Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000 FXUS63 KOAX 222124 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 324 PM CST Wed Feb 22 2017 .SHORT TERM...(tonight through Saturday) Issued at 241 PM CST Wed Feb 22 2017 ...Winter storm with near blizzard conditions will affect part of the forecast area Thursday night through Friday night... The calm before the storm today, with another record record breaking day at both Lincoln and Omaha with highs in the mid 70s! This will be in stark contrast to the expected wintry weather that develops by the end of the work week. Upper low across western US with 60-80 meter height falls and a 100-120 knot 300mb jet will close off tonight and then cross the Rockies Thursday then eject onto the Plains Thursday night and Friday. Dry weather expected tonight with northerly flow behind a cool front that has moved through the area. Surface cyclogenesis develops across the western High Plains Thursday then moves east northeast in a favored trace to bring heavy snow to the much of the central and northern Plains, and even a thunder threat in southeast NE and southwest IA within a dry slot. Early Thursday morning should be dry, but a rain/snow mix will be spreading eastward along the SD border area into northeast NE through the day. Meanwhile, thunderstorms may develop along south of I80 through mid afternoon Thursday into Thursday evening, although the 12z High-res ARW/NMM models and now most the 18z ESRL HRRR suggest these storms could even be south of the forecast area in northeast KS and northwest MO. Substantial wintry weather develops by Thursday evening in northeast NE, with rain and a chance for thunder for east central, southeast NE, and western Iowa. Isentropic lift on the 295K surface suggests 3 to 6 g/kg of moisture feeding into northeast NE, which would suggest at least 6 to 12 inches of storm total snow possible in that area. The rain/snow line may not even make it to the I80 corridor until early Friday morning, but then spreading across the remainder of the forecast area during the morning. There is some concern of the exact track of this storm, with various models showing slightly different paths. The Nam was generally discounted for being too far north, although the 18z Nam began trending a little further south. Generally used a consensus of other available models. There is also a high degree of concern that because of the strong wind gusts at or above 35 mph by late Thursday night into Friday, we could be potentially be near or at blizzard criteria in northeast NE. For this reason, the existing winter storm watch was converted to a blizzard watch for portions of SD and northern IA. Regarding headlines in our area, we have decided to upgrade the existing winter storm watch currently in effect to a winter storm warning, which begins at 6 pm Thursday. This includes the area Albion to Norfolk to Wayne and areas northwest, given confidence of heavier snow and potential near blizzard conditions that will eventually develop in that area. Have opted to issue winter storm watches southeast of this area, which includes Columbus to Fremont to Blair to Denison, with a staggered start time from 10 pm Thursday to 6 am Friday. In this area, we have upped the snowfall to the 4-7" range, but this area will also experience near blizzard conditions on Friday, thus the reasoning for the watch. Farther south, along I80, we have just 1-2" forecast, and just barely a dusting near the NE/KS/MO border area. Impacts from this storm will eventually be high, with a significant impact to travel expected Thursday night into Friday night, due to the combination of heavy snow, high winds, blowing snow, and eventually near blizzard conditions in some areas. We have also extended headlines to linger into Friday evening as impacts will still be ongoing as the storm system slowly pulls away. Saturday should be dry with high pressure across the forecast area. .LONG TERM...(Saturday night through Wednesday) Issued at 241 PM CST Wed Feb 22 2017 Didn`t have a lot of time to spend on the extended portion of the forecast. There is another quick moving front that could bring a slight chance of rain/snow to parts of the area Sunday. Another weather system could bring rain/snow Monday night into Tuesday and then dry for Wednesday. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1111 AM CST Wed Feb 22 2017 Deteriorating conditions are expected at all terminals late tonight with the approach of a strong storm system moving into the central Plains. Increasing low level moisture will result in widespread MVFR cigs advancing southward out of SD and into nern Neb shortly after midnight...then expand over the rest of ern Neb Thursday morning. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...Winter Storm Watch from Friday morning through Friday evening for NEZ034-044-045. Winter Storm Watch from Thursday evening through Friday evening for NEZ015-032-033-042-043. Winter Storm Warning from 6 PM Thursday to midnight CST Friday night for NEZ011-012-016>018-030-031. IA...Winter Storm Watch from Friday morning through Friday evening for IAZ043-055. && $$ SHORT TERM...DeWald LONG TERM...DeWald AVIATION...DEE is the U.S. government's official web portal to all federal, state and local government web resources and services.