Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
218 FXUS63 KOAX 252049 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 349 PM CDT Sun Jun 25 2017 .SHORT TERM...
-- Changed Discussion --
(Tonight through Wednesday) Issued at 348 PM CDT Sun Jun 25 2017 Several impulses rotating around base of eastern U.S. long wave trough creating streaks of light precipitation across central plains this afternoon. So far, precipitation has remained north and south of forecast area, but current WV loop picking up another impulse dropping southward from northern plains and associated weak boundary. CAM and synoptic models all depicting precipitation development, though are not consistent with timing, location and coverage. Instability looks weak, so broadbrushed slight to low chance PoP -SHRA across forecast area overnight. Otherwise, another cool night, as even though surface flow briefly becomes southerly, showers and evap cooling will mitigate. Showers, clouds and low level cool advection will delay return to seasonal temperatures again on Monday. Some downslope warming across western CWA may counter cooling behind front. Lower temperatures a tad across southeast part of CWA, where I think showers and clouds will be more persistent. Precipitation moves east and south of area by evening. Upper ridging builds over area on Tuesday, and will allow temperatures to rebound to seasonal values in the low-mid 80s. Ridging short-lived as Manitoba shortwave flattens mid-level flow by Tuesday evening. Lee cyclogenesis will ramp up low level flow, and help to draw moisture back into area. For now, Tuesday looks dry, but storms developing along frontal boundary in high plains. Per instability and shear parameters, storms likely will congeal into MCS that will into area Tuesday night. .LONG TERM...(Wednesday night through Sunday) Issued at 348 PM CDT Sun Jun 25 2017 Remnants of MCS will impact area Wednesday. Lingering boundary across southeast Nebraska and southwest Iowa will set the stage for additional convective development on Wednesday afternoon. There looks to be a brief reprieve Wednesday night into Thursday with narrow band of large scale subsidence in wake of short wave moving across northern plains. Reprieve is short, as yet a more potent short-wave drops out of Saskatchewan/Manitoba Thursday afternoon into Friday. Long wave trough remains quasi-stationary over central/northern plains through Sunday. Deterministic models having consensus issues with solution/evolution, with GEFS depicting quite a bit of spread. As such precipitation timing and location variable, and for now accepting consensus solution.
-- End Changed Discussion --
&& .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) Issued at 1223 PM CDT Sun Jun 25 2017 VFR conditions through the period. Northwest winds at 12 to 18 knots at KOMA will diminish by 21z. Otherwise, there will be 30 percent chance of showers at KOMA/KLNK in the 14-18z period. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Fortin LONG TERM...Fortin AVIATION...DeWald

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.