Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000 FXUS63 KOAX 151116 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 516 AM CST Fri Dec 15 2017 .SHORT TERM...(Today through Sunday) Issued at 328 AM CST Fri Dec 15 2017 Relatively mild to start the weekend, then cooler with a small chance for precip on Sunday. Mid level trough was exiting the Plains this morning, tracking southeast through southern Missouri. Heights are forecast to rise the next couple of days behind this wave and ahead of next shortwave ejecting into the region from mean trough position in the southwestern U.S. Much warmer airmass under the building height regime should put temperatures well into the 50s by Saturday over much of our area. 850 temps rise from sub-zero this morning to near 5C this afternoon then 10C on Saturday. Favorable west to southwest surface winds this afternoon and decreasing cloud cover suggest highs should reach the 45 to 50 degree range. Saturday will likely be warmer, especially in our south, given warming temperatures aloft. However weak surface front is forecast to settle across eastern Nebraska and southwest Iowa, turning winds to northeast to the north of the front and shaving several degrees off potential warming. So despite plenty of sunshine, expect highs in northeast Nebraska to hold in the middle 40s while southeast Nebraska should reach the upper 50s. Shortwave ejecting from the southwest Saturday night and Sunday morning is expected to track across Missouri, with bulk of deeper moisture drawn north on the east side of path from eastern Texas into the Ohio Valley. However weak lift and mid level moisture associated with minor potential vorticity anomaly will skirt our southeast CWA Sunday morning. Models have been advertising light precipitation there, and continue the trend this morning. Forecast soundings suggest nose of warm air over top of cooler near-freezing surface temperatures could provide a mix of precipitation types for a few hours Sunday morning. However given light QPF and short duration of any precipitation, expect impacts will be minimal in southeast Nebraska and southwest Iowa. Cooler temperatures will follow this system Sunday afternoon as northeast surface flow and more cloud cover hold temperatures closer to normal. .LONG TERM...(Sunday night through Thursday) Issued at 328 AM CST Fri Dec 15 2017 Another major pattern shift still looks likely by the end of the week, bringing much colder air to the region. Leading up to it, mainly northwest to west mid level flow will dominate the weather across the Plains through mid week as upper trough/low in the southwest U.S. gradually fills and tracks across the South. Meanwhile a deep low drifting through the Gulf of Alaska will creep southeast and eventually settle into the Rockies and Northern Plains by Thursday. Ahead of this system we should continue to see above-normal temperatures with only minor perturbations nudging temps one way or the other Monday and Tuesday. Wednesday looks to be the warmest day as stronger southerly flow develops ahead of approaching strong trough, then much colder air and a chance for precipitation will arrive Thursday. GFS and ECMWF have shown decent consistency in timing and precipitation placement the last few runs, so forecast confidence is increasing. Expect generally falling temperatures much of the day Thursday, with precipitation expanding across all of eastern Nebraska and southwest Iowa. Current indications point to mainly snow in our north and rain changing to snow in the south through the day. && .AVIATION...
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(For the 12Z TAFS through 12Z Saturday morning) Issued at 512 AM CST Fri Dec 15 2017 VFR conditions will prevail thru the fcst pd.
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&& .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Dergan LONG TERM...Dergan AVIATION...DEE

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