Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
429 AM EDT Sun Apr 20 2025
Day 1
Valid 12Z Sun Apr 20 2025 - 12Z Mon Apr 21 2025

..THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS THE CENTRAL
US TODAY INTO TONIGHT...

Introduced a Slight Risk area for the potential of excessive
rainfall from parts of Texas into the Upper Midwest/Northern
Plains. It is really a composite of multiple reasons to warrant a
Slight Risk area in different geographical areas. The northern
portion of the Slight Risk area covers the growing model signal for
2-3+ inches of rain due to a combination of deformation
zone/surface low and good divergence aloft from the highly curved
anticyclonic upper level jet all becoming more or less collocated.
Rainfall amounts in the central part of the US are forecast to be
less than areas to the north...but the Slight Risk area was more
targeted for overlap between future rainfall on top of what MRMS
has shown for the past 24-36 hrs in anticipation of how the FFG
values will change. Lastly...kept some parts of the Southern Plains
in an outlook area based on short term radar/satellite trends.
While rates have come down as the plume of highest equivalent
potential temperature has narrowed overnight...suspect that the
potential for at least some excessive rainfall will persist beyond
the start of Day 1 period at 20/12Z. Those areas can be removed in
the mid- morning Day 1 ERO assuming that trends continue downward.

Bann

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