Excessive Rainfall threat. Current system moving east pretty fast................so rains won't stay in the same locations that long. Next system taking shape west tomorrow.

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 in a couple of spots.

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.  Hottest in the West again. Major cool surge in the Plains/MidwestNortheast.

Dew points. 70+ on this scale makes it feel uncomfortable(sticky air)!  Humid over the eastern half of the country being shoved southeast.

Very dry air diving south and southeast into the Plains/Midwest today.

Heat and high humidity COMBINED. Feels like temperature. Feeling sultry in the south and east.

Highs days 3-7.

To start:  Pleasant from the Central Plains to Midwest to East.

Then: Heat shifts eastward bigtime into the Plains, then Midwest then East.

How do these days 3-7 temperatures compare to average at this time of year?  We are now 4 weeks past the climatological time of year when temperatures are the hottest.

Above average in Plains to Midwest and East after a cool start.

Much cooler in the West.

High temperature departures:

Low Temperature Departures:

Big weather maker in the Great Lakes!! MUCH COOLER air on its backside.

https://weather.com/maps/currentusweather

Here is the latest radar image...active in the Great Lakes eastward.

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

Satellite picture.  

Rains the past 24 hours. Numerous locations. 

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"

Missouri  to S.Plains was in horrible shape......the map below shows massive improvement in the S.Plains into Arkansas. Still a dry pocket  in MO.

Wet from NE/w.IA/sw.MN.

The 2nd map finally updated.

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.

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

Drought Monitor. This product is updated every Thursday. Drought has been shrinking.........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:  Cool surge in the Plains/Midwest.  

In 5+ days:

Heat that was in the West is on the move eastward......across the Plains and Midwest to Northeast!

In 10+ days   Warmest West again!!!! Heat has spread east..... ..positive anomalies across the country. Greatest anomalies north.

Day 15 Warmest West. Heat across most of the country.

Big Question now, is how long will the heat last in the Midwest/East?

Question now seems to be how long will the very impressive week 2  Heat ridge in the East last? Still there from S.Plains to East Coast late in week 2 today.

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

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

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 05, 2018 00 UTC

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

Today, we have widespread heat continuing in week 3 for the 3rd day in a row, with the biggest anomalies in the Great Lakes, then in week 4, the heat ridge backs up/retrogrades west and cools east.

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

Precip below:

https://twitter.com/Met_mdclark/status/1031896364794433536

bam-x guys talking heat also

Thanks mcfarm!

      The last 12z operational GFS backs the dome/heat ridge farther west during the first week of September(dang, we are almost done with August!). Previously the heat ridge was along the East Coast, thru 2 weeks,  now it retrogrades back to the Rockies and lets cooler air flow into the Northeast.

 Is this what will happen? It's just one solution from one model that appears to be an outlier at the moment.

      Days 14(336hrs)-15(360hrs) below.

gfs_namer_336_200_wnd_ht	gfs_namer_336_500_vort_ht
gfs_namer_336_1000_500_thick	gfs_namer_336_850_temp_ht

gfs_namer_360_200_wnd_ht	gfs_namer_360_500_vort_ht
gfs_namer_360_1000_500_thick	gfs_namer_360_850_temp_ht

The 12z Canadian ensembles have a few solutions(minority) that break down the heat ridge in the East like the last GFS but the weakening majority still have it thru 2 weeks. 

348h GZ 500 forecast valid on Sep 5, 2018 00UTC

12z GFS ensembles/mean still pretty strong with the heat ridge thru day 15 but do show it weakening a bit along the East Coast. 

Forecast Hour:  360
Image URL: http://mag.ncep.noaa.gov/data/gefs-mean-sprd/12/gefs-mean-sprd_namer_360_500_vort_ht.gif

NWS extended continues more of the same as expected.

Hot east, cool west.

Wet Upper Midwest, dry S/C Plains to SW Cornbelt.

6-10 day Temperature Probability

Precipitation Probability

8-14 day Temperature Probability

Precipitation Probability