FOUS30 KWBC 060033 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 833 PM EDT Fri Jun 5 2026 Day 1 Valid 01Z Sat Jun 06 2026 - 12Z Sat Jun 06 2026 ...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF EASTERN NEBRASKA/KANSAS INTO THE MID-MISSISSIPPI VALLEY AS WELL AS MUCH OF TEXAS/SOUTHERN OKLAHOMA... 01Z Update: Much of Texas remains in a SLGT risk as convection is ongoing across a good portion of the state with central and north Texas likely to be the focal point overnight. HREF probs remain high (40-70%) for >3" potential across the I-35 corridor where low-level confluent flow is shaping up to maintain an active evening between San Antonio up through Georgetown. Further north, we'll see the introduction of a LLJ help play a role, along with remnant outflows from convection to increase heavy rain prospects across western Rolling Plains up through southwestern OK where convection is already running rampant. There is way too much going on to deviate from the previous SLGT risk inherited in these zones, so the SLGT was maintained to account for everything ongoing, and expected to continue for several more hours. Over the Central Plains and Midwest, yet another shortwave will eject out of the High Plains with a focused convergence axis situated from southeastern NE through southern IA. This area will have some overlap from the previous period of heavy rainfall, so soils in some parts may be either compromised, or relatively close leading to a greater threat for flash flooding compared to normal. Neighborhood >2" probabilities are steady 40-70% across the aforementioned corridor with even a bullseye of ~80% located across southeastern NE. The potential for training convection will be greatest in that area in particular as low to mid-level flow backs for a period as the shortwave approaches. Look for cell motions to slow and provide a period of prolonged heavy rain potential overnight before we finally see everything shift eastward. Considering the nature of the setup and consistency in guidance, the SLGT from previous forecast(s) were maintained. Elsewhere over the Upper Midwest and Great Lakes, a quick-moving disturbance migrating east-southeast from the Northern Plains continues to plague portions of northern WI into the U.P. of Michigan this evening leading to some sporadic flash flood concerns near the southern shores of Lake Superior. Prospects for flash flooding remain lower compared to other areas of the CONUS, but the threat is right within the lower threshold for a MRGL risk when assessing the prob fields at both FFG exceedance and 3-hr QPF >2". Both were right within the bounds of convergence considering a MRGL risk, so opted to add the risk given the already issued flash flood warning that materialized recently with rain continuing. Kleebauer Day 2 Valid 12Z Sat Jun 06 2026 - 12Z Sun Jun 07 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF THE SOUTHERN PLAINS TO MISSISSIPPI VALLEY AND ALONG THE CENTRAL GULF COAST... 20Z Update... ...Central Gulf Coast... Both the 12Z HREF/REFS provided enough confidence to add a Slight Risk along the central Gulf Coast centered from southeastern Louisiana to coastal Alabama. Guidance shows a fetch of tropical moisture behind a northward-moving low-level wave that will push PWs upward of 2.25 inches (+2.5 std dev) -- supporting heavy rates. Raising the threat for heavy accumulations and excessive rainfall is the potential for training storms. The introduced Slight Risk area reflects the area where both the HREF/REFS show high probabilities for amounts over 3 inches. Elsewhere, made minor adjustments based on the HREF/REFS. Pereira Previous Discussion... ...Southern Plains/Mississippi Valley... The meteorological setup on Saturday across the south-central U.S. will be similar to Friday, through with the compact upper low gradually tracking north across the southern half of the Plains. The continued enhanced moisture and instability will yield an environment favorable for convection with intense rain rates causing flash flooding concerns. Areas farther north into Oklahoma should see stronger forcing, while the low level jet could be maximized farther south into Texas. Thus covered all this area with a Slight Risk. REFS probabilities (which extend through the Day 2 period) show scattered instances of QPF potentially exceeding FFG. Smaller scale boundaries leftover from thunderstorms on previous days could provide areas of focus that would likely be unclear before the near term. ...Ohio Valley... The northern stream shortwave is forecast to push through the Great Lakes/Ohio Valley and Northeast on Saturday, with a frontal system ahead of it. The front should lay west to east across the Ohio Valley, so scattered storms could train and cause isolated flash flooding. The Northeast can also expect some convection, but likely progressive enough to limit flash flood potential to below a Marginal. In this ERO issuance, connected the Plains and Ohio Valley Marginal Risks together. There is some potential for storms back into northern Missouri and vicinity, which could be very wet after multiple rounds of convection, so wanted to cover that area. Tate Day 3 Valid 12Z Sun Jun 07 2026 - 12Z Mon Jun 08 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF THE SOUTHERN/CENTRAL PLAINS TO LOWER/MIDDLE MISSISSIPPI VALLEY... 20Z Update... No large-scale changes were made to the previous forecast. Minor adjustments, included adjusting the Slight and Marginal Risk areas a little further east across the mid Mississippi and lower Ohio valleys. Pereira Previous Discussion... Into Sunday, southern stream energy will continue to push north through the central/northern Plains and Midwest while opening up into a trough. This will once again provide forcing for thunderstorms in the Plains and Mississippi Valley. A low level jet of 30-40 kt should bring instability and moisture into the region. The best overlap of ingredients for flash flooding, supported by GEFS/ECens probabilities for over an inch of rain, will likely be centered over Missouri south into Arkansas and west into eastern parts of Kansas and Oklahoma, so this is where the Slight Risk is drawn for Day 3. Some convection could linger farther south toward the Gulf Coast, which the Marginal covers. By Sunday night, a northern stream trough with a strong vort max is forecast to push into the northern High Plains, bringing enhanced QPF ahead of it for a Marginal Risk stretching through portions of the Dakotas and western Minnesota. Tate 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