Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000 FXUS63 KOAX 122011 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 311 PM CDT Thu Oct 12 2017 .SHORT TERM...
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(Tonight through Sunday) Issued at 311 PM CDT Thu Oct 12 2017 A shortwave trough over the northern High Plains this afternoon will continue northeast into Ontario tonight while the associated surface cold front advances through all but far southeast NE and southwest IA by 12z Friday. The front will slowly settle south into KS and northwest MO on Friday with a wave rippling northeast along the boundary during the day. This cyclone is apparently associated with a low-amplitude perturbation translating through the mid-MO Valley, embedded within a prevailing southwesterly mid-level flow regime. Forecast soundings across central and southern parts of the forecast area indicate a gradual "bottom-up" saturation within the post-frontal air mass with slight-chance PoPs warranted during the day. Cloudiness will temper daytime heating with highs mainly in the 60s. Friday night into Saturday night, 12z deterministic guidance remains consistent in suggesting that a potent shortwave trough will track from the Interior West into the Great Plains. This disturbance will induce a deepening frontal wave which will develop from central KS Saturday morning to southwest WI by Saturday evening. Increased forcing for ascent and destabilization ahead of the shortwave trough and surface cyclone will foster a growing shield of showers and thunderstorms late Friday night into Saturday across the southern half of the forecast area. It remains unclear what impact the early-day storms will have on how far north the surface warm sector can develop into southeast NE and southwest IA on Saturday. Nonetheless, it does appear that there will be some potential for a few severe storms and localized flooding over the southern CWA Saturday afternoon into evening. Highs on Saturday will range from around 60 near the SD border to lower to mid 70s over far southeast NE and southwest IA. Blustery northwest winds are expected to materialize Saturday night on the backside of the surface cyclone with precipitation chances diminishing from northwest to southeast. Sunday will be cooler (i.e. highs in the mid to upper 50s) owing to the passage of a deep-layer thermal trough through the mid-MO Valley. .LONG TERM...(Sunday night through Thursday) Issued at 311 PM CDT Thu Oct 12 2017 Latest medium-range guidance continues to advertise west-northwest flow aloft across the north-central States early next week; to the north of a subtropical ridge nosing through the Desert Southwest. By the middle to latter part of the work week, the spread in model solutions grows. In aggregate, these data suggest a transition to zonal and then southwest mid-level flow during that time frame. This translates to a seasonably warm and dry forecast.
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&& .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 1210 PM CDT Thu Oct 12 2017 An IFR stratus deck which has affected KOMA this morning is quickly dissipating with the onset of deeper boundary-layer mixing. Expect prevailing VFR conditions this afternoon with gusty south winds. Tonight, a cool front will advance southeast through the area with winds switching to north-northeast. Model guidance suggests that MVFR ceilings will become increasingly probable behind the front Friday morning from KOMA to KLNK. Some light showery precipitation is possible at that time as well. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Mead LONG TERM...Mead AVIATION...Mead

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