Grovespring, Missouri Weather Forecast Discussion

992
FXUS63 KSGF 212340
AFDSGF
Area Forecast Discussion
National Weather Service Springfield MO
640 PM CDT Sun Sep 21 2025
.KEY MESSAGES...
- Scattered to numerous showers and thunderstorms will occur
  across the area at times through tonight. Locally heavy
  rainfall and lightning will be the main risk. Where multiple
  storms are able to track over the same locations, localized
  flooding will be the primary risk.
- Confidence is increasing in the best chance for additional
  widespread heavy rainfall and flooding to occur across our
  southwestern counties Tuesday into Wednesday.
- Seasonal temperatures and lingering rain chances will occur
  late this week as several upper level disturbances move
  through the region.
&&
.SHORT TERM /THROUGH MONDAY/...
Issued at 330 PM CDT Sun Sep 21 2025
Current water vapor imagery shows a picturesque mid- and upper-
level low swirling away over MN. A shortwave extension is noted
with ribbons of dry air protruding southward into NE and KS.
East of the wave is a plethora of mid-level moisture over the
east CONUS. South and west of the wave is longwave ridging with
drier air aloft. At the surface, a stationary/warm front extends
from a surface low in SD eastward to Lake Erie. Despite the lack
of surface features, large scale lift within the moist region
across the east CONUS has forced scattered to numerous
showers and thunderstorms across whole region. For southwest
Missouri specifically, a band of heavier showers and
thunderstorms is noted on radar imagery across our central MO
counties. The next round is currently over NE OK and NW AR,
moving northeast into our southwest corner.
Numerous showers and thunderstorms expected today and tonight:
As the shortwave slowly moves eastward, rounds of showers and
thunderstorms are expected to continue this afternoon, through
the evening, and into the overnight hours, moving in from the
southwest (50-80% chances). CAMs and short-term guidance suggest
much of the widespread and heavier rainfall should stay along
and southeast of the I-44 corridor.
Marginal severe threat, but localized flooding is main hazard:
The environmental parameters in place across the region are
pretty marginal for severe weather today through at least
Monday. The main thing going for a severe weather threat is
slightly greater shear than recent days (15-25 kts effective
bulk shear), and sufficient instability (1500-2000 J/kg MUCAPE).
For that reason, a Marginal (1 of 5) Risk for severe weather is
in place across the whole area, as any given thunderstorm could
have the chance to reach severe limits. In fact, storms entering
from northeast OK have been known to produce near severe winds.
This round of storms will provide the greatest chance for any
severe weather and are expected to move through our CWA from 5
to 10 PM. Hazards would mainly be 60 mph wind gusts and small
hail.
Severe weather appears to be lower on the threat level scale,
though, with heavy rainfall and localized flooding being the
main hazard, especially over the saturated soils of the far
southwest corner of Missouri that received 3-5 inches of rain
last night. PWATs will constantly be in the 1.4-1.75" range
through at least Tuesday, with forecast soundings depicting high
low and mid-level relative humidity with tall, skinny CAPE
profiles in the 1000-2000 J/kg MUCAPE range. ALl these promote
efficient rain rates and heavy rainfall in any thunderstorm. The
main factor inhibiting more of a widespread flooding threat is
cloud-layer wind moderately fast at 15-20 kts. This is leading
to the storms progressing rather quickly to the northeast. That
said, Upshear Corfidi vectors are rather weak, so any
backbuilding of cells could result in a localized flash flooding
threat.
Since the coverage is pretty much across the whole area, model
means output 0.5-1.5 inch amounts across the region. But HREF
LPMMs suggest localized values up to 3-4 inches, much like last
night`s event.
Lingering rain chances and seasonable temperatures Monday:
The trough axis is progged to be straight down the middle of
Missouri during the day Monday. This leaves the zone of synoptic
ascent along and southeast of I-44. Therefore, this region will
be the focus for additional scattered thunderstorms throughout
the day. Much of the widespread and heavier rain may stay south
and east of the area, but some thunderstorms may still produce
heavy rainfall and subsequent localized flooding.
Cloud cover and rainfall should keep temperatures seasonable in
the upper 70s to lower 80s, though lows are expected to stay
mild in the middle to upper 60s.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Issued at 330 PM CDT Sun Sep 21 2025
Confidence increasing in widespread heavy rainfall Tuesday:
The story of the AFD the past few days has been ensemble
uncertainty in the timing of widespread heavy rainfall across
the area. Confidence in it occurring at some point was high, but
the timing was low confidence. Recent ensemble cluster runs are
starting to come into more agreement in timing, with the
timeframe between Monday night and Wednesday as the focus for a
potentially more impactful flooding risk. Monday night into
Tuesday morning, a potent shortwave is progged to eject off the
Rockies as the initial shortwave exits our area eastward.
Medium-range models depict a coupled jet streak to set up from
this pattern with a strong jet streak over OK/TX, and an exiting
jet streak over the Ohio River Valley. This places the Moksarok
(MO/KS/AR/OK) Region within a region of very strong synoptic
ascent. During this period, the end of HREF guidance brings a
thunderstorm complex into this region late Monday night into
Tuesday morning (a Marginal Risk is in place west of I-49 Monday
night for this complex). The wake of this system would likely
generate an MCV, which would be the focus for additional
development of thunderstorms somewhere across the region.
Therefore, timing is now better confidence, but exact location
is still up in the air depending on how an MCV evolves and
tracks. But synoptics and the environment are set for training
heavy thunderstorms. The Extreme Forecast Index shows an
impressive QPF signal across the Moksarok Region with values in
the 08.09 range, and 2 shifts of the tail suggesting several
members with "extreme" rainfall solutions compared to normal
September rainfall. 64% of models (leaning toward ENS and half
of GEPS) output a swath of 3-4 inches somewhere across our
region through Tuesday. 36% of models (leaning toward GEFS and
half of GEPS) are a bit drier and more eastward at 1-2 inches of
rain. So there`s still details to work out, but confidence is
increasing in a more widespread heavy rainfall and flooding
threat Tuesday into Wednesday. The WPC has a Slight (2 of 4)
Risk Excessive Rainfall Outlook for the Moksarok Region during
this time period.
Seasonal temperatures and lingering rain chances rest of the week:
As the main system exits eastward, rain chances will still
linger, but washouts are not necessarily expected after
Wednesday. At the same time, temperatures are forecast to be
cooler in the middle 70s to lower 80s. Lows are also expected to
cool down into the lower to middle 50s.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 640 PM CDT Sun Sep 21 2025
Waves of showers and thunderstorms are ongoing at all TAF sites.
As the TAF period progresses, coverage and intensity should
slowly dissipate and push eastward, but the chance for rain at
each TAF site remains above 40% through 12Z. After 12Z, JLN will
likely stay dry, but additional spotty showers and thunderstorms
may impact SGF and BBG. With any thunderstorm, visibility may
drop to around a mile, with gusty winds up to 20-30 kts, and
MVFR cigs.
Outside of any thunderstorm, cigs should stay within the VFR
realm, with background winds at 5-10 kts out of the south.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
KS...None.
MO...None.
&&
$$
SHORT TERM...Price
LONG TERM...Price
AVIATION...Price

NWS SGF Office Area Forecast Discussion