-- Discussion containing changed information from previous version are highlighted. --
731
FXUS63 KSGF 202305
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
605 PM CDT Mon May 20 2024

.KEY MESSAGES...

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- Another warm day is in store for the region Tuesday ahead of a
  cold front then a return to more seasonably mild temperatures.

- Chance for a storm or two across central MO into this evening
  otherwise dry overnight into Tuesday morning.

- Severe storms possible late Tuesday afternoon into the
  evening...with an Enhanced (3 of 5 level) risk over west
  central and central MO and a Slight Risk for much of the
  region southward to the Arkansas border. Damaging wind gusts
  are the primary concern followed by large hail. The tornado
  threat is limited.

- Potential for another round of severe weather Wednesday toward
  south-central Missouri (15% risk/confidence).

- Unsettled weather may persist through the end of this week and
  into Memorial Day weekend (daily 30-50% chances for showers
  and thunderstorms).
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&&

.SHORT TERM /THROUGH TONIGHT/...
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Issued at 215 PM CDT Mon May 20 2024

OVERVIEW...

Little change in the overall weather pattern featured by
shortwaves rotating through the western trough through the
Plains with related surface fronts/outflow boundaries being slow
to clear the region. Challenges in this regime exist in timing
and intensity of associated convection and cumulative impact of
rainfall leading to a flood threat.

An early-morning MCS left behind a wake low in eastern Kansas, and
pulse-like storms were forming along a boundary of favorable
convergence caused by interactions with a mesohigh near Kansas City.
These storms have pretty much petered out due to a lack of favorable
environment, with a cap developing and limiting convection in west-
central Missouri. This cap will likely erode going into the late
afternoon hours, but forcing for storms remains questionable, making
the thunderstorm potential very conditional for the northern extent
of our Missouri counties.

Remnant boundaries seen on satellite from morning convection
seem both unlikely and unsupported by models to persist into the
evening hours, but if any of those are able to withstand
synoptic-scale sinking motion, those will be the areas to watch
as the primary source of lift for any storms. A low-level jet
will advect moisture and potentially provide an additional
source of lift for thunderstorms towards the middle of the
night, but whether it gets far enough east to become impactful
to central Missouri remains to be seen.

An additional confounding factor to this conditional setup is
moisture- boundaries are set up along mesoanalysis-indicated
deep moisture convergence, while mid- and low-level water vapor
satellite imagery, in addition to NUCAPS soundings, indicate
deep dry air layers which are progged to persist into early
overnight hours. Severe threats are slim to none with these
thunderstorms; lightning would be the only, if any, impact from
evening and overnight convection.

Late afternoon temperatures will reach mid- to upper 80s amid
southerly flow ushering warm air into the Ozarks region. Winds
will remain light through the evening before strengthening
overnight, with gusts increasing through the early morning
hours. 25-30mph gusts from the south can be expected by early
Tuesday morning, with gusts increasing the further west you go.

Tuesday:
Models continue to track a wave that is coming ashore over the
base of the western trough this morning through the Plains,
pivoting to a negative tilt as it crosses Nebraska to along the
Iowa/Minnesota border by 00z Wednesday. While the combination of
instability and kinematics will support stronger convection
north of the forecast area...the potential for severe weather
will extend southward into the Ozarks. Convective inhibition of
50-100 J/KG at 18z will limit prefrontal convection, though the
cap will weaken with afternoon heating, allowing convective
development late in the afternoon. GEFS mean SBCAPEs at 00z
climbs to near 3500J/kg along the Missouri/Kansas border and
0-6km bulk shear approaching 50 knots will lead to organized
severe convection. There may be a period in which discrete
supercells form in this high instability; however, considering
anticipated hodograph relative to line movement, this period
would be limited with the resultant line of storms moving
through the forecast area.

As for impacts - the high instability combined with h700-h5 lapse
rates around 8C/km suggest a period of very large hail will be
possible over west central MO before the transition occurs. The
supercell tornado threat is lowered by the southwest winds
though 0-1km CAPE/shear will need to be monitored for any
storms that form out ahead of the line...followed by primarily a
damaging wind threat for much of the CWA.
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&&

.LONG TERM /TUESDAY THROUGH MONDAY/...
Issued at 215 PM CDT Mon May 20 2024

Tuesday Night - above mentioned convection will continue to track
across the forecast area overnight. Storm mode will likely be
transitioning from discrete cells to line segments.

Wednesday through Thursday - while an outflow boundary from
overnight convection may initially serve to become the
effective front south of the region...the actual frontal
boundary associated with Tuesday`s wave will lag behind as the
associated upper wave pivots northward into Canada. Severe
convection is anticipated to redevelop along and ahead of either
the effective or actual front with the latter leading to the
potential vicinity of I-44 early...exiting southern MO late
afternoon into early evening.

The southwest to northeast orientation of the upper flow combined
with the stalling of the front will also potentially set the stage
for training storms and excessive rainfall into Thursday. Precipital
water will increase to 1.5-1.75" which is 1-2 standard
deviations higher than normal for late May. Will need to watch
the range of model QPF output though at this point the NBM is
generally depicting a 25% chance for more than 1.5" and a 10-15%
chance 3" of rain over areas south of I-44 to the Arkansas
border from Wednesday-Thursday, on top of earlier rains this
week, setting the stage for flooding.

Friday into the Holiday Weekend -  Southwest to westerly orientated
upper stream will continue, and while the main stream of
shortwave energy shifts toward the Canadian border resulting in
weakening upper flow, successive slow moving frontal boundaries
look to periodically serve as the focus for convection. Thus,
there will be a daily chance for rain, though not all areas
will see rain each day.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
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Issued at 604 PM CDT Mon May 20 2024

A few isolated showers and storms may be possible this evening
mainly across central Missouri to the north but most locations
should remain dry. Surface low pressure will move across the
central Plains tonight and into Iowa on Tuesday. The pressure
gradient will tighten across the region with gusty southerly
winds developing on Tuesday morning into the evening hours.

A cap will be in place across the area on Tuesday with mainly
dry conditions expected through the afternoon hours. A cold
front will move through the area Tuesday evening night bringing
storm potential to the area just beyond this TAF period.
-- End Changed Discussion --

&&

.CLIMATE...
Issued at 100 PM CDT Wed May 15 2024

Record High Temperatures:

May 20:
KSGF: 90/1964
KJLN: 92/1956
KUNO: 89/1964

May 21:
KSGF: 91/1987
KJLN: 91/1987


Record High Minimum Temperatures:

May 20:
KSGF: 71/1902

May 21:
KSGF: 70/1902

&&

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

&&

$$

SHORT TERM...Camden/Runnels
LONG TERM...Runnels
AVIATION...Wise
CLIMATE...Burchfield