494
FXUS63 KSGF 171122
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
622 AM CDT Thu Sep 17 2026

.KEY MESSAGES...

- A Heat Advisory is in effect through Saturday. Highs near 100
  with Heat Index values 100-105 can be expected. Several daily
  records may be tied or broken.

- There is a less than 25% chance for isolated thunderstorms to
  form east of Hwy 65 this afternoon, especially toward central
  Missouri.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 326 AM CDT Thu Sep 17 2026

Unfortunately, nothing has changed from previous discussions
regarding the heat. The high pressure system continues to dominate
through the end of the week. It will keep high temperatures in the
mid to upper 90s through at least Saturday. The Heat Advisory
now continues through Saturday evening, in part due to the
apparent slowing of the incoming low pressure system. Heat Index
values will continue to approach and exceed 100 degrees through
the remainder of the week.

Widespread rain chances don`t arrive until early next week, though
there will be the potential for pulse thunderstorms again this
afternoon. Conditions will be similar to yesterday afternoon, though
coverage looks even more limited. While the severe risk looks
minimal, as we learned from yesterday, any stronger cores that
manage to find a pocket of stronger shear will be capable of
downburst winds. This potential is nearly impossible to pin down
given that deep-layer shear overall will be very lacking, but the
best instability will be in the northeastern portions of the CWA
toward central Missouri (not unlike yesterday). These areas of 2000+
J/Kg of CAPE will best support this scenario. Severe winds are
unlikely, but HRRR output does depict a few strong cells capable of
40-50 mph gusts roughly in the areas we saw the strongest storms
yesterday, quickly moving east into the St. Louis CWA. Again, most
areas will remain dry today.

Lows will be in the low to mid 70s again tonight, another factor
necessitating heat headlines to communicate the extended period
of far above-normal warmth that could have compounding impacts
to health and safety if proper precautions are not taken. CAMs
running into Friday afternoon depict very tiny pop-up storms
across roughly the northeastern half of Missouri with another
day of very high temperatures and a small amount of shortwave
energy breaking free to the south, but these are not expected to
have much of impact, if they are able to form at all.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 326 AM CDT Thu Sep 17 2026

Friday and Saturday will still be hot as promised. As it stands,
they look to be the last days that this high pressure will still
fully have a grip on us. The approaching low pressure center begins
to break down the high Saturday evening with the cold front
approaching Sunday morning. Specifics on timing are difficult,
but those in west-central Missouri may start to see
precipitation during the early morning hours Sunday. With
northeasterly movement initially, it will take some time for the
front to clear the area. Most will still see highs in the mid
to upper 90s Sunday, though overnight lows should manage to be
several degrees cooler.

By Sunday afternoon, PoPs north of I-44 are up to 30-60%. They
continue to spread southeast throughout the overnight and Monday,
though they decrease as bit as the front becomes farther removed
from the better support of the low. Those in south-central Missouri
may not see as much rain. From Monday onward, highs for most are
knocked down into the 80s.

The CPC 8-14 day outlook is showing a 50-60% chance to end September
with above normal temperatures...but the 3-4 week outlook has equal
chances for above and below normal temperatures. So, perhaps we can
hold out some hope for the start of October.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 620 AM CDT Thu Sep 17 2026

VFR conditions expected through the period. Light SSW winds
become light and variable midday. Isolated pulse thunderstorms
are possible this afternoon, most likely remaining east of the
TAF sites.

&&

.CLIMATE...
Issued at 326 AM CDT Thu Sep 17 2026

Record High Temperatures:

September 17:
KSGF: 96/1953
KJLN: 95/1953
KVIH: 97/1953
KUNO: 97/1953

September 18:
KSGF: 95/2019
KJLN: 97/2022
KVIH: 95/1953
KUNO: 96/1972

September 19:
KSGF: 96/1954
KJLN: 99/2024
KUNO: 97/1954

September 20:
KSGF: 97/1954
KJLN: 99/1954
KVIH: 95/1954
KUNO: 97/1954

September 21:
KUNO: 95/1955


Record High Minimum Temperatures:

September 17:
KSGF: 73/1978

September 18:
KSGF: 74/1931

September 19:
KSGF: 73/1931

September 20:
KSGF: 74/2018

September 21:
KSGF: 73/1931

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
KS...Heat Advisory until 8 PM CDT Saturday for KSZ073-097-101.
MO...Heat Advisory until 8 PM CDT Saturday for MOZ055>058-066>071-
     077>083-088>098-101>106.

&&

$$

SHORT TERM...Nelson
LONG TERM...Nelson
AVIATION...Nelson
CLIMATE...Nelson