AWUS01 KWNH 090034 FFGMPD MOZ000-IAZ000-KSZ000-NEZ000-090600- Mesoscale Precipitation Discussion 0647 NWS Weather Prediction Center College Park MD 833 PM EDT Wed Jul 08 2026 Areas affected...southern NE into northern KS, eastward to the MO River Valley Concerning...Heavy rainfall...Flash flooding possible Valid 090031Z - 090600Z SUMMARY...Expanding thunderstorm coverage with repeating and training may trigger flash flooding across portions of southern NE over the next 3-6 hours. The flash flood threat may evolve southward into northern KS and/or eastward toward the MO River Valley with time. Hourly rainfall of 1 to 2 inches (but locally up to 3 inches) is expected. DISCUSSION...00Z radar imagery showed clustering of cells east and northeast of Grand Island, NE, originating from a mixture of cell motions with a number of outflow boundaries interacting in the vicinity of east-central NE. The area of convection was located ahead of a cold front that extended from northwestern IA into northeastern NE, becoming stationary into southwestern NE via 00Z surface observations. The environment to the south of the front in NE contained moderate to strong MLCAPE of 2000 to 3000+ J/kg with little to inhibition noted in the 00Z SPC mesoanalysis and the 00Z OAX sounding, along with 1.5 to 1.9 inches of precipitable water. Upstream, a mid-upper level impulse was noted on water vapor imagery over west-central NE, advancing east, possibly related to recent convective development over eastern Lincoln County near I-80. Farther west, High Plains convection was noted over southeastern WY/northeastern CO, advancing toward the east into a weak low level upslope flow regime. The combination of increasing forcing for ascent ahead of subtle upstream impulses seen on water vapor imagery, diffluent flow aloft over the central Plains and lift ahead of the slow moving cold front should help to increase convective coverage overnight across southern NE. Outflow from thunderstorms should be met with an increasing low level jet, forecast to reach 30-40 kt over central KS, supporting overrunning of the rain-cooled air. While Corfidi vectors suggest any clusters of thunderstorms will propagate southeastward, there will be potential for training and repeating of cells, prior to cluster formation and along the western flank of any clusters that develop...at least briefly. The result will be potential for training with 1 to 2 inches (locally up to 3 inches) in an hour along with possible flash flooding. Peak storm total rainfall of 2 to 4 inches is expected (locally higher possible). Otto ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...DMX...EAX...GID...GLD...LBF...OAX...TOP... ATTN...RFC...KRF...NWC... LAT...LON 41999693 41869638 41539538 40889479 40169479 39809570 39639728 39629860 39750072 40120144 40610134 40930083 41559817