FOUS30 KWBC 220826
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
426 AM EDT Wed Jul 22 2026

Day 3  Valid 12Z Fri Jul 24 2026 - 12Z Sat Jul 25 2026

..THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
SOUTHEAST AS WELL AS FOR MUCH OF MISSOURI...

...Southeast...

The front that has been causing heavy rain across portions of the
Southeast through Thursday continues on into Friday, though begins
to weaken and in some areas lift back to the north as a warm front.
Due to this weakening forcing, the rainfall forecast footprint over
the Carolinas diminishes substantially (by about half) as compared
with prior days' rains. While many areas continue to see periods of
heavy rain, which may overlap with heavy rainfall from prior days,
the much lower rainfall forecast over North Carolina did allow for
the risk level to drop back into the Slight category for the Friday
period. That said, any increase in rainfall, especially for areas
hit hard on Wednesday and Thursday, could easily necessitate
another upgrade to a Moderate for portions of eastern North
Carolina with future updates.

The rainfall forecast increases from prior days further west into
northern Alabama and Georgia. The inherited Slight risk, as on past
days, was expanded west. In this case, the expansion went all the
way to the Mississippi state line with Alabama, as Alabama in
particular looks to have its wettest day of the week on Friday.
Considering prior days rains forecast for this same area, more
favorable hydrology and further increases in expected rainfall in
northern Alabama and Georgia could mean a Moderate Risk upgrade
with future updates isn't entirely out of the question. Certainly
eastern NC has a much higher chance of this happening.

...Missouri...

An MCS over the area Friday morning diminishes in intensity with
differential heating over the Plains and Ozarks on Friday. However,
guidance is not in good agreement as to whether or not the rainfall
dissipates entirely. Peak heating could provide enough instability
that the convective organization changes, but not its coverage.
Thus, A Slight Risk for a large portion of Missouri remains in
place. Any rain will continue in this area into Friday night.

...Texas..

Regardless of whether Bertha does better at maintaining its
intensity on Thursday, or if it dies earlier by taking a more
northerly track, by Friday the rainfall associated with the storm
will be long dissipated or diminished to nuisance showers. As
such, all flooding risks directly associated with Bertha will be
ended by Friday.

Wegman
 

Day 4 and Day 5  Valid 12Z Sat Jul 25 2026 - 12Z Mon Jul 27 2026

...THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL FROM THE MID
MISSISSIPPI VALLEY TO THE SOUTHEAST DAY 4 AND ACROSS PORTIONS OF
THE WESTERN U.S. DAYS 4 AND 5...

...Mid Mississippi Valley to the Southeast...
The overall trend in the overnight guidance was to shift the slow-
moving surface front and associated axis of deeper moisture farther
east and off of the Southeast Coast on Saturday, diminishing the
threat for widespread additional heavy rains across the Carolinas.
Therefore, the Slight Risk was removed from the eastern Carolinas.
However, cannot rule out an isolated threat for localized heavy
rains and an isolated flash flood threat. Therefore, the Marginal
Risk was maintained for the Day 4 period from eastern North
Carolina into the Southeast before notably drier air begins to
spread across much of the region on Sunday.

The Marginal Risk was also maintained farther northwest back across
the Tennessee Valley into the mid Mississippi Valley. Some models,
more notably the ECMWF and UKMET, show elevated storms that are
expected to develop Friday night continuing to propagate southeast
from the mid Mississippi into the Mid South, with deepening
moisture and training storms raising the potential for heavy
accumulations. As the associated mid level energy continues to drop
southeast, there is the potential for at least locally heavy
amounts and isolated flash flooding concerns as it interacts with
lingering deep moisture from the Tennessee Valley into Alabama and
Georgia on Saturday.

...Southwest to the northern Rockies...
After a dropoff late in the week, the footprint for diurnal
showers and storms is expected to expand once again by Saturday as
high moisture anomalies (+2 sigma) return to parts of Arizona and
New Mexico. This moisture along with mid-level energy moving
around the southern periphery of the high will raise the threat for
efficient-rainfall producers, raising flash flooding concerns
across parts of the Southwest both days. This elevated moisture and
enhanced forcing may support the need for an upgrade to a Slight
Risk in future updates.

Meanwhile deeper moisture and energy lifting along the northwest
side of the high will extend the threat into parts of the northern
Intermountain West and Rockies on Day 4, before moisture anomalies
drop off on Day 5.

Pereira
$$
--- MultiMail/DOS
 * Origin: capitolcityonline.net * KY, USA (618:250/10)