500 FXUS63 KOAX 270428 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 1128 PM CDT Sat Jul 26 2025 .KEY MESSAGES... - A renewed stretch of dangerous heat is forecast for Sunday and Monday, potentially stretching into Tuesday. Afternoon heat index values may reach 105 to 115 degrees. - Drier conditions are favored through at least Monday, with higher storm potential returning late Tuesday into Wednesday. Some of these storms could be strong to severe with damaging winds and localized flooding the main threats. - Cooler conditions return for next week`s second half with on and off rain chances. && .DISCUSSION... Issued at 300 PM CDT Sat Jul 26 2025 Upper level ridging continued to build in today leading to a quiet, but warm and humid day with temperatures as of 3 PM in the mid to upper 80s and dewpoints in the lower to mid 70s. Guidance is in good agreement of some storms moving through western and into central NE this evening, but all CAMs kill them off before they push into our area, as they run out of the moisture transport and into much drier air aloft. Plus lack of shear suggests they wouldn`t sustain themselves very long anyway. Otherwise, may need to keep an eye on potential fog development again tonight with mostly clear skies and light surface winds. However, winds aloft look a little stronger than they have been past nights, so development may be a bit more patchy/stratus and/or confined to low-lying areas. Ridging will continue to build in for Sunday and Monday with southerly low level flow ushering in even more heat and humidity. NAEFS guidance suggests 850 mb temperatures in the 90th percentile of climatology for this time of year on Sunday and 99th+ percentile on Monday. Furthermore, we`re basically at our annual climatological peak for temperatures right now, so "extra" impressive. As it stands, currently looking at widespread 90s both days, with Monday generally being 2-3 degrees warmer. In addition, dewpoints in the mid to upper 70s, and possibly around 80 in portions of IA will lead to heat indices well into the 100s and 110-115 for some locations, especially Monday. In addition, nighttime lows will be in the mid 70s for many locations, which won`t allow for much recovery. Therefore, issued an Extreme Heat Warning for most of the area for both Sunday and Monday, with a few counties in a Heat Advisory Sunday and an Extreme Heat Warning Monday. We`ll probably need another Heat Advisory for at least southern portions of the area on Tuesday as well, but a cold front will be pushing in from the north, so confidence in north/south extent is somewhat low at this time. Behind the front, temperatures will significantly drop, with highs in the mid 70s to mid 80s Wednesday, and then widespread 70s Thursday into next weekend. Latest guidance suggests a few places may not even get out of the 60s on Friday. Now regarding storm chances the next several days. We`ll likely stay dry through at least Sunday night and probably much of Monday. Some shortwave energy and a surface trough will dive southeast through the Dakotas, MN, and into IA Sunday night into early Monday. A vast majority of guidance keeps associated shower and storm activity well to our northeast, but a few pieces suggest far northeast NE and west- central IA could get clipped by a shower or storm (10% chance at most). Then by Monday night, the aforementioned cold front will be pushing into southern SD and possibly northern NE while another shortwave impulse slides through. Still some questions on how far south the front makes it, and thus, if we get any storms in our area, but if we do, there would be plenty of instability to work with to yield some strong to isolated severe storms. That said, weak vertical shear should largely limit storm organization in our area. Higher storm chances will likely arrive sometime late Tuesday afternoon into Wednesday as the front continues its track south and some more shortwave energy pushes through. Once again, we`ll have a very warm, moist, and unstable airmass ahead of the front which would yield a severe weather threat, but once again, shear looks to be somewhat limited, so storms could become somewhat outflow dominant and disorganized again. Still, think we`d have a damaging wind and heavy rain/localized flooding threat with guidance suggesting potential for training storms along the front. There remains a fair amount of spread in how quickly the front gets out of here, but at the very least, we`ll see additional post-frontal rounds of showers and storms as various bits of shortwave energy slide through. Basically every time period from Wednesday evening into next weekend has at least a 20% chance of rain. So again, confidence is low on exact timing and strength of any given system, but we`ll probably see on and off rain through end of the week. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1128 PM CDT Sat Jul 26 2025 VFR conditions this evening under mostly clear skies. Stronger winds just off the surface should help to keep the area clear of fog overnight, but we do have a 30% chance of fog impacting the terminals from 09Z-15Z. Otherwise, winds will be out of the south, increasing to 12G20kt by Sunday afternoon. Winds will relax again Sunday evening. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...Extreme Heat Warning from noon Sunday to 8 PM CDT Monday for NEZ011-012-015>018-030>034-042>045-050>053-065>068-090- 091-093. Heat Advisory from noon Sunday to noon CDT Monday for NEZ078- 088-089-092. Extreme Heat Warning from noon to 8 PM CDT Monday for NEZ078- 088-089-092. IA...Extreme Heat Warning from noon Sunday to 8 PM CDT Monday for IAZ043-055-069-079-080-090-091. Heat Advisory from noon Sunday to noon CDT Monday for IAZ056. Extreme Heat Warning from noon to 8 PM CDT Monday for IAZ056. && $$ DISCUSSION...CA AVIATION...McCoy