Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
812 PM EDT Sat Jun 13 2026
Day 1
Valid 01Z Sun Jun 14 2026 - 12Z Sun Jun 14 2026
...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
SOUTHWESTERN MISSOURI, SOUTHEAST KANSAS, NORTHEAST OKLAHOMA, AND
NORTHWEST ARKANSAS...
01Z Update: Moderate risk from prior forecast remains on track with
the core of heaviest precipitation likely to occur over the quad
state intersection of OK/KS/AR/MO overnight. Deep moist profiles
situated over the Central Plains to Mississippi Valley will fuel
the potential for significant rainfall this evening with the
upstream trough and cold front progression already underway for
areas further north. MUCAPE off the latest RAP analysis indicates a
corridor of 4000-6000 J/kg running through much of eastern KS down
into northeastern OK which has been targeted as the primary axis of
heavy precip from the latest hi-res. Models have struggled to grasp
the surface features present over the area with the recent 22z HRRR
finally coming into alignment with the current radar trends on
initialization. Expectation is for increased surface to BL
convergence along the cold front progression this evening with some
pre-frontal development likely to ensue across southern KS as a
shortwave migrates eastward ahead of the front. Signals for heavy
rainfall have been steady over eastern KS into southwest MO, but
trends for a bit more progressive cell motions have put portions of
OK/AR in play for more significant rains with the latter area (AR)
likely to see some overlap after previous rainfall this period.
Area FFG's are generally 1-1.5"/hr with 1.5-2"/3-hrs, both
thresholds that will likely be breached in this environment with
majority of hi-res signaling 2-3"/hr rates likely in the strongest
cells over the course of the evening. HREF probs continue to pin
>60% probabilities for >2" and >3" over the southeast KS and
southwest MO region, a testament to the consistency of that zone
being the primary target for the period. Thus, have maintained the
MDT risk with only some trimming of the eastern periphery as model
trends have given enough consensus to remove portions of
southeastern MO for the MDT.
SLGT risk was expanded southeast over the Memphis area and
surrounds as the current MCS propagation continues to plague the
area with flash flood warnings already in effect for parts of
western and southwest TN. In any case, the recent radar trends and
hydrologic impacts called for a short term upgrade to a SLGT risk
to correlate with what is happening currently.
Kleebauer
Day 1 threat area:
www.wpc.ncep.noaa.gov/qpf/94epoints.txt
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
403 AM EDT Sun Jun 14 2026
Day 1
Valid 12Z Sun Jun 14 2026 - 12Z Mon Jun 15 2026
...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL FOR THE SOUTHERN
PLAINS AS WELL AS FOR NORTHERN NEW ENGLAND...
...Southern Plains...
Today will likely be the calmest of the next 3 days across Texas,
which isn't saying much as it will still be plenty active. A very
slow moving cold front will sink south across Oklahoma and Arkansas
today. Ahead of the front, an impressively moisture-laden air mass
is in place over not just Texas, but much of the Gulf Coast. Across
eastern Texas, an ongoing MCS across Oklahoma and Arkansas
delineating the leading edge of the aforementioned cold front will
continue to drift south and weaken through the morning hours, which
is typical behavior for MCSs once the sun comes up. While the MCS
will have some forward speed to it, the availability of plentiful
moisture, with PWATs to 2 inches will continue to support heavy
rainfall with the strongest cells. The remnants of the MCS will
likely impact the Metroplex in the mid-to-late morning.
Meanwhile, plentiful southerly flow off the Gulf into southeast
Texas will lead to widespread but largely disorganized shower and
thunderstorm activity from the Houston and San Antonio metros
north. The plentiful moisture will still be available, so anywhere
where cell mergers or localized training features develop,
localized flash flooding will be possible today. Any urban areas
will only increase the flash flooding potential, though there's
considerable uncertainty whether any of the biggest cities in Texas
will be directly impacted.
