Area Forecast Discussion
Issued by NWS Omaha/Valley, NE
Issued by NWS Omaha/Valley, NE
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609 FXUS63 KOAX 120351 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 1051 PM CDT Tue Jun 11 2024 .KEY MESSAGES... - Staying warm into next week. Heat index values could approach or exceed 100 in at least parts of the area Wednesday, Thursday, Sunday, and Monday. - Our next chances for stronger to severe storms arrive Wednesday (northeast Nebraska) and Thursday (southeast Nebraska and southwest Iowa). - Details remain unclear, but we`ll have daily storm chances Friday into next week with potential for strong to severe storms at times. && .DISCUSSION... Issued at 328 PM CDT Tue Jun 11 2024 Early afternoon analysis showed a cold front continuing to sag south into southern NE and far southwest IA, with a few cumulus clouds bubbling up along it. Can`t completely rule out a few sprinkles along the front as we go through the afternoon/evening, but should be very few and far between if they develop at all. Otherwise, despite the front, it was still pretty warm across the area, with temperatures as of 3 PM in the mid 80s to around 90.| Heading into tonight, will have to keep an eye on potential shower and storm development across north- central into northeast NE as low level moisture transport ramps up and points into that area. Guidance is in decent agreement that we see some development on the nose of said moisture transport, but there remains spread on just how far north the development would be, with some guidance suggesting it all remains in SD. For what it`s worth, there does appear to be at least some decent deep layer shear for storm organization, though instability should remain somewhat limited (around 1000 J/kg of MUCAPE). Still, can`t completely rule out a stronger storm sliding southeast down the CAPE gradient into northeast NE during the early morning hours Wednesday (maybe a 10-20% chance). For the daytime hours Wednesday, expect strengthening southerly flow to usher in our fair share of warm, moist air into the area, with highs in the mid to upper 90s, possibly 100 in a few spots and dewpoints in the mid 60s. As a result, expect heat index values to approach or exceed 100 in some locations. In addition, this will lead to a fairly unstable airmass across the region, with 11.12Z HREF mean SBCAPE values of 2500-3000 J/kg. This will be ahead of an approaching cold front, currently off the Pacific Northwest coast. Expect storm development as the front moves in, though latest guidance suggests the front/strongest forcing will largely remain to our north and east through the afternoon hours, meaning we`ll have pretty weak forcing in our area. Instead, we may have to rely on broad warm air advection and/or reaching the convective temperature (around 100) or maybe an outflow boundary from early day convection to get anything to go in northeast NE. Should something develop in the afternoon, large hail, damaging winds, and localized flooding would be the primary threats. The surface front does eventually dive south into our are Wednesday evening, but guidance differs quite a bit regarding how far west any development will extend. Most CAMs keep storms to our east, but a few pieces of guidance suggest a few storms could move along the MO River before midnight. The front looks to stall out somewhere in vicinity of the NE/KS border by late Thursday afternoon. This will provide a focus for additional strong to severe storms Thursday afternoon/evening. Overall model trends are to keep the front and storm activity just to our south, or perhaps clip Pawnee and Richardson counties, but still some time for things to change. Once again, large hail, damaging winds, a locally heavy rain/flooding would be the primary threats. Otherwise, it will be another warm to hot day Thursday, especially south of the front where highs are expected to be in the mid 90s to around 100 once again. Areas to the north are expected to top out in the mid 80s to lower 90s. Friday will be slightly cooler as remain north of the front and dewpoints will remain in the 50s. Most of the day should stay dry, but storm chances look to return by Friday evening and overnight as a fairly strong shortwave slides through and brings our best chance for widespread storms in the forecast period. Still some questions on exact timing of this wave as well as how much instability will be in our area, but still should be a decent shot of rain for most. Precip could continue on and off into Saturday, but guidance still suggests some decent instability will be able to nose into the area by Saturday afternoon ahead of the primary shortwave trough axis moving through Saturday evening. This will bring perhaps our next best shot at strong to severe storms, but there will be a lot of smaller scale details to work out between now and then. We`ll remain in an active pattern heading into next week with southwesterly flow aloft and various bits of shortwave energy sliding through and interacting with a surface boundary draped somewhere across the area to bring shower and storm chances. Basically, expect at least pop-up showers and storms somewhere in or very near the area nearly every day next week. In addition, we`ll remain warm and humid with highs mostly in the upper 80s to mid 90s through at least Monday, though precip on any given day will certainly play a role in those temperatures for some. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 1050 PM CDT Tue Jun 11 2024 VFR conditions through the period. Southerly winds at TAF issuance 5-7 knots. Southerly winds increase to 16 knots with gusts to 27 knots by 14-15z, with speeds diminishing to 8-13 knots by 14/02z. There is a 20% chance of shower or storm at KOFK 12-16z, but still too low to include in the forecast at this time. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...CA AVIATION...DeWald