


Area Forecast Discussion
Issued by NWS Omaha/Valley, NE
Issued by NWS Omaha/Valley, NE
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854 FXUS63 KOAX 111726 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 1226 PM CDT Mon Aug 11 2025 .KEY MESSAGES... - Patchy fog has developed across eastern Nebraska and western Iowa, with visibilities dropping below 1 mile at times. - Scattered showers are possible again on this morning and early afternoon, mainly near/south of I-80. Severe storms and flooding are unlikely. - Mainly dry conditions and seasonal temperatures are expected through the mid-week. - Warmth returns by Friday, with increasing chances for heat indices to hit 100 degrees. && .DISCUSSION... Issued at 257 AM CDT Mon Aug 11 2025 Today through Wednesday: Water vapor imagery this morning features a broad, weakening trough centered over the Central Plains powering healthy convection across southern Kansas while the eastern edge of the trough/frontal system extends northeastward from Missouri into the Great Lakes region. Drilling down locally, relative high pressure has slid in behind the frontal system to the south and east and slackened winds. The quiet wind field has joined a gap in the cloud shield being sent downstream by the convection down south, increasing the amount of radiational cooling across the area before cloud cover becomes more widespread. So far, any lower visibilities have been sporadic at any one location -- bouncing below and back above 1 mile, across much of western Iowa and portions of far eastern Nebraska. If fog becomes more widespread and persistent, a Dense Fog Advisory will be warranted. Once fog begins to clear around or shortly after sunrise, it will be joined by an arm of scattered showers and a few rumbles of thunder beginning to move into far southeastern Nebraska. These showers and storms should be on the weak side and will decay as they go north, only mustering light rain and an occasional gust to 30 mph through mid-morning. The increased cloud cover will help continue the cooler temperatures, with highs only reach the upper 70s to low 80s this afternoon. An embedded shortwave is also expected to pivot through the backside of the slowly departing trough late this afternoon into the early evening, and may force a light shower or two across northeast Nebraska (10% chance). For Tuesday and Wednesday, we`ll see that embedded shortwave give a kick in the pants to the aforementioned larger trough and help sweep it east of the area. Mid/upper heights will rise and bring west- northwesterly flow aloft with our soggy pattern running dry through mid-week. Highs in the 80s alongside a light breeze will make for a great couple of days to go to the park, dine out on the patio, or at the very least not strain the A/C too much. Latest runs of the ensemble guidance does show a compact shortwave moving across South Dakota Wednesday afternoon, putting us not too far off from some low- end severe threat, but the best chances are still off to the north. Thursday and Beyond: By the latter half of the work week, we begin to see the upper pattern begin to shift, transitioning a low-amplitude ridge from the Desert Southwest towards the Lower Mississippi Valley. As it passes to the south and eventually settles to the southeast of the forecast area, we`ll see high temperatures trend towards the 90s before arriving area-wide Friday, lasting into early next. With the forecast area being on the far northern end of the ridge to the south, we`ll find a stationary front that will set up shop across southern South Dakota, helping to provide some forcing for ascent in addition to passing mid-level shortwave impulses that will drive nearly daily chances for rain Friday onward. A conservative forecast is currently in place for dewpoints during this period, and heat indices of 100+ look likely for most of the area late this week -- especially Friday afternoon. If surface moisture trends upwards, we would see the need for another Heat Advisory that would feel just a tiny bit warmer after such a pleasant early to mid-week. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1147 AM CDT Mon Aug 11 2025 Cloud deck at FL050 is bringing rain showers to areas along and south of I-80. This is expected to linger through the afternoon before pushing east. The remainder of the forecast should be dry. Will continue with VFR conditions through it all, Winds are expected to be below six knots at most times with easterly winds slowly becoming southerly and then westerly over the course of the next 24 hours. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...Petersen AVIATION...Nicolaisen