Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000 FXUS63 KOAX 022034 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 234 PM CST Fri Dec 2 2016 .SHORT TERM...
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(tonight through Monday) Issued at 234 PM CST Fri Dec 2 2016 Main forecast concern is the positively titled trough over the intermountain west this afternoon. The south end of this trough is expected to continue to dive into Mexico while the northern portion should continue to progress eastward through the northern and central Plains over the next 36 hours. Ahead of this trough we will see high level clouds increase tonight, with the deck lowering to mid clouds Saturday morning before deeper saturation occurs on Saturday afternoon. The models are in general agreement that broad isentropic upglide on the 285-295 K surfaces will continue into Saturday night until the axis of the mid-level trough passes. Precipitation type is an issue with initially a cold airmass in place, but warmer air aloft moving in from the south, as well as diurnal warming of the boundary layer. This will likely result in a rain and snow mix across the southern 2/3rd of the forecast area during the day on Saturday, with potentially a more concentrated period of light snow on Saturday evening associated with the strongest large-scale forcing for ascent before the warmer air aloft shifts northeast into the CWA. Precipitation may end on Saturday night as a little light rain/drizzle as we lose the introduction of ice into the column. Snowfall amounts would be light and mainly confined to grassy surfaces, but up to or a bit more than a half inch seems reasonable over west-central IA, with amounts for the OMA/LNK metro areas in the range of a couple tenths. This system exits to the east by Sunday morning with little in the way of sensible weather expected for Sunday through Monday. .LONG TERM...(Monday night through Friday) Issued at 234 PM CST Fri Dec 2 2016 Longer range models continue to struggle with how to handle a strong Pacific jet as it moves into the western US early next week. It appears over the last several days that the EC has been slowly moving toward a more GFS solution, and given the ensemble support this appears more likely. This would generally just mean a strong cold front by mid week with the coldest air of the season descending into the Plains. We will continue to mention some small chance pops associated with the incoming cold air, but chances of a significant winter storms appear very small currently. Once the cold air is in place by mid week we should see well below normal temperatures through the end of the forecast period.
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&& .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) Issued at 1142 AM CST Fri Dec 2 2016 Layer of low clouds has been pushing slowly south across the area during the morning with most recent short range models having some trouble with this feature. Have trended TAFs more toward this current scenario at least through the afternoon with MVFR cigs at all three sites. Ceilings becoming VFR again after 00Z but may need to adjust depending on southward extent of the clouds by late afternoon. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM... LONG TERM... AVIATION...Fobert

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