SPRING 2006 FORECAST
Springtime conditions across North
America in 2006 are going to be dominated by three very important features.
1) the dominating Drought which has developed over the lower Plains into the Mississippi Valley and the WCB over the last several months.
2) The current La Nina event which developed during the middle portion of the winter...
3) The shifting QBO winds... from the extreme negative of east values we of DEC / Jan towards neutral value by late spring and the Summer. .
As a general rule WxRisk.com does NOT like to forecast extreme events and I go out of my way to downplay mass media hysteria by taking a position of "scientific skepticism" when others are forecasting possible Major or Extreme events that could develop. However that does not mean given the right circumstances I will NOT forecast major or catastrophic hurricane... severe blizzard.... or a prolonged drought. It is just that I have to be very certain before I start sounding the "alarm". That is why I urge you to read the summary section with a great deal of care so you understand exactly what my position is as we move into March 2006.
I am NOT forecasting a Midwest drought -- yet. BUT if the rains do not show up in April and May 2006 for the dry areas of the WCB I will do so..
research shows that of the last 10 major droughts in the Plains and Midwest eight of them have occurred in La Nina events. It is still too early to forecast a significant Drought over the Midwest regions but the central & lower Plains are in serious trouble this growing season. There is still the chance that significant rain could fall over portions of the Midwest during the months of April and May which could alleviate the dryness and early drought conditions which have developed over the last several weeks ....especially over the WCB. However if the needed rains do not develop and we continue to run into a dry pattern in the Spring 2006.... as we move into the heart of Summer the probability of a significant drought over the Midwest would be dramatically increased.
These next serious map represents the expected conditions over the spring season in the lower portions of Canada and the continental US.
MARCH 2006 -- will feature a major trough over the western US during the first 10 to 14 days with much below normal temperatures and excessive precipitation in California... the Pacific Northwest... and well inland... while the lower Plains and Deep South generally run quite warm. There will be some cooling the second half the month with good rains over the Midwest and Atlantic states.
APRIL 2006: right now most of the data is showing the mean trough position over western Canada and the Pacific Northwest which strongly implies Above normal temperatures and dry conditions from the lower Plains into Kentucky & Virginia as well as all areas of the Deep South. Portions of the upper Plains and Great Lakes could see a pretty rainy month.
MAY 2006 --obviously with MAY 2006 being the third month of the the forecast period the reliability is somewhat diluted. But most of the data is showing a pretty strong ridge High-pressure over the Western US and a pretty deep trough along and just off the immediate US East Coast. This implies a warm and dry pattern for the Rockies and Plains and pretty cold & stormy pattern for the East Coast... and cool and dry for the Midwest.
CLICK ON THE MAPS TO ENLARGE
|MARCH JET STREAM||APRIL JET STREAM||MAY JET STREAM|
|MARCH TEMPS||APRIL TEMPS||MAY TEMPS|
|MARCH RAIN||APRIL RAIN||MAY RAIN|
METEOROLOGICAL REASONING ( in non technical terms)
Many of you have heard of the old adage that ...."drought begets drought...". Interestingly this is one of these
older farmer's almanac weather tales that has some very serious and sound
meteorology behind it.
What happens without getting too technical is that a persistent area of very dry or Drought conditions leads to a hotter and dry pattern because the dryness of the ground allows warmer than normal temperatures to radiate from the ground into the atmosphere. This heat rises into the middle and upper levels the atmosphere which in turn can feed an area of HIGH pressure in the upper atmosphere (if one happens to be around). In this way the hot dry / drought areas end up reinforcing any High-pressure ridges or Heat Domes that might be in the area. This is a referred to as a feedback process... and it also applies in the opposite way as well. That is to say very wet and / or soggy areas can end up reinforcing troughs or Low-pressure areas that that area.
Over the last few years we have seen a persistent deep long standing DROUGHT over the western portions of the CONUS. All I have to do it is briefly mentioned the extremely dryness and active forest fire seasons they have seen over the Rocky Mountain states in the last three summers and I am sure you will recall how hot and dry it has been over the western third of the US. These extremely dry conditions developed because of a series of rather cold Winters and Springs over the eastern and central US which produced normal to above normal snow/ rain and below normal temperatures in those areas. However over over the western US this same weather pattern resulted in series of very warm and dry winter's in 2002-03 2003-04 and 2004-05 .
