Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
403 AM EDT Sun Jun 14 2026
Day 3
Valid 12Z Tue Jun 16 2026 - 12Z Wed Jun 17 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR THE WESTERN AND
CENTRAL GULF COAST...

...South Texas...

The entire focus of heavy rainfall across South Texas Tuesday will
be the speed of movement of the upper level disturbance which
likely in part the upper level circulation of former east Pacific
tropical storm Cristina. The global guidance is in alright
agreement, but it could certainly be better. The EC is far slower
with its movement than the GFS. For this period, the difference
between the two is small enough that there is at least some
confidence in the subsequent meteorological effects. Essentially
the upper level Pacific moisture with Cristina will combine with
exceptionally deep Gulf moisture along the western periphery of the
Gulf, to raise PWATs to near record territory for this time of year
for some areas of deep south Texas, particularly along the coast.
With the disturbance in place, and strengthening with time, this
abundant moisture will be focused into slow-moving bands of heavy-
rain producing thunderstorms. PWATs will exceed 2.5 inches along
the coast, with some areas even nearing 2.75 inches. The exact
track of the slow-moving disturbance will be key as to who sees the
most rain, as the storms ride north off the Gulf and into coast to
the east of the center of circulation.

Rain wrapping around the circulation will spread west across all of
deep south Texas, right to the Rio Grande. This will lead to a
second consecutive day with exceptional rainfall totals in spots,
with areal average rainfall for the period likely exceeding 3
inches (with much higher localized amounts) from essentially
Galveston south and west. At the moment, the heaviest totals look
to concentrate for the portion of south Texas from Corpus Christi
south and west to the Rio Grande, but again any change in track or
speed of the upper low and any possible surface circulation will
change this dramatically. Regardless, considering the overlap from
the Day 2/Monday period, should this rainfall forecast remain
similar with future updates, a Moderate Risk will be necessary as
FFGs in this area will be much lower than they are now. Further,
there will be urban flooding impacts from Brownsville to Corpus
Christi as well.

...Louisiana into the South...

Up the coast from south Texas, the plume of abundant Gulf moisture
will continue to stream north into the slow moving front that will
remain set up from east Texas through northern Louisiana and into
western Mississippi. The good news for Tuesday is that the likely
influence of the upper level low over deep south Texas/Mexico will
make for downstream ridging, which should limit the coverage of
heavy rain from Houston east across the South. That said, the front
will still be a potent forcing feature, and training storms
tracking east parallel to the front will still pose a localized
flash flooding problem. Thus, the inherited Slight for this region
remains in place, especially considering the likely much more
favorable hydrology as this will be the second or third day
(depending on where you are) of heavy rain for this region. This
will likely offset the somewhat lighter rainfall totals expected
Tuesday and Tuesday night. A faster forward speed of the upper
level disturbance could also re-increase the rainfall forecast for
this region and also push some areas close to Moderate Risk
territory with future updates.

Wegman

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