300
FXUS63 KSGF 132315
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
615 PM CDT Sun Sep 13 2026

.KEY MESSAGES...

- A Heat Advisory is in effect for south-central and southwest
  Missouri, and extreme southeast Kansas beginning 11 AM Monday,
  and lasting through 8 PM Tuesday. Highs in the 90s with heat
  index values of 100-105 can be expected during this period.

- A stalled frontal boundary northwest of the area brings low
  15-40% chances of rain northwest of I-44 through the week,
  with a Marginal (1 of 5) Risk of severe weather clipping
  portions of west and central Missouri on Tuesday.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 245 PM CDT Sun Sep 13 2026

Current visible satellite and radar imagery shows the remnants
of a thunderstorm complex that was over Kansas last night has
almost completely dissipated across our area this morning as it
progresses east of a mid-level shortwave ridge axis centered
along the OK/AR and MO/KS border. The leftover cloud debris is
producing variable temperatures across our area. In general,
cooler temperatures in the lower 80s are observed northwest of
I-44, with hotter temperatures in the upper 80s to lower 90s
observed southeast of I-44.

North of this ridge axis, the jet stream is starting to take on
aspects of fall, with enhanced flow and energetic troughs over
the Great Lakes and NW CONUS. Unfortunately, this jet stream is
forecast to stay north well to the north for the forecast
period, bringing well above normal temperatures back into our
region.


Low 15-20% chance for isolated showers and thunderstorms today:

The cloud debris and leftover "cold" pool has made it difficult
for any meaningful instability to redevelop today. Our morning
balloon showed a whopping 16 J/kg of MLCAPE and -350 J/kg of
MLCIN, with a bulb of dry air noted through 600 mb. Current RAP
mesoanalysis continues to show very weak instability and strong
capping over much of the area. There is perhaps some better
instability and weaker capping in the eastern Ozarks where
temperatures are highest and a few cumulus clouds are starting
to be seen. This is where there may be a 15-20% chance for an
isolated shower/thunderstorm or two this afternoon before sunset,
but confidence is much higher in dry weather persisting today.

&&

.LONG TERM /MONDAY THROUGH SUNDAY/...
Issued at 245 PM CDT Sun Sep 13 2026

Heat Advisory in effect for from 11 AM Monday until 8 PM Tuesday:

Models forecast a pretty pronounced ridge axis to develop and
move over the area Monday as the potent upper low over the NW
CONUS continues eastward. As a result of this, warm air
advection and an attending warm front will blitz through the
area early Monday morning, bringing moisture and hot (well above
normal) temperatures back to the area for at least Monday and
Tuesday. Highs are forecast to be in the 90s (near 100 west of
Highway 65). With dewpoints near 70 F entering with this air
mass, Heat Index values are forecast to be in the lower 100s,
especially west of Highway 65. The heat is then expected to move
eastward Tuesday, enveloping much of our area Tuesday. For this
reason, a Heat Advisory has been issued for portions of our
area starting at 11 AM Monday and lasting through Tuesday.

Depending on the exact location of the warm front during the
heat of the day on Monday, some temperatures may be in the
upper 80s, especially near central Missouri. For this reason,
those counties have been left out of the Heat Advisory for now.
However, as the ridge progresses eastward into Tuesday, the heat
should fully engulf our CWA, and those counties may need to be
added for Tuesday.

While in the grand scheme of things, Heat Index values will be
just around or below 105 F, the heat being well above normal for
this time of year (EFI values are essentially maxed out, which
makes sense as records in the upper 90s are going to be
challenged) leads to a Major to Extreme Heat Risk for areas
within the Advisory. Therefore, heat-related precautions should
be taken regardless of if Heat Index values are 100 or 105. This
is especially true as low temperatures are forecast to be in
the middle to upper 70s, which is near unheard of for this time
of year and will provide little heat relief for people that have
already endured so much heat the past few weeks.


Marginal (1 of 5) Risk for severe weather Tuesday evening:

Once the ridge axis moves of east of our area, the jet stream
will settle into a stagnant SW to NE orientation, stretching
from Nevada, up into Minnesota. This will stall out an
associated surface cold front Tuesday, somewhere northwest of
our CWA. While the bulk of the frontal lift and shear from the
jet stream should stay northwest of our area, depending on exact
location, some storms and better shear values may leak into our
extreme NW portions of the CWA. For this reason, there is a
Marginal Risk for severe weather Tuesday. This seems to mainly
be in the evening into the overnight hours as storms are
expected to develop along the front NW of the area, and may push
into our area later in the evening. That said, confidence is
still pretty low, with only a 15-40% chance of rain northwest of
I-44.


15-40% chances of rain Tuesday onward, mainly northwest of I-44:

The jet stream and associated frontal boundary are forecast to
stall in the aforementioned position through the week. This will
bring daily 15-40% chances for showers and thunderstorms
northwest of I-44, depending on the exact position of the
synoptic features each day. Additionally, with plentiful
moisture in this air mass, some isolated pop-up showers and
thunderstorms would be possible anywhere in the CWA each
afternoon and evening.

Global ensemble members really start to diverge toward the end
of the week. Some members start top flatten the ridge with the
jet stream and front sagging SE into our area, some members keep
the ridge strong, some members bring a bit more amplified
shortwave through. The averaged solution starts to bring the
15-40% chances of precipitation further southeast during the
weekend, but we will have to see which scenario pans out.

If the ridge holds strong, we could be looking at extended heat
with Heat Index values between 100-105 through at least
Thursday/Friday. Therefore, look for any indication in the
potential extension in time of the current Heat Advisory beyond
Tuesday.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 611 PM CDT Sun Sep 13 2026

VFR conditions are likely through the TAF period. A few isolated
showers along a frontal passage will be possible after 18Z, but
confidence in both initiation and coverage were too low to
include in the current TAFs.

Winds will shift to the south by 18Z and increase, with gusts up
to 15-20 kt.

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
KS...Heat Advisory from 11 AM Monday to 8 PM CDT Tuesday for KSZ073-
     097-101.
MO...Heat Advisory from 11 AM Monday to 8 PM CDT Tuesday for
     MOZ066>068-077>082-088>098-101>106.

&&

$$

SHORT TERM...Price
LONG TERM...Price
AVIATION...Didio