273
FXUS63 KSGF 291715
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
1215 PM CDT Mon Apr 29 2024

.KEY MESSAGES...

- Widespread flooding is ongoing in a majority of the forecast
  area with significant flooding continuing over parts of west
  central Missouri and southeast Kansas from earlier heavy rain.

- Dense Fog Advisory until 9 AM for extreme southwest Missouri.
  Some light drizzle may also occur within this area and along
  the Ozark Plateau (15-30% chance).

- The unsettled pattern continues with additional storm chances
  this week (20-40% chances). Highest chance for showers and
  thunderstorms occurs Thursday (70-90% chance).

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 330 AM CDT Mon Apr 29 2024

Widespread flooding is ongoing in a majority of our area:

A decaying thunderstorm complex associated with a mid/upper-
level shortwave is currently exiting our CWA bringing a much
needed dry weather break. Some lingering stratiform rain will
continue in the eastern Ozarks through the morning, but much of
the heavy rain is over. Unfortunately, effects from the heavy
rain will continue today with at least 90% of our forecast area
under some sort of flood headline for at least minor flooding.
In the last 72 hours, MRMS QPE estimates put almost our entire
area at over 2 inches of rain with several corridors of at least
4 inches. Pay attention to the roadways when traveling,
especially near low-water crossings and rivers. Turn around,
don`t drown!


Significant flooding continues over parts of W MO/SE KS:

The hardest hit area was in west MO and SE KS, including areas
like Nevada, Pittsburg, KS, and Fort Scott, KS. These areas
received 6-10 inches of rain in the last 72 hours on top of
4-5 inches from days prior. AHPS precipitation analysis puts
Fort Scott in the 10-15 inch range over the last 7 days.
Needless to say, this has led to some dangerous and significant
flooding in that area. The Little Osage and Marmaton Rivers have
notably reached Major Flood stage. While no rain is expected in
the short-term, it will take a bit of time for these rivers and
areal flooding to recede. Once again, pay attention to alerts
and stay away from any suspected flood waters.


Dense Fog Advisory until 9 AM for extreme southwest Missouri:

With the upper-level shortwave trough and surface low lifting
to the NE, an associated cold front will sag through the area
this morning. Ahead and just behind the front, dewpoint
depressions have dropped to 0 and below (lows and dewpoints are
in the mid-50s). This, paired with weak surface winds and
generally clearing skies will promote fog formation, especially
in extreme SW MO along the NW edge of the Ozark Plateau where
NW`ly upslope surface flow will enhance saturation/condensation.
Locations including Joplin and Pittsburg have already seen a
narrow band of fog associated with the front briefly drop
visibilities to a half mile.

Additionally, with the low-level relative humidities generally
>80%, no cloud ice present, a band of upward omegas moving in
along the front, and NW`ly upslope flow along the plateau,
light drizzle will also be possible within and around the
regions of fog. Both the fog and drizzle will dissipate by 9 AM
at the latest when clear skies promote increased surface heating
and mixing after sunrise, leading to high temperatures in the
mid-70s.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 330 AM CDT Mon Apr 29 2024

Additional storm chances return this week:

After the upper-level wave exits, the longwave pattern that sets
up will exhibit a broad trough axis over the northern Rockies
with the jet stream max staying within the northern Plains. This
will keep surface low tracks generally well to the NW of our
area. Indeed, a surface low will move across the northern Plains
beneath the longwave, allowing for S`ly surface flow across our
area. This will lift the cold front back to the north out of SW
MO and advect in high temperatures in the lower 80s for
Tuesday/Wednesday with lows in the lower 60s for those nights.

Within the aforementioned longwave pattern, several shortwaves
are expected to revolve around the axis. Though the waves should
stay to our NW, each one will force rounds of convection that
could clip our area, generally along and NW of I-44. This brings
20-40% PoPs for Tuesday/Wednesday evening/night NW of I-44. With
GEFS probs bringing 80-100% chances for CAPE >1000 J/kg along an
axis generally west of Hwy 65, severe weather may be possible
with these rounds of convection. However, with the mid-level waves
displaced well to our NW, the threat appears to be more focused
within the OK/KS/NE area. The SPC tends to agree with only a
Marginal (1/5; 5%) risk just clipping our western counties
Tuesday/Wednesday. This means we would most likely see scattered
remnant convection Tuesday/Wednesday evening/night that could at
times be marginally severe for our western counties.

Our best chance for showers/thunderstorms looks to be Thursday
as a deeper shortwave rounds the broad longwave axis. This will
allow for greater shear and surface frontal forcing to
overspread our area. This will bring 70-90% chance for showers
and thunderstorms Thursday evening/night. GEFS probabilities
give a 40-60% chance for CAPE values >1000 J/kg, and with the
wave passing closer to our area, shear would be greater, so
severe weather could be possible. However, uncertainty in exact
details is still too high to give a probability on severe
weather. CSU machine learning guidance does put much of our CWA
in a 15%, though the centroid is out to the west in KS. Later
updates will further evaluate this system for severe weather
potential.

After the shortwave clears the area, cooler weather will filter
in behind with highs going from near 80F Thursday to the mid-70s
for the weekend. Lows will hover in the 50s for the same period.
Model spread increases after Thursday, but more chances for some
showers/thunderstorms exist into the weekend. PoPs are currently
at 15-30% highlighting the timing and ensemble uncertainties.
GEFS has a shortwave ejecting out of the SW, bringing widespread
rain chances. EPS and Canadian ensembles do not show this
shortwave, generally keeping our area dry. We will see how
models come to agreement in the future, but with the late-spring
warm sector settling in across the central/southern CONUS,
showers and thunderstorms appear more possible from a day-to-day
basis, especially with ensembles hinting at a longwave trough
setting up over the western US in the long range.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1211 PM CDT Mon Apr 29 2024

For the 18z TAFS, sky has cleared out at SGF/BBG with some
stratus as of 17z still at BBG. The stratus should continue to
clear at BBG and should be cleared out by 18z or 19z. VFR
conditions are expected through much of the forecast period.
With a light and variable wind and clear sky tonight, may see
some fog redevelop especially at BBG and will put a tempo MVFR
group in there from around 09-12z.

&&

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

&&

$$

SHORT TERM...Price
LONG TERM...Price
AVIATION...Lindenberg