Across west Texas and the Hill Country, afternoon and evening
thunderstorms will impact those areas, with portions of west Texas
recently hard hit from heavy rains at a higher threat for
additional flash flooding. A higher-end Slight has been issued for
this region. For the Hill Country, the main flooding threat will be
tonight, as an MCS develops due to plentiful merging thunderstorms
and a southward push of the cold front in that region. The storms
will run into increasing resistance tonight in the form of a
strengthening LLJ, which should slow down the forward speed of the
storms as the traverse the Hill Country. Due to the flashy nature
of the terrain in the Hill Country, the higher-end Slight was also
introduced for this region as well. Back into New Mexico,
afternoon and evening storms could interact with both the terrain
features in the area, such as the Sacramento Mountains, urban El
Paso, and any burn scars in the area.
...Northern New England...
A Slight Risk upgrade was introduced with this update in
coordination with BTV/Burlington, VT and CAR/Caribou, ME forecast
offices. The same cold front that will be impacting the Southern
Plains will have a much easier time pushing eastward, as a large
upper level low over Canada pushes frequent shortwave disturbances
east across the northeastern U.S. Despite the progressive nature of
the front, a surge of moisture will rapidly advect north into New
England ahead of the front, aided by increasing upper level support
as a strong shortwave becomes more negatively tilted with time as
it rounds the southeastern periphery of the upper level low. The
moisture surge will also increase the instability, with MUCAPE
values around 1,000 J/kg expected on average, and values up to
2,000 in some areas, including southeastern VT. The plume of
moisture and instability will support numerous fast-moving
thunderstorms training northeastward along the Canadian border. The
training storms will impact recently hard hit areas of northern New
England, where soils are wetter than normal going into this event.
While there's some question as to how strong the storms will get,
the likelihood they will train along and south of the plume of
greatest rainfall is high. The storms will train over northern New
England for several hours before the cold front sweeps across from
west to east tonight. Topographic effects could locally increase
rainfall rates, as well as worsen any possible flash flooding.
This further supports the Slight Risk upgrade for the area.
...Elsewhere...
The Marginal Risk for the Mid-Atlantic and the east coast of
Florida are largely the same. For the Mid-Atlantic afternoon and
evening storms feeding on the same moisture plume that will advance
into New England could lead to localized instances of flash
flooding, especially in urban areas along the I-95 corridor, though
the severe threat appears greater.
On the east coast of Florida, sea breeze interactions with the
abundant moisture over the state should allow for a renewed
development of afternoon and evening thunderstorms today. The
storms will be nearly stationary, so mergers will pose the greatest
threat for more prolonged periods of heavy rain, though all strong
cells will be capable of localized heavy rain.
Wegman
Day 1 threat area:
www.wpc.ncep.noaa.gov/qpf/94epoints.txt
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
403 AM EDT Sun Jun 14 2026
Day 2
Valid 12Z Mon Jun 15 2026 - 12Z Tue Jun 16 2026
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM SOUTH TEXAS
THROUGH THE LOWER MISSISSIPPI VALLEY...
As far as changes to the inherited forecast go, the day 2 forecast
is the most similar to the prior forecast. A strong cold front over
north Texas through southern Arkansas at the start of the day will
continue making painfully slow progress south towards the western
Gulf Coast on Monday. Meanwhile a surge of deep tropical moisture
will actually further increase the amount of available moisture
the storms will have to work with as they push south across Texas.
The MCS from Sunday night along the Rio Grande will continue south
into Monday morning along the Rio Grande and the Texas Hill
Country. This MCS will weaken by midday, only to be replaced with
far more numerous showers and thunderstorms all across southern and
eastern Texas. These storms will form as the surge of moisture and
plentiful instability from the Gulf advects north and west into
southeast Texas. The storms from any morning MCs will quickly
evolve into a slow moving line of storms from east Texas into
Mississippi due to the abundant moisture and instability running
into the very slow-moving cold front roughly near the AR/LA border.
For some areas of east-central Texas, northern Louisiana, and
western Mississippi, there may be no stop between any early morning
rain from overnight MCS and the afternoon convection that quickly
blossoms along the frontal interface. High FFGs and somewhat drier
than normal surface soils going in to the Day 2 (depending on what
happens today), should work to preclude Moderate Risk level
coverage of flash flooding, but the whole area is in a higher-end
Slight and a Moderate Risk upgrade is possible with future updates.
