716 FXUS63 KOAX 251956 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 256 PM CDT Fri Jul 25 2025 .KEY MESSAGES... - Thunderstorms developing along a slow-moving boundary may produce heavy rainfall, potentially leading to localized flooding in southeast NE through tonight. A Flood Watch remains in effect. - A renewed stretch of dangerous heat is likely Sunday and Monday, potentially stretching into Tuesday. Afternoon heat index values may reach 105 to 115 degrees. - Drier conditions are expected through at least Monday, with rainfall potential returning late Tuesday into Wednesday. && .DISCUSSION... Issued at 235 PM CDT Fri Jul 25 2025 Today and Tonight... This afternoon`s synoptic scale pattern features a mid- to upper- level ridge centered over the southeastern CONUS and an approaching trough over the Pacific Northwest. In between these features, our area sits within zonal to southwesterly flow aloft. As of 2 PM, a slow moving MCV positioned over north-central KS is bringing a few showers to southeast NE and southwest IA. Although some sunshine may break through the cloud cover in place, highs will remain generally in the low 80s. Dewpoints in the low 70s will bring a moist and somewhat comfortable airmass. At the surface, a stationary front remains draped from extreme northeast KS into northwest MO and south-central IA. The precise position of this boundary will significantly influence the risk for excessive rainfall and flooding this evening. As of 2 PM, a vorticity maximum centered over north-central KS is expected to lift northeastward through the evening, potentially brushing extreme southeast NE. This feature may help to nudge the stationary front slightly northward, although guidance has trended away from previous solutions that lifted the boundary closer to the I-80 corridor. Now, it appears the front will struggle to move much beyond the NE-KS border. In the wake of this vorticity maxima, a band of training thunderstorms is expected to develop along the front, capable of producing heavy to excessive rainfall and localized flooding concerns. Atmospheric conditions remain favorable for very efficient rainfall production, with PWAT values of 2.00-2.25" (above the 95th percentile of late July OAX sounding climatology) and warm cloud depths of 4 to 4.5 km. The key uncertainty remains whether this band of thunderstorms will reach into southeast NE and southwest IA or remain confined to northeast KS/northwest MO. All factors considered, have opted to leave the Flood Watch in place through the evening for extreme southeast NE. This is a conditional threat, hinging on whether the axis of heavy rainfall shifts far enough north. The most likely scenario brings storms into far southeast NE, primarily affecting the Richardson and Pawnee county vicinity. Rainfall rates may reach 2 inches per hour, and with 1- hour Flash Flood Guidance in the area ranging from 1.25 to 1.50 inches, on top of the 3 to 5 inches of rain over the past 48 hours, localized flooding will be a concern if these storms materialize. WPC includes extreme southeast NE in a moderate risk (Level 3 of 4) for excessive rainfall. PoPs peak around 75% this evening in far southeast NE, tapering off sharply to the north. A few stray showers and thunderstorms will be possible across the remainder of the forecast area, though PoPs generally peak at 20-30% elsewhere. Severe weather potential remains limited, as deep-layer shear is weak (around 20 kts of 0-6 km shear). Still, a few stronger wind gusts or even a brief tornado can`t be ruled out near the boundary and vorticity maximum, though the risk should stay mainly south of the NE-KS border. Given the proximity to the vorticity maximum and sufficient 0-3 km MLCAPE, we could also see a few brief, weak funnel clouds in any storms that do form. Saturday... Lingering precipitation is expected to taper off early Saturday. In its wake, a moist air mass combined with calm winds and residual cloud cover will support another round of fog development overnight into the morning. Areas of dense fog will once again be possible, particularly in low-lying and sheltered areas. Fog should gradually dissipate after sunrise as skies begin to clear, allowing afternoon temperatures to climb into the upper 80s to low 90s. With dewpoints holding in the low 70s, heat index values will likely reach 95 to 103 degrees. Sunday and Beyond... Toward the end of the weekend, the ridge centered over the southeastern CONUS will expand into the region, ushering in a stretch of dangerous heat. Sunday and Monday are expected to be the hottest days of the week, with highs climbing into the upper 90s and heat index values ranging from 105 to 115 degrees. Heat headlines will be needed for entire CWA, with an Extreme Heat Warning probable for most. Heat will persist into Tuesday for some areas, though a shortwave disturbance moving across the northern Plains will help amplify a trough over Ontario and Quebec, which in turn will flatten the ridge locally. An associated cold front is expected to push through the region on Tuesday, with high temperatures depending on the timing and extent of the frontal progression. High temperatures could range from the mid 80s behind the front to the mid 90s ahead of it. Additional heat headlines may be needed for portions of the area, with heat index values of 105 possible for the southern portion of the CWA. The front is expected to bring a round of precipitation Tuesday evening into Wednesday, with PoPs currently ranging from 30- 60%. Some severe weather potential exists with this system, as machine learning guidance indicates a 5-15% probability of severe weather; however, confidence in timing and details remains low in this extended time frame. Forecast confidence decreases further beyond Tuesday, as long-range guidance suggests the front may stall somewhere nearby, potentially supporting additional rounds of precipitation during the latter half of the work week. With northwesterly flow aloft, lingering showers, and increased cloud cover, high are expected to cool into the upper 70s to low 80s Wednesday through Friday. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1200 PM CDT Fri Jul 25 2025 Patchy MVFR conditions continue early this afternoon as low- level stratus lingers around, though VFR conditions should persist across all terminal for the bulk of the afternoon. Winds will remain calm and out of the southeast. Stray showers and thunderstorms will be possible at KOMA and KLNK through the evening, though confidence in this occurrence is low (20% chance). Meanwhile, a band of heavier storms will set up along the NE/KS border later this afternoon, though these storms should remain south of the terminals. Fog and low-level stratus will redevelop tonight (after 04-06Z), bringing MVFR to IFR conditions across all three terminals. Areas of dense fog will be possible, potentially bringing LIFR conditions. Conditions will gradually improve after sunrise with a return to VFR conditions expected by 14-18Z. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...Flood Watch until 1 AM CDT Saturday for NEZ090>093. IA...None. && $$ DISCUSSION...Wood AVIATION...Wood