782 FXUS63 KOAX 132016 AFDOAXArea Forecast Discussion National Weather Service Omaha/Valley NE 316 PM CDT Sat Sep 13 2025
.KEY MESSAGES...
- A chance of showers and thunderstorms Sunday into Sunday night (30-50%). A few strong to severe storms are possible. Rain chances return Tuesday afternoon into at least Thursday.
- Cooler, but still above-normal highs in the 80s Sunday through Tuesday. Temperatures fall into the 70s Wednesday through Friday.
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.DISCUSSION... Issued at 316 PM CDT Sat Sep 13 2025
Rest of this afternoon and tonight:
Early afternoon water vapor imagery and objective analysis show a mid-level trough centered over the Rockies, with an embedded vorticity maximum located near the Four Corner region, within the trough base. The vorticity maximum will progress northeast into the High Plains tonight, in tandem with mid/upper-level jet streaks, and a concentrated area of height falls/forcing for ascent. At the surface, a weak area of low pressure was analyzed over eastern SD, with an associated cool front extending southwest from the low through north-central into southwest NE, before linking with a secondary low over northeast CO. Ahead of the front, deep, boundary-layer mixing has allowed for the downward transfer gusty southwest winds and warm air aloft, with 3 PM temperatures in the upper 80s to mid 90s across our area. Even though record high temperatures will remain out of reach, it`s still a hot day by September standards.
Latest CAM data indicate a gradual increase in shower and thunderstorm development across the central High Plains this afternoon into tonight, within a zone of forcing for ascent preceding the mid-level trough. A few showers and thunderstorms could spread east into central NE overnight along the low- level jet; however, our area is expected to remain dry.
Sunday and Sunday night:
The above-mentioned, mid-level trough is forecast to consolidate into a closed low over western parts of SD and NE, with an embedded vorticity maximum pivoting through the eastern side of the trough across the mid MO Valley Sunday night. The progressive nature of the embedded perturbation will encourage the eastward advance of widely scattered showers and thunderstorms into our area, mainly Sunday afternoon into Sunday night (peak PoPS of 30-50%). Rainfall is likely to be streaky, with many locations probably not seeing a whole lot, and a few areas seeing an inch or more.
There is a consistent model signal for the development of a more organized thunderstorm line over central NE Sunday afternoon, which moves into our western counties Sunday evening, before weakening. The forecast environment ahead of that line features modest amounts in instability and vertical shear, which will limit the potential for a more robust severe-weather threat. Nonetheless, the presence of moderately steep lapse rates and a unidirectional wind profile will support the risk for isolated occurrences of strong wind gusts and/or hail approaching severe levels.
High temperatures on Sunday will be a function of cloud cover and the areal extent of any shower and thunderstorm activity. This update will indicate readings ranging from the low 80s in our northeast NE to around 90 in extreme southwest IA.
Monday through Friday:
The mid-level trough discussed in the previous section will continue northeast through the northern Plains and upper MS Valley, ahead of another trough evolving across the northern Intermountain Region. The 12z global models indicate the latter disturbance slowly progressing east, and eventually stalling across the northern and central Plains into upper MS Valley. Monday and Tuesday are expected to remain warm ahead of the next trough, with highs in the 80s. Precipitation chances increase Tuesday afternoon into Tuesday night, and continue at least Thursday as the mid-level system stalls across the region. Maximum PoPs of 40-70% are forecast Tuesday night.
The various ensemble-based, machine-learning systems indicate some severe weather potential on Tuesday afternoon and evening with the movement of a surface cool front into the area. Pockets of locally heavy rain also appear possible. Daytime temperatures cool into the 70s behind the front from Wednesday through Friday.
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.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1155 AM CDT Sat Sep 13 2025
VFR conditions are expected to prevail through the forecast period, with increasing clouds at FL200-250. Sustained south- southwest winds of 12-13 kt with gusts to 19-22 kt this afternoon will diminish to below 12 kt by 14/00z. LLWS is expected to develop overnight at KOFK.
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.OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None.
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DISCUSSION...Mead AVIATION...Mead
NWS OAX Office Area Forecast Discussion