Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000 FXUS63 KOAX 171956 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 256 PM CDT Fri Mar 17 2017 .SHORT TERM...
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(Tonight through Monday) Issued at 255 PM CDT Fri Mar 17 2017 Temperatures will be the main forecast problem into Sunday, with potential for low clouds moving in Saturday night and lingering into Sunday also a concern. A ridge of cool high pressure will build over the area tonight, then slide east on Saturday. Northwest winds have been bringing in somewhat drier air and with not much sky cover we look for lows in the mid 20s to lower 30s. Due to a cool start and weak to moderate mixing on Saturday, highs should reach the mid and upper 50s in western Iowa / mid 50s to lower 60s in eastern Nebraska. Increasing southerly flow should bring low level moisture and possibly low clouds into the area Saturday night, as suggested by the 925 mb and 850 mb relative humidity progs from the GFS. The pattern also suggests that there may be some drizzle, but did not add drizzle to the forecast at this time. There is also some elevated instability that moves into the area. Best chances for any measurable precipitation Sunday afternoon or Sunday evening should stay to our east and southeast. Will have to keep an eye on that though because a fairly strong front is expected to push down through the area Sunday evening. Record highs for Sunday are - Lincoln, 82 set in 1921 / Omaha, 85 set in 1976 / Norfolk, 82 set in 1921. The fire danger could reach the very high category in southeast Nebraska. On Monday, it will be quite a bit cooler with highs in the 50s for our northern zones and mostly upper 50s to lower 60s in southwest Iowa and southeast Nebraska. .LONG TERM...(Monday night through Friday) Issued at 255 PM CDT Fri Mar 17 2017 This period in general will be unsettled, with several chances for light precipitation for at least parts of the area from Monday night into Wednesday. There is fairly good model agreement with the large scale pattern at the start of this period. A 500 mb ridge should be over the Rockies, with a trough off the west coast. The trough will deepen and the ridge will move east, and then by Thursday a portion of the trough should be moving into the four corners region. There are some model differences with the details, but a fairly strong disturbance is expected to move through the central Plains for Thursday into Friday. Started to increase POPs Wednesday night (into the 30-50 percent range) and 40-70 percent for Thursday. The 12Z operational GFS was a bit stronger with the mid level wave, so preferred a solution closer to a blend of the 12Z GFS ensemble mean and the 12Z ECMWF. The Canadian model was slower and was also considered to be an outlier, so not given much weight. The 12Z ECMWF was the strongest with the surface low, and appeared too strong at this time (especially for late Thursday night into Friday morning). Nighttime temperatures suggest that a rain/snow mix is possible, but for now chances for accumulating snow look to be low.
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&& .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) Issued at 1220 PM CDT Fri Mar 17 2017 VFR conditions are expected through the TAF cycle, with scattered clouds at around cirrus level and unrestricted visibility. Northwest winds at around 10-15kt will subside this evening, becoming light and variable into Saturday morning as high pressure moves across the area. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Miller LONG TERM...Miller AVIATION...Mayes is the U.S. government's official web portal to all federal, state and local government web resources and services.