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 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