Excessive Rainfall threat. If(when) there is an upper level ridge along the East Coast, this can(will) be a significant factor in the Midwest to pump in moisture for heavy rain events.

Current system is progressive so heaviest rains won't stay in the same place. Labor Day weekend will be different.

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. Current system weakening and moving southeast. Next one revs up storms in  the Western Cornbelt Friday............this will be the start of a stormy/wet period out there.

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 with the southerly winds! Gulf of Mexico moisture +fairly high soil moisture in the eastern half of the country.

Dry air Plains to Upper Midwest.

Heat and high humidity COMBINED. Feels like temperature. Heat Index a big  factor.

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.

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!

High temperature departures:

Low Temperature Departures:

Huge High, the center is now in the Southeast. Winds on it's backside are from the south..........transporting in deep level moisture from the Gulf of Mexico(and very warm temps) which has been providing copious H2O for rains.

That cold front is sinking southeast, crossing the Eastern Cornbelt to the S.Plains today. It will come back as a warm front later this week and really set off heavy rains.

https://weather.com/maps/currentusweather

Here is the latest radar image.

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

Satellite picture.  

Rains the past 24 hours.  Central Cornbelt got bombed.

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...but  starting to  dry out again.  Still a dry pocket  in N. MO which will go away in the next week.

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.

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    

Temperature Anomalies from GFS ensembles(fairly reliable product) going out 2 weeks. These maps show the Northern Hemisphere. The map of the US is front center. Look for the state borders in  white.

Today:     Heat has moved East..........cool surge is pushing thru the Plains and  Midwest right now and will sink southeast, then fizzle the next 2 days.

In 5+ days:

Heat rebounds quickly late this week, setting up for a hot Labor Day weekend.  

In 10+ days: Positive anomalies across much of the country. East uncertain.

Day 15  Hot West............... Cooling East???? Maybe not.

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! ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

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 13, 2018 00 UTC

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

Today, marks a big change.  The solution from the previous 3 days, with much cooler air in the Plains/Midwest has vanished.

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:

Main weather event(s) coming up........too much rain!

This was the last 12z GFS total rain for 2 weeks. September is seasonally the driest month of the year. Amounts of this magnitude would produce historical flooding for the month of September.

The biggest danger is if the guidance, indicating the excessive rain signal will continue into week 2, verifies. 

If that happens, 10+ inches of rain could fall over a 10 day period!

Latest extreme weather map from the NWS. Long lived excessive rain threat over the same area in the 3-7 day period:

NWS extended has changed a bit today......high probability of above average temperatures over the Eastern half of the country(decreasing with time)...........cooler in the Plains/Western Cornbelt.  

Above average rains over almost all of the country. Only the Pac Northwest has below normal rain.  There is a strong excessive rain signal in week 1 that could continue into week 2. High probability for above average rains. 

6-10 day Temperature Probability

Precipitation Probability

8-14 day Temperature Probability

Precipitation Probability