11.4 5.2 4.0 6.2 17.3 36.5 43.3 25.4
1974 44.9 43.8 39.8 31.5 23.3 11.9 5.2 4.1 4.7 19.4 31.3 38.8 24.9
1975 43.9 43.7 40.2 31.5 20.4 10.6 5.1 3.6 5.2 17.0 31.4 41.3 24.5
1976 44.5 44.3 40.9 30.8 22.5 14.3 6.6 4.4 6.3 27.3 33.8 41.3 26.4
1977 48.1 43.3 38.6 29.8 19.7 11.5 5.8 4.1 7.8 19.4 30.5 43.4 25.2
1978 48.5 50.2 42.4 29.2 22.7 15.0 7.7 5.6 7.4 18.5 32.4 43.5 26.9
1979 48.8 46.7 42.9 34.5 22.3 11.1 6.5 4.6 5.7 14.2 27.9 36.9 25.2
1980 44.5 46.5 41.1 33.6 20.3 10.2 5.3 4.7 5.4 14.1 31.9 36.2 24.5
1981 41.3 42.9 42.2 33.2 21.6 13.3 6.1 4.8 4.5 16.2 33.9 43.0 25.3
1982 47.5 45.2 40.1 31.1 18.3 9.3 3.6 3.2 6.2 19.6 34.0 42.6 25.1
1983 46.0 46.1 40.1 30.2 21.3 10.8 4.6 3.8 5.5 17.9 31.7 43.5 25.1
1984 44.9 43.8 40.1 29.6 17.3 7.3 3.6 2.7 4.1 16.4 32.8 41.5 23.7
1985 48.1 46.5 42.4 31.8 21.8 12.4 4.9 3.2 4.5 18.0 39.1 44.6 26.4
1986 44.7 46.1 38.2 30.4 20.0 10.4 4.4 3.2 6.1 17.1 34.0 40.2 24.6
1987 46.3 44.8 42.7 29.7 17.8 12.2 5.5 3.1 4.8 13.5 32.5 41.7 24.6
1988 46.8 44.2 38.7 27.4 18.8 7.8 3.6 2.5 4.3 13.1 30.6 40.2 23.2
1989 44.8 43.2 37.8 28.8 18.1 9.2 4.2 2.6 6.2 16.5 33.0 43.9 24.0
1990 44.6 43.0 36.5 27.3 16.3 6.4 3.3 2.6 3.9 14.7 29.7 43.9 22.7
1991 45.1 44.6 38.1 28.4 18.7 9.9 4.1 3.4 4.5 16.7 34.6 41.7 24.1
1992 44.9 42.2 37.7 28.1 17.7 10.0 3.9 2.8 5.3 16.2 34.3 44.6 24.0
1993 45.6 44.2 39.3 27.7 18.0 8.2 3.7 2.8 6.0 18.8 37.7 42.7 24.6
1994 44.1 44.7 38.1 28.2 18.5 9.3 4.0 3.1 4.9 14.5 32.2 42.1 23.6
1995 45.2 41.8 37.4 32.2 19.3 9.5 4.1 4.0 6.5 17.2 33.3 43.5 24.5
1996 46.0 43.9 40.5 32.8 20.3 10.5 4.4 3.0 6.7 19.7 35.5 40.6 25.3
1997 45.3 44.1 37.8 31.1 19.7 9.5 4.8 3.9 6.7 17.4 34.9 43.1 24.9
1998 44.7 43.5 40.7 30.0 17.8 9.4 4.3 3.5 5.1 18.9 34.1 42.3 24.5
1999 43.3 42.6 38.9 29.1 18.3 8.2 3.1 2.3 5.1 18.0 33.2 42.1 23.7
2000 46.4 43.8 38.0 27.7 18.6 9.1 3.0 2.5 7.0 17.8 34.7 43.1 24.3
2001 45.3 43.8 39.0 28.3 16.4 7.4 3.0 2.3 5.7 17.9 31.1 44.0 23.7
2002 44.9 40.9 35.5 29.4 18.2 8.1 2.9 2.5 5.4 23.0 35.5 44.5 24.2
2003 46.3 46.5 39.7 30.7 19.4 9.3 2.8 2.2 4.7 .0 . 0 . 0
MEANS 45.5 44.4 39.5 30.2 19.5 10.1 4.5 3.4 5.6 17.5 33.3 42.1
STD DEV 1.6 1.8 1.8 1.9 1.8 2.0 1.2 .8 1.0 2.8 2.3 2.0
WINTER 2003 - 04
1. Weak El Nino develops by DEC that begins to affect the overall pattern in Mid January.
2. QBO will continue to rise and reach Neutral levels by Jan 2004 and Positive levels in MARCH
3. Snowcover will reach slightly above normal Levels in NOV in Canada.
4. Pacific Jet will be active and strong all winter but especially first half of Winter.
5. JAN 15- MARCH 20 will be colder and stormier East of The Mississippi River then DEC 1-JAN 14
6. Middle DEC significant snowstorm over central Plains Lower Midwest/ Tenn. Valley VA NC Lower MD
THE MAPS This forecast will be update NOV 25-28