905
FXUS63 KTOP 041951
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
251 PM CDT Thu Jul 4 2024

.KEY MESSAGES...

- Low chance (20% or less) for storms this afternoon or early
evening, mainly in Anderson County.

- Dry weather Friday and most of Saturday gives us a short break
from the wet pattern.

- Another chance for storms Saturday night into Sunday, otherwise
slightly below normal temperatures continue into next week.

&&

.DISCUSSION...
Issued at 251 PM CDT Thu Jul 4 2024

Surface cold front has continued to trend faster this morning, and
is through most of the forecast area as of 19Z. It has also become
more diffuse, but looks to be located near the I-35 corridor. As
clouds have cleared, this should allow for enough destabilization
for 1000-2000 J/kg of MUCAPE, but convergence still looks weak along
the boundary. Lapse rates also don`t look overly impressive (7 deg
C/km at best) and the best upper support remains well north of the
area with the trough axis over the northern Plains. All this points
to low confidence in storm development along the front before it
exits the area completely. Previous runs of CAMs were hinting at
post-frontal storms rooted somewhere in the 850-700mb layer along
the boundary at that level, but more recent HRRR and RAP runs have
backed off on this, so confidence is low on that possibility as
well. Have maintained PoPs around 20-25% to account for it, but even
that may be overdone at this point. If any storm were to develop,
Anderson County stands the best chance of seeing strong winds with
it, but once again even that is low. All storm chances should come
to an end by 8pm.

Sfc high pressure pushes into the area tonight into Friday while the
upper trough passes well northeast. Even with clearing skies and
light winds, current thinking is that the drier air behind the front
should preclude the development of fog but still something to
monitor for the overnight hours. A quiet Friday is forecast with
lows around 60 and highs in the 80s.

Northwest upper flow sets up Saturday with return flow developing in
the lower levels. This looks to bring some warmth and moisture back
into the region, though perhaps not quite to the extent that we`ve
had recently. Still, a shortwave passing through the flow aloft
brings our next best chance for showers and thunderstorms late
Saturday through Sunday. If north central KS sees these early enough
Saturday, the environment could be supportive of damaging wind gusts
as forecast soundings show an inverted-V type of profile. The main
time period for storms, however, looks to be Sunday afternoon and
evening for the entire area when PoPs increase to 60-70%. Although
Pwat forecasts around 1.5" are not nearly as high as the moisture
has been recently, there is still plenty of time for this to change
and places that have seen repeated rounds of heavy rain could still
have issues with this. Mid-range guidance indicates rain amounts up
to 1" or even 1.5" on the higher end may be possible.

The main troughing pattern looks to set up east of the region to
bring more subdued weather for the early part of the next work week.
Temperatures remain slightly below average for early July with highs
mostly in the 80s and lows in the 60s.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1232 PM CDT Thu Jul 4 2024

Seeing the clouds breaking up in eastern KS via satellite, so
expecting VFR conditions to return to TOP/FOE in the first hour
or so of the period. Frontal boundary has passed all terminals,
so the chance for any isolated showers or rumbles of thunder to
impact terminals is very low the rest of today. Hi-res guidance
has been backing off on any post-frontal activity as well. With
clearing skies and light winds overnight, will monitor potential
for patchy fog especially in the river valley, but there may be
enough dry air advecting into the area to preclude this, so
confidence in that is low at this time. Otherwise, expect NW
winds under 10 kt through the period.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Picha
AVIATION...Picha