000 FXUS63 KOAX 261945 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 245 PM CDT Sat Apr 26 2025 .KEY MESSAGES... - Lingering showers and thunderstorms this afternoon into early evening in northeast Nebraska. - Isolated occurrences of large hail and/or damaging winds are possible Sunday night. However, thunderstorm coverage is uncertain. - Severe weather is likely along and east of a front Monday afternoon and evening. The frontal location at that time remains uncertain, with the most probable location being along or just east of the Missouri River. && .DISCUSSION... Issued at 244 PM CDT Sat Apr 26 2025 ...Rest of this afternoon and tonight... Scattered showers and isolated thunderstorms ongoing across portions of northeast NE are expected to linger into early evening before shifting east of the area. Most of the precipitation will remain light with generally less than a tenth of an inch expected. Tonight, persistent southeast winds will advect an increasingly moist low-level air mass into the region, leading to widespread low clouds and potentially some fog development toward daybreak Sunday across our western counties. Latest CAM output has backed off on shower and thunderstorm potential tonight, so the PoPs have been lowered. The best QPF signal is late tonight into Sunday morning across portions of southeast NE and southwest IA, where forecast soundings suggest the potential for drizzle or light rain showers. ...Sunday and Sunday night... Clouds are expected to linger through much of the day, which will limit daytime heating. As such, this forecast update will indicate slightly cooler highs in the mid 60s to low 70s. The models have also trended drier across our area as the primary forcing for ascent will remain over the northern and central High Plains, in closer proximity to a surface low and lead shortwave trough overspreading western portions of SD and NE. A tightening pressure gradient east of the surface low and associated lee trough will lead to increased wind speeds with south-southeast winds gusting to 25-35 mph Sunday afternoon into Sunday night. Interestingly, most of the 12z CAMs are at odds with the parameterized models with respect to thunderstorm potential over the mid MO Valley Sunday night. The CAMS largely maintain a dry forecast, whereas many of the parameterized models show a QPF signal. Given the inconsistencies, PoPs have been lowered to 20-40%. The presence of a moist and moderately unstable air mass would support strong to severe storms capable of isolated occurrences of hail and locally strong winds, given storm development and sustenance. ...Monday and Monday night... A vigorous shortwave trough and attendant, mid-level jetstreak over the central High Plains Monday morning are forecast to rapidly translate northeast into the upper MS Valley and upper Great Lakes region by Monday evening. In the low levels, the primary surface low is expected to develop from SD into MN, while a trailing Pacific front advances into eastern NE and western IA. Model differences exist in how far east that boundary progresses by mid to late afternoon when thunderstorm initiation is expected. That frontal location will ultimately dictate how much of our area will be subject to a risk of severe weather. East of the front, the models continue to indicate that a moderately unstable, warm sector air mass will coincide with 50-60 kt of deep-layer shear; supportive of supercells capable of very large hail and locally damaging wind gusts. The overall tornado threat could be limited --at least initially-- by veered low-level winds, which reduce low-level hodograph curvature/SRH. Any storms that develop in our area will quickly move the east/northeast by Monday evening. Highs on Monday are expected to top out in 80s at most locations. ...Tuesday through Friday... Loosely phased, polar and subtropical-branch shortwave troughs are forecast to move through the central U.S. on Wednesday into Thursday. That will result in increasing shower and thunderstorm chances (peak PoPs of 30-50%) during that timeframe. Cooler afternoon temperatures in the 60s on Tuesday are expected to warm into the 70s Wednesday-Friday. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1205 PM CDT Sat Apr 26 2025 An area of light showers and isolated thunderstorms ongoing across portions of north-central and northeast NE will continue northeast this afternoon with periodic -SHRA expected at KOFK into late afternoon. Elsewhere, an MVFR (FL020-025) cloud deck has developed across southeast NE (including KLNK) with model soundings suggesting that the MVFR conditions could last into early evening. Those clouds are expected to remain to the immediate south of KOMA, so prevailing VFR conditions will be maintained there. MVFR to potentially IFR ceilings are expected to become widespread late tonight into Sunday morning, which has been reflected in the terminal forecasts. Finally, gusty east- southeast winds have developed as of mid-day, with those winds continuing this afternoon before decreasing slightly tonight. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...Mead AVIATION...Mead