477
FXUS63 KSGF 142331
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
631 PM CDT Wed Aug 14 2024

.KEY MESSAGES...

- Much warmer temperatures today and Thursday with heat indices
  reaching 100-108 degrees west of Springfield where a Heat
  Advisory is in effect from 12pm-9pm today.

- A remnant thunderstorm complex will bring a 20-50% chance for
  showers and thunderstorms along and north of I-44. Main
  hazards will be heavy rain and wind gusts up to 50 mph.

- Slight risk for severe thunderstorms Thursday afternoon and
  evening. Damaging wind and large hail are the main severe
  weather risks (15% chance), with tornadoes being a lower risk
  (1-2% chance).

- 20-40% chance for scattered showers and thunderstorms Friday
  night and Saturday night, preceding calmer weather Sunday
  onwards.

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 109 PM CDT Wed Aug 14 2024

Current radar imagery depicts a small thunderstorm complex
riding the NE periphery of a mid-level ridge. It is continuing
to chug southward through the eastern Ozarks. As of 145 PM, an
outflow boundary was noted escaping the main line of storms,
hinting that gradual weakening should continue through the
afternoon. As such, the Flood Watch will be allowed to expire at
3 PM, yet be aware that flooding in the eastern Ozarks may still
be ongoing, and slightly elevate if a remnant storm moves over
strained/waterlogged areas from last night/this morning.


Heat Advisory Today/Thursday with 100-108 F Heat Index Values:

Cloud cover this morning has inhibited high Heat Index values
along Hwy 65. West of there, however, Heat Index values are in
the 100-105 F range and will likely climb to max of 150-110 F
through this afternoon (50-70% chance west of I-49). It may be
difficult for the Springfield area to reach above 105 F as
outflow-induced cloud cover is entering the area this afternoon.
Additionally, winds have been a bit stronger than predicted
across the Springfield area as SE`ly winds funnel through the
White River Basin. These will keep "feels like" temperatures
slightly below the Heat Index values. Nevertheless, exercise
caution when working outdoors today and Thursday.

With continued strong southerly flow Thursday, warm air and
moisture advection will bring middle to upper 90s highs and
middle 70s dewpoints across the region, especially in extreme SW
MO. This will support widespread Heat Index values between
100-108 F. A Heat Advisory will be in effect from 12-9 PM for
much of our area to capture this. Our west MO and central MO
counties are left out due to uncertainty of lingering rain and
cloud cover from an early morning MCS (see below for more
details).


20-50% chance for thunderstorms north of I-44 Thursday morning:

An MCS is forecast to develop across east KS/NE late today and
move through N MO tonight. The tail-end of this MCS will reach
into west MO between 5-8 AM. Most CAMs dissipate this complex
through the morning, however, given known model biases, HREF
mean MUCAPE values ahead of the system at 1500-2000 J/kg, and
observed patterns of MCSs the last few days, would not be
surprised to see convection and rain survive through the I-44
corridor, possibly impacting Joplin and Springfield (20-40%
chance). There is increasing confidence that thunderstorms will
at least impact areas such as Warsaw, Versailles, and Nevada.


Slight risk for severe thunderstorms Thursday afternoon/evening:

A bulbous trough will traverse the Northern Plains Thursday.
Surface cyclogenesis across MN associated with this trough will
continue to pull moisture northward, creating a broad warm
sector across all of MO. This warm sector will be characterized
by 2000-3000 J/kg MLCAPE beneath 25-35 kts of deep layer shear
as a jet streak attached to the trough enters the region. A SW-
NE oriented trailing cold front will sag into the region from
the NW. Despite weak convergence, this should be enough to
force a broken line of scattered thunderstorms across our area
during the afternoon and evening hours. A few storms may become
severe given the ripe warm sector environment. The best chance
of these storms will be between 3-9 PM, generally along and then
east of I-44.

The threat for severe weather is quite conditional at the
moment. There are a few scenarios that we are watching out for:

Scenario 1: The current morning MCS forecast pans out as
expected and stays north of I-44. This will allow for an
unstable warm sector along and SE of I-44, primed for scattered
severe storm development.

Scenario 2: The morning MCS works its way much farther south
and east than currently forecast (which is a viable scenario
given the past few days). This could work over the area and
produce more rain-cooled/stable air, making it difficult for
severe storms to develop.

Scenario 3: The morning MCS works its way farther south and
east than currently forecast, but the mass response lifts any
outflow boundary northwards and destabilizes the atmosphere
enough for scattered severe storms. In this scenario, any
outflow boundary storms interact with could bring increased
threats for damaging winds, large hail, and possibly a brief
tornado.

No matter the scenario, the kinematic environment will be
largely unchanged. Deep-layer shear at 25-35 kts will mainly
support multicellular clusters. This will bring damaging winds
up to 60 mph, and hail up to the size of quarters as the main
hazards. Heavy rainfall will also be a hazard with PWATs in the
1.75-2.00" range, though the storms will be progressive, so
widespread flooding is not expected. However, any flow
modification along any outflow boundary could bump local values
up to 30-40 kts, which would support a supercell or two. With
storm-relative inflow rather weak (<25 kts) and HREF model
soundings depicting high RH through 700-500 mb, these will
likely be mini supercells, capable of the same hazards. There is
a low-end risk of tornadoes (1-2%) with these supercells,
mainly resulting from any favorable storm-storm or storm-
boundary interactions. Though with shear vectors mostly
perpendicular to the cold front keeping storms semi-discrete,
and storm-relative inflow from the SE with the line of storms
oriented SW to NE, storm-to-storm interactions will be few and
far between.

Afterwards, lows Thursday night will be mild in the lower 70s.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 109 PM CDT Wed Aug 14 2024

Calmer weather and lower chances for storms through Tuesday:

After the cold front and trough progresses east after Thursday
night, deeper ridging will take hold of the south-central
Plains. NW`ly flow will then overtake our region. This will
bring seasonable temperatures and relatively calmer weather
through Tuesday. However, with our region between a deep ridge
to the west and deep trough to the east, any perturbation
dropping through the region could bring scattered showers and
thunderstorms, possibly as remnant MCSs. The first of these
opportunities will be Friday night with 20-40% chances, higher
chances toward the SW corner of MO. Lower chances will then
exist Saturday night (15-25%), but could increase as greater
model agreement occurs with subsequent forecasts.

After Saturday night, PoPs will be below 20% through Tuesday.
Highs during this period will be seasonable in the upper 80s to
lower 90s with lows in the middle to upper 60s.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 629 PM CDT Wed Aug 14 2024

VFR conditions will occur across the TAF sites this evening.
Storms have developed across the Central Plains this evening and
this activity could start to move southeast into the area late
tonight into Thursday morning. Additional storm chances will
then occur Thursday afternoon and evening. Winds will be south
to southeasterly this evening into tonight and will become more
southwesterly during the day on Thursday and could be gusty at
times.

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
KS...Heat Advisory until 9 PM CDT this evening for KSZ073-097-101.
     Heat Advisory from noon to 9 PM CDT Thursday for KSZ097-101.
MO...Heat Advisory until 9 PM CDT this evening for MOZ066>068-
     077>080-088>091-093>095-101>104.
     Heat Advisory from noon to 9 PM CDT Thursday for MOZ077-
     079>082-088>097-101>106.

&&

$$

SHORT TERM...Price
LONG TERM...Price
AVIATION...Wise