The Drought monitor maps which are produced every Tuesday afternoon from the USDA clearly show the effective of the Drought in the last three Winter / Spring season's over the western US. This first series of maps dates back to 2004 and as you can see during the winter months of very dry conditions developed over the Western Us... from the Rockies to the West Coast. It is very important to note that over most of the Winter and Spring months the VERY dry or drought conditions never really move and stay deeply entrenchment over much the same location from late February into early Summer.
Consider the 2004 season. From FEB 24... MARCH 30... APRIL 24... and MAY 25... note that there was very little movement in the extreme dry conditions over the Great Basin and Rocky Mountain regions.
Taking a look at the 2005 growing season we see the same sort of thing. Very dry conditions continued right through the winter and into the early Spring-- see FEB 22 map. By the middle of April the drought area again had not really shifted... and by the middle JUNE... there was some easing of the very dry conditions over the Rockies with a secondary dry area developing from the Delta into the Mississippi Valley.
However over course of this past Winter of 2005-2006 there has been a fundamental shift in the overall patterns across North America which has resulted in the super dry conditions of the last several years over the western US coming to an abrupt that have now been replaced by abundant and indeed excessive moisture over the entire western third of the nation. The Map from NOV 1 shows rather dry conditions over the northern Rockies with a second and dry area over the Deep South. However by the end of January the dry areas over the western US were now completely gone and very dry conditions to developed over eastern Texas eastern Oklahoma portions of Arkansas and with lighter Drought conditions over the WCB.
The fact of that matter is that for many locations the last several months in the western US have reported record or near record precipitation. It was the rainiest October on record in Portland and Seattle as well as the rainiest November the wettest January and one of the wettest February. Snowfall levels have exceeded many records over the mountains of the Cascades and the Sierra Nevada's on the West Coast as well as the Bitterroot Mountains in the Pacific Northwest... the Wasatch... the Rockies and the Great Basin. It is no wonder then that the very dry conditions we have seen all the last several Winter/ Spring over the western third of the US has now ended.
The drought maps of February 28 continues to show how unbelievably dry it has been over the lower Plains and the western portions of the Delta during the last few months. It is the driest winter on record for many locations in Texas Oklahoma Arkansas the southwestern states and the western Louisiana. The very dry areas have expanded into the central Plains and WCB and among the 10 driest winter on record over KS eastern COL western ARK and western MO.
I cannot be emphasized enough how fundamentally different this Spring's Drought map is when compared to what we've seen all the last three or four years. The dryness of the western US is gone and has been replaced by excessive dryness over the central lower planes and portions of the WCB. Therefore it is bizarre to suggest that with a fundamentally different Drought map we are going to end up with the same sort of excellent weather patterns we have seen over the last 2 growing seasons in the US. The fact that this drought map is so fundamentally different from looking seen all the last three or four years strongly indicates that the weather pattern we are going to see this Spring /Summer 2006 could be fundamentally different from what we have seen over the last three or four years.
Indeed the placement of the extreme Drought conditions over the eastern portions of Oklahoma in Kansas with a moderate drought conditions pushing up into the Mississippi Valley Nebraska and the WCB strongly suggests that unless there is significant rain coming in the months of April or May that this hot dry area is going to act like anchor and become a feedback mechanism for the position of High-pressure ridges... much like we have seen over the past 3 years in the Rockies. However this time around the dryness in the central portions of country could end up affecting or increasing the the over the central US.
THE DROUGHT RIGHT NOW
As you can see as of MARCH 1 the Soil Moisture anomaly was very impressive.... this map shows 100 to 200 % below Normal moisture over central and eastern TX into ARK eastern OK MO ILL eastern KS and Lower IA.
This next map show what the SHORT TERM drought OR wetter than normal conditions are based upon the various climate zones of all 50 states based on the past 3 months. AS you can see many of the climate zones over the SW states are at D3 and D4 ( drought level 3 and 4) .... with more D3 and D4 over eastern OK eastern KS western MO... and D 1-2 over the Lower WCB .
