FOUS30 KWBC 020809 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 409 AM EDT Tue Jun 2 2026 Day 1 Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026 ...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF WEST TEXAS INTO NEW MEXICO AND NORTH DAKOTA... ...Dakotas... A mid to upper level system and associated surface front will approach the region during the period. Ahead of it, warm moist air will expand across the area with the latest guidance showing precipitable water values over 1.2" and by afternoon, MUCAPE values in excess of 1000 J/kg. Deep convection firing up in the afternoon will initially be more discrete but is expected to evolve into linear segments as the evening commences with a ramp up late in the period possible with the developing low-level jet. The 00Z HREF shows the threat for rainfall totals in excess of 3" across the Slight Risk area with the greatest potential across central to northeastern ND (50-80 percent). Isolated maximum hourly rainfall totals of 2 inches will be possible. For these reasons, the Slight Risk for flash flooding looks appropriate and no significant changes were made for this update. ...Eastern New Mexico into West Texas... Another day of isolated to scattered thunderstorms across the region is expected as moist southeasterly flow expands further westward into eastern New Mexico. With cool temperatures aloft given the baggy trough in place, this should be sufficient for greater coverage of thunderstorms, initially tied to the terrain and then moving eastward toward the NM/TX border. Peak hourly rainfall totals in excess of 1 inch will be possible across eastern NM and total amounts of 1" to locally 3" will be possible. The Slight Risk is maintained for the potential of isolated to widely scattered flash flooding particularly for sensitive areas like burn scars and steeper terrain. ...Gulf Coast into South Florida... A frontal boundary analyzed early this morning across the Gulf Coast is expected to slowly drop southward through the period. Along and ahead of this feature, precipitable water values range from 1.5" to locally over 2", which is around 1.5 std above normal for some locations. The frontal position, combined with a favorable upper pattern, will provide the forcing for ascent today. With expected instability values exceeding 1500 J/kg (MUCAPE) during peak heating, scattered to numerous showers and thunderstorms are likely. The latest HREF probabilities show potential for hourly rain totals between 1-2" (up to 50 percent probability), peaking during the afternoon to early evening hours. Totals of 1-3" are expected within the risk area, with isolated totals of 3-5" possible in the strongest/slowest thunderstorms, most likely to occur across portions of FL Panhandle and across South Florida. Isolated to scattered instances of flash flooding are possible given the potential for intense rain rates, particularly over sensitive locations like urban corridors. Taylor Day 2 Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS WEST TEXAS INTO NEW MEXICO... ...West Texas into New Mexico... Weak troughing aloft and the remaining relatively higher moisture in place across the region will likely promote the development of isolated to scattered thunderstorms again on Wednesday. The focus for the greatest concentration of thunderstorms and rainfall totals will shift a bit further east this day, likely along the NM/TX border into the TX Panhandle where amounts of 1-2" with isolated 3" totals likely. Isolated to scattered instances of flash flooding will be possible. ...Great Plains... An axis of higher moisture will be present ahead of an advancing cold front moving across the Northern Plains. Moist unstable air ahead of it will promote the development of several clusters of thunderstorms capable of producing intense rain rates between 1-2"/hr. Isolated to scattered flash flooding is anticipated with a possible upgrade to a Slight Risk needed for parts of eastern ND and far western MN if trends continue for a more concentrated area of thunderstorms and heavy rainfall. Day 3 Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF THE PLAINS, UPPER MIDWEST, AND TEXAS... ...Northern Plains into the Upper Midwest... Shortwave energy ejects into the Plains during the period with the frontal boundary expected to become increasingly west to east oriented as it drapes across the Upper Midwest by Thursday. This will allow the moisture to pool ahead of it while also creating a more favorable setup for training/repeating thunderstorms that are expected to develop during the peak heating and continue into the overnight hours with the surging low level jet. While there remains uncertainty on placement (north solutions versus some that are further south), the ingredients appear to be in place for heavy rainfall from portions of the Dakotas eastward toward Minnesota. For now, a Marginal Risk remains in place but an upgrade to a Slight Risk may be needed in future updates if trends continue for a training thunderstorm scenario. ...Plains to Texas... A mid to upper level system slowly moving east out of western Mexico will approach the region during the period. As it does so, it will continue to pull into the area copious amounts of Gulf moisture. This will bring additional rounds of thunderstorms to the area, some of which will be locally heavy given the PWs in place and potential for repeating rounds. For now, will keep a Marginal Risk in place, but if greater organization of storms or confidence on specific areas rises, a Slight Risk may be needed for portions of western to central Texas with future updates. Taylor 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