985
FOUS30 KWBC 222005
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
305 PM EST Sat Nov 22 2025

Day 1
Valid 16Z Sat Nov 22 2025 - 12Z Sun Nov 23 2025

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF SOUTHEAST ARIZONA INTO CENTRAL ARIZONA...

...16z Update...

Introduced a Marginal Risk with the 16z update, as the latest 12z
CAMs support a lower-end, localized flash flood threat later today
with mostly clear skies and building insolation over portions of
southeast into central AZ. SB CAPE should climb to ~250 J/kg with
updrafts tending to initially favor higher terrain and points
north, as storm motions of 15-25 kts to the north to northeast are
expected within the mean flow. With precipitable water values
anticipated to build to around 0.8" (well above the 90th percentile
and more representative of September/October), a period of localized
1"+/hr rates are possible with small downdrafts and relatively
fast motions generally capping hourly totals around 0.5". Some
repeating and training of cells may locally support hourly totals
of 0.5"+ and short-term (2-3 hour) totals of 1.5-2.0" are possible.
This may result in a few localized instances of flash flooding
(mainly concentrated late in the period from 00z-09z).

Churchill


Day 2
Valid 12Z Sun Nov 23 2025 - 12Z Mon Nov 24 2025

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR MUCH OF CENTRAL
AND NORTHERN TEXAS INTO PORTIONS OF SOUTHERN OKLAHOMA...

...20z Update...

Consensus QPF guidance has continued to focus on the western side
of the inherited Slight Risk, making the primary adjustment with
this update to shift both the MRGL and SLGT areas a bit west. The
upper-level system driving the expected rainfall (which is expected
mostly after 00z on Mon) continues to look less amplified and cut-
off, placing the area of concern closer to the base of the trough
and tilted the QPF axis a bit more west-to-east than previously.
While this may increase the risk locally for training convection,
the main axis is also now more solidly north of the bulk of the
Hill Country (particularly where heavy rainfall occurred earlier
this week) into much of the Big Country/Northwest TX. While the
rainfall axis still impinges on western portions of the Dallas-
Fort Worth metro, the best probabilities for 3" exceedance are
concentrated to the west of the populous areas (as well as north
of San Angelo proper). While this less populated region of Central/
Northwest TX within the south-central portion of the updated SLGT
risk has indications of 5"+ potential (per 40-km HREF 5" exceedance
probs of ~15%), this signal is being driven seemingly entirely by
one member (the FV3, which is generally one of the less reliable
members) with the bulk of the CAM guidance in good agreement
indicating 2-4" totals. Given that much of this QPF is also
expected in the last 6 hour period of the forecast, there is still
plenty of time to see if this FV3 run is an outlier or if more CAM
guidance comes into alignment with this heavier solution. This may
necessitate a future targeted upgrade to Moderate Risk (which is
also possible for San Angelo and/or the DFW metro areas, should the
QPF axis shift a bit south and/or east).

Churchill


...Previous Discussion...

The latest guidance continues to depict a southwest-northeast
orientated axis of heavy rain panning from the northern part of the
Hill Country to northeast Texas. General consensus suggests 1 to 3
inches however, the ECMWF is persistent on the higher end with
amounts 3 to 5+ inches and placed further south/southwest than
other solutions. This is somewhat concerning, as this brings the
forecast axis of QPF even more into alignment with areas that
realized heavy rainfall in prior days.

A Slight Risk remains in effect and seems appropriate given at
least three days of recovery from the previous heavy rainfall
event and uncertainty with regard to the amount of training and
resultant QPF.

Campbell/Churchill


Day 3
Valid 12Z Mon Nov 24 2025 - 12Z Tue Nov 25 2025

...THERE IS A SLIGHT RISK FOR EXCESSIVE RAINFALL FOR MUCH OF
ARKANSAS AND NORTH TEXAS INTO ADJACENT PORTIONS OF SOUTHEASTERN
OKLAHOMA, NORTHERN LOUISIANA, AND NORTHWEST MISSISSIPPI...

...20z Update...

Organized convection is expected to be ongoing Monday morning
across a good portion of North TX and into southeastern OK and the
Ark-La-Tex, moving east across Arkansas and into the Mid-South
during the day. Confidence is highest in robust convection in the
vicinity of North TX early in the period, whereas solutions diverge
somewhat later in the day...with one camp of guidance suggesting
training convection and localized totals as high as 3-5" from a
relatively hydrologically sensitive region from southwest OK into
northwest/north-central AR (mainly driven by the GFS/GEFS) and the
other camp indicating higher odds for 3" exceedance farther south
into the Ark-La-Tex and southern AR (led by the ECMWF/ECENS, but
also having greater support from the CMC suite and UKMET as well).
Overall this led relatively to little change to the inherited SLGT
risk, mainly shifting the area a bit west and flattening it out to
account for the (aforementioned) less amplified upper-level trough.
There may need to be considerations for a future targeted Moderate
risk upgrade, though for this to occur more guidance would most
likely need to shift towards the northern solution (or consolidate
towards the southern solution while also getting wetter, as FFGs
indicate much less sensitive soils that would require a broader
area of 3"+ before meeting Moderate coverage criteria).

Churchill


...Previous Discussion...

The broad area of showers and thunderstorms are expected to shift
to the eastern portion of the Southern Plains and the Lower
Mississippi Valley. The highest amounts are expected to focus over
the AK-LA-TX region. While areal averages of 1 to 3 inches are
forecast, isolated maximums of 4+ inches will be possible. There
will be some overlap of heavy rainfall from the previous day which
will lower local FFGs. Training and back building of storms may be
possible, particularly for norther Texas and Arkansas. A Slight
Risk is in effect from northeast Texas/northern Louisiana to
western Tennessee/northwest Mississippi.

Campbell


Day 1 threat area: https://www.wpc.ncep.noaa.gov/qpf/94epoints.txt
Day 2 threat area: https://www.wpc.ncep.noaa.gov/qpf/98epoints.txt
Day 3 threat area: https://www.wpc.ncep.noaa.gov/qpf/99epoints.txt