For South Texas, the primary flash flooding threat for the period
will occur overnight Monday night. While the abundant moisture will
be in place in this region, there will be a lack of forcing, due
to the distant cold front over the Hill Country, until the arrival
of a potent upper level disturbance. This disturbance is likely at
least in part the remnant circulation of former East Pacific
tropical storm Cristina. As this feature pushes northeast out of
the mountains of Mexico towards south Texas, it will not only
increase the low level inflow of tropical moisture, but will
provide ample forcing to organize the storms into slow-moving lines
of training cells that track northwestward with time up the Rio
Grande. PWATs will be 4 sigma above normal, exceeding 2.5 inches at
times, so any and all storms will have impressive amounts of
moisture to work with to produce heavy rain. Instability due to
extensive cloud cover commensurate with such amounts of moisture
will likely be the only limiting factor for coverage of heavy rain.
A Moderate Risk may also need to be considered in south Texas
should coverage of storms remain similar with more CAMs coverage and
portions of this area get significant rainfall on Day 1/today.
Wegman
Day 2 threat area:
www.wpc.ncep.noaa.gov/qpf/98epoints.txt
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
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
403 AM EDT Sun Jun 14 2026
Day 4 and Day 5
Valid 12Z Wed Jun 17 2026 - 12Z Fri Jun 19 2026
...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL FOR PORTIONS OF
MIDDLE MISSISSIPPI VALLEY, OHIO VALLEY, MID-SOUTH, AND GULF COAST
ON DAY 4 AND DAY 5...
An anomalous upper-level pattern will be the catalyst for active
days 4-5 timeframe from the Gulf Coast on north to the OH Valley
and as far east as the central Appalachians. Southeast TX and
portions of the Deep South will also experience widespread
thunderstorms.
On Day 4 (Wed.) a robust 500mb vorticity maximum will spawn a
strong area of low pressure at the nose of a 500mb jet streak.
ECMWF SAT percentiles show show MSLP values that are among the
lowest in the CFSR database (1979-2009) over the Midwest by 00Z
Thursday that continue into early Thursday morning over the Great
Lakes. 850mb winds will be roaring to the tune of 50 kts and
potentially stronger than that over the OH Valley. The combination
of highly anomalous low pressure over the Midwest paired with high
pressure south of Bermuda will force Gulf moisture to race
northward into the Middle MS Valley and on east into the OH Valley.
With PWs also above the 90th climatological percentile, storms may
be fast movers, but they will contain efficient warm rain
processes. A Slight Risk was introduced from the MS Valley to as
far east as central OH to account for the increased flash flood
potential. Farther south, the pool of anomalous PWs accompanied by
a strengthening southerly IVT over the western Gulf will keep the
TX Coast at risk for Excessive Rainfall. While guidance still shows
some differing solutions, the region will only continue to see
soils grow more sensitive after multiple days of rain prior to
Wednesday. A Slight Risk was introduced for the Lower and Central
TX Gulf Coast, aligning with where the heaviest WPC QPF is located.
For Day 5 (Thurs.), between the NAEFS and ECMWF SATs, the
southerly winds within the 1000-500mb layer over the western Gulf
are remarkable with the entire layer's southerly wind anomalies
averaging at least the 97.5 climatological percentile. This means
the Gulf is wide open for business, not just with low-level
moisture but into the mid-to-upper levels as well. ECMWF and GEFS
ensemble means on Day 5 have PWs above 2.2" over the central Gulf
Coast with >90th climatological PWs as far north as the OH Valley.
A strong cold front will trigger widespread thunderstorms within
this environment that is likely to pose a flash flood threat in
portions of the recently more sensitive soils of the OH and TN
Valleys, leading to the issuance of a Slight Risk in these areas.
