Area Forecast Discussion
Issued by NWS Omaha/Valley, NE
Issued by NWS Omaha/Valley, NE
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857 FXUS63 KOAX 310751 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 251 AM CDT Fri May 31 2024 .KEY MESSAGES... - Thunderstorms will linger into tonight. If storms repeat over areas that received heavy rainfall last night, some localized flooding could occur. - Additional storms could move in by late Saturday afternoon/evening (20-40% chance) with daily chances continuing into at least Wednesday. The highest chances for strong to severe storms look to be Sunday and Tuesday. - Slightly warmer through next week with highs in the upper 70s and 80s. && .DISCUSSION... Issued at 251 AM CDT Fri May 31 2024 Watching a couple areas of showers and storms leading to perhaps some localized flooding early this morning. The first being along a surface boundary basically splitting NE from northeast to southwest and the second on the nose of some moisture transport pointing into far southeast NE and southwest IA. Guidance suggests the precip associated with the boundary should taper off toward sunrise as shortwave energy pushes off to the east and moisture transport into the area weakens. However, the latter area of precip does look to continue with persistent moisture transport through much of the day. The good news is that instability in that area is rather minimal so rain over the last few hours has been rather light, and this looks to continue. So while there is some concern with localized flooding in that area just given 4+ inches of rain already in that area, rainfall rates should remain on the lighter side at least through early this afternoon. Unfortunately, the surface boundary looks remain relatively stationary today and with some additional shortwave energy sliding in by this afternoon and MUCAPE values approaching 2000 J/kg, expect storm redevelopment in vicinity of the boundary and in areas that received heavy rainfall last night. While weak shear will limit storm organization and overall severe weather threat once again, this will lead to slow storm movement and an increased flooding threat, especially with precipitable water values of 1.25-1.50" and increasing moisture transport into the boundary by mid to late afternoon into this evening. Most short term guidance puts an end to storms by midnight tonight, with only a few spotty showers perhaps lingering into the overnight hours. Expect most of the area to remain dry for much of Saturday, but yet another bit of shortwave energy is progged to slide east into the area by late Saturday afternoon/evening, bringing yet another chance for showers and storms. For what they`re worth this far out, CAMs suggest we`ll see a weakening cluster/broken line of storms moving in, but still could be just strong enough to produce some gusty winds. Still plenty of details to work out there, though. A few of those storms could linger into Sunday, potentially playing a role in strong to severe storm chances for the evening hours. The general idea is that they should dissipate by the afternoon with continued southerly flow ushering in a warm, moist, and unstable airmass ahead of a somewhat stronger shortwave trough and surface cold front approaching from the west. Guidance is in fairly good agreement that we see a line of strong to severe storms form, but the early day convection/clouds could limit destabilization. In addition, shear still looks to be rather disorganized and on the weaker side, so would think any line of storms that does form should weaken as it pushes southeast into the area. However, relative to previous days, the shear does look to be a bit stronger Sunday evening so in turn, the severe weather threat should be at least a little higher. Expect a few lingering showers and storms Monday as the boundary stalls in/near the forecast area and southerly flow ushers in more moisture. This will eventually lead to a setup on Tuesday similar to that of Sunday with a stronger shortwave trough and surface cold front sliding through at some point (still a fair amount of spread on exact timing). This would be our next highest chance for severe weather, but once again, lots of details and rounds of storms to get through between now and then. So overall, the pattern looks to remain active with daily shower and storm chances and occasional severe weather chances (especially Sunday and Tuesday), though relatively weak shear should somewhat limit those chances. Temperatures will be on a slight upward trend, with highs largely in the upper 70s and 80s Saturday through next week, though precipitation will almost certainly impact those temperatures some days. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1126 PM CDT Thu May 30 2024 A frontal boundary has stalled across northeast Nebraska and will continue to train storms near KOFK through the overnight hours leading to occasional showers and storms moving near or into the terminal through the next few hours. This could last as long as through 12Z, but for now have it in the TAF through 09Z. Other than that, the next concern is MVFR/IFR cigs spreading across the area overnight. These cigs will hang around through the morning hours with occasional showers or drizzle reducing visibility. Cigs will lift to VFR by Friday afternoon, but we`ll see additional scattered showers and storms develop which may impact the terminals through Friday afternoon and evening. Winds will main primarily out of the southeast, apart from occasionally becoming variable near stronger showers and thunderstorms. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...CA AVIATION...McCoy