276
FXUS63 KTOP 051009
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
509 AM CDT Fri Jun 5 2026

.KEY MESSAGES...

- Highs are forecast to be around 90 this afternoon, but it is
  expected to feel like 95 to 100. Take it easy if working outside
  this afternoon.

- A stormy pattern is forecast to remain over the region through the
  weekend. Slow moving storms with heavy rain will be a concern.

- Hot and humid weather is forecast by the middle of next week. Heat
  indices could be around 105 degrees for several days.

&&

.DISCUSSION...
Issued at 313 AM CDT Fri Jun 5 2026

08Z water vapor imagery showed a subtle shortwave moving through the
middle MO river valley. Upstream were a couple closed upper lows
over northern Mexico and over the Gulf of Alaska. Surface obs placed
an area of low pressure over the CO high plains with an inverted
trough extending east along the NEB/KS state line. The 850MB winds
have slowly veered more to the west which has allowed the convection
over far northeast KS to finally move east. A humid airmass with
dewpoints in the mid 60s to around 70 remained over eastern and
central KS.

For today and tonight, models struggle to develop any convection
from what looks like a lack of synoptic scale forcing. However
models prog a very unstable airmass developing with sfc based CAPE
values on the order of 5000 J/kg with little inhibition. As low
level winds become more southerly through the day, low level
convergence along the inverted trough could be enough to set off a
new round of storms. Have kept a 20 to 30 percent POP mainly across
the northern half of the forecast area because of this. Bulk shear
around 25KT may favor slow moving clusters again with a heavy rain
threat being the most likely hazard. Confidence in storms developing
in KS is a little to low to reissue the flood watch, but if the
boundary slips south during the day it may be needed. Models show
some warm air advection with southwesterly winds at 925 and 850MB.
This is expected to help push temps to around 90 for highs this
afternoon assuming convection doesn`t initiate early and put out
some cold pools. Heat indices are expected to be in the middle 90s
to near 100 degrees. This is kind of marginal for a heat advisory,
but people out working through the mid afternoon will probably feel
the heat and humidity and are encouraged to take it easy.

For Saturday and Sunday, the upper low currently over Mexico is
progged to lift north through eastern KS. Models don`t seem to
develop much precip on the northern side of the disturbance on
Saturday, but widespread showers and storms are forecast for Sunday.
PWs are forecast to be between 1.5 and 2 inches with weak bulk
shear. So slow moving storms with heavy rain could be a problem once
again. More cloud cover and chances fore rain are expected to hold
afternoon highs in the middle 80s for Sunday.

Once the upper disturbance lifts north of the region by Monday
evening, southwesterly upper flow is progged to set up for the rest
of the week. This is expected to allow warm air to advect in from
the southwest and push highs into the middle 90s by mid-week. With
nothing to scour out the boundary layer moisture, we could be
looking at several days with heat indices around 105 degrees and
wetbulb global temperatures in the high category for heat illnesses.
Precip chances look to be limited with an upper trough and much of
the synoptic energy remaining west of the forecast area. There are
indications of a frontal boundary moving in from the west late in
the week. This could bring better chances for rain.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 509 AM CDT Fri Jun 5 2026

Satellite is showing the stratus expanding across southeast KS.
Because of this will go ahead and bring MVFR CIGS into TOP and FOE
through much of the morning.

Issued at 500 AM CDT Fri Jun 5 2026

First challenge with the forecast is whether a nearly saturated
boundary layer will result in MVFR GIGS. Some stratus has developed
just north of TOP but has not filled in to the south. This may be due
to good mixing within the boundary layer entraining some dry air.
Will include a TEMPO at TOP and keep it out of the forecasts for FOE
and MHK based on latest satellite imagery. Second challenge is where
will TS redevelop today. Most guidance washes out any boundary left
from last night`s storms with an inverted trough setting up across
southern NEB. This should be the focus for low level convergence and
storm initiation. With the CAMs keeping TS north of the terminals,
will maintain a dry forecast at this time.

&&

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

&&

$$

DISCUSSION...Wolters
AVIATION...Wolters