388 FOUS30 KWBC 051553 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 1153 AM EDT Tue May 5 2026 Day 1 Valid 16Z Tue May 05 2026 - 12Z Wed May 06 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR THE MEMPHIS METRO AND SURROUNDING AREAS... ...16Z Update... In collaboration with MEG/Memphis, TN forecast office, a Slight Risk upgrade has been introduced with this update for the Memphis metro and surrounding areas. Ongoing locally heavy rainfall on the southern bow end of otherwise light rain near and over Memphis has dropped up to 2 inches of rain over small areas of northeastern Arkansas this morning. This morning rainfall, while all beneficial, is working to saturate the very dry soils in the area, while simultaneously moistening the atmosphere. Behind the line of rain this morning, a much more moist and unstable air mass moves in from the south and west. PWATs across western Tennessee and surrounding areas rise well above 1.5 inches, while instability over southern Arkansas could rise above 2,000 J/kg of MUCAPE. This evening and tonight, as a cold front approaches from the north and the nocturnal LLJ to the south strengthens, a renewed round of showers and thunderstorms are expected to develop across Arkansas and southwest Tennessee before moving into Mississippi. As the storms are forming into a line, there will be increased potential for training. As this appears likely to occur over the same areas currently picking up up to 2 inches of rain, expect a small area of higher potential for flash flooding. For northeastern Arkansas, there was more rain there this morning, so the soils will be more primed by tonight. Meanwhile for southwest Tennessee, in addition to the ongoing rainfall, urban concerns around the Memphis metro could also support more widely scattered instances of flash flooding. Once the line moves into northern Mississippi late tonight, the storms are expected to organize into one progressive line, which should limit any flash flooding concerns to isolated instances. Across southern Arkansas, the storms, while strong and capable of heavy rainfall rates, are likely to be much more widely scattered. They will be unlikely to train in such a way as to cause more than isolated flash flooding, especially considering the very dry soils in place there. Wegman Day 2 Valid 12Z Wed May 06 2026 - 12Z Thu May 07 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF THE INTERIOR SOUTHEAST UNITED STATES... Maintained the slight southward shift of the previously issued Slight Risk area introduced a couple of days ago. The coverage and rainfall intensity should be increasing on Wednesday as a large scale trough over the northern Plains continues to amplify and result in a 140 kt to 160 kt upper level jet over the Tennessee Valley during the latter part of the period. The resulting upper divergence, steepening mid-level lapse rates and increasing moisture and instability should result in convection capable of producing heavy rainfall rates and embedded areas of rainfall amounts of 3 to 5 inches as suggested by the latest run of the RRFS. There is a fairly wide spread in the north/south placement of that heavier axis. As a result...the Slight area was expanded somewhat and tended to cover the greatest overlap of higher QPF and exceedance probabilities. Thinking is that there are some probabilities supportive of a higher-end slight risk embedded within the broader Slight. The continued amplification of the upper trough should keep the convection moving southward with time during the overnight hours. Bann Day 3 Valid 12Z Thu May 07 2026 - 12Z Fri May 08 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF THE GULF COAST REGION TO THE SOUTHEASTERN UNITED STATES... Showers and thunderstorms along and ahead of a surface cold front will be lingering into Thursday from parts of the Gulf coast region northeastward into parts of Georgia and South Carolina. At this point...rainfall rates look to be decreasing as the better upper level dynamics pull off to the northeast and low level flow becomes directed along...rather than normal...to the front. Maintained a Marginal Risk area where there could be overlap with areas somewhat higher soil moisture content from recent rainfall. Overall the rainfall looks to be more beneficial than not. Bann 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