706
FXUS63 KSGF 130745
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
245 AM CDT Tue Aug 13 2024

.KEY MESSAGES...

- Round of showers and thunderstorms this morning (40-80%
  chance) with lightning and brief heavy rainfall.

- A heavier round of showers and thunderstorms tonight into
  Wednesday morning could cause flash flooding. A narrow
  corridor of 2-4 inches of rain with localized amounts up to 7
  inches could occur however location of this corridor remains
  uncertain. Highest chances of rainfall (70-90%) are currently
  northeast of Springfield.

- Much warmer temperatures Wednesday and Thursday with heat
  indices reaching 100-108 degrees west of Springfield.

- Additional rain chances Thursday through Saturday (20-40%)
  with temperatures closer to average.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 215 AM CDT Tue Aug 13 2024

Current Conditions and Synoptic Pattern: Water vapor and upper
air analysis shows the center of a mid level high over northeast
Texas with our area remaining in a complex west/northwest flow
pattern. A 35kt low level jet across the Texas/Oklahoma
panhandles along with a reservoir of MU CAPES around 3000j/kg
was currently feeding a MCS across southwest Kansas. A
stationary front extended from the MCS, due east through
southeast Kansas and southern Missouri with northeast winds and
patchy fog across the Lake of the Ozarks region, north of the
front. It was rather humid and mild south of the front with
temps in the upper 70s and dewpoints around 70.

Today: Given the current MCS vectors pointing east to
east southeast and a instability/moisture gradient over the
area, the MCS over Kansas is likely to continue east towards the
area this morning. Current timing would have it moving into
southeast Kansas and western Missouri around 6-8am. This
activity would then continue east through the morning and
turning more southeast with time. The area is removed from the
higher wind shear therefore not expecting severe storms however
a few may produce gusty winds up to 50mph along with frequent
lightning. The MCS will be fairly progressive however given PW
values increasing would expect heavy rainfall rates with the
latest guidance showing 0.25 to 1 inch with a few areas locally
receiving 2 inches.

This MCS will likely move out of the area by the afternoon
however cloud cover will keep highs in the lower to middle 80s
for most areas. Areas southwest of Springfield may be slightly
warmer if sunshine returns quicker.

Tonight into Wednesday Morning: The morning MCS will likely keep
the stationary front in place through the evening however after
midnight a 40kt low level jet will develop again but farther
north into central Kansas, nosing into western/northwest
Missouri. Therefore the front will begin to slowly lift northeast
as a warm front. Strong lift from the low level jet and the
right entrance region of the upper jet will allow for the
development of showers and thunderstorms overnight. Latest high
res guidance shows a rather ominous scenario of strong
instability and moisture interacting with a front with corfidi
vectors pointing almost due south/perpendicular to the low level
jet. This could create a north to south zone of training
showers and thunderstorms. Forecast PW values from the RAP are
near climatological max (2.2-2.4in) therefore ingredients are in
place for a zone of very heavy rainfall rates.

Models have struggled the last few days with the placement of
heavier rainfall areas. This is not uncommon in active
west/northwest flow patterns as mesoscale features play a
pivotal role in the overall evolution. The 00z HREF guidance
suggests that the corridor of overnight training storms resides
from near Kansas City, to Lake of the Ozarks, to Rolla/Salem
(Generally northeast of Springfield). That being said, this
could shift, especially if this mornings activity lingers
longer into the day and complicates the environment.

Wherever that corridor develops is where a narrow band of 2-4
inches of rain will likely occur. HREF LPMM is showing 5-7
inches in small localized areas with a 40-50% chance of rainfall
over 4 inches shown in that corridor. While antecedent
conditions are dry, rainfall of that magnitude will cause flash
flooding given our terrain. It should also be noted that areas
southwest of the zone of rainfall may not see much rain at all. We
will need to get a handle on that zone of rainfall today and
will continue to investigate an area for a Flood Watch. The
timeframe of the heaviest rainfall looks to be between 2am and
10am Wednesday with rainfall weakening after that as the low
level jet subsidies.

Wednesday Afternoon: The zone of heavy rainfall will also play a
role in the afternoon excessive heat potential. 850mb temps of
20-24C will nose into southwest Missouri during the day and
areas unaffected by the rain will experience hot temperatures in
the middle 90s with dewpoints in the 70s. This will likely
create a corridor of heat index values of 100-108 degrees.
Latest HREF data suggests a 50-80% chance of heat indicies
reaching 105 or higher across southeast Kansas and the I-49
corridor. Areas further east, including Springfield will be
right on the edge of this heat. A Heat Advisory will likely be
needed for western areas on Wednesday.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Issued at 215 AM CDT Tue Aug 13 2024

Thursday through Friday: Ensembles suggest that the ridge will
begin to be suppressed south and west as stronger shortwave
energy moves through the northern plains. This will allow for a
cold front to drop south into the area on Thursday with showers
and thunderstorms developing perhaps by afternoon or evening.
Wind fields will be stronger therefore will need to monitor for
the potential for some severe storms. Excessive heat may also
occur ahead of the front on Thursday with heat indices of
100-105 along and south of I-44 however confidence is low given
the frontal timing. Rain chances generally remain less than 30
percent on Friday with cooler temperatures.

Saturday through Monday: Ensembles are in decent agreement that
the mid level ridge will remain southwest of the area with our
area in northwest flow. This pattern typically resembles cooler
temperatures with NBM data suggesting highs in the upper 80s.
Precip chances are always a challenge in this pattern with
current chances less than 30 percent.


&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1255 AM CDT Tue Aug 13 2024

VFR conditions should prevail through the TAF period other than
the potential for showers and thunderstorms to move into the
sites after 12z. Confidence is not high with respect to location
or coverage of storms so have gone with prob30 for now however
may need prevailing tempo groups in future updates. Winds will
be light and variable ahead of the potential rain with a brief
switch to the north late in the morning then back to the
southeast. Additional rain may move into SGF after this TAF
period.

&&

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

&&

$$

SHORT TERM...Burchfield
LONG TERM...Burchfield
AVIATION...Burchfield