Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
406 AM EDT Wed Jul 28 2021
 
Day 3
Valid 12Z Thu Jul 29 2021 - 12Z Fri Jul 30 2021 

...THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL ACROSS PORTIONS 
OF THE SOUTHWEST INTO THE NORTHERN ROCKIES AND PARTS OF THE 
CENTRAL PLAINS INTO MID MISSISSIPPI VALLEY...

...SOUTHWEST INTO NORTHERN ROCKIES...
Monsoonal moisture will continue to impact the Southwest CONUS 
northward into portions of the Northern Rockies. PW values 
continue to sit near 1.75 inches for much of this area and with 
antecedent conditions making soils even more susceptible to 
flooding, confidence in additional flooding events continues into 
the day 3 time period. A Marginal Risk was put into effect

...CENTRAL PLAINS INTO MID MS VALLEY...
Troughing across the region coupled with modest instability will 
increase chances of heavy rounds of precipitation with convection 
and training storms. PW values sit near 2.0 inches during this 
time period with MU CAPE values sitting near 2000 J/kg. FFG is on 
the higher end for some of these areas and steering flow is on the 
faster end, however the possibility of training is the main 
concern with some of these storms expected to drop heavier 
amounts. Guidance is wavering a bit on where to place the swath of 
precipitation and as such, confidence in placement for the 
Marginal Risk for this area is on the lower end. Adjustments will 
likely be made as newer guidance comes in and hopefully a better 
handle on where the band of precipitation will set up. 

Chiari


 
Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt