643 FXUS63 KOAX 080834 AFDOAXArea Forecast Discussion National Weather Service Omaha/Valley NE 334 AM CDT Mon Sep 8 2025
.KEY MESSAGES...
- 20-40% chance of storms in southeast Nebraska this morning with a lingering 15% chance through the rest of the day.
- Higher storm chances arrive late this evening and overnight (40-60%) with a strong storm or two possible. In addition, repeated rounds of storms could lead to isolated pockets of 2-3+ inches of rain with some localized flooding possible (5% chance).
- Cooler weather continues today with highs mostly in the 70s before temperatures warm into the 80s for the rest of the week.
- Intermittent shower and storm chances (15-30%) persist into next weekend.
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.DISCUSSION... Issued at 334 AM CDT Mon Sep 8 2025
Early morning analysis showed an upper level ridge axis starting to push into the Rockies, though some shortwave energy was pushing through the ridge and into western NE/KS and leading to some showers. Farther east, some additional showers and storms were going up along in south-central NE into north- central KS on the eastern periphery of low level moisture transport, maybe a few hours earlier than most guidance was suggesting. This activity should push east into southeast NE and possibly southwest IA through this morning and lead to brief downpours in some spots, though instability decreases quickly as you go east, so they should generally be on a downward trend.
Could see some additional spotty showers through the day as the shortwave passes through and surface low pressure develops eastward through the Dakotas, but most short term guidance keeps them pretty spotty and light. For now, carrying a 15-20% chance from noon through 7 PM. Otherwise, expect strengthening southerly flow ahead of an incoming surface trough with gusts near 30 mph at times. This will help to increase moisture with a plume of lower to mid 60s dewpoints edging into eastern NE by this afternoon/evening. With the passing shortwave and potential showers, we expect quite a bit of cloud cover which should limit instability, though 08.12Z HREF mean MUCAPE values still sit in the 1000-2000 J/kg range near and west of Highway 77 by this evening. While overall forcing isn`t particularly strong, there should be just enough moisture transport and shortwave energy still sliding through to see some additional shower and storm development this evening and overnight. Deep layer shear of 25-30 kts could be just enough to keep storms somewhat organized and yield a threat for an isolated stronger or even severe storm with hail and gusty winds. However, model soundings reveal quite a bit of capping to overcome with latest CAMs suggesting very limited storm coverage through the evening hours.
We`ll most likely be waiting until after midnight when moisture transport strengthens further and we see a little more convergence in our area. With precipitable water near 1.5" and warm cloud depths approaching 3500 m, we could see some locally heavy rainfall and CAMs do indicate some potential for repeated rounds of storms with hints at pockets of 2-3". As a result, can`t completely rule out an isolated flooding threat, but chances currently appear fairly low (5%).
Precip could linger into Tuesday morning, but looks to exit by mid- day. Upper level ridging will then build in through the day and start our return to warmer weather. Expect highs on Tuesday in the mid 70s to mid 80s with widespread 80s by Wednesday and into the weekend, though we`ll also have some incoming smoke to deal with (most likely remaining aloft) that could keep temperatures a few degrees cooler. Despite the ridging in place, we`ll see continued off and on precip chances as various bits of shortwave energy round a cutoff low in the Pacific Northwest and slide through the ridge. Unfortunately there remains a fair amount of spread on timing and strength of these disturbances, though we`re currently favored to be mostly dry Wednesday and Thursday (10-15% chance of precip). Higher look to arrive Friday night (20%) and again Saturday night into Sunday (20-40%). At this point, it doesn`t look too impactful, but probably worth keeping an eye on if you have outdoor plans this weekend.
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.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1142 PM CDT Sun Sep 7 2025
VFR conditions are forecast over the next 24 hours with quick southerly winds of 7-12 knots overnight and stronger winds at FL010 of about 25-35 knots. Stronger winds find their way to the surface by mid-morning Monday with southerly winds of sustained winds near 15 knots and gusts of near 25 knots.
There is a 20-30% chance of showers and storms in the LNK and OMA areas after 7am Monday morning, but did not include them in the TAF due to low confidence. Chances peak near 10am, but linger through the afternoon. KOFK should remain mostly dry.
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.OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None.
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DISCUSSION...CA AVIATION...Nicolaisen
NWS OAX Office Area Forecast Discussion