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.  Elevated risk Great Lakes today...........shifting southeast with the cold front tomorrow.

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

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

High Temperatures today and Wednesday. Hot today S. Plains to East. More like July!

New cool intrusion Plains/Upper Midwest.

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 N. Plains to Upper Midwest.

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

Highs days 3-7.

Brief shot of cooler air for the Midwest ushered out at the start the heat starts to return by the end of this week! Labor Day Weekend very warm to hot!

First week of September looking very warm to hot!

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 late July, not the end of August/start of September!

High temperature departures:

Low Temperature Departures:

Huge High, the center is 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 will provide copious H2O for rains in much of the Cornbelt over the next 2 days...........with a cold in the Plains/Upper Midwest sinking southeast this week.

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.  Northern parts of the country. 

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.

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.

            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 across the Midwest/East..........but a cool surge is hitting the N.Plains/Upper Midwest right now and will sink southeast this week.

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..not looking as hot East

Day 15  Hot West............... Cooling East?

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. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

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 12, 2018 00 UTC

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

Today, for the 3rd day in a row, we have huge upper level ridge in Western Canada..................Very cool, dry Canadian air dowstream in the Midwest and East during week 3.

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:

The last 12z GFS continues to cool things off early in week 2 like previous solutions but is not as cool later in week 2.

To me, the most significant weather coming up is going to be the massive rains in the Central Cornbelt. 

6+ inches from later this week into next week over a several state area.

Probably from around the KS/MO border to slightly northward.........into IA but the specific zone with the heaviest, REPEAT rains could be shifted from that.

Forecast Hour:  384
Image URL: http://mag.ncep.noaa.gov/data/gfs/12/namer/precip_ptot/gfs_namer_384_precip_ptot.gif

NWS extended has changed a bit today......high probability of above average temperatures over much of the country but cool Northwest shifts to the N.Plains.  Above average probabilities decrease  in the later period. 

This is in line with the cooler pattern that may be coming up during the 2nd week of September.

Above average rains over almost all of the country. Only the Pac Northwest has below normal rain. 

6-10 day Temperature Probability

Precipitation Probability

8-14 day Temperature Probability

Precipitation Probability

As noted the last couple of days, the main weather event coming up is going to be heavy rain events from late this week into early next week.

Here is the area that the NWS is currently targeting for potentially excessive rains from this Friday thru next Tuesday,. This has been shifted a bit north from the previous outlook:

 if anybody is anywhere near Iowa City Iowa and north in the corridor between Iowa City and Cedar Rapids seek cover now

.... this is no joke please seek cover I'm trying to get ahold of my sister who is in North Liberty Iowa tornadoes are down and making a path right towards North Liberty Iowa I need to go

Sister and her children are safe in the basement but if anybody wants to see a really good example of rotation and a storm right now it's a beautiful rotation counterclockwise in a bow celll go to channel 9 KCRG pinpoint Doppler radar

Thanks SS:

Go to: Most Recent Imag

 Current Day 1 Outlook severe storms beloww
           

Flash flooding risk below

The ZIP code is 52240 and if you want to go to channel 9 KCRG pinpoint Doppler radar they have the absolute best radar

... find your safe place

The latest guidance 18z GFS and ensembles are warmer late in week 2 vs previous runs. 

However, the big weather story is going to be the excessive rains from late this week into next week.  If the upper level ridge holds in the East, then those heavy rains could continue into the 2nd week of September. 

               18z GFS at 15 days below. Then below that, the total rains.

gfs_namer_360_200_wnd_ht	gfs_namer_360_500_vort_ht
gfs_namer_360_1000_500_thick	gfs_namer_360_850_temp_ht

Forecast Hour:  384
Image URL: http://mag.ncep.noaa.gov/data/gfs/18/namer/precip_ptot/gfs_namer_384_precip_ptot.gif