MY VIEWS ON NEXT 7-10 DAY IN US GRAIN WX
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Started by wxdavid - July 12, 2020, 10:29 p.m.

My view is that the various weather models are not in good agreement with regard to the specifics of what's going to happen with regard to agricultural weather in the Plains and the Midwest over the next two weeks. But they are in agreement with the overall General pattern.

  2-day rainfall == Friday to Sunday



 As I stated last week the key feature here is a large trough with an embedded  UPPER LOW that is swinging through western Canada and across the Canadian prairies into Manitoba. This feature is fairly strong and it will drive a cold front southward into the Plains and the Midwest over the next few days. The position of this cold front during the next several days is going to be critical and determining what happens with temperatures and rainfall between now and July 24.


 The operational GFS model is most bullish or aggressive with this cold front driving it deep into the Plains and the Midwest. This in turn forces the heat Ridge or dome which everybody was talking about last week to be suppressed further to the South.

As a result large portions of Ohio Illinois Indiana Kentucky eastern Iowa southwest Wisconsin sees anywhere from 0.5 - 2.5 “/ 12-60mm of rain according to the GFS model. Lighter rains of 0.25-1.5”/ 6-38mm  cover 50 to 60% of Nebraska eastern South Dakota and much of Minnesota. Let's be clear about this   The reason  WHY  the  GFS has so much rain  Sunday afternoon run is because it drives  a cold front deep into the Midwest and the central Plains during the next  7 days.

In the 6 to 10-day the  GFS model has a band of 1-3”/ 25-75mm   rains across central and eastern Nebraska into much of western and central Iowa and then into west-central Illinois. This is where the front is located so the model produces significant showers and thunderstorms right along the frontal boundary.  South of the front is where the heat …  while to the north of the front it is much cooler with temps in the 70s and low 80s.


Not surprisingly with the cold front that far to the south the temperatures are much cooler on the GFS model. For example over the next 14 days Des Moines Iowa does not go above 90 degrees on the GFS model. Neither does most of Illinois Indiana Ohio. Temperatures do reach 95 to 105 degrees in the western and central Dakotas..  western and central Nebraska ...all of Kansas Oklahoma Texas   and the southern half of Missouri and all of Arkansas.



 That is not the only viable solution however. Because the GFS loves to develop big troughs  like this in the jet stream it ends up pushing cold fronts too far to the South which during the summer months produces a lot of rain.


 The operational European model is the exact opposite. It is a blowtorch showing days and days of extreme heat in the heart of the Midwest. On July 16th the   Euro has  95 degree isotherm along the Kansas Nebraska state line and through central Missouri down into southern Tennessee. However, by 17 July   95 degrees is in central Iowa and along the South Dakota Nebraska border as well as central Illinois. St Louis is 98 Springfield  96  and Indianapolis 94 degrees on the European model. Over the next several days the European model shows 95° + as far north of Chicago and Rockford.   . And it shows an impressive stripe of 100-plus degree temperatures from eastern Colorado to St Louis and as far east as Evansville and this heat on the Euro last through July 22nd.

 



Why is the European model so hot?

. Because the cold front does not come as far south and so the Heat Ridge is not suppressed to  the South. This means that the cold  front is further to the north so the temperatures are much hotter south of the front. Indeed the European model rainfall over the next 5 days shows 0.5 -1.5”/ 12-38mm  n with locally higher amounts covering 50 to 60% in the Nebraska Iowa Minnesota and Wisconsin and  much less rain in Indiana Ohio Illinois and Missouri.


Not surprisingly in the 6-10ay all the rain on the European model 1-- 1-2”/ 25-75mm   with  60 to 70 %   coverage is  in  North Dakota South Dakota southern Minnesota and much of Wisconsin but nothing in the Nebraska Iowa Illinois Missouri most of Indiana or Ohio.


WHAT DoES   THIS ALL MEAN?


  •  There is going to be an important cold front which is going to come south of the end of the week then stall somewhere across the Plains and the Midwest in a more or less W to E direction  ( wnw to see ).  
  • This front  is going to play a huge role in determining who gets the rain ...how much... and what sort of temperatures there  to  south of the front and north of the front. 
  • The temperature contrast either side of this front will be huge. South of the front 95 to 105 is quite possible. North of the front temperatures stay 75 to 80 degrees probably with some rain.


 the GFS Ensemble however shows a BIGGER   heat ridge further north. It has temperatures in Des Moines getting to 92  degrees   95 in St Louis and Kansas City and 103 in Grand Island Nebraska on July 17th.   Temperature stay like that with readings in a low to mid 90s  in central and southern Illinois ...the southern half of Iowa into South Dakota right through July 25.   And it even has temperatures above 105 degrees and portions of south central Nebraska much of Kansas and Oklahoma.