Farther south, guidance shows varying solutions of what could
transpire in east TX. The 12Z ECMWF EFI has a swath of >1 Shift of
Tails (SoT) from east TX to as far north as northern MS, and even a
small >2 SoT north of I-10 in east TX, indicating a signal for
locally significant rainfall being possible in these areas. The
details on the development of low pressure in the Deep South remain
unclear. That said, there is no denying the copious amounts of
moisture at these thunderstorms disposal and soils throughout the
region will have only grown more sensitive after multiple days of
Excessive Rainfall. A Slight Risk was introduced over the Upper TX
coast on east into southwest LA where it aligns with not only the
ECMWF EFI signal but the overlap with the more anomalous moisture
content and the heavier WPC QPF within the TX/LA area.
Mullinax
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
403 AM EDT Sun Jun 14 2026
Day 4 and Day 5
Valid 12Z Wed Jun 17 2026 - 12Z Fri Jun 19 2026
...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL FOR PORTIONS OF
MIDDLE MISSISSIPPI VALLEY, OHIO VALLEY, MID-SOUTH, AND GULF COAST
ON DAY 4 AND DAY 5...
An anomalous upper-level pattern will be the catalyst for active
days 4-5 timeframe from the Gulf Coast on north to the OH Valley
and as far east as the central Appalachians. Southeast TX and
portions of the Deep South will also experience widespread
thunderstorms.
On Day 4 (Wed.) a robust 500mb vorticity maximum will spawn a
strong area of low pressure at the nose of a 500mb jet streak.
ECMWF SAT percentiles show show MSLP values that are among the
lowest in the CFSR database (1979-2009) over the Midwest by 00Z
Thursday that continue into early Thursday morning over the Great
Lakes. 850mb winds will be roaring to the tune of 50 kts and
potentially stronger than that over the OH Valley. The combination
of highly anomalous low pressure over the Midwest paired with high
pressure south of Bermuda will force Gulf moisture to race
northward into the Middle MS Valley and on east into the OH Valley.
With PWs also above the 90th climatological percentile, storms may
be fast movers, but they will contain efficient warm rain
processes. A Slight Risk was introduced from the MS Valley to as
far east as central OH to account for the increased flash flood
potential. Farther south, the pool of anomalous PWs accompanied by
a strengthening southerly IVT over the western Gulf will keep the
TX Coast at risk for Excessive Rainfall. While guidance still shows
some differing solutions, the region will only continue to see
soils grow more sensitive after multiple days of rain prior to
Wednesday. A Slight Risk was introduced for the Lower and Central
TX Gulf Coast, aligning with where the heaviest WPC QPF is located.
For Day 5 (Thurs.), between the NAEFS and ECMWF SATs, the
southerly winds within the 1000-500mb layer over the western Gulf
are remarkable with the entire layer's southerly wind anomalies
averaging at least the 97.5 climatological percentile. This means
the Gulf is wide open for business, not just with low-level
moisture but into the mid-to-upper levels as well. ECMWF and GEFS
ensemble means on Day 5 have PWs above 2.2" over the central Gulf
Coast with >90th climatological PWs as far north as the OH Valley.
A strong cold front will trigger widespread thunderstorms within
this environment that is likely to pose a flash flood threat in
portions of the recently more sensitive soils of the OH and TN
Valleys, leading to the issuance of a Slight Risk in these areas.
Farther south, guidance shows varying solutions of what could
transpire in east TX. The 12Z ECMWF EFI has a swath of >1 Shift of
Tails (SoT) from east TX to as far north as northern MS, and even a
small >2 SoT north of I-10 in east TX, indicating a signal for
locally significant rainfall being possible in these areas. The
details on the development of low pressure in the Deep South remain
unclear. That said, there is no denying the copious amounts of
moisture at these thunderstorms disposal and soils throughout the
region will have only grown more sensitive after multiple days of
Excessive Rainfall. A Slight Risk was introduced over the Upper TX
coast on east into southwest LA where it aligns with not only the
ECMWF EFI signal but the overlap with the more anomalous moisture
content and the heavier WPC QPF within the TX/LA area.
Mullinax
