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Area Forecast Discussion (AFD)

Issued by Topeka, KS (TOP)

FXUS63 KTOP 182043

Area Forecast Discussion
National Weather Service Topeka KS
343 PM CDT Sat May 18 2019

.SHORT TERM...(This evening through Sunday)
Issued at 343 PM CDT Sat May 18 2019

Convection associated with a lead shortwave over the southern Plains 
has slowly diminished this afternoon but not after producing very 
strong winds this morning in the Emporia area. Precipitation 
production was very efficient despite fairly fast motions and some 
rivers are already responding in mainly east central Kansas where 
estimated rainfall of near 2 inches fell. Local skies remain fairly 
cloudy downstream of the southern Plains convection with temps only 
in the 60s but afternoon clearing has ensued in south central Kansas 
near the surface low and synoptic stationary boundary where visible 
satellite shows some development. Additional elevated storms were 
forming near the main upper trough in southeastern Colorado and far 
southwestern Kansas. 

Guidance remains fairly consistent in destabilization returning to 
eastern Kansas late this afternoon and evening with minor mid-level 
cooling. This may be able to support some severe weather concern 
with convection forming in the next several hours along the 
convergence zone to the southwest. Confidence in precip trends over 
the next several hours remains low given several ongoing areas of 
convection however. Higher confidence exists for scattered showers 
and storms later tonight to around sunrise Sunday as the upper 
low swings east to northeast across the state with more limited 
instability. Will need to keep an eye on short-term rainfall 
amounts where recent bands of heavy rain fell but the potential 
for widespread flash flooding is too low for a Watch. Clearing
skies and breezy northwest winds should dominate Sunday with
another cool day. 

.LONG TERM...(Sunday night through Saturday)
Issued at 343 PM CDT Sat May 18 2019

The area remains under deep subsidence into Sunday night until 
the next upper trough makes its way into the central Rockies then 
swings northeast to north as a negatively-titled trough Monday night 
into Tuesday. There continues to be some model variation in timing 
and locations of the highest precip amounts but these are rather 
minor given the setup. Deep isentropic upglide over the departing 
surface ridge leads to initial precip Monday with the trough axis 
approach and passage for a wet Monday night and Tuesday. Widespread 
amounts of a few inches still seem likely with locally higher amounts 
very likely. Given responses to today's rainfall, flash and river 
flooding remains quite possible. Some mainly elevated severe 
potential exists around Monday evening, though eastern areas could 
have some surface-based storms Tuesday if a break can occur early in 
the day. 

Pattern becomes quite amplified in the middle to later portions of 
the week, particularly if the 12Z ECMWF verifies, with upper trough 
over the West and upper high over the Southeast. Although 
differences are noticeable in the large scale,  the low-level 
baroclinic zone will likely be over the region at least temporarily 
and brings additional shower and thunderstorm potential for much of 
the period from Wednesday into the end of the week. 


.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1252 PM CDT Sat May 18 2019

Challenging aviation forecast with ongoing and periods of
additional convection expected. Have tried to give some indication
of trends but much will depend on small-scale features and will
attempt to fine-tune as the afternoon transpires.