FOUS30 KWBC 141605 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 1205 PM EDT Tue Apr 14 2026 Day 1 Valid 16Z Tue Apr 14 2026 - 12Z Wed Apr 15 2026 ...THERE IS A SLIGHT RISK FOR EXCESSIVE RAINFALL ACROSS THE CENTRAL L.P. OF MICHIGAN,SOUTHEAST WISCONSIN, AND THE OHIO VALLEY... ... Ohio Valley... 16Z Update: The Slight Risk for Excessive Rainfall was expanded farther south to include central Illinois to central Indiana.Radar and surface observations show an outflow boundary lingering across the region from early morning showers and thunderstorms that may be a focal point for locally heavy rainfall this afternoon and evening. The RRFS and ARW model camps in particular are highlighting this region with QPF maxima in the 2-5 inch range. High seasonable PWATS and abundant instability also support the potential for high hourly rainfall rates. ...Wisconsin and Michigan... 16z Update: The forecast continues to support the risk for flash flooding as storms are expected to form along a stationary boundary over Wisconsin and then congeal into a line of storms that progresses southeastward into Michigan. The low level jet will transport moisture orthogonal to a stationary boundary across the region with the training of storms possible. Most of the area remains at near or above record spring rainfall and soils are fairly saturated. Cells capable of 1.5-2"/hr rates and localized totals of 2-3+" suggest the placement of a Slight Risk of Excessive Rainfall from southern Wisconsin to eastern Michigan. ...Previous Discussion... A Slight Risk for excessive rainfall remains in effect for portions of the Great Lakes region. A shortwave/vorticity center lifting out over the mean ridge in the Great Lakes region will drive stronger confluence of the low level jet across Iowa to trigger another round of strong to severe thunderstorms Tuesday evening. Overall deep layer steering flow and fairly orthogonal ascent over boundary should help to focus a similar west to east (WNW to ENE) oriented axis of training thunderstorms. Upper-level dual jet couplet will further enhance up-scale growth to a broader complex to maintain through the overnight period. Most of the area remains at near or above record spring rainfall and soils are fairly saturated, so with cells capable of 1.5-2"/hr rates and localized totals of 2-3+" suggest the placement of a Slight Risk of Excessive Rainfall across portions of eastern WI and central MI (along and north of I-94). ... Lower Trans-Pecos/Big Bend... 16 Update: Latest model guidance indicates a higher QPF maxima across the Lower Trans-Pecos region into the Big Bend as storms fire along the dry line in presence of a seasonally moist environment. HREF 24 hour QPF neighborhood probabilities are around 50-70% for 2 inches and 10-20% probabilities for 3 hour QPF exceeding flash flood guidance. A Marginal Risk was maintained, but this area will be a focus for locally heavy rainfall. ...Oklahoma and Kansas... 16z Update: Another targeted area for heavy rainfall will be span south of the Norman area, northeastward into the Tulsa metro and southern Kansas. Hi-res guidance indicates multiple rounds of storms could traverse this region as storms fire along the dry line boundary and south of a stationary front in Kansas. HREF 24 hour QPF probabilities exceeding 2 inches are fairly high (50-70%) and 20-40% for exceeding 3 inches. ...Previous Discussion... A steady stream of PW values of 1.25 to 1.5 inches will be advecting northward through the Southern/Central Plains nearly parallel to the dryline. This will be conducive for slow storm motion with locally heavy rainfall. Consensus suggests 3 to 4 inches possible within the isolated cells. The Marginal Risk area is connected to the area of concern over the Great Lakes and just note the coverage will decrease northward along the dry-line. Campbell/Gallina Day 2 Valid 12Z Wed Apr 15 2026 - 12Z Thu Apr 16 2026 ...THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL FROM TEXAS TO THE UPPER MIDWEST/GREAT LAKES REGION... The surface to mid-level environment remains very similar to the prior 3 days, with a stark dry line extending from the Pecos River Valley across the Southern Plains into the Upper Mississippi Valley. During this period the longwave trough will finally be making progress toward the Central Plains albeit as it begins to weaken and the deep layer moisture axis and instability shift slightly eastward. Thunderstorms are expected to break out with hourly rates pulsing up to 2 inches/hr. Some locations ahead or along the frontal boundary may receive over 3 inches between the Ozarks Plateau and northeast Texas. Further north, the environment over the Midwest/Great Lakes region will have notably less moisture and instability present then the days prior, however additional rains will maintain an elevated threat for localized flooding over the hydrologically sensitive/saturated areas of the northern Great Lakes region. The most favorable location for appreciable precipitation will be from northeast Illinois to souther Michigan. The Marginal Risk area was maintained and in spans from northeast Texas northward to Wisconsin/Lower Michigan and east to western New Yorks and Pennsylvania. Campbell/Gallina Day 3 Valid 12Z Thu Apr 16 2026 - 12Z Fri Apr 17 2026 The probability of rainfall exceeding flash flooding guidance is less than 5 percent. 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