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Area Forecast Discussion (AFD)

Issued by Topeka, KS (TOP)

FXUS63 KTOP 251743

Area Forecast Discussion
National Weather Service Topeka KS
1243 PM CDT Sun Aug 25 2019

...Update to aviation forecast discussion...

.SHORT TERM...(Today through Monday)
Issued at 346 AM CDT Sun Aug 25 2019

MCS associated with a seasonally-strong shortwave continues to push 
east-southeast early this morning. Overall weakening trends have 
been noted with some cell mergers ahead of the primary line leading 
to some more intense updrafts. The persistent low cloud over the 
region has helped keep instability in check to the east of this 
system and expect a general decline in strength through the 
remainder of the morning and early afternoon. Earlier training 
storms has also subsided and heavy rainfall concerns continue to 
diminish as well. Plenty of cloud and rain-cooled air should again 
keep temperatures cool though some late day insolation is possible 
especially in western locations.

The next upper wave dropping southeast into the northern Plains 
induces lee cyclogenesis to the northwest tonight with a moderate low-
level jet developing over the cool boundary-layer air. There could 
be enough isentropic upglide for drizzle or light showers late 
tonight into Monday morning in northern and eastern areas. Models 
continue to show stout ML CIN resulting but also rather quick 
erosion of it in southeastern locations as a cold front approaches. 
The upper trough remains well north and the cap erosion remains in 
question with dewpoints rising through the day potentially keeping 
stratus in place, but isolated to scattered deep moist convection 
remains possible in the late afternoon and early evening before the 
front exits to the southeast. 500 mb winds remain progged to reach 
around 45 knots from the west for a moderate shear and strong CAPE 
combination and severe weather potential, with hail and wind the 
primary concerns. Highs Monday should return to the middle 80s in 
the south given some afternoon insolation with the elevated 
dewpoints pushing heat index values into the 90s. 

.LONG TERM...(Monday night through Saturday)
Issued at 346 AM CDT Sun Aug 25 2019

A weak shortwave pushes southeast toward Kansas Tuesday into Tuesday 
night though this serves to reinforce the surface ridge with 
moisture depths rather weak to support any precipitation. A weak 
elevated WAA regime could develop Wednesday night behind the surface 
ridge mid-week for small precip chances. A stronger wave in the 
continued northwest flow brings greater potential in the Friday to 
Saturday periods. Temperatures Thursday could push back to near 
normal after a few more cooler days with cooler temps again late in 
the forecast. 


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1203 PM CDT Sun Aug 25 2019

Lingering showers continue to slowly exit the region to the east
this afternoon impacting KTOP/KFOE terminals. Expecting at least
MVFR stratus -- to VFR at times -- also linger across the area
impacting all terminals through most of the period. CIG/VIS could
drop back to low MVFR or IFR for a period overnight but confidence
is only medium at this time in this scenario so have mentioned SCT
coverage for low clouds. Expecting more stratus than fog set up
with no real opportunity for radiational cooling and a slightly
mixed surface layer overnight.