562
FXUS63 KSGF 060854
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
354 AM CDT Mon May 6 2024

.KEY MESSAGES...

- Strong to severe thunderstorms late this evening into Tuesday
  morning, with the greatest risk west of Highway 65. SPC
  highlights an Enhanced Risk (3/5) for this area. Primary
  hazard is damaging wind gusts of 70 to 80 mph. Additional
  hazards include a few short-lived tornadoes and half dollar
  sized hail.

- Additional strong to severe thunderstorms on Wednesday. Exact
  hazards remains in question, but very large hail, damaging,
  and a conditional tornado threat are all in play. SPC has a hatched
  Enhanced Risk (3/5) for most of the area.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 345 AM CDT Mon May 6 2024

Main attention is on severe potential late this evening into
tonight, but we do have some ongoing dense fog over western and
southern portions of the area. The fog will dissipate this
morning.

For the rest of today, weather looks quiet until late today.
Widespread severe convection is expected west of the CWA during
the afternoon, which spread east into the CWA late this evening
(most likely after 9pm) into early Tuesday morning as a
shortwave and cold front move through.

Most likely scenario: Expectation is for storms west of our area
to develop strong cold pools with upscale growth to linear storm
mode by time storms get into our area. Depending on upstream
evolution, more than one line of storms is possible. Forcing
from a 110-120kt upper jet streak nosing into the area, a
developing 40-50kt LLJ, and the shortwave itself will be
supportive of maintaining convection all the way through the
eastern CWA by early Tuesday morning. As far as mesoscale
analysis, the environment over the western CWA will see the
greatest instability with MLCAPE of 1,500-2,500 J/kg, weakening
to a still respectable 1,000-1,500 J/kg by time storms reach the
eastern CWA. The entire area will see 0-6km shear of 50-60kts
and 0-3km shear of 35-40kts. With storm mode expected to be
primarily linear with ample shear and strong cold pools,
damaging winds up to 70-80 mph will be the primary threat, along
with a threat for short lived QLCS tornados in segments bowing
to the northeast. Hail up the size of half dollars is also
possible, primarily over the western CWA where any storms can
develop ahead of the line (or lines). Overall expect a gradually
diminishing trend in severe threat as storms move east through
the CWA.

Alternate scenario over the western CWA: Some guidance is
showing discrete convection going up over the western CWA this
evening. If that does occur, a narrow corridor mainly along and
west of I-49 could see a threat for even larger hail (up to
golf ball size), damaging winds, and perhaps tornadoes. This
potential will have to be monitored through the day.

Storms will exit the area Tuesday morning with clearing skies
through the day. Look for highs in the mid 70s to low 80s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 345 AM CDT Mon May 6 2024

For Wednesday: SPC has introduced a hatched Enhanced Risk for
most of the area with the greatest concern at this time being
potential for very large hail. All modes of severe weather are
on the table though.

The setup will come from a strong shortwave moving well NW of
the area Tuesday night into Wednesday. As it does so, surface
low pressure will develop and move from SW KS to northern MO
Tuesday night into Wednesday morning. This will pull the cold
front that passes through tonight into Tuesday back north as a
warm front Wednesday morning, then back to the southeast as a
cold front through the rest of the day Wednesday.

Threats are tricky at this point given uncertainty in initiation
time and storm mode. Could see a variety of storm modes,
including supercells, splitting supercells, and multicell
clusters. The cold front will move slowly SE through the day,
with severe potential along and ahead of the front.

Early to mid morning Wednesday: Unsure how much convection will
fire during this time, but there is concern that storms will
develop along the warm front as it lifts through the CWA,
especially the western CWA where a 40-60kt LLJ will be shifting
east into the area during the morning. Since the surface low
will be to the west or northwest at this point in the day, wind
profiles will be supportive of all modes of severe weather,
including tornadoes. This is a more conditional threat that will
have to be monitored as the event gets closer.

Late morning through the evening: The most obvious concern is
for large hail from late morning through the evening given good
overall agreement in MLCAPE values of 2,000-3,500 J/kg, mid-
level lapse rates of 7-8 C/km, and 0-6km shear values of
50-60kts. By time late morning comes around, the low will be
over northern MO and shear profiles will be nearly
unidirectional, favoring splitting cells. Areas roughly along
and south of I-44 are shown by models as having Large Hail
Parameter values of 15-25, which is impressive. If ideal storm
modes result, the largest hail stones around baseball size are
possible if the forecast remains on track. Damaging winds would
also be a concern. Little to no tornado threat is expected by
this time of day given wind fields becoming unidirectional.

For Thursday through Sunday, little to no precip is in the
forecast and temperatures should be near normal.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1256 AM CDT Mon May 6 2024

Drizzle and fog are expected early this morning. Will have to
watch observations to see how dense fog will become. VFR
conditions are then expected today until thunderstorms (some
severe) move in from the west late Monday into Monday night.

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
KS...Dense Fog Advisory until 9 AM CDT this morning for KSZ073-097-
     101.
MO...Dense Fog Advisory until 9 AM CDT this morning for MOZ066-077-
     082-088-091>097-101>105.

&&

$$

SHORT TERM...Titus
LONG TERM...Titus
AVIATION...Titus