This Map is the LONG TERM drought map for the various Climate zones based on the last 1-2 years... and as you can see the long term conditions over the Delta .... eastern RX eastern OK into the LA MO and IL show very dry conditions.... this map means that should there be a problem with getting even "normal " rainfall in these areas these regions could slip in D3 and D4 on the weejkly drought monitor maps.
THE LA NINA EVENT
Here are some good Links for Traders who need a basic understanding. La Nina
The La Nina event --cold water along the equatorial Pacific --is the opposite of El Nino -- warm water along Equatorial Pacific. see Map
Over the last 10 years our understanding of La Nina and El Nino events have greatly improved. El Nino and La Nina events come in all different shapes and sizes... strong events moderate event and weak events. These events are centered in two distinct areas --- see the map above. These regions are 1.2 ( the WHITE box off the coast of Peru on the map above) and region 3.4. (the Yellow and Red box).
The Current La Nina developed over the winter. As it turns out WXRISK.COM was the ONLY well known private forecast company that CORRECTLY forecasted the development of the La Nina event.
If were consider the WINTER 2005-05 for a moment.... we quickly realize that a MUCH drier than Normal pattern has developed over the Lower and central Plains.... Much below Normal temps over the Pacific NW.... excessively went over the western US ... few in any Major winter storms ... NO deep prolonged cold patterns .... warmer than Normal temps for much of the US (winter 2005-06 was the 5th warmest winter ever !!!)
Now as you look at this Link.... How La Nina affects WINTER weather note that from this map you see almost EXACTLY what we experienced this winter! In other words the Winter of 2005-06 was a a classic La Nina winter
If we go on the assumption that the weak to Moderate La Nina is going to last into the SUMMER 2006 months of JJA... then we can get sense of what the overall pattern COULD look like. These two links show what typical La Nina SPRING & SUMMER patterns looks like --How La Nina affects SPRING and How La Nina affects SUMMER . Not that there does NOT does not seem to be a lot of hope of getting a very wet Spring and / or Summer. The TYPICAL Spring and Summer patterns from La Nina show above normal temps and dry conditions over the WCB.
Rather than bore you with a bunch of weather model Jargon let me assure that the overwhelming amount of weather / climate model data shows that the La Nina will continue into Mid Summer at least.
LONG RANGE CLIMATE MODELS FOR SPRING AND SUMMER 2006
Wxrisk uses a lot of climate models in making the seasonal forecast some of which are also used by other meteorologists but many of then are not. Two of the best climate models are the GERMAN CLIMATE MODEL which covers the Northern Hemisphere out to 4 months and the CAS or Soil moisture Model. This Model is run by the Climate Prediction Center -- CPC -- and is run every few days out to 6 months.
Briefly both of these long range climate models did an outstanding JOB this past autumn in correctly forecasting this winter. While may private weather forecast companies forecasted a severe winter that drove up the energy markets on wild speculation these climate models correctly forecasted that ONLY DEC 2005 would be a cold month over the East US and that a severe drought WOULD develop over the central and Lower Plains over the winter.
GERMAN CLIMATE MODEL FOR SPRING 2006
The Green line which I have
superimposed on these three maps represent the mean jet stream position
around the various High and Low pressure areas that the German climate
model each depicting. In the month of March climate model is depicting
blocking pattern over southern Greenland which would tend keep a trough over
the Eastern US ... colder temps.... and a weak Ridge over the West coast .
This pattern would tend to keep the Plains very dry and allow some rain
events over the ECB.
The German Climate model for APRIL 2006 shows a massive trough over western Canada into Alaska with a Ridge of HIGH pressure over the Eastern Third of the CONUS. This sort of pattern keeps the Pacific NW and Northern Rockies cold and excessively wet and eastern US warm & dry. The storm track would keep major rain events away from the Plains and Midwest.... with systems tracking Northeast into from say MT to Manitoba and the western Great Lakes.
