Area Forecast Discussion
Issued by NWS Omaha/Valley, NE
Issued by NWS Omaha/Valley, NE
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121 FXUS63 KOAX 160818 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 318 AM CDT Mon Sep 16 2024 .KEY MESSAGES... - Periodic shower and storm chances through the weekend, typically peaking at night. Highest chances are currently Tuesday night into Wednesday and Friday night into Saturday (40-70% chance). - Temperatures are expected to remain above-normal through the work week with highs in the 80s. - Cooler weather favored this weekend into next week with highs in the 70s. && .DISCUSSION... Issued at 318 AM CDT Mon Sep 16 2024 Early this morning, scattered showers and storms associated with a low level jet/moisture transport and some weak shortwave energy extended from western ND southward into western KS. These are expected to gradually push eastward through this morning, and while the ongoing storms are expected to dissipate prior to reaching our area, guidance seems to be in decent agreement that low level moisture transport refocuses farther east around daybreak, leading to redevelopment across central into eastern NE. These also will dissipate as they push east, so precip chances will largely be confined to areas near and west of Highway 77. An additional bit of shortwave energy also looks to slide through early this afternoon which may lead to some lingering precip in northeast NE as suggested by several CAMs, but soundings are somewhat dry so wouldn`t expect it to amount to too much. Expect amounts to mostly remain below 0.25" through this afternoon. Otherwise, expect highs in the mid 80s, though any lingering precip/cloud cover could keep us a few degrees cooler in some spots. Expect a similar setup tonight heading into Tuesday with another weakening broken band of showers and storms pushing east into the area. Once again not expecting much in the way of rainfall for most, though a few spots could near 0.25". Highs are expected to be in the mid to upper 80s, pending clouds and precip. Meanwhile, a trough will continue to dig over the western CONUS with a cutoff low ejecting northeastward into WY/MT by Tuesday afternoon/evening. An attendant surface boundary will push east into the area with guidance in good agreement of a more organized band of showers and storms moving across much of NE before weakening just as it approaches IA as moisture transport decreases during the day Wednesday. However, expect redevelopment over eastern NE/southwest IA Wednesday evening into Thursday morning as the low level jet ramps back up. We`ll remain in a pattern of periodic storm chances Thursday through the weekend with additional bits of shortwave energy sliding through and low level moisture transport pointing into our area nightly. By Thursday evening, precip chances climb above 30% for a vast majority of the area and remain there through throughout most of the weekend. The strongest system looks to move through sometime Friday evening through Saturday, bringing shower and storm chances into the 50-70% range. However, still some questions on exact timing and track of the system, so those chances probably still have room to increase once that gets narrowed down. Throughout this timeframe, severe weather chances currently appear to be on the lower side as deep layer shear looks pretty weak, but there will be a little bit of instability to work with at times, so can`t completely rule out a few periods of interest. For what it`s worth, various GEFS-based machine learning severe weather probabilities suggest daily 5% chances at least clipping our area Wednesday through Saturday. Currently thinking highest chances will be when that stronger system moves through Friday night/Saturday, but still lots of details to be worked out between now and then. Otherwise, expect continued highs in the 80s to perhaps lower 90s Thursday and Friday, before we cool off into the 70s and perhaps upper 60s with and behind the weekend system. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1141 PM CDT Sun Sep 15 2024 VFR conditions favored through the period, but will need to keep an eye on shower and storm chances at OFK mid morning into early afternoon. Latest guidance suggests any precip will be on a dying trend as it approaches OFK, so only included TEMPO -SHRA for now, but can`t completely rule out some -TSRA and brief MVFR conditions. There could be a few spotty showers near OFK early in the period, but confidence in them occurring is too low to include at this time. Otherwise, expect passing mid to high level clouds with southeast winds gusting 18-25 kts by mid to late morning and into Monday evening. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...CA AVIATION...CA