Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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283 FXUS63 KOAX 242026 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 326 PM CDT Sat Jun 24 2017 .SHORT TERM...
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(Tonight through Tuesday) Issued at 325 PM CDT Sat Jun 24 2017 Long wave trough positioned over eastern North America will dominate the sensible weather across the region through the short term. A series of short waves will rotate around the periphery, with a quasi-stationary jet core anchored over the mid-upper Mississippi Valley. Channeled nature of short waves do not bode well for moderate to strong forcing, but jet dynamics could generate transient bands of showers/sprinkles. Caveat is large scale surface ridge will limit large scale moisture advection, so will keep forecast tonight into Sunday dry for now. Moist, isentropic ascent increases late in the period late, as surface ridge moves east and more potent short wave carves long wave extent of long wave. Not much in the way of instability, so continued previous forecast trend of mentioning only showers for Sunday night. Warming temperatures and increased moisture advection on Monday, will increase instability, though SBCAPE values still less than 1000 J/Kg. As such, broadbrushed chance of isolated storms. Another cool night temperature-wise, with mostly clear skies and low level cold-advection. Low temperatures will be at or near those seen Saturday morning. Low-level CAA continues into Sunday, with less deep mixing expected, as such maximum temperatures likely will be slightly cooler. Downslope warming may counter across western CWA. Sunday min temperatures likely to occur early, as surface flow returns to a southerly direction. Backed flow will keep temperatures from rebounding too much on Monday, but expect max temps to be a couple degrees above those seen on Sunday. .LONG TERM...(Tuesday night through Saturday) Issued at 325 PM CDT Sat Jun 24 2017 H5 ridging builds over central plains on late Monday into Tuesday, and will allow temperatures to rise at or slightly above seasonal norms for Tuesday. Ridge begins to flatten by mid week, as short wave swings across southern Canada, and helps develop broad trough across CONUS through the rest of the forecast period. Various short wave features will affect the area, through the forecast period. Deterministic and ensemble models fairly consistent with timing and strength through Thursday, but then ensembles showing quite a bit of spread late Thursday into Saturday. First glimmer of storms arrives Tuesday night with the possibilty of storms that develop across western high plains moving into the area, sustained due WAA/isentropic ascent. Limiting factor will lessening moisture and increased stability as storms move into eastern Nebraska and western Iowa. Better chances will occur Wednesday into Thursday, as surface front moves through the area. Low and large scale flow becomes southerly, and that too should increase moisture availablity. Exact timing, location and intensity still questionable thus will keep PoP only in high chance categories. Storm chances Friday-Saturday look probable, but phase differences H5 pattern in ensembles, not generating a clear solution.
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&& .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) Issued at 1219 PM CDT Sat Jun 24 2017 A weak cold front analyzed from southwest MN into north-central NE as of 17z will progress southeast with winds across eastern NE shifting to northwest with its passage. A deepening boundary layer will yield gusty winds and scattered clouds (FL060-080) this afternoon, before both diminish this evening. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Fortin LONG TERM...Fortin AVIATION...Mead is the U.S. government's official web portal to all federal, state and local government web resources and services.