Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
417 AM EDT Fri Jun 6 2025
Day 1
Valid 12Z Fri Jun 06 2025 - 12Z Sat Jun 07 2025

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE SOUTH-CENTRAL PLAINS, THE LOWER OHIO, LOWER TENNESSEE AND
MIDDLE MISSISSIPPI VALLEYS AND FROM EAST CENTRAL NEW YORK STATE
INTO CENTRAL NEW ENGLAND...

...South-Central Plains.....
There is a strong model signal for another round of organized
convection late Friday afternoon into Friday night/early hours of
Saturday across the south-central plains as additional shortwave
energy is forecast to drop east southeastward from the Central
Rockies into the Central to Southern Plains Friday into Friday
night/early Saturday. The low level flow is expected to again
strengthen into the west to east oriented frontal zone across the
Southern Plains, supporting potential for another round of
organized convection in the vicinity of this front. PW values
along this front will remain above average...2+ standard deviations
above the mean, supporting heavy precip potential. There is fairly
good model consensus for an axis of heavy rains along this front
from far southeast CO/far southwest KS, across much of OK into the
OK/KS/MO/AR border region. The slight risk was drawn to fit the
axis of the highest HREF neighborhood probabilities for 2"+ amounts
and the HREF EAS axis of highest probabilities for 1"+ amounts. The
next round of organized convection will likely track along the same
areas that are currently receiving heavy rainfall late Thursday
evening into early Friday.

...Mid Mississippi Valley, Lower Ohio Valley, Lower Tennessee
Valley...
The lead area of shortwave energy initiating current early morning
convection across the Southern Plains will be pushing toward the
Mid Mississippi Valley, Lower Ohio and Lower Tennessee Valleys
Friday afternoon/evening. Similar to areas upstream along the west
to east oriented frontal zone that extends into the Mid MS, Lower
OH,Lower TN Valley, PW values will be above average, 2+ standard
deviations above the mean. Convection likely to enhance Friday
afternoon/evening ahead of these height falls in the much above
average PW axis, supporting heavy rain potential and localized
flooding issues. A slight risk area was added from the previous
issuance, aligned with where the axis of the highest HREF
neighborhood probabilities for 2"+ amounts and the HREF EAS axis of
highest probabilities for 1"+ amounts are forecast.

...Southern Great Basin into the Central to Southern Rockies...
Not a lot of changes expected to the large scale flow across the
southern Great Basin into the Central Rockies. PW values forecast
to remain above average with additional shortwave energy moving
across the region in the west south west flow aloft. This should
support another day of widespread scattered convection and
localized heavy rain and isolated runoff issues. No significant
changes made to the previous marginal risk area across this region.

...East-central New York into Central New England...
A slight risk area was added for portions of east-central New York
State into central New England from central to southern New
Hampshire, across southeast Vermont, western Massachusetts into
east central NY state. There is good agreement in the last hi res
guidance for enhancing convection in the 1800 UTC Friday to 0000
UTC Saturday period in the axis of above average PW values along
the slow moving frontal boundary draped across this area. The
slight risk was drawn to fit where the axis of high HREF
neighborhood probabilities are for 2 & 3"+ totals. This corresponds
also to where the HREF hourly probabilities for 1"+ totals are
high in the 1800 UTC Friday to 0000 UTC Saturday period.

Oravec


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