Severe Thunderstorm Warning 220, NWS Springfield, MO

Area Forecast Discussion
National Weather Service Springfield MO
600 AM CDT Mon May 18 2026

.KEY MESSAGES...

- A Moderate Risk (3 out of 4) for repeated rounds of
  thunderstorms and heavy rainfall that may result in flash
  flooding this morning into the afternoon. Increasing
  confidence in a thunderstorm complex stalling into west
  central and central MO. A Flood Watch in effect for an area
  north of Interstate 44 towards the Highway 54 corridor.

- A Slight Risk (2 out of 5) for a few strong to severe
  thunderstorms this morning into the afternoon. Primary hazard
  is damaging wind gusts.

- A Slight Risk (2 out of 5) for severe thunderstorms overnight
  tonight into Tuesday. A line of thunderstorms expected to
  quickly move through the area, with the primary hazard being
  damaging wind gusts.

- Additional rainfall chances (30-50%) mid to late week along
  with cooler temperatures.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 300 AM CDT Mon May 18 2026

This Morning-This Afternoon:
A thunderstorm complex is gradually sliding southeast this
morning across portions of eastern KS and northwest MO. This
complex has become outflow dominant in nature, with any severe
potential limited to damaging wind gusts at this point. This
complex is expected to continue to sink southeast into portions
of west central and central MO by early this morning/near
sunrise. The environment becomes less favorable for organized
thunderstorms given the lack of sufficient wind shear into this
area. However, there may be just enough (20 to 30 knots deep-
layer) in the vicinity of MUCAPE (1500 to 2000 J/kg) to support
a few strong to severe thunderstorm segments. Much of the
activity becomes elevated in nature this morning. The primary
risk would be damaging wind gusts up to 60 mph. SPC has a
Marginal (1 of 5) to Slight (2 of 5) to capture this severe
potential. Expectations are for this complex to stall by mid-
morning in the general area north of Interstate 44 towards the
Highway 54 corridor. This will be key to a rapidly increasing
concern for heavy rainfall and flash flooding that will be
discussed in more detail below. An additional severe potential
occurs late this morning into the afternoon with redevelopment
as a low- level jet persists over the area. CAMs depict
scattered thunderstorms rapidly developing across southern MO
and lifting towards the stalling complex. Confidence in this
scattered development is low to medium given the strong CIN to
the south. Nonetheless, any activity that does develop will pose
the potential hazards may include hail to the size of quarters
and damaging wind gusts up to 60 mph. It is plausible some
locations remain dry through this morning and afternoon across
far southern MO, with PoPs 60-90% along and north of Interstate
44, falling off to 10-30% along the MO/AR border. Overall, there
is still some subtle uncertainties remaining on how the
mesoscale unfolds this morning and afternoon, and the true
extent of the associated severe potential.

As for the heavy rainfall and flash flooding potential, the
attention is focused on the complex stalling into west central
and central MO this morning. This environment is increasingly
favorable for heavy rainfall to occur, with the complex slowing
into this area thanks to very weak steering flow as seen with
Corfidi vectors becoming west to east oriented at 5 knots or
less. As moisture (PWATs 1.5 to 1.8 inches) continues to advect
into the area, efficient rainfall rates are likely as repeated
showers and thunderstorms occur over the same areas this morning
into the afternoon. Guidance has trended into widespread
agreement on this heavy rainfall, further increasing our
confidence in heavy rainfall that will likely result in some
areas of flash flooding today. The latest HREF Localized
Probability Matched-Mean (LPMM) depicts a widespread corridor
of 1 to 3 inches along Highway 54, with localized amounts
approaching 4 to 6 inches. Given this trend and increasing
confidence, a Flood Watch has been issued for portions of west
central and central MO. This watch begins at 7 am this morning
and runs through this evening. Further expansion in time and
space may be warranted if needed. WPC has captured this heavy
rainfall/flash flooding potential with an upgrade to a Moderate
Excessive Rainfall Outlook (3 out of 4). There is some lingering
uncertainty on how long this activity festers across the area
into the afternoon/early evening, that will be best captured
with trends through this morning.

Tonight-Tuesday Morning:
As we progress into tonight, the low-level jet will strengthen
again as lift increases. Widespread severe thunderstorms are
expected to develop across central/eastern KS and quickly grow
upscale into a line of thunderstorms. Ensembles continue to
depict the strongest lift and wind shear are focused north and
west of the area where Enhanced to Moderate Severe Outlooks are
present. Further to the southeast into our area, a Slight Risk
(2 out of 5) is draped through the area. The most likely
scenario is for the line of thunderstorms to gradually weaken as
it pushes into southeast KS and west central MO overnight
tonight. However, we do not want to downplay the uncertainty in
the mesoscale, as just a bit more shear and instability may
further fuel strong to severe thunderstorms in our area
overnight into Tuesday morning. Primary hazard is damaging wind
gusts up to 60 mph. Additional hazards may include large hail up
to the size of quarters and a brief tornado, though these are
more focused across the north and western portions of the area
as line enters the area overnight. The current speed of the
front and associated line moving through the area are expected
to be quick, with the front potentially clearing the area by mid
Tuesday morning. If this quick moving scenario plays out, any
severe potential on Tuesday afternoon would be nullified.
Additionally, a progressive front would limit the potential for
heavy rainfall and flash flooding.