The German Climate model for MAY 2006 shows two Ridges -- one on the West coast and one on the East coast and weak trough over central Canada . This sort of pattern COULD BRING normal rainfall events to the Upper Plains and WCB.
|MARCH 2006||APRIL 2006||MAY 2006|
CAS MODEL FORECAST FROM THE SPRING
By far away the most accurate of the
the climate models in the past few years has been the CAS or the soil moisture
Climate model. This model is heavily based upon the current soil moisture levels
combined with the climatology of what has occurred from similar events in the
Each for these maps has two panels ... the Upper maps is the temperature forecast and the bottom map is he Rainfall forecast.
This first map shows in April of 2006 above normal rains for portions of Kansas and Nebraska and slightly above normal over the WCB... and much above normal temperatures over most of the eastern Plains the Delta and of the entire Midwest. The second map which is May 2006 shows a very cold pattern east of the Mississippi River.. very warm over the Southwest with extremely dry conditions over most of the Plaines from the Dakotas and down into Southwest Texas. Note again that there are no areas on either the April or the May soil moisture models which show above normal rainfall over the Midwest
. The third map which is June 2006 shows a rather chilly Pacific NW but near seasonal temperatures over the rest of the US.... and very dry conditions over the entire Lower Plains from eastern COL to TX. Note that the Model does show a slightly above normal rainfall over Iowa but most of this region is over the Great Lakes not Midwest.
Finally in JULY of 2006 which is LONG way off and so this Model should not be relied upon too heavily ... shows very HOT western US and very cool East coast near Normal temps over the WCB and central Plains. Note again the VERY dry forecast for all of the Plains from TX to Canada and into Much of the WCB! Once again Please note that this model still does NOT show any areas of above normal rainfall over the Midwest.
IF THE LA NINA LASTS INTO THE SUMMER... WHAT DOES IT MEAN?
As we take a look into the Summer of
2006 the absolutely critical question is going to be whether or not the ongoing
La Nina continues into what the Summer or whether it will falls apart. As you
can see from these next set of maps the impact of La Nina over the central
portions of the US during the late Spring and Summer months is VERY significant.
As I stated earlier since 1900 .... 8 of the last 10 droughts that have occurred
over the central US have done with so with La Nina conditions in place.
Each of these diagrams have SIX set of maps for your consideration. The LEFT hand side refers to Temperatures the RIGHT hand side refers to Rainfall. The first row refers to El Nino events... the second row is for La Nina event and the 3rd row is for Neither .
This first map refers to the period from May June and July and if we look at the second row which is the La Nina maps
out of 12 previous La Nina events.... the Midwest experienced near normal temperatures with the Plains seeing slightly above normal temperatures. However the main point here is the Rainfall during La Nina event... Notc that it shows a huge area of a much Below Normal Rain fall at least centered over the central Plains and the entire Midwest in the period of May June and July. This map clearly shows the impact of why La Nina events often bring about drought conditions over the Midwest and portions of the Plains.
This second map refers to the period from June July & August . Once again looking at the second row which is the La Nina maps.... temperatures were running about + 0.50 to +1.0 above normal over the Midwest and the Upper Plains.... with another very strong signal for below and much rainfall over the heart of the Midwest .
This third map refers to the period July August & September.... Once again looking at the second row which is the La Nina maps.... temperatures were running about a half a degree above normal over the Midwest and most of the Plains.... with another very strong signal for below and much rainfall over the heart of the Midwest
Finally there is a new
experimental climate model which is being run by the CPC and is heavily based
upon the current soil moisture as well as the short long-term drought pan
indicators. These maps are pre-self explanatory. These first to maps in this set
cover the expected Temperatures and expected rainfall for the period July August
As you can see in the June Jul Aug period there are no strong signals for temperatures running Above or below normal over much of the Plains and Midwest... but the Bottom map shows a strong signal...60% chance ...of seeing near normal temperatures over the Midwest and Upper Plains. The second man here shows map is rainfall for JJA ... what a strong signal for below home rainfall over the WCB and Great Lakes as well as the western US.
The second set a maps here refers to the period July August September began with the first mapping temperatures the second at being precipitation. As you can see there is a very strong signal above normal temperatures over all of the Plains and the Midwest based upon the current trends ... with a secondary chance for near normal temperatures over the central Plains an to the WCB. Note there is almost no chance whatsoever of any portion of the Plains or the Midwest seeing Below Normal temps if this Summer and this is due mainly to the very dry conditions which have of already developed.