Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1202 PM EDT Mon Jul 20 2026
Day 3
Valid 12Z Wed Jul 22 2026 - 12Z Thu Jul 23 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL FOR THE CAROLINAS,
PORTIONS OF THE INTERMOUNTAIN WEST, AND THE CENTRAL GULF COAST...

...Carolinas into Southeastern Virginia...

A strong cold front that impacted much of the Mid-Atlantic on
Tuesday will stall out over central Virginia on Wednesday. Ahead of
the front, abundant Gulf moisture will continue streaming
northeastward from Tropical Depression 2, likely to be centered
south of the Mississippi Delta. Since the front will remain strong,
and the moisture will remain well above normal for the Carolinas,
as PWATs spike above 2.25 inches at times, the front will act as a
train track for numerous training and backbuilding thunderstorms.
The focus for these storms will be where the front interacts with
the deepest moisture, which is expected from central North Carolina
northeast through the Tidewater of Virginia.

This area should get a break in the rain on Day 2/Tuesday, such
that by the time the heaviest rains impact NC and VA on Wednesday,
some draining from prior days' storms should work to limit the
flash flooding risk somewhat. Thus, for now the area remains in a
higher end Slight. The forecast rainfall will continue to be
monitored as a Moderate Risk upgrade remains a possibility.

...Central Gulf Coast...

Tropical Depression 2 is expected to be drifting west to the south
of Louisiana on Wednesday. The conditions impacting the system will
remain much the same on Wednesday as on prior days. Northerly shear
will remain in place, pushing most of the associated convection
south of the circulation center, keeping nearly all of the heaviest
rains over the Gulf. Only a tiny fraction of the storm's overall
rainfall will impact land areas, with the best chance expected
along the immediate Gulf Coast of southeastern Louisiana. The
inherited Slight Risk was trimmed to just the immediate coast,
dropping the threat for metro New Orleans, in coordination with
LIX/Slidell, LA forecast office. Of course, trends in the storm
will continue to be monitored, as subtle changes in the environment
around the storm could result in large changes in the rainfall
forecast.

...Intermountain West...

The combination of well above normal moisture across much of the
intermountain West on Wednesday, strong upper level disturbances
tracking northeastward ahead of a longwave trough over the Pacific
Northwest, and numerous mountain ranges will all work to promote a
much higher than normal flash flooding potential over the area from
the 4 Corners north through much of southeastern Idaho. The Slight
Risk for Idaho and Wyoming was expanded south due to yet another
day of expected showers and thunderstorms impacting the highly
flash flooding prone areas of Utah and western Colorado. The
greatest rainfall totals are likely into northwestern Wyoming, from
Yellowstone south. Few changes were needed north of Wyoming's
southern border.

Wegman

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