779
FXUS63 KTOP 011038
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
538 AM CDT Tue Sep 1 2026

.KEY MESSAGES...

- Late season heat persists through Labor Day weekend. Highs in the
upper 90s, near 100 in north central Kansas, with heat indices of
100 to around 105.

- No Heat Advisory should be needed today. Thursday and Friday are
the most likely days to reach criteria as it looks now.

- Warm lows in the middle and upper 70s keep record warm minimums in
play through Thursday.

- The overall pattern may last into mid to late next week before a
meaningful airmass change brings temperatures back to around normal.

&&

.DISCUSSION...
Issued at 223 AM CDT Tue Sep 1 2026

The 00Z analysis shows a strong anticyclone centered over the
southern into the central Plains with a compact low over the
Canadian Prairies and the jet running along the international
border. A trough is digging into the Pacific Northwest while
Tropical Storm Edouard sits just off the Louisiana coast. WV imagery
suggests dry and subsident air over the region beneath the ridge,
with monsoon moisture streaming across the Desert Southwest into the
Rockies. At the surface the weak quasi-stationary boundary that held
northern Kansas a few degrees cooler Monday has lifted into
Nebraska, leaving the entire area in the warmer air to the south.
H85 temperatures in the middle 20s C supported yet another day with
temperatures around 100 degrees at many area locations.

The forecast question this period continues to center on whether
heat headlines will be needed and when, and it revolves around
dewpoint uncertainty. Ensemble high temperatures remain tightly
clustered in the upper 90s, near 100 across north central Kansas,
with spread of only a few degrees through Saturday. Ensemble
dewpoints are not as clear. The mean sits near 60 today, dips
Wednesday in association with some of the deepest mixing of the
week, then climbs into the middle 60s Thursday and Friday in
association with southerly return flow and holds through the
weekend. The member spread for Thursday and Friday runs from the
upper 50s to the upper 60s, and that spread will ultimately factor
into the headline decision making. Low 60s dewpoints yield heat
indices near 100 and no advisory issue, but still hot and dry.
Middle 60s, the current ensemble mean, push heat indices to 103 to
105. Upper 60s bring the 105 to 107 range. NBM heat index
probabilities follow the same trend, with values above 100 likely
Thursday and Friday, while 105 remains unlikely for most of the area
but still possible across north central Kansas late week. Near-
record warm overnight lows add to the overall concern with little
cooling to start the day. Lows in the middle and upper 70s puts
Topeka and Concordia on record warm minimum watch through Thursday
morning. No headline is currently needed for today as confidence in
the temperature forecast is high. With the depth of mixing and thus
the distribution of moisture through the boundary layer dewpoints
today should hold in the low to mid 60s.

The ridge still holds through the Labor Day holiday weekend.
Ensemble mean mid level heights over Topeka dip slightly Thursday as
a low amplitude northern stream disturbance passes well to the north
of the area, then the ridge re-amplifies and builds directly over
the central Plains Saturday through Tuesday with tight overall
member agreement. H85 temperatures hold in the middle 20s C through
the same period with no meaningful downward trend, and WPC cluster
analysis keeps the ridge axis over Kansas in every cluster through
Monday. That continues to argue against the NBM cooling trend for
the weekend, which reflects widening spread in the tails rather than
a shift in the mean, and highs were held in the upper 90s through
Sunday and middle 90s on Labor Day. Rain chances remain minimal
through Friday barring an unforeseeable mesoscale change to the
going forecast pattern. Slight chances for precipitation return
Saturday onward as the western flank of the ridge works east,
possibly allowing smaller scale mesoscale complex activity to push
into the area, but predictability is low at this time.

The overall weather pattern may finally change by mid to late next
week as a more amplified Pacific trough swings through the northern
Plains in the Thursday time frame. Ensemble mid level heights hold
through Wednesday and then fall sharply, hinting at a frontal system
working into the region. Meanwhile, H85 temperatures in the LREF
drop several degrees C as well, which appears to be the first real
cooling signal in the current guidance. Cluster analysis splits
sooner, in the Tuesday time frame, between holding the ridge and
flattening it. Either way, the signal is that a change in airmass
may finally be on the way.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 538 AM CDT Tue Sep 1 2026

VFR conditions persist through the period. Winds increase from the
SSW as mixing begins an hour or two after sunrise this morning with a
few gusts through the afternoon. The LLJ may become slightly
stronger again this evening and overnight especially around KMHK.
Will need to monitor trends to see if criteria for LLWS are met but
right now the overall impact appears to remain in the marginal
concern category.

&&

.CLIMATE...
Issued at 631 PM CDT Mon Aug 31 2026

Record highest minimum temperature information:

                      Record                   Forecast

September 2  Topeka     80, set in 2011            77
             Concordia  79, set in 1929            78


September 3  Topeka     77, set in 1939            78
             Concordia  80, set in 1947            79

&&

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

&&

$$

DISCUSSION...Drake
AVIATION...Drake
CLIMATE...Drake/Poage