Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 282039

Area Forecast Discussion
National Weather Service Omaha/Valley NE
339 PM CDT Fri Apr 28 2017

.SHORT TERM...(Tonight through Monday)
Issued at 339 PM CDT Fri Apr 28 2017

A vigorous shortwave trough which brought rain and snow to the
area today is in the process of translating through the mid MO
Valley this afternoon with large-scale forcing for ascent expected
to diminish through this evening. As a result, ongoing light
showers across the northern half of the CWA should, likewise,
diminish from south-to-north late this afternoon into early
evening. Later tonight into Saturday, strengthening frontogentical
forcing and low-level moisture flux will yield the northward
expansion of precipitation into the mid MO Valley. A few
thunderstorms are possible Saturday afternoon into evening across
southeast NE and southwest IA, while a mixture of rain and snow
could occur early Saturday across northeast NE.

Saturday night into Monday, a significant synoptic cyclone will
advance from the southern High Plains to upper Midwest with the
associated low-level circulation tracking through the southern
part of the forecast area. We continue to see slight differences
amongst deterministic model guidance with respect to where the
associated deformation precipitation axis (and resultant potential
for some accumulating snow) will set up. Currently, it appears
that our northwest counties will be most likely to experience a
couple of inches of snow, mainly Sunday night into Monday. A
mixture of rain and snow could affect all but our far southwest IA
counties during that time frame.

In addition to the snowfall potential, the prolonged period of
precipitation could result in storm-total rainfall amounts
approaching 2.0-2.5 inches; consistent with latest WPC guidance.
Temperatures --especially daytime highs-- will be unseasonably
cool through the weekend into Monday, before gradually warming

.LONG TERM...(Monday night through Friday)
Issued at 339 PM CDT Fri Apr 28 2017

A deep-layer cyclone over the Great Lakes at the onset of the
extended range will weaken while shifting east ahead of the next
mid-level trough amplifying over the central CONUS. After a brief
period of dry weather Monday night through Tuesday night,
precipitation chances will increase by Wednesday in conjunction
with the former weather disturbance mentioned above.


.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1240 PM CDT Fri Apr 28 2017

First round of precipitation is lifting north across the TAF sites
with -sn/ra at KOFK this afternoon and light rain ending early
this afternoon at KOMA and KLNK. Although there was a little break
near KOMA...expect MVFR/IFR cigs and some MVFR vsbys to last
through the afternoon. Relatively drier low level flow from the
northeast will try to improve cigs at KOFK then KOMA 00Z to 03Z
and some of this low level drying could reach KLNK after
midnight. This is shortlived though as the next round of
precipitation (rain) moves in to LNK around 12Z and 12-15Z at
KOMA.Northeast winds 10 to 20kts and gusty at KOMA/KLNK. Did
include LLWS at KOMA/KLNK after 09Z.




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