Overall, it is expected to be an active next 24 to 36 hours,
with some lingering uncertainties in the mesoscale. Confidence
has increased in the heavy rainfall and flash flooding this
morning into the afternoon, in additional to a few scattered
strong to severe thunderstorms. Highs today reach into the lower
to middle 80s, with dewpoints making it feel quite muggy in the
upper 60s to near 70. Gusty southerly winds around 25 to 35 mph
persist through today and tonight. By late tonight into early
Tuesday morning, attention turns towards the quick moving line
of thunderstorms with an additional severe potential. Continue
to follow the forecast for updates.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 300 AM CDT Mon May 18 2026

Remainder of Tuesday:
Behind the frontal passage, winds will turn out of northwest as
cooler air gradually funnels into the region. Lows Tuesday night
fall into the 50s to near 60.

Wednesday-Thursday:
Ensemble guidance suggests low rain chances (20-50%) lingering
post- frontal into Wednesday, particularly across southern MO.
Meanwhile, cooler temperatures prevail on Wednesday with highs
topping out in the upper 60s.

This pattern persists into Thursday, with additional rain
chances (20-50%) into Thursday afternoon and night.
Temperatures will gradually be on the rebound with subtle mid-
level height rises.

Next Weekend:
The general pattern remains southwesterly flow, with additional
shortwaves tracking through the region into next weekend. There
is uncertainty on the exact timing and strength of these
waves,that will be better resolved over the coming days.
Nonetheless, carrying additional rain chances into next weekend.
A warming trend returns into next weekend as well.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 600 AM CDT Mon May 18 2026

A thunderstorm complex is stalling out to north of the TAF sites
this morning, with isolated showers developing across southern
MO if the vicinity of a strong low-level jet. PROB30 group for
isolated showers through this morning, before introducing
thunderstorm chances late morning into the afternoon. Instances
of MVFR to IFR flight conditions within any thunderstorms as a
result of reduced visibilities and ceilings. TAF sites should
become shower/storm free by late afternoon and evening, before a
line of thunderstorms approaches towards 12Z on Tuesday morning.
Mid to high level clouds persist through the period. Gusty south
winds through today, with gusts around 20 to 30 knots. LLWS
introduced overnight tonight around 40 to 50 knots.

&&

.CLIMATE...
Issued at 200 PM CDT Sun May 17 2026

Record High Temperatures:

May 18:
KSGF: 88/1962
KJLN: 90/1987
KVIH: 88/1996
KUNO: 89/2001

Record Warmest Low Temperatures:

May 18:
KSGF: 68/1996
KJLN: 74/1996
KUNO: 66/2017
KVIH: 70/1996

May 19:
KSGF: 69/2013
KJLN: 74/1996
KUNO: 70/1996
KVIH: 70/1996

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
KS...None.
MO...Flood Watch through this evening for MOZ055>058-066>071-
     078>081.

&&

SHORT TERM...Perez
LONG TERM...Perez
AVIATION...Perez
CLIMATE...Burchfield

Hazardous Weather Outlook
National Weather Service Springfield MO
446 AM CDT Mon May 18 2026

KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-191000-
Bourbon-Crawford-Cherokee-Benton-Morgan-Miller-Maries-Vernon-
St. Clair-Hickory-Camden-Pulaski-Phelps-Barton-Cedar-Polk-Dallas-
Laclede-Texas-Dent-Jasper-Dade-Greene-Webster-Wright-Newton-
Lawrence-Christian-Douglas-Howell-Shannon-McDonald-Barry-Stone-
Taney-Ozark-Oregon-
446 AM CDT Mon May 18 2026

This Hazardous Weather Outlook is for portions of the Missouri
Ozarks and extreme southeast Kansas.

.DAY ONE...Today and Tonight.

Weather hazards expected...

  Slight tornado risk.
  Slight hail risk.
  Slight thunderstorm wind damage risk.
  Elevated lightning risk.
  Significant excessive rainfall risk
  Limited non thunderstorm wind risk.

DISCUSSION...

A Moderate Risk (3 out of 4) for repeated rounds of thunderstorms
and heavy rainfall that may result in flash flooding this morning
into the afternoon. Increasing confidence in a thunderstorm
complex stalling into west central and central MO. A Flood Watch
in effect for an area north of Interstate 44 towards the Highway
54 corridor.

A Slight Risk (2 out of 5) for a few strong to severe
thunderstorms this morning into the afternoon. Primary hazard is
damaging wind gusts. Additional hazards include severe hail.

A Slight Risk (2 out of 5) for severe thunderstorms overnight
tonight into Tuesday. A line of thunderstorms expected to quickly
move through the area, with the primary hazard being damaging wind
gusts. Additional hazards include severe hail and a brief tornado
or two.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

A line of thunderstorms will be ongoing on Tuesday morning. There
is uncertainty with how quickly the front clears the area and will
determine if we see redevelopment Tuesday afternoon.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed today and tonight for the entire
area.

&&

More detailed information can be accessed at:
http://www.weather.gov/sgf/dsspacket

This product in graphical format...along with other weather...
hydrological and climate information...at
http://www.weather.gov/sgf

Perez