Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
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759 FXUS63 KTOP 250959 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 459 AM CDT Tue Jun 25 2024 .KEY MESSAGES... - Heat Advisory continues through 8pm this evening, with heat indices up to 109 degrees today. - Isolated thunderstorms are possible this morning along and south of I-70, although better chances (30-60%) are in far eastern KS this evening and overnight. Damaging wind gusts are the main concern with storms tonight. - Hot weather returns Friday, otherwise more seasonal temperatures midweek through the weekend with mainly nighttime storm chances. && .DISCUSSION... Issued at 404 AM CDT Tue Jun 25 2024 Upper ridge is holding strong across the southern US early this morning, while zonal flow dominates the northern third of the CONUS with a couple of embedded perturbations within it. One of those perturbations can be seen rounding the ridge in western KS, where decaying convection has been slowly moving through that part of the state and is expected to stay west of our area before it dissipates into the morning. HRRR runs have been consistent in developing isolated to widely scattered showers and thunderstorms mainly along and south of I-70 during the mid to late morning hours. The FV3 has shown this too, while most other CAM guidance remains dry. The HRRR`s persistence makes it tough to dismiss this completely, although it`s also tough to see much forcing causing the precip, aside from perhaps weak isentropic ascent in the 320K layer that could be just enough to develop a few storms. Have limited PoPs to 20% or less given the low confidence. Shear looks weak during this time frame as well, so would not expect anything to become severe if it develops this morning. The main storm risk comes later tonight, but in the meantime, expect another hot and humid day across the area. Deep mixing (albeit not quite as deep as yesterday) plus the thermal axis remaining overhead will contribute to temperatures rising to the upper 90s to low 100s again. Heat indices up to 109 are expected and have made no changes to the Heat Advisory for today. Another embedded shortwave ejecting out into the central and northern Plains is expected to help push a cold front southward from NE late this afternoon and eventually move across our area this evening and overnight. Plenty of instability should develop ahead of the boundary with 2000-4000 of MLCAPE (highest toward far northeast KS and into NE/IA) with deep-layer shear around 30 kt. The best forcing for ascent is expected to be along the front in eastern NE and IA, where a complex of storms looks to develop late this afternoon or early this evening. The main question for us is related to the western extent of storms into our area as this MCS moves south/southeast tonight. Some guidance, such as the NAM/RAP/HRRR, suggests storms may miss us completely and stay in MO. Other CAMs have at least some portion of eastern KS impacted, but vary slightly in their timing and western extent as storms move south. At this time, locations along and east of Hwy 75 stand the best chance of seeing storms as this area is where PoPs above 50% are focused. Timing generally looks to be after 9-10pm when putting all guidance together. Damaging winds are the main threat as storms move through the area, which should end before sunrise Wednesday morning. More seasonal temperatures are expected Wednesday and Thursday with highs in the 80s to low 90s, as the upper ridge becomes more established over the southwest CONUS and we transition to more northwesterly flow aloft. Another perturbation on the periphery of the ridge brings more storm chances late Wednesday night into Thursday morning, followed by a better chance Thursday night as a more substantial shortwave trough over the northwestern US helps to flatten the ridge. The thermal axis returns with low-level southerly flow on Friday, bringing a brief return to hot and humid conditions with heat indices around advisory levels possible once again. Another cold front is progged to bring additional storm chances into the weekend with a return to seasonal temperatures. && .AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/... Issued at 456 AM CDT Tue Jun 25 2024 VFR conditions are expected through the period. Southerly winds increase late morning with gusts subsiding after sunset. The main challenge is with convection late this evening and overnight. Models vary on how far west storms will be as they track south out of NE/IA. For now have left mention out of MHK with VCTS mention at TOP/FOE, although timing may also be adjusted with future issuances. Storms could also miss terminals entirely as suggested by some models. Will continue to monitor trends and adjust accordingly. There is also a small chance for a weak shower or storm this morning, but that chance is too low to mention. && .CLIMATE... Issued at 622 PM CDT Mon Jun 24 2024 Record hot temperatures are possible Tuesday Record High Forecast High June 25 Topeka: 106 (1911) Topeka: 97 Concordia: 104 (1988) Concordia: 100 Record Highest Minimum Forecast Minimum June 25 Topeka: 82 (1911) Topeka: 79 Concordia: 80 (1952) Concordia: 78 && .TOP WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 8 PM CDT this evening for KSZ008-KSZ009- KSZ010-KSZ011-KSZ012-KSZ020-KSZ021-KSZ022-KSZ023-KSZ024-KSZ026- KSZ034-KSZ035-KSZ036-KSZ037-KSZ038-KSZ039-KSZ040-KSZ054-KSZ055- KSZ056-KSZ058-KSZ059. && $$ DISCUSSION...Picha AVIATION...Picha CLIMATE...Poage