Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000 FXUS63 KOAX 192335 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 535 PM CST Fri Jan 19 2018 .SHORT TERM...(Tonight through Monday) Issued at 335 PM CST Fri Jan 19 2018 The main forecast issue is in regards to the winter storm system that will affect the area Sunday into Monday. Freezing drizzle is expected to develop over parts of the area Saturday night, which will need to be monitored as we get closer. Right now that is not expected to have a large impact, but things could change. Mid level shortwave energy will be moving into the southwestern United States tonight and that will be better sampled in the upper air network this evening and Saturday. A couple of things noted from the 12z upper air maps this morning included the following. A broad area of height falls at 500 mb stretched from CA into Saskatchewan and Manitoba at 12z this morning. At 850 mb, mild air was noted over much of the plains, with 850 mb temperatures from 8 to 16 degrees C. Tonight, expect variable clouds, mainly high clouds, with lows in the 20s. Saturday should be dry with highs in the 40s. Things start to change Saturday night, with drizzle or freezing drizzle developing as low level moisture increases. Chances are highest across southwest IA and southeast NE. The main upper level support by early Saturday evening will still be back over the southern and central Rockies, and the surface low with this system is expected to move from southeast CO into the OK panhandle Sunday morning. Surface temperatures will be critical for precipitation type, but temperatures are currently expected to warm above freezing in all of the area Sunday. Kept the timing of our Winter Storm Watch as it was, but did add some counties on the western side. Axis of heaviest snow is expected to be from western NE into northeast NE/southeast SD, northwest IA and southern MN. We will closely monitor that and adjust if needed. Snow amounts could reach 6 inches or more in the watch area and winds gusting to around 40 mph will be strong enough to create considerable blowing and drifting snow Sunday night into Monday morning. Current mid level mixing ratios/specific humidities average about 3 g/kg with about 12 to 18 hours of moderate to strong upward vertical motion. See our WSW product for more details. Some light snow could linger through into Monday afternoon, but mainly in western IA. Highs Monday should mostly range from around 30 to the mid 30s. .LONG TERM...(Monday night through Friday) Issued at 335 PM CST Fri Jan 19 2018 The period from Tuesday through Friday morning is expected to be mainly dry with highs in the 30s and 40s. Lows will be mainly teens and 20s. Our next chance of rain and snow arrives Friday afternoon. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) Issued at 1047 AM CST Fri Jan 19 2018 VFR conditions are expected through the period. Light southerly winds will swing around to the northwest late tonight and into Saturday morning, as a weak cold front drops into the area. && .AVIATION...
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(For the 00Z TAFS through 00Z Saturday evening) Issued at 532 PM CST Fri Jan 19 2018 VFR conditions with quite a bit of high cloudiness. The guidance is hinting at fog developing overnight with the weak boundary slipping southward overnight and the weak flow through at least h8 and melting of snow. Light southwest winds will veer to the northwest with the frontal passage.
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&& .OAX WATCHES/WARNINGS/ADVISORIES... NE...Winter Storm Watch from Sunday afternoon through Monday morning for NEZ011-012-015>018-030>033-042-043-050-065. IA...None. && $$ SHORT TERM...Miller LONG TERM...Miller AVIATION...Zapotocny

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