608 
FXUS63 KTOP 062344
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
644 PM CDT Wed Oct 6 2021

...Update to aviation forecast discussion...

.DISCUSSION...
Issued at 309 PM CDT Wed Oct 6 2021

Lower cloud rather prevalent again today after some morning fog in 
western locations dissipated. The cloud cover is farther west than 
yesterday at this time and may be enough to keep more fog formation 
in check tonight, though light winds and a moist boundary layer 
bring the potential in any consistent clearing. Later shifts will 
again need to monitor trends into Thursday morning. An area of 
showers rotating around the Arkansas upper low was working west 
across southern Missouri but looks to stay just east late this 
afternoon. The upper low is ushered northeast tonight into Thursday 
as southwest flow aloft expands over the central Rockies. Decreasing 
clouds and veered low-level winds should bring warmer afternoon 
temps.

A decent isentropic upglide setup takes shape late Thursday evening 
into early Friday morning as lapse rates aloft steepen giving rise 
to a MUCAPE of around 200 J/kg. Moisture is somewhat lacking and 
keeps the chances for anything more than isolated convection low. 
Temps Friday continue to rise under continued modest WAA and good 
mid-day insolation though mixing is somewhat limited. Warmest temps 
of this forecast still expected for Saturday as 850 mb temps rise in 
the lower to mid 20s C, supporting highs in the upper 80s to lower 
90s, though there are again questions on mixing potential with a 
surface low nearby. Even with weaker winds elevated fire danger is 
expected as RH values fall into the 20s and 30s. 

An active pattern takes shape over the late weekend and into the 
middle of next week as a few upper troughs/lows move northeast 
through the central CONUS. The first wave is more closed then 
earlier runs for better precip potential late Sunday into Monday, 
though instability still is somewhat in question with the handling 
of a lead wave to the northeast and its impact on a cold front ahead 
of the main trough. Instability should be much more readily 
available for the next low in the Tuesday into Wednesday night 
periods as the first front stalls in north Texas, and though the 
timing of the associated cold front may not be ideal, some 
thunderstorms are likely with plenty of shear. 

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 623 PM CDT Wed Oct 6 2021

Most numerical models show low stratus developing across the
terminals between 6Z and 9Z THU. Ceilings will drop down to the
low MVFR level but may dip below 1000 feet at times. Light fog
will begin to develop shortly after 9Z as visibilities will drop, 
after 10Z THU, down to 1 to 2 miles. However, if the stratus does
not develop then dense fog may occur at the terminals between 10Z
and 13Z with visibilities of 1/4 mile or less. The fog and or 
stratus should mix out after 15Z.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

DISCUSSION...65
AVIATION...Gargan