297 
FXUS63 KTOP 231004
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
504 AM CDT Fri Jul 23 2021

...Update to aviation forecast discussion...

.DISCUSSION...
Issued at 259 AM CDT Fri Jul 23 2021

The main hazard for the period continues to be the focus on hot
and humid conditions. A heat advisory has been issued for part of
the area with the highest likelihood of seeing widespread
heat advisory conditions being met. This advisory could be
extended across the entire area eventually. But right now, it
appears that sufficiently deep mixing should set up from north
central into portions of east central Kansas to keep heat index
values closer to the 100 degree range vs the next category of the
105 or slightly higher range. Again, the lack of deeper mixing
over northeastern Kansas areas should allow for the heat and
humidity to have more of an impact. Please reference heat advisory
products for further details and safety tips. 

The overall pattern doesn't really change over the entire forecast
period. A semi-permanent and building anticyclone sets up and
expands over the southwestern into central portions of the CONUS.
This will push any meaningful portions of the upper flow pattern
well north and east of the area. Thus, with a mainly hot and dry 
column of air in place, chances for precipitation would appear to
be hinging on only one possible opportunity late Sunday into 
Monday time frame. A weak shortwave may temporarily flatten part
of the ridge in place and allow for a weak complex of storms to
develop along a weak cold front and eventually move into the area.
Confidence in this scenario appears to be mixed, so have capped
chances of rain and a few storms at around 30 percent right now.
The probability of severe weather during this period also appears
to be low.  

After this, the ridge is reinforced and continues to build with H5
heights on the order of 591 to 595 decameters. Under this ridge of
high pressure, H85 temps could be around 25C or higher. This would
likely mean a prolonged period of heat starting Tuesday of next
week and continuing for several days. Will hold off any mention of
heat headlines for this period likely until after this Saturday. 

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 501 AM CDT Fri Jul 23 2021

No significant changes to the going forecast with continued VFR
conditions and a SSW breeze through the day.  

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from noon to 8 PM CDT Saturday for KSZ010>012-023-
024-026-038>040.

&&

$$

DISCUSSION...Drake
AVIATION...Drake