FOUS30 KWBC 121553 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 1153 AM EDT Fri Jun 12 2026 Day 1 Valid 16Z Fri Jun 12 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... 16Z Update: Quasi-stationary front across ME will be a focal point for heavy convection late this morning and afternoon. 12z sounding out of KGYX depicted a robust, deep moist profile with PWATs well- above normal (1.92"), hitting closer to the 99th percentile when adjusted for climatology. A stout warm cloud layer presence was also noted on the morning sounding with the WBZ height right around 13-13.5k ft, a sounding more respectable for environments based in the south, let alone northern New England. These type of environmental conditions lend to efficient warm rain processes that are notorious for overperformance within any precipitation schema, but especially anything convectively driven. Reports this morning from just area showers and isolated thunderstorms produced one to locally two inches of precipitation across portions of New England in the past 6 hours, a testament to the efficiency of the rainfall. Complex terrain and flashier streams and rivers across northern New England offer better potential for flash flood concerns when convective activity is introduced and today offers one of the better potentials in quite a long time. Flow will be weak as steering flow remains meager leading to slow-moving showers and thunderstorms likely to materialize in proxy to western ME into northern NH with heavy rain potential of 1-2"/hr plausible in the stronger cell cores. Considering the light and variable flow within proximity to the terrain, a quick 1-2+ inches can cause issues in regards to flash flooding as has been historically the case for these types of environmental conditions in place. 12z HREF neighborhood probabilities for >3" are quite robust with a formidable area of >70% probability for the referenced threshold. This alone is more than enough to justify a targeted SLGT risk upgrade for the period, which has been introduced in coordination with the local ME offices. Timing for the threat will occur between now and sunset with the loss of diurnal heat flux likely to put an end to the threat as a cold front approaches out of Quebec. Kleebauer ...Eastern Kansas into Southwest Missouri... 16Z Update: Highly conditional setup for significant rainfall exists across portions of the central CONUS with the main axis of potential aligned over eastern KS down into southwest MO. Recent rainfall over the region has provided a decent soak to the top soil layer with elevated streamflows being seen across portions of the above area. A mid-level vorticity maxima is forecast to motion out of the adjacent High Plains of eastern CO and western KS with a migration eastward within the mean flow aloft. Some CAMs are pretty aggressive with the potential for convection to fire across eastern KS and motion southeast into MO as we move into the back end of the forecast period. The timing of the disturbance entering the area coupled with a nosing 850mb LLJ over KS would in theory aid to the development of convection with a rapidly improving mid- level shear profile capable of sustaining a stronger mesocyclone initiation leading to a focus of heavy precipitation. The HRRR/NAMNest are the most aggressive with this signature with the AIFS also inferring at least the threat of some convective development in that 06-12z Sat window. Recent HREF neighborhood probs for >2" have adjusted up closer to 20-30%, doubling the previous probabilities from the last forecast cycle. HREF EAS still remains weak in the depiction which exemplifies the conditional nature of the threat, and a split in the guidance on handling the convective potential and eventual evolution. Despite the conditionality of the risk, there was a SLGT risk added to the area for two reasons. The first was the antecedent soil moisture and streamflows are currently conducive for flash flood capabilities as any heavy rainfall will pose a threat for run off and hydrologic issues. The second is the environmental conditions leading in are genuinely favorable for locally higher rates within any cells that do materialize as PWATs remain 1-2 standard deviations above normal across the region. Models that do show the rapid convective development and impacts are depicting rates between 2-3"/hr at peak, a range that would easily breach the current hourly FFG threshold in place over much of the area (1-1.5"/hr). In coordination with the local WFO's across the area, the SLGT risk was added for the conditional threat. Kleebauer ...West Texas... 16Z Update: Modest theta_E ridge across southwest TX into the High Plains of NM will allow for sufficient low to mid-level buoyancy this afternoon ahead of a weak diffluent axis approaching from the west during the period. MUCAPE between 1000-2500 J/kg will be positioned across the western RGV up through the mountains of southwest TX through the Upper Trans Pecos, plenty enough instability to maintain isolated strong convective cores to materialize across the area. Initiation will likely occur over the Sacramento Foothills down into the Davis Mountains with cells likely drifting eastward off the terrain and migrating into the adjacent High Plains. Isolated flash flood concerns will arise from the convection in the area, enough of a signal to warrant a continuation of a MRGL risk across the region. Kleebauer ...Central and Southwest Florida... 16Z Update: No changes to the previous forecast as the 12z guidance remains consistent in its interpretation of locally heavy rainfall across central and southwest FL this afternoon with the main threat along the sea breeze(s) and any convergence. 12z HREF neighborhood probs for >5" are between 40-70% across south-central FL towards the southwest FL coast, a signal relevant enough to maintain continuity from previous forecast. Kleebauer ..Previous Discussion.. Anomalous moisture will reside over southwest and central portions of the Florida Peninsula today, though it should be a little less in terms of PW compared to Thursday. Convection along the sea breezes should produce very heavy rainfall that could lead to flooding concerns for urban areas in Central and Southwest Florida. A Marginal Risk remains in effect with Tampa Bay removed due to CAM consensus to the east/south of there. Jackson Day 2 Valid 12Z Sat Jun 13 2026 - 12Z Sun Jun 14 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE CENTRAL PLAINS THROUGH THE MIDDLE MISSISSIPPI VALLEY INTO THE LOWER OHIO VALLEY... An upper trough swings down the northern Plains Saturday, pushing a cold front across the central Plains and Midwest through Saturday night. Meanwhile, a warm front tracks from Oklahoma through Illinois ahead of the cold front, creating focus for strong convergence in a very warm, moist, and unstable air mass. Resultant heavy thunderstorms look to organize and repeat from the central Kansas/Oklahoma border through central/southern Illinois and western Kentucky where the Slight Risk was expanded a bit. Particular focus for heavy rain remains near the Kansas/Missouri border where a higher than normal Slight Risk is noted. Scattered instances of flash flooding can be expected and a targeted Moderate Risk is possible. More isolated heavy thunderstorms are also expected over the eastern New Mexico and west Texas terrain and nearby plains where the Marginal Risk remains. The Marginal Risk was removed from most of Michigan based on the 00Z high-res solutions available with little PW anomaly noted. Jackson 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... ...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... 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 $$