Area Forecast Discussion
Issued by NWS Omaha/Valley, NE
Issued by NWS Omaha/Valley, NE
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988 FXUS63 KOAX 280919 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 419 AM CDT Fri Jun 28 2024 .KEY MESSAGES... - Moderate flooding is ongoing or expected to begin along the Missouri River the next day or two. It`s forecast to last into next week for Omaha and points south. - A few severe storms are possible this afternoon and evening with the potential for large hail, damaging winds, localized flash flooding, and perhaps a tornado or two. - Quiet and cooler for the weekend, with highs in the mid 70s to lower 80s. Then warming back up and becoming more active for the holiday week. && .DISCUSSION... Issued at 419 AM CDT Fri Jun 28 2024 .Today and tonight: A mid/upper-level low and associated trough from southern parts of Alberta and Saskatchewan into the northern Rockies and adjacent High Plains will track southeast into the northern Plains and upper MS Valley by tonight. In the low levels, a surface low situated over central SD early this morning will develop east into MN by afternoon while a trailing cold front advances southeast through our area this afternoon and evening. Ahead of the front, warm advection along a 40-50 kt low-level jet has fostered widely scattered thunderstorms along and south of I-80 as of 3 AM. And, latest CAM output suggests that activity will gradually shift east out of the area by 6 or 7 AM. While some small hail is possible with the strongest updrafts, warm midlevel temperatures and resultant melting effects are likely to limit hail sizes. By this afternoon, the models suggest that moderate to strong instability will develop ahead of the front moving into the area. However, considerable variability exists in the number of thunderstorms that actually develop along/ahead of the boundary this afternoon into evening. Should storms develop and become sustained, the combination of the moderate to strong instability and strengthening deep-layer shear will support organized storm modes, including supercells capable of large hail and damaging winds. The tornado threat remains uncertain due to relatively weak low-level shear. However, given the presence of the boundary in the area, a tornado or two certainly cannot be ruled out. Locally heavy rainfall also is a concern, especially across southeast NE and southwest IA. Additional thunderstorms developing over western NE and vicinity this afternoon and evening will move toward the area tonight with most models suggesting that the strongest activity will remain to our west and south. Highs today will be in the mid 80s to lower 90s. .This weekend: Cooler and drier conditions are expected as surface high pressure builds through the region. Highs will be in the mid 70s to lower 80s on Saturday, and in the mid to upper 70s on Sunday. .Monday into Thursday: The 00z global models are in good agreement in suggesting that another mid-level trough will slowly advance from northern Intermountain Region through the north-central U.S. during this time frame. In the low levels, an associated surface front is forecast to settle south through the area Tuesday before stalling across KS and MO by the middle of next week. That pattern evolution appears favorable for additional severe weather and flash flooding chances, especially on Monday and Tuesday with the ongoing river flooding potentially being exacerbated/prolonged. Near-seasonal daytime temperatures are forecast with highs in the 80s to low 90s. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1136 PM CDT Thu Jun 27 2024 VFR conditions at TAF issuance with southeast winds at 15 to 25 mph, with LLWS at all three TAF sites, southerly winds around 190 degrees with winds at 2000 feet around 45 knots. LLWS diminishes by 12z, and that there could be showers or thunderstorms at KOFK 15-18z, and KLNK/KOMA 18-22z. Winds shift to the northwest after the rain chances, with speed less than 12 knots. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...Mead AVIATION...DeWald