669
FXUS63 KSGF 181038
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
538 AM CDT Tue Aug 18 2026

.KEY MESSAGES...

- Heat ramps back up today and through the end of the week, with
  a Heat Advisory in effect from 1 PM to 8 PM this
  afternoon/evening.

- Marginal (Level 1 of 5) to Slight (Level 2 of 5) Risk of
  severe storms very late tonight into Wednesday morning as a
  storm complex moves through central Missouri, with damaging
  winds being the primary severe hazard.

- Marginal (Level 1 of 5) to Slight (Level 2 of 5) Risk of
  severe storms again Wednesday evening/night as another storm
  complex develops across southern Missouri. Damaging winds are
  the primary severe hazard, though hail and tornadoes could be
  possible if the ingredients align properly.

- Excessive rainfall leading to flooding will be possible with
  any/all storms between tonight and Thursday morning.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 243 AM CDT Tue Aug 18 2026

Synoptic analysis shows the upper level ridge over the western
CONUS, with an upper low pivoting southeast towards
Manitoba/Ontario, Canada and its associated upper level trough
pushing through the northern Plains. This is placing the
forecast area in northwesterly flow aloft. Surface high pressure
still resides over the region, with satellite imagery showing
mostly clear skies (other than some mid to high level clouds
over far southern MO) and observations depicting temperatures
ranging in the 60s (much of the area) to low 70s (far southern
MO).

Southerly flow returns today, with a warm front attached to a
surface low over Kansas lifting into the southwest portion of
the area. This will usher in a hot airmass to the area once
again, leading to highs in the upper 90s to low 100s for areas
generally southwest of a Nevada to Springfield to West Plains
line. Areas northeast of that line remain in the low to mid 90s.
With heat index values ranging between 100-110 degrees, a Heat
Advisory goes into effect for portions of far southeast KS and
far southwest MO from 1PM -8PM this afternoon and evening.

Later tonight, an upper level shortwave is progged to push
across northern MO, with an MCS developing along the nose of a
nocturnal LLJ. Latest CAMs show storms initiating northwest of
the area over northeast KS/northwest MO before developing into a
slightly more organized cluster as they approach our northern
counties. Assessing the environment, guidance shows 0-6km Bulk
Shear of 40-50kts over Central MO and about 30-35kts over our
northern forecast area, with maximum MUCAPE between 1000-1500
J/kg. The current trajectory looks to push storms southeast
through the northeast portion of the CWA overnight beginning as
early as 1AM. The environment does look to weaken the further
southeast these storms push, which is represented in the latest
SPC Outlook. The Slight (2 of 5) risk was pushed back northeast,
with it only nudging into Vernon/St. Clair/Benton counties now,
with the Marginal (1 of 5) risk along/north of a Pittsburg to
West Plains line. Damaging winds of 60-70mph look to be the
primary hazard, with hail up to quarters as a secondary risk.
Localized heavy rainfall will also pose a flooding risk,
especially with training storm potential. HREF LPMMs show
localized pockets of 2-3" over our northeast counties, so we`ll
need to monitor for flash flooding with these storms.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 243 AM CDT Tue Aug 18 2026

Wednesday looks to bring a large range in afternoon highs, with
areas north of Highway 60 remaining between 85-95 degrees, and
areas south of the highway climbing between 95-105. If this
occurs, then heat index values would once again climb between
100-110 degrees, and the heat advisory would need to be extended
through Wednesday. There`s still much uncertainty in how the
overnight convection will influence temperatures, so there`s low
confidence in those higher temps being fully realized. Because
of that, decided to hold off on extending the Advisory into
Wednesday for now, but can`t rule out a future extension in
later packages.

The aforementioned shortwave trough will move out of the Plains
and towards the Mid Mississippi/Ohio Valleys during the day on
Wednesday. Periodic showers/storms are possible (20-30%)
throughout the day, however the better chances (50-70%) for
storms exist in the evening and overnight. The Storm Prediction
Center has highlighted the southeast portion of the CWA in a
Slight risk (2 of 5), as this area will see the greater
instability (1000-2000 J/kg MUCAPE) and shear (0-6kt bulk shear
of 40-50kts). The primary hazard with these storms will once
again be damaging winds, however if key mesoscale features can
line up, all modes will be possible, meaning a lower-end tornado
and hail threat.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 533 AM CDT Tue Aug 18 2026

VFR conditions should prevail through the TAF period. Surface
winds continue to shift out of the south this morning, generally
remaining below 10kts. Towards the end of the period, a system
will push through central MO bring showers and storms, however
this activity looks to remain well north of the terminals, with
precipitation chances <15%. LLWS will begin to ramp up at all
three sites, generally between 06Z-09Z, persisting through the
remainder of the period.

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
KS...Heat Advisory from 1 PM this afternoon to 8 PM CDT this
     evening for KSZ073-097-101.
MO...Heat Advisory from 1 PM this afternoon to 8 PM CDT this
     evening for MOZ066-077-088-093-101>104.

&&

$$

SHORT TERM...Melto
LONG TERM...Melto
AVIATION...Melto