Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
816 PM EDT Sun Apr 21 2019
 
Day 1
Valid 01Z Mon Apr 22 2019 - 12Z Mon Apr 22 2019 

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL NEAR THE UPPER 
GREAT LAKES...

...East-Central Minnesota/Northern Wisconsin/U.P. of Michigan...
The surface front stretching from southeast South Dakota into 
south-central Minnesota, northern Wisconsin and into the western 
portions of the U.P. of Michigan is expected to remain 
quasi-stationary across this region through tonight. Shower 
activity is likely to persist along and to the north of this 
boundary through the period in an axis of PW values that are 1.5 
to 2+ standard deviations above normal for this time of the year 
-- 1-1.25". Concerns for potential runoff issues are primarily 
overnight into Monday morning. The moist low-level 
south-southwesterly flow into and over the boundary is expected to 
strengthen tonight ahead of a deepening surface low moving out of 
the central Plains toward the upper Mississippi Valley. This 
should drive an increase in areal coverage of rainfall, with 
heavier rainfall rates, and also some potential for elevated 
convection north of the front that will be capable of training 
west to east over the same area. The latest hires guidance is in 
agreement in showing the potential for a narrow axis of heavy 
rainfall totals with as much as 1 to 2+ inches along and just 
north of the front from east-central portions of Minnesota east 
across far northern Wisconsin and into the western portions of the 
U.P. of Michigan. With stream flows high across these regions, per 
the National Water Model, the additional rainfall and localized 
areas still seeing some snowmelt will be susceptible to some 
runoff problems and flooding.

Roth/Orrison
 
Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt