672
FXUS63 KTOP 181904
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
204 PM CDT Sat Jul 18 2026

.KEY MESSAGES...

- Scattered showers or storms this afternoon and evening and again
  on Sunday

- Heating up Sunday and Monday. Heat index values around 105 degrees
  are forecast Monday afternoon.

- A slight cooldown is expected by the middle of next week,
  along with chances for showers and storms Wednesday night
  through Friday.

&&

.DISCUSSION...
Issued at 204 PM CDT Sat Jul 18 2026

The synoptic pattern remains stagnant across the region this
afternoon with broad mid-level ridging stretching from the western
CONUS into the Plains and an upper low over the TX/OK panhandles.
Another typical hot and humid summer day has evolved with
temperatures in the 90s and heat index values approaching 100
degrees. While forcing is lacking, an uncapped and unstable airmass
has again allowed for cumulus to develop, although sustained
updrafts have not been observed to this point. Nonetheless,
scattered showers and isolated storms could develop this afternoon
and evening. Meager lapse rates and weak shear will preclude severe
weather, but any storm that does form could produce heavy downpours
and gusty winds. There is some signal from CAMs for isolated showers
to continue overnight, similar to last night. A lack of forcing and
the loss of diurnal heating favors dry conditions, but there remains
enough elevated instability for a couple of showers or even of
rumble of thunder overnight.

The mid-level ridge expands southeast Sunday and Monday, leading to
slightly warmer temperatures over the next couple of days. With
little change in the overall airmass, an unstable and uncapped
environment will support scattered showers and storms again on
Sunday, with at least some potential extending into Monday. Given
the potential for precipitation and cloud cover, the NBM has trended
a few degrees lower for high temperatures both Sunday and Monday,
but it will still be plenty hot with heat index values of 98-102
degrees Sunday and 100-106 degrees Monday. A Heat Advisory may be
needed on Monday, especially if it becomes more clear that the
daytime hours will be dry.

A cold front is progged to move through the area Monday night into
Tuesday morning. Speed of the front and the cooler, drier post-
frontal air is varied amongst ensemble members, shown by a 5-8
degree spread in the 25th-75th percentiles for high temperatures on
Tuesday. The majority of guidance shows the front through the
forecast area by early afternoon, which increases confidence in
temperatures being cooler than Monday, but exactly how much cooler
remains in question. Guidance also favors a dry frontal passage due
to the unfavorable timing and limited deep moisture. That being
said, there is a small chance for showers/storms along the front,
especially if the front is slower to move through the area. The
cooler airmass does spill into the region for the middle of next
week; highs are forecast to be near or slightly below normal
Wednesday and Thursday. Perturbations moving through the flattened
flow leads to increasing precipitation chances Wednesday through
Friday, with highest chances (30-55%) coming Wednesday night into
Thursday morning.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1205 PM CDT Sat Jul 18 2026

VFR conditions expected. Coverage of showers/storms this afternoon
and evening should be isolated to scattered with low confidence
in direct impacts to terminals. Maintained a PROB30 group given
uncertainty in exact location and timing of precipitation. Winds
from the SSW today and tonight become southeasterly Sunday morning,
but remain light.

&&

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

&&

$$

DISCUSSION...Flanagan
AVIATION...Flanagan