FOUS30 KWBC 130058 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 858 PM EDT Fri Jun 12 2026 Day 1 Valid 01Z Sat Jun 13 2026 - 12Z Sat Jun 13 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF EASTERN KANSAS, SOUTHWEST MISSOURI, AND NORTHERN NEW ENGLAND... ...Northern New England... Decreasing intensity and decreasing areal coverage on radar imagery combined with warming cloud top temperatures shown on satellite imagery point to a rapidly diminishing excessive rainfall threat. The Slight and Marginal areas were removed from the Northeast. Mid-Atlantic Region. The downward trend in rainfall intensity noted in New England was also occurring in the Mid-Atlantic region...but the convection was still strong enough to support localized rainfall rates in excess of an inch per hour. The threat is expected to diminish quickly...perhaps as early as 03Z or 04Z...given the loss of daytime heating. However it was too early to remove the Marginal in this part of the country. Eastern Kansas into Southwest Missouri... Maintained the Slight Risk area from parts of Kansas into southwestern Missouri in deference to latest CAMs showing upscale growth of convection later tonight as storms initially over parts of Colorado and New Mexico move eastward and encounter greater instability and forcing. The 00Z sounding at DDC showed 30 kt southerly flow above 850 mb that was drawing higher dewpoints into the region. The latest mesoscale guidance has a good signal for heavy rainfall...with the expectation that hourly rainfall rates reach 2.5 inches per hour with total amounts to 4 hours that results in isolated to widely scattered flash flooding. There latest CAMs introduce some doubt about the northern extent of rainfall in Kansas and Missouri...but daytime runs of the HREF and REFS consistent in the rainfall footprint expansion given the low level jet and the evolving shear pattern. See Mesoscale Precipitation Discussion 0400 for latest details. Bann Day 2 Valid 12Z Sat Jun 13 2026 - 12Z Sun Jun 14 2026 ...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF EASTERN KANSAS AND SOUTHWEST MISSOURI... ...Central Plains to Mid-Mississippi Valley... 20Z Update: In coordination with the local WFO's across eastern Kansas into Missouri, a Moderate Risk was issued for the D2 period with emphasis across eastern Kansas into southwestern Missouri. Deep moist environment will preclude the arrival of a prominent shortwave ejecting into the Central Plains, making headway into the mid-Mississippi Valley on Saturday afternoon and evening. Instability gradient will be present across northern MO into Iowa as a cold front begins to slowly press south with the guide of a potent shortwave trough dropping out of Canada. This is the making of an increasingly convergent low to mid-level setup within a very favorable environment across the nation's mid-section. Instability across eastern KS into MO will be quite robust with model forecast MUCAPE along and east of I-35 into the 3500-5000 J/kg range by the time we reach peak diurnal heating. Coupled with a deep moisture pool in the column, any convective development will comprise of significant rainfall rates as noted via elevated hourly and 3-hourly prob fields within the latest 12z HREF. Deterministic output from various CAMs indicate rates between 2-3"/hr with likely higher intra-hour rates exceeding 4" at times, especially as you get further south into southeastern KS and southern MO where instability will be maximized. QPF forecasts are consistent for 2-4" totals across the area south of Topeka down into the Joplin/Springfield region of southwestern MO. Kansas City at this time on the edge of the potential with a split in guidance on where the heaviest precip will reside for the northern and northeast periphery of any established maxima. Considering such a close proximity to the max, and the D2 error in convective forecasting still a concern, there's potential that the urban center can get into some of the heavy precip as it materializes on Saturday evening. With a Flood Watch issued over the metro and surrounds, decided to include the city in the MDT risk to maintain consistent messaging and signaling a heightened threat compared to normal. A high-end SLGT is forecast for much of the remainder of Missouri not encompassed within the MDT risk. There could very well be an initial round of thunderstorms in the morning across southern MO in conjunction to the shortwave moving across the area as referenced in the D1 update. Any rainfall occurring would be a priming scenario for what would transpire later as the cold front to the north begins pushing south with a strong low-level convergence pattern taking shape over the mid-Mississippi Valley. The area of greatest concern, outside the MDT risk, is likely across northeastern MO where recent rainfall over the past 72hrs have led to significant flash flooding over portions of the area allowing for highly compromised soils and swollen streams and creek beds located in the area. Local FFG's in the 1/3/6 hour thresholds continue to run much lower than normal with most of the thresholds between 1-2" for either temporal range meaning any heavy convection will be susceptible to flash flood prospects. As of now, the saving grace for areas north of I-70 will be a majority of the precip will be due to the frontal progression and any convection should be more progressive in the grand scheme. This typically negates significant flooding prospects as rainfall will only last for so long before it moves away and we see a de-escalation of hydrologic impacts. In any case, the threat is still elevated across much of the mid- Mississippi Valley, so the period will bear watching for any short term upgrade potential if trends allow. ...Midwest... 