There is still some decent rain in Iowa Illinois Indiana southern Minnesota and Wisconsin over the next five days on the GFS Ensemble but 6 to 10 day has that rain shifted into Indiana Ohio and Kentucky western Illinois Iowa Missouri Nebraska Kansas South Dakota are all fairly dry if not completely dry.


The European ensemble is pretty close to the GFS ensemble. It has 0.5 to 1.5" /12-38mm  rains along the Minnesota Iowa border across the South Dakota Nebraska border ...right into  Chicago and Wisconsin into Michigan and Ohio. Everything south of that is dry and it's hot.


Interestingly  the Canadian model is much closer to the European model in that it has a lot less rain over the heart of the Midwest and all of its rain in the 1-5  day and  6-10  day is further to the north much like the European. It also has temperatures in the low to mid-90s  in all Nebraska much of Iowa into central and southern Illinois and southern Indiana starting on July 18th and continuing through July 22nd.   It also has 100 + degree temperatures in central Nebraska Kansas Southern and Central Missouri and Oklahoma.

 The Canadian is a pretty good compromise of all the model data.


 SUMMARY

clearly the risk, if the GFS model is correct, is that there IS going to be more rain than what the forecast had last week  for portions of the Midwest. This is a high-risk forecast for the next 7 to 10 days.  If the front is further to the north like the European in the Canadian models then much of the Midwest will not   see a lot of rain and  it will see a lot of heat. But the GFS model could be correct .  The RISK  is that if the GFS model is correct then the threat to the corn crop is going to be reduced. The bust ability--  the risk of the forecast that you are counting from any source  .. me  … anyone being wrong is pretty high. A difference of 75 or 100  miles on this front is  going to have huge implications after July 16th.


 even if the GFS models are correct there is still going to be a lot of heat and not a lot of rain in Nebraska … South Dakota ...Kansas and central and southern Missouri. I am not an agronomist so  I am not going to tell you how much of the Corn is grown there or what condition  it is in but again even if the GFS model is correct for the next two weeks those areas are going to take a beating with this heat and lack of rain.

Comments
By metmike - July 13, 2020, 12:32 a.m.
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Top notch post Dave!


Much appreciated. 

And I agree completely with your forecast philosophy!


For those not aware of it, Dave is a meteorologist that runs a private weather service for paying clients and is sharing some of that information with us.

By cutworm - July 13, 2020, 6:46 a.m.
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Thanks David

By hayman - July 13, 2020, 9:02 a.m.
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Monsieur DAVID WX Sensei,

Breathtaking presentation of nature's atmospheric dynamics, Sir.  Interpretation as relates to grain futures price trajectory is given foundation with your eloquent rendition of weather science.  Apologies for my harsh response to prior posting.  Which in fact, was bullseye correct in terms of the decline of grain price subsequently.  In other words, you were right on target.  I am not worthy, but grateful indeed for your attendance here at Met Mike's forum home!


For the record, long one Kansas City September wheat and long one Christmas Soybean Meal.  Both still profitable, but both drained of much of the profit left unrealized just a few days ago.

By bowyer - July 13, 2020, 9:12 a.m.
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Thanks for the post !

By wxdavid - July 13, 2020, 10:22 a.m.
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 DUDE   thansk for the kind words.

Its Just SCIENCE.  Its for everyone !!!


Monsieur DAVID WX Sensei,

Breathtaking presentation of nature's atmospheric dynamics, Sir.  Interpretation as relates to grain futures price trajectory is given foundation with your eloquent rendition of weather science.  Apologies for my harsh response to prior posting.  Which in fact, was bullseye correct in terms of the decline of grain price subsequently.  In other words, you were right on target.  I am not worthy, but grateful indeed for your attendance here at Met Mike's forum home!


For the record, long one Kansas City September wheat and long one Christmas Soybean Meal.  Both still profitable, but both drained of much of the profit left unrealized just a few days ago.