Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000 FXUS63 KOAX 181750 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 1150 AM CST Sat Nov 18 2017 .SHORT TERM...(Today through Monday) Issued at 255 AM CST Sat Nov 18 2017 Precipitation ending this morning, cloud cover today and temperatures the next few days will provide the main forecast challenges. Two main jet segments were noted at 00Z on the 300 mb chart. One extended from ND into northern MN (120-125 knots) and another was punching east from CO. At 500 mb, strongest height falls were over Ontario Canada, but values of 50 meters or more extended down as far as NM and north TX. Modest thermal gradient was in place at 700 mb, and upper level dynamics were acting on this to produce mid level frontogenesis. At the surface, low pressure was over eastern KS, while a cold front trailed from near Chicago to near Kansas City and then to north of Amarillo. A couple of frontogenetically forced bands of precipitation have affect then area, and as of around 215 am the most prominent band stretched from around Grand Island to Wahoo, Omaha and Harlan Iowa. Heaviest precipitation should be along and south of Interstate 80 through mid morning, decreasing from north to south with time. Snow accumulations do not seem likely, although there will probably be a rain/snow mix at times. Some low level clouds may linger well behind the precipitation shield, as noted by recent RAP model output. Expect sunny to partly cloudy skies by the afternoon for most of the forecast area. North/northwest winds will be somewhat gusty today, but will decrease this evening. Tonight, winds turn more to the west as surface ridge axis builds east across the region. Lows should drop into the lower and mid 20s, despite weak warm air advection late tonight. Look for dry conditions Sunday and Monday with highs in mostly in the lower and mid 50s Sunday, then mid to upper 50s on Monday. .LONG TERM...(Monday night through Friday) Issued at 255 AM CST Sat Nov 18 2017 A mainly dry pattern is forecast through the week, with models in good agreement that a 500 mb ridge will build over the Rockies. There are some weak signals for light precipitation from both the 00Z runs of the GFS and ECMWF by Friday night into Saturday. That will be associated with a trough moving across the region from the northwest. Tuesday and Wednesday will be noticeably cooler than Monday. Thursday and Friday expect highs mainly in the 50s, with some lower 60s possible Friday. && .AVIATION...
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(For the 18Z TAFS through 18Z Sunday afternoon) Issued at 1150 AM CST Sat Nov 18 2017 VFR conditions will prevail through most of the period with northwest winds diminishing by 00Z. High pressure will build into the area overnight with winds becoming light. A period of MVFR cigs is possible through 22Z as area of low level moisture over southeast South Dakota drops southeast this afternoon.
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&& .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Miller LONG TERM...Miller AVIATION...Fobert

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