20Z Update: A strong cold front will migrate through the region allowing for convective initiation over the Central Midwest into the western Great Lakes, overlapping areas that have been hit recently with periods of heavy rainfall. The highest potential is across southern and eastern IA into northern IL where significant rains have impacted area FFG's considerably over the past 72hrs meaning chances for flash flooding are easier to attain. Progressive nature of precip is the reason this area is just outside the more significant rainfall prospects, however environmental conditions are still favorable over the area with deep moisture pooled as far north as I-80 for the setup. As the front moves out of the area, drier air will advect into the region in its wake ending the threat for the rest of the forecast period. Widespread 1-3" with local to 4" is forecast in this area of the CONUS, certainly enough to cause scattered flash flood threats as the pattern evolves when you couple with the lower FFG's in place. A broad SLGT risk is forecast for the potential. Kleebauer Day 3 Valid 12Z Sun Jun 14 2026 - 12Z Mon Jun 15 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF TEXAS AND THE LOWER MISSISSIPPI VALLEY... 20Z Update: Little changes were necessary for the D3 period as guidance remained fairly consistent on the premise of heavy rainfall across the Southern Plains to Lower Mississippi Valley on Sunday. The SLGT risk across west TX was pushed further west into southeastern NM to reflect the latest QPF increase from 12z guidance. Overall synoptic pattern remains favorable heavy rain across much of the area south of I-40 with the heaviest rain likely to occur over the Lower Mississippi Valley given the approach of the cold front to the north and a very moisture rich environment thanks to advection of Gulf air. Will be monitoring closely for any targeted upgrades, but will likely have to see how the previous period's convection evolves before doing so. Kleebauer ...Southern Rockies, Texas to Southeast... A cold front pushes down the Southern Plains into Texas on Sunday. This shunts the heavy rain focus south of Saturday and provides a strong focus for convective development in a rich Gulf-sourced moisture environment. PW anomalies are 2 to 3 sigma above normal across Texas (south of the Panhandle) by that afternoon with 2 sigma anomalies expanding east to Alabama by late Sunday night. Expansion of the Slight Risk to both North Texas and the Houston metro areas are warranted given the environment as well as the 00Z consensus of the UKMET and EC-AIFS for the Houston area, and the RRFS and RDPS for North Texas. Furthermore, a decent signal for lasting thunderstorm development is over West Texas in the Permian Basin into the Concho Valley, so a Slight Risk was raised there as well. Additional terrain driven diurnal activity is expected over the Southern Rockies/Sacramento and Davis Mtns. This activity should spread southeast through the evening, so the Marginal Risk was expanded over the southern High Plains. A surge of moisture up the southern Appalachians Sunday morning brings enough of a heavy rain threat for a Marginal Risk expansion up to the westernmost section of Virgina. ...Hampton Roads and Delmarva... Southwesterly low level flow from the Carolinas bring 2" PW to the Mid- Atlantic coast Sunday afternoon ahead of a cold frontal passage that night. Evening thunderstorms should be heavy and slow enough to warrant a Marginal Risk. Jackson Day 4 and Day 5 Valid 12Z Mon Jun 15 2026 - 12Z Wed Jun 17 2026 ...A SLIGHT RISK OF EXCESSIVE RAINFALL EXISTS FOR PORTIONS OF THE SOUTHERN PLAINS, LOWER MISSISSIPPI VALLEY, AND THE SOUTHEAST... 20Z Update... The suite of 12Z guidance has largely remained consistent with the large scale flow pattern and the higher chances of heavy to excessive rainfall being confined in proximity to the gulf coast. There was little need to make more than subtle nudges to the Marginal Risk areas in the previously-issued outlook...and no changes were made to the Slight risk areas on either day, Bann Previous Excessive Rainfall Discussion Overall, not much change from the previous forecast, with the overnight guidance continuing to present a good signal for highly- efficient training storms along a slow-moving front settling into the region. Models continue to show a cold front settling slowly south though the southern Plains, lower Mississippi Valley, and the Southeast as shortwave energy gradually amplifies a broad upper trough centered along the Mississippi Valley on Monday. A deepening pool of moisture along the front, fed by southerly low level inflow from the western Gulf, will fuel the potential for highly-efficient showers and storms. Guidance continues to show PWs increasing to 2.25 inches (2.5 to 3 std dev above normal) along and ahead the front from south South Texas to southern Alabama on Monday. Interacting with this moisture is expected to be an area of enhanced ascent provided by right-entrance region upper jet forcing positioned along the base of the amplifying trough. In addition to the deep moisture and large-scale ascent, repeating storms are expected to raise the potential for heavy amounts and flash flooding concerns. A Slight Risk was maintained from southeastern Texas to central and southern Alabama on Day 4. By Tuesday, the upper trough axis begins to shift to the east, pushing the front, deeper moisture, and the better chance for heavy rain farther south and east along the Gulf Coast. For Day 5, a Slight Risk was drawn from southeastern Louisiana to southwestern Georgia. While Slight Risks were drawn for both periods, given the potential for several inches of rain in some locations, an upgrade to a Moderate Risk may be required in future updates if the signal persists as the event draws nearer. Pereira 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 $$