Excessive Rainfall threat. When there is an upper level ridge along the East Coast, it pumps  moisture into the Midwest for heavy rain events.

There will be an increasing risk of excessive rains in the Midwest for the next several days................high confidence.

Current Day 1 Forecast

Day 1 Threat Area in Text Format  

Current Day 2 Forecast

Day 3 forecast below

Severe Storm Risk.  Hit the map for full screen. Western Cornbelt the target today and Friday. ..........maybe Saturday. 

https://www.spc.noaa.gov/products/outlook/

Current Day 1 Outlook
Current Day 2 Outlook
Current Day 3 Outlook
Current Day 4-8 Outlook

Dew points. 70+ on this scale makes it feel uncomfortable(sticky air)!  

Humid air in place over the southern 1/2 of the country. Gulf of Mexico moisture +fairly high soil moisture.This will be pooling into  our huge rain maker the next several days.

Dry air N.Plains to Upper Midwest to Great Lakes.

Heat and high humidity COMBINED. Feels like temperature. Heat Index a big  factor in the southern half of the country and in the East.

Highs days 3-7.

Labor Day Weekend very warm to hot!

First week of September looking very warm to hot. Some cooler air gets into the N.Plains to Upper Midwest in the middle of next week.

How do these days 3-7 temperatures compare to average at this time of year?  We are now 5 weeks past the climatological time of year when temperatures are the hottest.

These temperatures will be close to normal..................for early August, not the end of August/start of September for the  eastern half of the country!

High temperature departures:

Low Temperature Departures:

That cold front with cool air to the north has stalled out. It will be returning as a warm front. As warm, moist air returns on it's western side with southerly winds, waves of heavy thunderstorms will continue the next several days.

https://weather.com/maps/currentusweather

Here is the latest radar image.

http://www.nws.noaa.gov/radar_tab.php

Satellite picture.  Blobs of thunderstorms will be visible.

Rains the past 24 hours.  

You can go to this link to see rain totals from recent time periods:

https://water.weather.gov/precip/

Go to precipitation, then scroll down to pick a time frame. Hit states to get the borders to see locations better. Under products, you can hit "observed" or "Percent of normal"

Southern Plains was in horrible shape......the map below shows massive improvement there.  Still a dry pocket  in N. MO which is going away right now.

Much of the Cornbelt is great shape for Late August so the crops have been fed lots of yield making H2O in August.

Wet from NE/w.IA/sw.MN..............and the East Coast. It will become TOO WET for the central cornbelt in the next week.

Below are rains compared to average of the last 7, 14, 30 and 60 days. Usually not updated for previous day until late the next day.

Bountiful rains for most of the Cornbelt..............and points eastward and westward. This has increased yields in August!!!

Now we will get too much rain!

https://www.atmos.illinois.edu/~snodgrss/Ag_Wx.html

Drought Monitor. This product is updated every Thursday. Drought has been shrinking but still persists in N.Missouri and Texas.........this measure takes into account the long term precip/sub soil moisture and goes back over MANY months.

Drought in N.Missouri could be wiped out in the next week.

            http://droughtmonitor.unl.edu/Maps/CompareTwoWeeks.aspx    

Maps below of the Canadian ensembles are for 2 weeks from today.

The top map is the ensemble average, the maps below are the individual members that make up the average.

The heat ridge breaks down?   OK, maybe it doesn't according to some solutions! Here on Thursday, there is tremendous uncertainty for the late week 2 period.

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Each member is like the parent, Canadian model operational model.......with a slight tweek/variation in parameters. Since we know the equations to represent the physics of the atmosphere in the models are not perfect, its useful to vary some of the equations that are uncertain(can make a difference) to see if it effects the outcome and how.

The average of all these variations(ensembles) often yields a better tool for forecasting. It's always more consistent. The individual operational model, like each individual ensemble member can vary greatly from run to run.........and represent an extreme end of the spectrum at times. The ensemble average of all the members, because it averages the extremes.............from opposite ends of the spectrum............changes much less from run to run.

360h GZ 500 forecast valid on Sep 14, 2018 00 UTC

The low skill, longer range CFS model for weeks 3 and 4.

This  product has been changing the last few days. Now it has the heat ridge from the N.Rockies to N.Plains and the country drying out.

September is gradually getting cooler, almost every year and heating degree days start replacing cooling degree days as being the most important.

Check in tomorrow to read something different............."low skill" (-:

Precip below:

This is the latest area targeted for excessive rains from 9-2 to 9-6:

NWS extended much the same. Heat east, wet almost everywhere.

However, week  2 becomes very uncertain and may turn out drier than depicted in the 8-14 day below:

6-10 day Temperature Probability

Precipitation Probability

8-14 day Temperature Probability

Precipitation Probability

An example of how changeable the solutions have been as we get into week 2, here is the last 12z European model for day 10.   The heat ridge backs up to the middle of the country, causing hot and much drier weather(except the northern tier) vs being on the East Coast and pumping in moisture with troughing in the Plains.

This solution is an outlier: