Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
861 FXUS63 KTOP 241713 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 1213 PM CDT Mon Jun 24 2024 .KEY MESSAGES... - Heat Advisory is in effect from noon today through 8pm Tuesday, with heat indices between 105-110 degrees. - Thunderstorms are possible tonight through Tuesday night, with highest confidence in eastern KS Tuesday evening. A few storms could produce damaging wind gusts. - More seasonal temperatures midweek through the weekend (except Friday) with mainly nighttime storm chances. && .DISCUSSION... Issued at 407 AM CDT Mon Jun 24 2024 Upper ridge is holding strong over the southern US with the main westerlies over the northern third of the CONUS. A shortwave trough is noted within that flow along the Canadian border with MT. A sfc trough axis in response to that wave extends from eastern MT southeastward through the High Plains. Deep mixing up to 800-700mb will bring very warm temperatures aloft down to the surface this afternoon. This in addition to increasing southerly low-level flow supports high temperatures in the upper 90s to near 100 in eastern KS and highs between 100-105 in central KS where mixing is deeper. That mixing should result in lower dew points in central KS compared to further east, but overall heat indices are still forecast in the 105-110 degree range widespread across the area this afternoon. Mixing doesn`t look nearly as deep on Tuesday, but overnight lows only falling back to the mid to upper 70s in the morning means it wouldn`t take as much time to heat back up to the upper 90s to low 100s again. The thermal axis looks to remain over the area as well. Given that the vast majority of the area is forecast to have heat indices in the 103-108 degree range Tuesday afternoon, and warm lows in the morning will provide little relief overnight, have opted to extend today`s Heat Advisory through the night into Tuesday afternoon. The one potential caveat to having widespread advisory conditions Tuesday is related to whether or not we have morning convection that would then lower temperatures for the afternoon. Confidence in showers and thunderstorms tonight through Tuesday early afternoon is rather low, however, considering the CAMs have varying ideas on timing and placement and forcing for ascent is weak. Confidence in storms increases later in the afternoon into the evening, and if clouds and precipitation hold until then, very hot and humid conditions would justify continuing the advisory. Speaking of storm chances, late this afternoon and early this evening, scattered storms look to develop in western NE/KS. These are driven in part by a subtle perturbation rounding the upper ridge and also by a weak frontal boundary developing in NE associated with the system to the north. The NAM and NAM Nest have consistently been farthest east with bringing convection through southeast NE into northeast KS overnight into early Tuesday morning, whereas most other guidance appears to favor western KS initially before bringing storms into north central and northeast KS after dark. Given variations among guidance to this point, have kept PoPs between 15- 25% between 00-12Z. Shear doesn`t look impressive (20 kt at best), so wouldn`t expect storms that make it into this environment to be severe. If something were to develop in north central KS in the late afternoon, a well-mixed BL with an inverted-V profile could support collapsing updrafts with damaging winds. However, the more probable scenario is for storms to hold off until later in the evening when inhibition increases and the environment no longer supports this. Low-end PoPs continue through Tuesday morning and early afternoon, but the more favorable setup for thunderstorms comes in the late afternoon to evening as an upper wave passes to our northeast and brings a frontal boundary through the area. Plenty of instability exists ahead of this boundary and shear around 30 kt would better support more organized updrafts. The main question becomes whether there will be enough convergence along the front to overcome capping and how widespread storms will be as a result. Any storms that develop and can become organized would again pose a damaging wind threat with collapsing updrafts. Behind the front, relatively cooler temperatures are forecast for Wednesday and Thursday with the upper ridge holding to our southwest. Heat may return briefly on Friday with return flow bringing higher temperatures and dew points, but uncertainty in the forecast increases midweek onward as embedded perturbations continually round the ridge and bring overnight MCSs through the region each night Wednesday night through the weekend. Each wave will likely impact the following one, so exact details on timing and placement of each round should become clearer as we get closer to each day. This could impact temperatures each day as well, leading to lower confidence in Friday`s heat. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1213 PM CDT Mon Jun 24 2024 VFR conditions are expected through the period. Winds south to southwest 10-15kts with gusts to 24kts through 00Z, then decreasing to around 10kts by 02Z. && .CLIMATE... Issued at 610 PM CDT Sun Jun 23 2024 Record hot temperatures are possible Monday and Tuesday Record High Forecast High June 24 Topeka: 104 (1937) Topeka: 100 Concordia: 106 (1937) Concordia: 103 June 25 Topeka: 106 (1911) Topeka: 98 Concordia: 104 (1988) Concordia: 100 Record Highest Minimum Forecast Minimum June 25 Topeka: 82 (1911) Topeka: 77 Concordia: 80 (1952) Concordia: 77 && .TOP WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 8 PM CDT Tuesday 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...53 CLIMATE...Poage