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Area Forecast Discussion (AFD)

Issued by Topeka, KS (TOP)

                            
000
FXUS63 KTOP 161744
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1244 PM CDT Tue Jul 16 2019

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 355 AM CDT Tue Jul 16 2019

Eastern Kansas was under modest mid/upper subsidence early this
morning with the old tropical remnants in south-central Missouri.
Areas of convection to the southwest and northwest should be
entering an increasingly unfavorable environment with light to
northerly lower level flow nearer to the Missouri system. A few
observations in far eastern Kansas suggest patchy ground fog has
attempted to develop in weak winds and clear skies and continued
clear and calm conditions should support some further development
through sunrise. 

Have kept today dry with IR satellite showing generally-weakening
convection and little change in downstream conditions to support 
an increase in lift. Modest west to southwest 850 mb flow brings 
a warmer lower troposphere in today with temps at this level 
rising around 5C from Monday afternoon. Mixing remains to be a 
challenge with weak surface ridging over far eastern Kansas into 
early afternoon and highs a few to several degrees warmer should 
result. Heat indices rise notably and should reach to the mid 90s 
to around 100 for most locations. 

THere is a rather consistent signal for some elevated convection
to form in northeast Kansas late tonight as modest isentropic
upglide takes place around 315K and combines with 700 mb dewpoints
around 6C for some elevated instability to develop in modest CIN.
Have included small PoPs but any rainfall looks light. 

.LONG TERM...(Wednesday through Monday)
Issued at 355 AM CDT Tue Jul 16 2019

Any overnight convection should diminish early Wednesday us upper
heights rise a bit. Stronger low-level south to southwest winds
downstream of a weak front and lee trough lead to better mixing
and and dewpoints ticking up for the more concerning period of
heat to settle in. Convective chances associated with the 
upstream boundary look small at best in very weak convergence and 
700 mb temps pushing 15 C. Lower level thermodynamics change 
little into the late week periods though there remains some 
uncertainty in specific values. 0Z GEFS plumes are consistent with
850 mb temps in the mid 20s C but the operational run was a high 
outlier on dewpoints. The going Watch remains very prudent for the
this prolonged period of high heat and with little overnight 
relief under a moderate though seasonally-strong low level jet. 
There continues to be decent agreement in a pattern change later 
in the weekend and will keep somewhat cooler temps for early next 
week. 

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1241 PM CDT Tue Jul 16 2019

VFR conditions are expected through the TAF period. Winds should
remain light and variable through today before increasing during
the mid-morning hours Wednesday to 10-15 kts. There is a small
chance for thunderstorms near the terminals after sunrise, but
confidence is too low to mention in the TAFs at this time.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Excessive Heat Watch from Wednesday afternoon through Saturday 
evening for KSZ008>012-020>024-026-034>040-054>056-058-059.

&&

$$

SHORT TERM...65
LONG TERM...65
AVIATION...Baerg/Picha