FOUS30 KWBC 130736 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 336 AM EDT Sat Jun 13 2026 Day 1 Valid 12Z Sat Jun 13 2026 - 12Z Sun Jun 14 2026 ...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR SOUTHWESTERN MISSOURI... In coordination with SGF/Springfield, MO and EAX/Pleasant Hill, MO forecast offices, the Moderate Risk was shifted south out of the Kansas City metro with this update, but expanded southeast to cover more of the Missouri Ozarks. CAMs guidance of the QPF footprint for the day has followed a very common pattern, which is to shift the heaviest rainfall totals southward. Thus, it appears the greatest flash flooding threat has shifted out of the Kansas City metro. This is most certainly not to say that the flooding threat has reduced to zero for the Kansas City metro, which remains in a higher-end Slight, but that the greatest impacts from flash flooding due to heavy rainfall are no longer expected to reach Moderate Risk thresholds in the Kansas City metro. However, not far to the south, the threat remains significant. Training thunderstorms are expected to begin across Missouri this afternoon. The training and overall coverage of the thunderstorms will increase during the evening with the usual diurnal strengthening of the low-level jet. This will pump abundant tropical moisture into Missouri from the southwest on 40+ kt winds at 850 mb. Since the line of storms is expected to align northwest to southeast, the storms will be orthogonal to that southwesterly flow, which will be essential for the continued redevelopment and training of additional convection as the cells within the line track southeastward. Once the storms reach around the Arkansas border, the low level jet weakens significantly. This should allow for breaks to develop in the line from Arkansas into Tennessee, which will greatly diminish the flash flooding threat in those states. The topography of the Ozarks across southern Missouri supports a heightened flash flooding threat as the mountains quickly funnel the heaviest rains into narrow valleys, worsening the impacts of any flooding that develops there. This fact too supports the southeastward expansion of the Moderate Risk area. Meanwhile, a strong cold front will push southeastward out of the Plains and eventually into Missouri. This front will end all of the rain from northwest to southeast. This too supports the south and eastward shifting of the greatest flash flooding threat. While portions of far eastern Kansas still will have a threat for extended periods of heavy rain, the advancing front reaching those areas before points further east should also reduce the time heavy rain will impact eastern Kansas, allowing for the Moderate to be trimmed a bit. That said, there remains considerable uncertainty as to how far east the best lines of training thunderstorms will set up, so far eastern Kansas remains in an elevated threat for flash flooding. Guidance has come into better agreement that the heaviest rains will occur over Missouri today and tonight, and will struggle to continue further north and east. Thus, the inherited Slight Risk area over Iowa, most of northern Illinois, and all but the southwestern tip of Indiana was downgraded to a Marginal Risk with this update. ...Florida... A Marginal Risk area was introduced with this update for all of the Florida Peninsula. Abundant moisture and slow-moving thunderstorms are expected to develop all up and down the Peninsula this afternoon. Since the storms will be stationary, it stands to reason that the most heavily impacted areas will see extended periods of heavy rain. HREF neighborhood probabilities for over 3 inches of rain are over 70% for the entire Peninsula. Thus, while the urban areas on both east and west coasts are more flood-prone and are likely to miss out on the heaviest rains, any urban areas such as Orlando in the middle of the Peninsula could have isolated instances of flash flooding. Wegman Day 2 Valid 12Z Sun Jun 14 2026 - 12Z Mon Jun 15 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR AREAS FROM SOUTHERN NEW MEXICO THROUGH WESTERN MISSISSIPPI... A slow-moving but potent cold front will approach portions of north Texas through into Arkansas on Sunday. The MCS that caused the Moderate Risk flooding in Missouri Saturday night will be responsible for the heavy rains that elevate northeast Texas through the lower Mississippi Valley into the Slight Risk category. Associated heavy rain will be ongoing at the start of the period Sunday morning, and will weaken and dissipate by midday. Since the forward/southward progression of the heavies rains will slow after daybreak Sunday, some areas may see several hours of weakening but still heavy rains. Abundant moisture will remain in place south of the front, as PWATs rise as high as 2.25 inches. Thus, any cells producing rains will have no trouble doing so efficiently. During the afternoon and evening, this area may see additional widely scattered storms with the strong front stalled out in the area, but coverage will be somewhat in question as the stalled out front alone will not be enough forcing due to flow on either side of the front weakening to light and variable winds. Further west into west Texas and New Mexico, a shortwave trough running into some of the same Gulf moisture as further east should allow for scattered showers and thunderstorms to develop in clusters from the