689
FXUS63 KSGF 161922
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
Issued by National Weather Service St Louis MO
222 PM CDT Mon Jun 16 2025

.KEY MESSAGES...

- Scattered showers and thunderstorms continue through this
  evening over south-central Missouri

- Thunderstormcomplex remnants will pose a Marginal (1 of 5)
  to Enhanced (3 of 5) Risk for severe wind gusts up to 60-70
  mph and quarter-sized hail during the late night and early
  morning hours Tuesday. The greatest risk will be across
  extremesoutheast Kansas and west-central Missouri.

- A Slight(2 of 5) Risk exists for much of our area Wednesday
  afternoon and evening. All hazards will be possible, though
  the dominant risks will be damaging wind gusts and large hail.

- Abnormally humid conditions are expected through the week.
  Signals point to temperatures nearing 90 F towards the end of
  the week. Therefore, we will see heat index values in the
  mid-90s to around 100 at times.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 212 PM CDT Mon
Jun 16 2025

Current RAP analysis depicts a weak mid-level low still
churning away across southern Missouri. This is forcing an even
weaker surface low pressure system and associated wind shift
boundary draped across the Ozarks. Elsewhere, a more potent
upper-level jet streak is nosing into the west CONUS across
Nevada and Utah. This jet streak is at a lower latitude than the
northern branch of the jet stream currently north of the
US/Canada border, supplying very weak mean atmospheric flow and
a stagnant very moist airmassacross the central and east CONUS.
The jet streak entering the west CONUS will be our main weather
maker Tuesday and Wednesday. But for now, the mid-level low
embedded in weak surrounding flow and the moist air mass is
producing scattered showers across south-central Missouri in the
vicinity of the aforementioned boundary.

Scattered showers and thunderstorms continue through the
evening:
These scattered showers will continue through this evening,
following the diurnal cycle. Daytime heating will supply
1500-2500 J/kg of SBCAPE according to mean HREF soundings. Weak
flow will only contribute 10-15 kts of deep-layer shear at most.
Therefore, expect mostly showers with a few thunderstorms
through the evening before daytime heating ceases after sunset.
Given the weak shear, not expecting any severe threat. However,
as the story has been going the last few days, the slow-moving
nature of the storms paired with abnormally high PWATs at
1.6-1.8 will pose a very localized flooding risk, especially for
areas that see multiple showers. These pesky little showers
should finally exit our area after 9 PM or so, giving way to
clearing skies and lows in the middle to upper 60s.

Heights will then rise Tuesday in the wake of the exiting mid-
level wave and, with mostly clear skies, highs will warm into
the upper 80s. There is a very slim chance (15-25%) that remnant
showers and thunderstorms will enter the region from the NW
Tuesday morning, but CAM guidance is all over the place given
the weak steering flow. However, with our area downstream of the
ridge axis, weak deep-layer shear Tuesday morning, and a
capping inversion, only elevated stratiform rain and perhaps a
non-severe embedded thunderstorm would be the most we get, if
anything at all. It is worth noting that the MPAS models--which
generally handle the longevity of MCSs better--has the complex
dissipating faster than the HRRR. So, confidence is quite low on
what happens with the MCS, but dont be surprised to see some
remnant rain Tuesday morning.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 212 PM CDT Mon Jun 16 2025

Enhanced (3 of 5) Risk for severe thunderstorms Tuesday night:
Tuesday night into Wednesday morning is a repeat of tonight
into Tuesday mornings forecast. An MCS is forecast to develop in
NE/KS and drop southeast. The only change is that there is
higher confidence in this MCS making it into portions of our CWA
as a mid-level trough axis shifts closer to our area,
increasing deep-layer shear. This risk is mainly along and north
of I-44 where the Slight (2 of 5) Risk is in place. An Enhanced
(3 of 5) Risk clips our far southeastern Kansas counties.
Expectation is for the MCS to be decaying by this time, but with
deep-layer shear increasing to 25-35 kts, enough organization
would remain for some damaging wind gusts up to 60-70 mph and
perhaps some severe hail up to quarter size. The timing of the
system entering far southeast Kansas and west Missouri would be
as early as 11 PM or as late as 3 AM, with a dissipating trend
into the morning.

Slight (2 of 5) Risk for severe thunderstorms Wednesday:
The more widespread and severe risk will exist Wednesday
afternoon and evening as the trough axis and attendant surface
cold front scoots through our region. Ahead of the synoptic lift
from the cold front and upper-level support downstream of the
trough, SREF places mean MLCAPE values at 2500-3000 J/kg, with
some medium-range models suggesting up to 4000 J/kg of MLCAPE
thanks to forecasted dewpoints in the mid-70s. Ensemble guidance
like the GEFS and SREF suggest meager deep-layer shear values
at 25-35 kts. Medium-range deterministic guidance like the NAM
and GFS suggest a bit higher values at 30-40 kts. The amount of
shear will determine our threat level and storm mode. Theres two
main scenarios here. Scenario 1: Deep-layer shear remains on
the weaker side at 25-35 kts. In this case, shear is still
sufficient for severe weather, especially with 3000+ J/kg of
MLCAPE ahead of sufficient convergence along a surface cold
front. However, this is low shear for organized supercells,
thus, line segments and multicell clusters would be the dominant
mode. With high CAPE, the dominant hazards would be wind gusts
up to 60-70 mph, and hail up to half dollars to golf balls.
Scenario 2: Deep-layer shear is a bit better at 30-40 kts. This
would be sufficient for supercells. The main question then
becomes how long supercellular mode can be sustained before
deeper CAPE and strong cold frontal forcing develops a more
linear structure. GEFS/ENS shear vectors appear to be semi-
perpendicular to the front, which would suggest at least initial
supercellular mode. If this occurs, tornadoes will also be a
hazard since necessary low-level shear and curvature of the
hodographs will be in place. This would be a lesser threat and
in a narrower window before storms are expected to congeal into
a system. The more dominant threats would still be damaging
winds and large hail in this scenario, it merely introduces the
tornado threat. Regardless of the scenario, a QLCS spin-up
tornado threat seems much lower since 15-25 kt 0-3 km shear
vectors are forecast to be parallel to the cold front and thus
the line orientation. Also, regardless of the scenario, timing
will be during the afternoon and early evening hours, moving
from west to east.

Abnormally humid conditions this week, 90-100 F Heat Index values:
After the system moves through, very pronounced ridging will
take hold. NBM spreads are very small for the late week into the
weekend timeframe, depicting high confidence in the high
temperature range. Highs Thursday are expected to be in the
middle 80s, with highs increasing to the upper 80s and lower 90s
Friday through Monday. With ESATs still depicting >97.5th
percentile mean specific humidity for the foreseeablefuture,
heat index values will reach the middle 90s to lower 100s at
times. Additionally, lows are forecast to be in the lower to
middle 70s during this timeframe, little heat relief will be had
for our first heat wave of the year. Make sure to stay hydrated
and limit outdoor times this weekend. It will feel very muggy
for this time of year!

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1214 PM CDT Mon Jun 16 2025

VFR conditions are becoming more prevalent over the region,
though intermittent MVFR CIGs are still impacting the terminals
and may continue to do for a few hours more. Winds are forecast
to calm this evening, and with clearing skies, open the
opportunity for MVFR fog at the TAF sites. I wouldn`t be shocked
if conditions become intermittently IFR, and a TEMPO was added
at each TAF to account for this. Convection will largely hold
off until after the valid TAF period, mainly arriving Tuesday
night into Wednesday morning.

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
KS...None.
MO...None.

&&

$$

SHORT TERM...Price
LONG TERM...Price
AVIATION...MRB