FXUS63 KTOP 190522 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 1222 AM CDT Tue Aug 19 2025 .KEY MESSAGES... - Scattered showers and thunderstorms return early Tuesday morning and linger through the afternoon. Hot and humid weather continues outside of storms. - Not quite as hot Wednesday through Friday, then a more meaningful cool-down comes this weekend. && .DISCUSSION... Issued at 248 PM CDT Mon Aug 18 2025 A decaying MCV has kept some isolated shower and thunderstorm activity around into the early afternoon hours today, but it looks as though it may finally be losing its strength with weakening isentropic ascent over our area and the original shortwave well to our northeast in IA and WI. Assuming clouds clear out quickly enough, most locations should still reach the 90s, but a few places may struggle to do so. Areas that have already cleared out should have no problem reaching the mid to upper 90s this afternoon. A mostly dry forecast is in place for the late afternoon through the evening hours. A weak perturbation on the periphery of the upper ridge over the southern US is progged to trigger convection off the High Plains early this evening. Storms should generally weaken as they move east along the associated frontal boundary, which looks to push into northern KS from Nebraska overnight. There isn't much forcing for vertical ascent by the early to mid-morning hours of Tuesday, but the 12Z CAMs have a general tendency to increase storm coverage across eastern KS during that time frame, which could happen if the overnight convection develops into another MCV. Overall, confidence is low in the coverage and location of storms overnight into Tuesday morning, as models haven't been very consistent. The HRRR and ARW in particular are showing another line of storms developing Tuesday afternoon, stretching from somewhere in southwest to central KS. The exact location would depend on where any remnant outflow boundaries set up as well as the synoptic boundary, although the convection would likely wash that out. Highs are forecast in the upper 80s to 90s, which could end up slightly cooler in some places pending clouds and precip, similar to today. Wednesday and Thursday, sfc high pressure pushes south from the Upper Midwest while we have meridional flow aloft due to Hurricane Erin pushing the upper ridge westward. This should help keep temperatures down from what they otherwise could be, resulting in highs in the mid 80s to mid 90s. We warm up a touch on Friday, but overall not much different than the previous two days. A more meaningful cool-down comes this weekend as a shortwave trough passes from Manitoba to Ontario, transitions us to northwest flow aloft, and pushes an associated sfc cold front into the area. A few disturbances within the northwest flow bring on and off rain chances through the weekend, but differences in the strength of the aforementioned shortwave keep uncertainty in the timing and placement of any other waves of energy nearby. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1222 AM CDT Tue Aug 19 2025 Latest surface analysis suggests there is a weak area of convergence across the southern parts of the forecast area with a weak southwesterly low level jet across northern OK and southern KS. A moisture axis with dewpoints in the lower to middle 70s remains across northeast KS. An MCV over northwest KS is evident from radar and profiler data. Think the main focus for convection may end up just south and west of the terminals. where the weak boundary is, but confidence in this is low and convection is possible just about everywhere. Will opt to amend if storms become obvious rather than broad brush SH for the next 18 hrs. Outside if any precip, VFR conditions should prevail. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Picha AVIATION...Wolters