afternoon well into the evening. Topographic assistance by the Sacramento Mountains and other ranges may locally produce heavy rains, where any burn scars may take over at raising the flash flooding risk. The same front extends into the Appalachians and interior Northeast. While the storms will be racing in these areas, the abundance of moisture advecting north into the front will support the storms in their capability of producing heavy rainfall. The Marginal Risk for these areas was expanded along the Canadian border through northern Maine. The Marginal for portions of the Mid-Atlantic was split into 2 areas with this update. One for the I-95 corridor from DC to Philly, and a second for the Hampton Roads area. Abundant Gulf/Atlantic moisture in these areas will support fast-moving but training storms capable of producing heavy downpours. Due to ongoing drought, the threat really is focused on the urban areas where FFGs are lower. The intermediate rural areas were removed with this update as any training storms that occur over most of the Delmarva will be over rural and flood-resistant/flat areas. Wegman Day 3 Valid 12Z Mon Jun 15 2026 - 12Z Tue Jun 16 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE LOWER Mississippi VALLEY TO EASTERN TEXAS... A large, half-continent sized upper level low over northern Ontario will spin numerous shortwaves around its periphery over the eastern 2/3 of the country. The jet stream will coincide with a strong but stalled out cold front over north Texas and southern Arkansas. To the south of that front, Gulf moisture will pool to well-above normal levels, with PWATs to 2.25 inches over east Texas and northern Louisiana. When the shortwaves track over that cold front, it will both allow it to continue drifting southward, but also provide sufficient upper level forcing to trigger numerous and persistent thunderstorms along the east-west oriented front and south. This will support an extended duration of training storms, especially from east Texas through southwest Mississippi. A higher-end Slight remains in effect for this area. The inherited Slight was trimmed out of south-central Texas and central Alabama on the west and east ends, but expanded north-south over Louisiana through the Houston Metro. Rainfall totals in some areas could easily exceed 6 inches, with totals to 10 inches in localized areas possible due to the extended duration of heavy rain, especially along the Texas/Louisiana border. The area remains in a higher end Slight for now primarily due to very high FFGs and dry soils in the area, but further increases in rainfall, especially as this period moves into the CAMs range, could allow for a Moderate Risk upgrade due to the very high rainfall amounts forecast for some areas. Wegman Day 4 and Day 5 Valid 12Z Tue Jun 16 2026 - 12Z Thu Jun 18 2026 ...A SLIGHT RISK OF EXCESSIVE RAINFALL EXISTS FOR PORTIONS OF THE CENTRAL GULF COAST... The first half of the medium range will see two particular threats for flash flooding. First, along the Gulf Coast, a stationary front will work in tandem with with tropical moisture to develop thunderstorms capable of torrential downpours both on Day 4 (Tuesday) and Day 5 (Wednesday). There is greater confidence in Tuesday's flash flood threat given better model agreement in placement of QPF and the nearby frontal boundary remaining strong enough to help trigger numerous showers and thunderstorms. PWs will remain above 2.0" in many cases as well, allowing developing thunderstorms to contain highly efficient rainfall rates. Soils will be more saturated in wake of Monday's thunderstorms as well, making the region more susceptible to flash flooding. The forecast remains largely on track for Tuesday (Day 4) with only some minor tweaks to the inherited Marginal and Slight Risks to more closely resemble the latest WPC QPF. By Wednesday (Day 5) the frontal boundary will undergo frontolysis and the source of lift at the surface will weaken. However, ensemble guidance continues to show ample tropical moisture along the Central Gulf Coast, which at by Wednesday will have dealt with multiple rounds of Excessive Rainfall. A Marginal Risk was introduced along the I-10 corridor from the Houston metro on east to the FL Panhandle to account for the flash flood potential around the more urbanized communities along the central Gulf Coast. Farther north, Wednesday looks like an active day from the Midwest on east into the OH Valley. A 500mb shortwave trough racing east towards the Great Lakes late Wednesday will provide healthy upper- level ascent aloft to foster the development of low pressure. Meanwhile, a strengthening LLJ will direct anomalous moisture located over the South northward into the region. NAEFS shows an impressive IVT for mid-June that surpasses 750 kg/m/s over the eastern Corn Belt that will provide copious amounts of moisture. Guidance is not in agreement yet as to which locations are most favored to witness the heaviest thunderstorm activity. Fast storm motions should also help to limit residency times of developing storms. That said, PWs ranging between 1.75-2.0" will be the norm late Wednesday with storms likely containing efficient rainfall rates. A Marginal Risk was introduced to account for the localized flash flood potential on Wednesday from the Middle MS River on east into the OH Valley. Mullinax 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 $$