


Area Forecast Discussion
Issued by NWS Omaha/Valley, NE
Issued by NWS Omaha/Valley, NE
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960 FXUS63 KOAX 302331 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 631 PM CDT Sat Aug 30 2025 .KEY MESSAGES... - Cool and wet conditions are expected through the holiday weekend. - Multiple rounds of heavy rain and embedded thunderstorms through Monday could lead to localized flooding, though the risk for damaging winds or hail remains low. - Temperatures stay on the cool side into next week, with highs in the 60s to low 70s. && .DISCUSSION... Issued at 216 PM CDT Sat Aug 30 2025 Today through Monday... Water vapor imagery this afternoon displays a mid- to upper-level high centered over western TX, with a mid- to upper-level trough over the northeastern CONUS. Between these features, a vorticity maxima is sliding through the zonal to northwesterly flow present across west-central Nebraska. A messy cluster of additional vorticity maxima are present across the Dakotas, with guidance continuing to consolidate these disturbances into a mid-level low with an associated surface low that slowly drifts southeast across east-central NE through the holiday weekend. As of 1 PM, surface analysis places a weak surface low over east-central Nebraska along with a surface trough extending to its north into south-central SD. This evolving system will sustain widespread showers and embedded thunderstorms through the weekend. As of 2 PM, MRMS composite reflectivity displays a wide area of precipitation across east- central NE. CAM guidance continues to expand this footprint eastward through the afternoon and evening, persisting through much of Sunday and into Monday. PoPs peak overnight into Sunday morning (60-90+%), gradually tapering off by late Monday (50-75%). The greatest coverage is expected west of the Missouri River, peaking across east- central and southeast NE. Persistent cloud cover and rainfall will hold temperatures below seasonal norms, with highs in the 70s today, falling to the mid to upper 60s Sunday and Monday. A misty/foggy start is likely Sunday morning, with visibility reductions in areas that receive heavy rainfall into the overnight period. Locally heavy rainfall and flooding concerns remain the primary focus. Showers will be efficient rain producers given PWATs of 1.50- 1.75", warm cloud depths near 3.5 km, and long, skinny CAPE profiles on model soundings. However, the weak instability may limit how many heavy showers are able to initiate. Guidance favors a swatch of 2-3" totals extending from southeast NE towards the Grand Island-Kearney corridor, with localized 4-5" amounts possible. Roughly 75% of ECMWF ensemble members support 3" totals in this area, with 90th percentile values peaking near 4-5". While rainfall rates may occasionally approach 1-1.5"/hour under locally heavier showers, most accumulations will result from the prolonged shower duration. Flash flood guidance remain on the higher side given our recent dry conditions (1hr ~2.5", 3hr ~3", 6hr ~3.5-4.5"). Thus, a Flood Watch has not been issued at this time, though heavier pockets may approach thresholds. Recent CAM guidance has trended towards keeping the majority of the heavier pockets just west of our CWA border (towards the Grand Island to Ord, NE vicinity), but this will be monitored closely as guidance and convective trends evolve. WPC maintains a slight risk (level 2 of 4) for excessive rainfall across eastern NE today and Sunday. Given the relatively weak instability (MLCAPE <500 J/kg) and bulk shear (<20 kts), severe weather concerns remain low. However, frequent lightning will accompany any embedded storms, something to be mindful of if you have outdoor plans over the long weekend. Given the proximity to the surface low on Sunday, we could see the potential for a few funnel clouds, particularly in east-central NE. However, funnel clouds under these conditions rarely reach the ground. Tuesday and Beyond... By Tuesday, precipitation is expected to taper off (PoPs 15-30%) as the departing low gradually becomes absorbed into a broad trough over the east-central CONUS. Partial clearing may allow highs to step back into the 70s. Late Tuesday night into Wednesday, a vigorous shortwave trough tracking across Manitoba/Ontario toward the Great Lakes region will drive a cold front through the region. Precipitation chances (20-40%) returns ahead of the front`s passage. In its wake, a seasonable strong speed max will usher in cooler air. Highs on Wednesday and Thursday are expected to fall into the 60s, with overnight lows dipping into the 40s and 50s, roughly 15-20 degrees below seasonal norms. Cooler-than-average conditions are expected to persist through the remainder of the work week as strong northwesterly flow dominates. The CPC 6-10 day outlook (valid Sep 4-8) strongly favors below- normal temperatures across much of the east-central CONUS. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 631 PM CDT Sat Aug 30 2025 Showers and perhaps a few thunderstorms will continue to move through the area through the period. VFR conditions are expected to prevail at the TAF sites early in the period, though can`t rule out some occasional drops to MVFR or even IFR this evening. MVFR to IFR ceilings are expected to become more widespread overnight and into Sunday with any heavier showers also leading to MVFR to IFR visibility, though latest guidance generally favors lighter rain through much of the period. Otherwise, winds should be around 6-12 kts, mainly out of the east to southeast. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...Wood AVIATION...CA