FOUS30 KWBC 010053 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 853 PM EDT Sun May 31 2026 Day 1 Valid 01Z Mon Jun 01 2026 - 12Z Mon Jun 01 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF EASTERN KS AND CENTRAL MISSOURI... ...Kansas and Missouri... Expanded the Slight risk with this update across most of central MO and portions of eastern KS. As of 01z a surface low is situated near the KS/OK border, with extreme instability (MLCAPE of 4000-5000 j/kg) over eastern KS and southwestern MO. Recent observations show increasing low level convergence ahead of this low over eastern KS, and expect convection to initiate along this convergence axis this evening. Supercells will be possible, locally enhancing rainfall rates. Storm motion vectors are off to the northeast at ~30 kts, however right moving supercell motions are only around 10 kts. There is a lot of mid/upper level dry air which may support cell forward propagation, but given the instability in place and supercell motions, there is probably still an opportunity for isolated to scattered flash flooding from this activity. While not the strongest low level jet, there will likely be enough of a nocturnal uptick in low level moisture transport to result in upscale growth of convection as it moves into MO during the overnight hours. The orientation of convection and weak corfidi vectors suggest some training potential, and think scattered flash flooding is probable, with rainfall locally exceeding 3". ...Southeast... Localized flash flooding will remain possible this evening over the Southeast. A developing surface low off the coast may locally enhance convection for a few hours near the SC coast, but confidence on this remains low, as the better activity could very well remain offshore. ...West TX... A localized flash flood risk continues along the dryline in west TX, although this activity should weaken and diminish shortly. ...Dakotas... Enhanced convergence near an occluded front will result in an isolated flash flood risk this evening across portions of the Dakotas, where convection is showing signs of some backbuilding. Higher rainfall totals and any flash flooding should stay small scale, and thus the Marginal risk should cover the threat. Chenard Day 2 Valid 12Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF THE NORTHERN ROCKIES, GREAT PLAINS, AND MID-SOUTH... Northern Rockies... Precipitation lingers over northwest Montana as a slow moving mid- and upper-level system lingers over the Canadian border. The cumulative effect of the additional 1-2" rain (12Z HREF and REFS consensus) maintains a limited risk for additional flooding concerns. Central Plains... Expanded the Marginal Risk more into Northeast Colorado and into more of north-central Oklahoma while trimming out the heart of the Nebraska Sandhills. SSEly low level flow will increase over the central Plains through the morning and promote strong diurnal heating. Late afternoon High Plains activity should track east over the central Plains. Mid-South... MCS activity is expected tonight over Missouri. This should track from southeastern MO and over much of the Mid-South through the morning with potential for additional evening activity along remnant boundaries. Moist low level flow veers westerly late tonight over the region which should be parallel to at least segments of the activity and increase heavy rainfall duration at least locally. 12Z CAM consensus paints a fairly decent heavy QPF footprint across the Mid-South with 1-3"+ likely through the day. The 18Z HRRR essentially agrees with the tracks of 12Z CAMs along with the later additional activity. Raised a Marginal Risk for the Mid- South on account of the ingredients and CAM output along with 3hr FFG around 2.5". West Texas into New Mexico... South-southeasterly low level flow intensifies Monday afternoon, promoting decent westward expansion of Gulf moisture across the Pecos River Valley to the Sacramento Mountains and south to the Big Bend. Diurnally driven activity is a sure bet on the Davis and Sacramento Mtns. How much activity spreads from the terrain remains to be seen. For now the Marginal Risk was trimmed a bit on the north and expanded over the Big Bend based on 12Z CAM consensus. Jackson Day 3 Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF EASTERN NEW MEXICO AND WEST TEXAS... ...West Texas into New Mexico... Southeasterly low level flow backs further easterly Tuesday bringing more Gulf-sourced moisture across West Texas and southeast New Mexico than was present on Monday. Terrain driven activity should spread across this area with QPF generally in the 1-2" range. Slow moving activity should result in scattered flash flooding, especially over sensitive areas such as burn scars and steeper terrain. The Slight Risk was trimmed a bit to exclude El Paso based on 12Z consensus QPF. ...Great Plains... Warm moist air surges up the Plains in earnest starting Monday night. Sufficient shear from a trough over the Northern Rockies, forcing along a low level convergence zones, and early June heating should promote heavy/potentially organized thunderstorms throughout the Great Plains. A Marginal Risk is maintained from the Dakotas to the Texas Panhandle. ...North Florida through the Gulf Coast... A Marginal Risk has been raised from east Texas through the Florida/Georgia border. A slow moving cold front stretching from Georgia to east Texas Tuesday morning drifts south through the Gulf Coast Tuesday night. High moisture laden air pools ahead of the front with a 2" PW swath from north FL to east Texas in the afternoon which is 2 sigma above normal. Repeating heavy thunderstorms should occur along this corridor and result in a localized flash flood risk. Jackson 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