Area Forecast Discussion
Issued by NWS Topeka, KS
Issued by NWS Topeka, KS
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192 FXUS63 KTOP 172246 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 546 PM CDT Mon Jun 17 2024 .KEY MESSAGES... - Chance of thunderstorms Tuesday afternoon through Wednesday morning will bring threat for severe thunderstorms and heavy rainfall. - Highest confidence in 1-3" of rainfall will be north of a line from Abilene to Manhattan to Seneca. Locally higher amounts possible. - Storm chances dwindle Thursday as stalled boundary finally begins to retreat north. && .DISCUSSION... Issued at 207 PM CDT Mon Jun 17 2024 Looking at the latest surface analysis, a strong pressure gradient is driving gusty southerly winds across the state of Kansas. Strong southerly winds are keeping dewpoints in the 70s, bringing yet another hot and humid day. Winds will continue to gust between 30-40 mph this afternoon and overnight. They will be close to wind advisory criteria, but confidence in widespread wind gusts of 45 mph is very low. Tomorrow, a strong upper-level jet rounds the base of a trough in the northern Rockies, but most of the dynamic support will be further to the north. Across north central KS, a convergent boundary will be the focus for CI during the late afternoon tomorrow. Initially, storms that form on the boundary will have access to between 1000-2000 J/Kg of surface CAPE, supporting large hail and damaging wind gusts. Effective shear of only ~20 kt along with good frontal convergence will lead to upscale growth, and a transition to clusters of storms with an increasing damaging wind threat. The boundary is likely to stall, and outflow rushing out from under the storms will lower the severe threat by late evening. The main concern comes later in the evening and overnight, when strong southerly flow will overrun a nearly stationary boundary, providing a good environment for heavy precipitation and training storms. PWAT values will be near the climatological maximum, between 1.75-2". Guidance varies on where the maximum band of heavy rain will set up, but there is a high probability (70-90%) that portions of North Central KS will see 1-2" of rainfall. The HREF mean is 2", and amounts could locally reach 3-4". The area with the highest chance of seeing this heavy rainfall is roughly north of a line from Abilene to Manhattan to Seneca. Rainfall totals will drop off significantly to the south of that line, and portions of east central Kansas may see little to no rain. Training thunderstorms will continue overnight through Wednesday morning. As the trough lifts off Wednesday, the surface boundary and any remaining outflows left behind could be a trigger for more convection during the day. Shear will be weak, but high levels of moisture remain in the atmosphere, and heavy rain will once again be possible. Thursday, the boundary finally lifts to the north and the area becomes dry. Temperatures will remain above average for the period except Wednesday, when cloud cover and precipitation will keep temperatures at or below average. Perturbations in the flow may provide additional storm chances through the weekend, but predictability is low at this point. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 546 PM CDT Mon Jun 17 2024 The terminals look to remain between the mean westerlies to the northwest and upper ridging to the east. This should limit forcing with no obvious lift expected. So a dry forecast should persists. Some low level moisture advection Tue morning may allow for some stratocu to move in before dawn. So there may be some MVFR CIGS through mid morning before deeper mixing lifts the CIGS. A tight pressure gradient and turbulent mixing of the boundary layer through tonight is expected to keep gusty surface winds and mitigate wind shear potential from the low level jet. && .CLIMATE... Issued at 211 PM CDT Mon Jun 17 2024 Record Warm Low Temperatures June 17 Record Low as of 2 PM Concordia 75 (2018) 75 Topeka 78 (1918) 76 June 18 Record Forecast Concordia 80 (1953) 74 Topeka 81 (2021) 76 && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Montgomery AVIATION...Wolters CLIMATE...Montgomery