Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
827 PM EDT Sun Sep 14 2025
Day 3
Valid 12Z Tue Sep 16 2025 - 12Z Wed Sep 17 2025


...THERE ARE MARGINAL RISKS OF EXCESSIVE RAINFALL IN SOUTHERN NEW
MEXICO, THE CENTRAL PLAINS, AND COASTAL VIRGINIA/NORTH CAROLINA...

20Z Update...

Broadened the Marginal Risk over southeastern Virginia to also
include portions of northeastern North Carolina. Some models,
including the ECMWF, show additional heavy amounts carrying over
into Day 3 across the region -- which given the anticipation of
heavy amounts impacting this region on Day 3, may prolong runoff
concerns. As on Day 2, continued to lean toward the more easterly
guidance. However, given the uncertainty, additional adjustments
may be forthcoming.

Further west, the upper trough moving across the Rockies has
trended slower. The general consensus of the models shows the axis
of associated precipitation shifting further west, with many of the
models showing their heaviest amounts centered over the flood-resistent
Nebraska Sandhills. Therefore, shifted the previous outlook
further west, confining the footprint to the more sensitive areas
from the southern Nebraska Panhandle to northwestern Kansas.

Pereira

Previous Discussion...

...Southern New Mexico...

Moisture will start to nudge upward over southern NM (though much
more well west of there) with some afternoon instability and
expected isolated convection, mainly over the mountains close to
the Mexican border. Low-end Marginal Risk is outlined here though
activity should be rather isolated.

...Central Plains...

Positively-tilted trough over the Northern Rockies will move
eastward to the High Plains Tuesday afternoon. Broad westerly mid-
level flow amid increasing moisture will help fire off some storms
over at least NE near the better forcing but also southward into
KS. A Marginal Risk is outlined here for an isolated flash flood
threat.

...Coastal Virginia...

Over the past couple of days, the models have trended toward
bringing in an area of low pressure near the Outer Banks Tuesday
morning or so. Rain should spread inland on Monday with additional
and perhaps heavier rain on Wednesday. This area has been rather
dry recently and rain rates may not be all that high, but some
convection-driven rain is possible depending on the flavor of this
area of low pressure. A Marginal Risk is depicted for
southeastern/coastal Virginia and far northeastern North Carolina
but with a lot of uncertainty in the rainfall
pattern/rates/duration.

Fracasso

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