Area Forecast Discussion
Issued by NWS Omaha/Valley, NE
Issued by NWS Omaha/Valley, NE
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203 FXUS63 KOAX 052029 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 329 PM CDT Sun May 5 2024 .KEY MESSAGES... - Low clouds move in overnight tonight with south- southeasterly winds increasing Monday morning. Wind Advisory issued for northeast Nebraska for 10 AM through 7 PM Monday. - Potentially strong storms are expected Monday evening, primarily from 4 to 10 PM as a line of storms moves thought the area. Damaging wind, hail, and embedded tornadoes are possible. - Light showers and a few rumbles of thunder linger through the end of the work week, with drier conditions and highs in the 70s returning for the weekend. && .DISCUSSION... Issued at 329 PM CDT Sun May 5 2024 This afternoon - Monday Night: We`re seeing high clouds stream up this afternoon from the surface low down over north-central Texas. Otherwise, southeasterly winds are making for a pleasant day with highs in the mid 60s. Only thing that would make it better would be if it were in the 70s. We have an upper-level trough that has moved onshore out on the West Coast that will be responsible for our chance for severe weather tomorrow evening. Right now we are watching the preceding shortwave trough which is developing the area of low pressure across the lee side of the Rockies this afternoon. We`ll see increasing winds out out of the south-southeast across central Nebraska overnight associated with this developing system and the strengthening pressure gradient across Nebraska. The stronger winds will reach eastern Nebraska Monday morning, when we see winds start to really ramp up between 7 and 10 AM. Strongest winds tomorrow will be in northeast Nebraska where we could see wind gusts as high as 50 mph, so we have issued a Wind Advisory for this area from 10 AM to 7 PM. Now for the severe storm potential. Overnight tonight we`re going to see low clouds spread across eastern Nebraska and western Iowa associated with the surge in moisture being advected in by the low-level jet out ahead of this developing surface low. This may provide a failure point for the severe potential tomorrow as there is some question about when we will see this widespread cloud cover clear out Monday afternoon. If it holds together most of the day, it would limit how much the environment will be able to destabilize during the afternoon ahead of the dry line moving through which would weaken any storms that may move through during the evening. Right now, high-resolution convective-allowing models do not show this to be the case, but our lower-resolution, synoptic models are the ones holding on to the cloud cover longer into the afternoon. It will certainly be something to watch. Convective mode certainly seems likely to primarily be some form of Quasi-linear convective system, meaning a line of storms along the dry line, with the possibility of a few discrete storms out ahead of the line of storms. The greatest amount of low-level instability will likely be found across southeast Nebraska south of I-80, where the Storm Prediction Center has the Enhanced Risk drawn up. However, with how potent this system is, don`t rule out the rest of the Slight Risk area across eastern Nebraska and western Iowa. We will have a strong QLCS moving across eastern Nebraska into Western Iowa, from around 4 PM to 10 PM, with the potential for large hail, damaging winds, and embedded tornadoes. 0-6km bulk shear vectors are oriented normal to the line of storms, so we`ll have to monitor closely any bowing segments for potential circulations that may develop. Tuesday-Wednesday: Once this system moves through, we see a broad upper-level trough set up across much of the Inter-Mountain West, putting us in a fairly baroclinic regime with another chance for showers and thunderstorms, albeit weak, Tuesday night into Wednesday. Highs on Tuesday will be in the 70s but drop back down into the 60s on Wednesday. Thursday - Saturday: Models are less confident in the pattern shift late in the week than yesterday, though they still show a cooler, showery pattern going into the weekend. Drier, warmer weather looking possible to return Saturday and Sunday. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1230 PM CDT Sun May 5 2024 VFR conditions continue through this evening with winds relaxing to around 10 kt. We`ll see winds increase again around 07-09Z as mid-level clouds start to move in. Low clouds will arrive towards the early morning hours on Monday ahead of an approaching low pressure system which will bring storms Monday evening beyond the end of this TAF period. These low clouds will hold through the end of the TAF period at 18Z on Monday with drizzle or light rain showers possible (30 percent chance). && .OAX WATCHES/WARNINGS/ADVISORIES... NE...Wind Advisory from 10 AM to 7 PM CDT Monday for NEZ011-012- 015>018-031>034. IA...None. && $$ DISCUSSION...McCoy AVIATION...McCoy