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 rains won't stay in the same place. Labor Day weekend might be different.

Current Day 1 Forecast

Day 1 Threat Area in Text Format  

Current Day 2 Forecast

Day 3 forecast below

evere Storm Risk.  Hit the map for full screen.  Elevated risk  Midwest to central Plains 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 Tuesday. Hot surge today continues east. More like July!

New cool intrusion N.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.

Heat and high humidity COMBINED. Feels like temperature. Heat Index an increasing factor again. Afternoon readings above 100 from Chicago southward.

Highs days 3-7.

Brief shot of cooler air for the Midwest at the start then the Northeast but the heat starts to return by the end of next week...........and the end of August/Start of September!

First week of September looking 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 early August, not the end of August......with more heat to start September!

They are cooler THIS week than last Thursday's forecast  near record hot forecast but similar to yesterday's!

High temperature departures:

Low Temperature Departures:

Huge High, the center is now along the East/Southeast Coast. 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 early 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.  Still a dry pocket  in N. MO which may get more rain 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 in the S.Canadian Rockies is hitting the N.Plains/Upper Midwest right now and will sink southeast 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.

Day 15  Very Warm across most of the country. Not looking as hot.

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 11, 2018 00 UTC

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

Today, for the 2nd day in a row, we have huge upper level ridge in Western Canada..................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:

NWS extended still the same as recent days........high probability of above average temperatures over much of the country(cool Northwest). Above average rains over all of the Cornbelt.....expanding to most of the country.

Despite this NWS product being updated, the last couple of weather model runs in the last day are telling us that later in week 2, the forecast below.....in the 8-14 day period is in need of some cooling! 

6-10 day Temperature Probability

Precipitation Probability

8-14 day Temperature Probability

Precipitation Probability

Extreme weather threat days 3-7..................lengthy period with potential for excessive rains in the Central Cornbelt. This will likely result in some rare, early September flooding:

All the latest guidance continues  to move towards a much cooler weather pattern evolving during the 2nd week of September............compliments of a building upper level ridge in Western Canada and downstream troughing, ushering in much cooler Canadian air masses :

gfs_namer_360_200_wnd_ht	gfs_namer_360_500_vort_ht
gfs_namer_360_1000_500_thick	gfs_namer_360_850_temp_ht

Despite this  potential change, which would eventually usher in much drier air during the 2nd half of September, there is a strong heavy rain signal in a large part of the Midwest during the next 10 days. The heat ridge in the East will pump in copious amounts of moisture which will serve as fuel to ignite organized areas of thunderstorms, which could repeat over the same general areas on several occasions.