FOUS30 KWBC 011552
QPFERD
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1152 AM EDT Wed Apr 1 2026
Day 1
Valid 16Z Wed Apr 01 2026 - 12Z Thu Apr 02 2026
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL STRETCHING FROM
CENTRAL OKLAHOMA INTO NORTHERN MISSOURI AND THE CONCHO VALLEY...
...Central to Southern Plains...
16Z Update: The previous forecast remains on track with a heavy QPF
signature focused within the warm sector of a maturing synoptic
pattern as a lee surface low migrates eastward through the Central
Plains. Latest 12z HREF neighborhood probabilities for >3" remain
very elevated (50-70%) across areas of southeast KS up into
west-central MO, coincident with the axis of greatest convergence
where a propagating cold front will couple with a budding LLJ and
maximized mid-level forcing to create a solid area of heavy
convection beginning this afternoon, carrying through the overnight
hours. Heavy rain signature remains most prominent between the
quadrant of I-35/44/49/70 with portions of both the Wichita and
Kansas City metros in mix for heavy precipitation. Backed flow for
a time across zone will allow for some training elements prior to
the precip field migrating east-northeastward as a frontal passage
finally puts an end to the setup. Overall, this setup has
relatively good continuity in guidance going back to a few days
ago, thus only minor adjustments were made to the overall SLGT risk
area with the "biggest" change being more of an extension eastward
through MO for areas along and north of I-70 to correlate with some
overlap of heavy precipitation over areas that saw heavy rainfall
the past 12hrs.
Kleebauer
..Previous Forecast Discussion..
The latest hi-res and global guidance noted a south/southwest-ward
shift of the axis of highest precipitation to central Oklahoma to
northern Missouri from its previous position of northeast Kansas
into east-central Iowa where areal averages of 1 to 3 inches are
expected. There remains a decent signal for localized 3+ inches in
the vicinity of the Topeka-Kansas City metros. The Slight Risk
area was adjusted to now cover eastern Oklahoma to northern
Missouri while the Marginal Risk was maintained from the Texas
Hill Country to the Mississippi/Ohio Valleys.
A prominent warm-sector will materialize from west-central Texas
into Missouri with a surface low forecast to be positioned over the
Central Plains by Wednesday afternoon. Several shortwaves will
eject northeast within and ahead of the mean trough leading to
multiple waves of rainfall from the south-central Plains into the
Middle Mississippi Valley. Some training potential, leading to 1-3
inch areal average amounts in this region, with some potential for
isolated higher amounts of 3+ inches. Farther south, a long axis
of convection is expected from Texas to Kansas along the cold
front, but storms in this area should be more progressive and soils
are even more dry than to the north.
Campbell/Santorelli
...Texas...
A SLGT risk was added across the Concho Valley in west TX as trends
for back-building convection along a well-established dryline will
open the door for heavy precipitation totals where training
convection is plausible. Recent HREF QPF trends were pretty
substantial in the last few cycles of the hi-res ensemble with the
blended mean QPF a solid 2-3" across the area between the Lower
Trans Pecos and points east-northeast to the northern fringes of
Hill Country. A lot of this setup stems from a sharpening dryline
that tilts back to the west-southwest as a maturing nocturnal LLJ
takes shape after 23z. Convergent signature within a favorably
unstable environment and stout 45-55kt bulk shear axis should allow
for the initiation of supercellular convective modes the first 2-4
hrs of any development followed by an eventual merger of cells as
the LLJ matures further. This is a classic scenario of the southern
edge of a larger ascent pattern in spring that tends to be more
appreciable for heavy rainfall with the dryline and LLJ convergence
zone becoming the focal point for where the higher QPF concerns
arise. Latest HREF neighborhood probabilities for >3" of rainfall
are between 40-60% with the bullseye centered over the Concho
Valley, including the San Angelo area where terrain and
urbanization factors lend credence to a better localized flash
flood risk for the area of interest. Hourly rate probabilities for
1"/hr are very high (50-70%) for several hours across the same
area(s) which will be the driving force for the entire setup. In
coordination with the local San Angelo WFO, the SLGT risk was added
due to the evolving threat.
Kleebauer
Day 2
Valid 12Z Thu Apr 02 2026 - 12Z Fri Apr 03 2026
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
EASTERN IOWA, NORTHERN ILLINOIS, WISCONSIN AND MICHIGAN...
The front will span from the Mid-Atlantic back into the Ohio and Mid-Mississippi Valleys during this period. Models have persisted
in placing the precipitation shield over much of the Upper Great
Lakes/Upper Midwest region. The moisture and instability along with
the upper-level support could lead to flooding concerns across
parts of the Great Lakes region. Colder air filtering across the
northern tier will allow for wintry weather concerns in the Great
Lakes to Interior Northeast thus limiting the area where flash
flooding may occur/cause impacts. Some areas could see
transitioning precipitation types throughout the event. A Marginal
Risk area remains in effect for portions of southern Wisconsin,
Lower Michigan and northern Illinois where precipitation is most
likely to stay mostly/all rain.
Campbell/Santorelli
Day 3
Valid 12Z Fri Apr 03 2026 - 12Z Sat Apr 04 2026
...THERE IS A SLIGHT RISK FOR EXCESSIVE RAINFALL FOR PORTIONS OF
THE SOUTHERN/CENTRAL PLAINS...
Strong to severe thunderstorms along with embedded heavy rainfall
will track across the Southern/Central Plains into the Midwest
during this period. Moisture (with PWs over the 90th, perhaps 95th
percentile) and instability are likely to pool along and ahead of
the associated cold front and produce widespread convection.
Storms likely beginning in the afternoon are expected to get
reinforced through the evening and night hours as a low level jet
picks up ahead of the cold front. A Slight Risk was maintained and
adjusted to span from northern Texas to southwest Missouri.
Campbell
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)