Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000 FXUS63 KOAX 241952 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 252 PM CDT Wed May 24 2017 .SHORT TERM...
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(Tonight through Saturday) Issued at 250 PM CDT Wed May 24 2017 Temperatures are the main concern into Friday night, then will be looking more at thunderstorm chances/rain amounts for Saturday. System that helped bring showers to the area yesterday continue to move away, while the next closed mid tropospheric low of concern was dropping southeast from southern Alberta. 12 hour height falls associated with that feature were quite impressive, up to 270 meters at 500 mb at 12Z this morning. Models are in good agreement that the low will move to southern Saskatchewan by 12Z Thursday and that mid level ridging will move into our area. Combination of weak forcing and increasing moisture may be enough to trigger some showers or isolated thunderstorms over parts of the forecast area on Thursday. Forecast soundings suggest that atmosphere will be capped during the day relative to any surface based convection, but some fairly high based activity is possible. Chances should be a bit higher Thursday night, as a weak cold front pushes through the region. A the surface, weak ridge axis over the area this afternoon will slide off to the east/southeast tonight, with southeast winds increasing a bit toward morning. Lows should range from the mid 40s to around 50, with highs Thursday reaching mainly 73 to 78. Highs Friday are expected to be a couple of degrees warmer. For Friday night and Saturday, it appears that a convective system may develop out over the High Plains by Friday evening and then move/spread east overnight toward eastern Nebraska. The 12Z runs of the NAM and ECMWF are just slightly slower than the GFS, but the GFS was given a little more weight than the others. Mid level flow across the region will be mostly from the west or southwest until Sunday, when the flow turns to northwest. .LONG TERM...(Saturday night through Wednesday) Issued at 250 PM CDT Wed May 24 2017 Pattern aloft in this period will be highly amplified to start out, but should become more zonal mid to late week, based on the GFS and Canadian models. The ECMWF has more ridging to our west by late Thursday and a trough extending back southwest from the Great Lakes region. The weekend will be unsettled, but at least it appears that any amounts would be pretty light. Chances seem highest Sunday afternoon into the evening and then again that way for Monday. Highs Sunday through Wednesday should be mainly upper 60s to mid 70s, and lows in the mid 40s to lower 50s.
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&& .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 102 PM CDT Wed May 24 2017 Lingering cumulus field remains across eastern Nebraska at the start of the period as upper low sinks slowly south over central Missouri. VFR conditions are expected to prevail through the period with the sct-bkn cu layer dissipating with loss of heating after 00Z. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Miller LONG TERM...Miller AVIATION...Fobert

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