


Area Forecast Discussion
Issued by NWS Omaha/Valley, NE
Issued by NWS Omaha/Valley, NE
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738 FXUS63 KOAX 162026 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 326 PM CDT Mon Jun 16 2025 .KEY MESSAGES... - Severe storms and heavy rain will be possible (15-30% chance) into the evening and overnight hours tonight. Storms will be most intense early on, with gusts in excess of 75 mph possible alongside large hail, and localized flooding being the main concerns. - Severe storms (15% chance) and heavy rain/flooding potential (5-30% chance) return Tuesday, especially in southeast Nebraska into southwest Iowa, though questions remain on north/south extent of storms. - 50-75% chance for oppressive heat overspreading the central plains Friday and persisting through the weekend, with heat indices expected to reach at least 100 degrees. && .DISCUSSION... Issued at 326 PM CDT Mon Jun 16 2025 Early afternoon analysis showed a surface cold front stretching from near Mitchell, SD, southwest into northeast/north-central NE and into the NE panhandle. By 2 PM, a few storms had fired in southeast SD and convection was starting to "zipper" down the front. There was still fair amount of MLCIN in place ahead of the front, and some fairly dry low level air per the 18Z OAX sounding farther southeast, so generally think convection should be on a downward trend as it pushes southeast the rest of this afternoon into this evening. Still, do think it will continue for a few hours despite many CAMs suggesting otherwise, as deep moisture convergence will slide into northeast NE. They`re not perfect, but the 16.12Z NSSL WRF and and NAM Nest solutions seem to make sense with storms going up in northeast NE/southeast SD with potential for supercellular structures at times producing a large hail, damaging wind, heavy rain, and even a low-end tornado threat this afternoon. Eventually things should congeal along southeastward-moving outflow boundary with additional storms along it, but they should generally run out of steam as they approach the Platte River. All that said, a less probable, but possible scenario depicted by the HRRR could pan out where we only get spotty convection along the boundary through the afternoon. Instead we`d wait for a shortwave currently in eastern WY to push in around or just after midnight and bring an MCS and mainly a damaging wind and heavy rain/flooding threat. The MCS moving through into early Tuesday will help push instability largely to our south and while we should see a break in precip during the morning, lingering cloud cover should still help to limit instability building through much of the area during the day. Still, guidance is in decent agreement that the surface boundary and instability plume still remain in place across portions of southeast NE and into southwest IA, though a few solutions keep them to our south. Low level moisture transport will point into that boundary by the afternoon and lead to more storm development heading through the evening and overnight hours. Along the boundary, shear profiles look sufficient for all severe weather hazards. In addition, ingredients are in place for training storms to lead to heavy rain and flooding (1.75" to 2.00" precipitable water, warm cloud depths of 3750 m, and strong moisture transport pointing directly into a boundary). Several CAMs do have pockets of 3"+ rainfall totals near the boundary, but again, still some differences on north/south placement of the boundary that we`ll need to work out. Tuesday night into Wednesday, a surface low will develop northeastward into eastern IA and while our severe weather threat should be over on Wednesday, we`ll likely have some lingering showers and isolated storms through the day. Temperatures will also be more comfortable, with highs in the upper 70s to lower 80s. Precip should exit by Wednesday evening with the surface low pushing into the Great Lakes and surface ridging moving through overnight. By Thursday morning, southwesterly flow will return with a warm front advancing northward through the area. This will bring a return of warm, humid weather as temperatures get back in the mid 80s to lower 90s. Several pieces of guidance suggest we`ll see some storm development along the warm front by Thursday afternoon/evening, with consensus suggesting northeast NE/west-central IA would see the highest chances (30-40%). Still a little early to determine severe weather potential with plenty of smaller scale details to work out, but initial looks suggest there would be sufficient instability and shear for at least a small threat. Upper level ridging starts to build in Friday through the weekend with southerly flow continuing to usher in warm, humid air. We should see widespread 90s Friday through Sunday with dewpoints in the mid 60s to lower 70s. The warmest day currently looks like it`ll be Saturday when several spots could make a run over 100 degrees with some heat indices approaching 105/heat advisory criteria. NAEFS guidance does indicate 850 mb temperatures in the 25 to 28 C range, good for the 99th percentile of climatology and mixing those down would get us into the 100s. So bottom line, looking hot for the weekend. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1239 PM CDT Mon Jun 16 2025 Main forecast concern will be timing of potential thunderstorms and associated MVFR to IFR conditions. There remains a large spread in guidance with some firing storms in northeast Nebraska, including near OFK by 21Z and pushing those southeast toward OMA and LNK by 23-00Z. However, more likely scenario is that storms go up later, pushing toward OFK by 02Z and overspreading the rest of the area overnight. A few storms could be severe with damaging winds and large hail. Otherwise, outside of storms expect VFR conditions with southerly 10-12 kt winds this afternoon with a few gusts of 20 kts. Winds will be lighter Tuesday with somewhat variable direction. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...CA AVIATION...CA