Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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163 FXUS63 KOAX 030913 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 313 AM CST Sat Dec 3 2016 .SHORT TERM...(today through Monday) Issued at 225 AM CST Sat Dec 3 2016 Precipitation will likely develop today as a short wave lifts through the northern Plains with strong warm air advection developing across the region. Greatest precipitation chance will be along/south of I80 where we will increase pops into the 60-70 percent range today, with all precip slowly shifting east tonight and east of the forecast area by daybreak Sunday. We are expecting a mixture of precip today, which could start as snow in southeast Nebraska yet this morning as the column saturates down to the wet bulb. As temperatures warm through the day, should mix with or change to rain, then back to a snow/rain mixture by early this evening, with precip pulling to the east through the night. A lot of the snow accumulation should melt today with daytime insolation, and even with temps still in the mid 30s during the evening, a lot of melting will occur. Even lows overnight in southeast NE and southwest IA will be still just above freezing in the lower 30s, which should help to limit accumulations. 4" soil temperatures are also running fairly warm along/south of I80 in the lower 40s. Note, the raw model snow output from various solutions would suggest 1-3" might be possiblein southeast NE and southwest IA along/south of I80. However, due to the rain/snow mix and expected melting, we`ll have an inch or less in our grids, and then mostly just on grassy surfaces. QPF through the next 24 hours ranges from 0.1" to 0.2". Very mild conditions develop for both Sunday and Monday. Northwesterly downsloping flow will prevail for Sunday which will help boost temps back into the mid 40s. Southwesterly flow Monday should yield one more much above normal day in the mid to upper 40s with dry conditions. .LONG TERM...(Monday night through Friday) Issued at 225 AM CST Sat Dec 3 2016 A cold front will arrive Monday night, which will begin to usher in a brief period of arctic-like temperatures through the end of the week. There could be a few snow showers or flurries with the front Monday night. The initial surge should be east of the area early Tuesday, but will still hang on to a 20 percent chance of light snow or flurries based on previous model blends, but new 00z models are suggesting it will probably be dry Tuesday. The next trough moving out of the Rockies appears to be taking a slightly more southern track mid week based on GFS and ECMWF. The Canadian model is even further south and would keep the area dry. Thus, will reduce overall probabilities in our area into the 20-30% range from Tuesday night through Wednesday, and then for just the southern half of the forecast area as the system is trending south. Still too early to focus on snowfall amounts, but if it does snow, the amounts appear to be on the light side. Sharply colder temperatures are probably the bigger weather story in the extended period. Highs both Wednesday and Thursday will only be in the teens. When combined with blustery northwest winds, wind chill values will drop into the single digits above and below zero. Temps do begin to rebound a little by Friday into the mid 20s, but still well below normal. We may even see moderation back into the 30s for Saturday, so this first arctic intrusion appears to be fairly brief. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) Issued at 1132 PM CST Fri Dec 2 2016 Mid and high-level clouds will continue to overspread the area tonight in advance of a short-wave trough progressing into the High Plains. The impulse will subsequently track east across the region on Saturday, promoting development of a southwest-to- northeast-oriented precipitation shield across portions of eastern Nebraska and southwest Iowa. While KOFK is expected to remain to the north of this precipitation, it will be impacted by the arrival of MVFR ceilings late Saturday afternoon. At KOMA and KLNK, precipitation is expected to begin by late morning or early afternoon and continue into at least Saturday evening. Model variability in the structure of the low-level thermodynamic profiles yields various precipitation type forecasts. For now, the highest probability scenario is a rain-snow mix with precipitation rates peaking in intensity from mid afternoon into early evening. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...DeWald LONG TERM...DeWald AVIATION...Mead is the U.S. government's official web portal to all federal, state and local government web resources and services.