676
FXUS63 KSGF 230144 AAA
AFDSGF

Area Forecast Discussion...UPDATED
National Weather Service Springfield MO
844 PM CDT Wed May 22 2024

.KEY MESSAGES...

- Scattered thunderstorms will develop overnight for locations
  along and south of Interstate 44. A few storms could produce
  hail up to the size of quarters and frequent lightning.

- An additional Marginal (level 1 of 5) to Slight (level 2 of 5)
  risk Thursday night into Friday morning for a few strong to
  severe thunderstorms.

- 50-70% chance for thunderstorms late Saturday into Sunday will
  bring the potential for additional severe weather and
  localized flash flooding. All day washouts are not expected at
  this time.

&&

.MESOSCALE CONVECTIVE DISCUSSION...
Issued at 829 PM CDT Wed May 22 2024

00Z KSGF sounding measured 500j/kg of elevated CAPE from a
parcel lifted from 800mb with very little inhibition. Effective
shear was also measured at 50kts therefore the environment is
conducive to shower and thunderstorm development this evening
and overnight if enough lift is present (already seeing a few
cells try to form). This lift appears to occur in three forms.
One being a surface front that appears to be slowly lifting
north towards West Plains given the return of southeast winds
and lower 60 dewpoints there. The second is an expected
increase in a 850mb low level jet overnight across Arkansas.
Latest KSGF VAD supports a slow increase in winds already at
that level. The third source of lift is subtle shortwave energy
as seen on water vapor imagery pushing east across Kansas.

Given the moisture, lift and shear, scattered thunderstorm
development seems likely overnight in that corridor along and
southeast of Interstate 44 and we have increase rain chances for
that area (may need to increase further if development becomes
widespread). While shear is more than adequate for severe
storms, the amount of elevated CAPE is in question as the area
will be on the northern fringes of the higher CAPE. It does look
like values may approach 1000j/kg which would promote a few
elevated severe storms with hail to the size of quarters
overnight. Elevated storms typically have a lot of lightning
therefore frequent lightning will also be common. These storms
look to peak in intensity during the 3am to 8am timeframe then
weaken as the low level jet and other lift exits.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 252 PM CDT Wed May 22 2024

Synoptically, the frontal boundary responsible for yesterday`s
severe weather has settled into northern Arkansas to the
Missouri bootheel with an H8 front extending on the south side
of I-44.

Showers and some thunderstorms that formed along and west of the
H8 front will move eastward across southern Missouri into this
evening. MUCAPES of 500-1000 J/KG may allow a few stronger
storms but widespread severe weather is not expected.

Low end storm chances (20-40%) will continue into Thursday as a
short wave pivots negatively over the Dakotas leading to surface
cyclogenesis over the western Plains. The resultant southerly
flow will advect the front over northern Arkansas northward...setting
off warm advection convection aided by a subtle shortwave
crossing the southern Plains.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 252 PM CDT Wed May 22 2024

With the aforementioned Dakotas wave generating a cold front
that will extend southward into the Plains, thunderstorms will
form across the Plains advecting into the forecast area
Thursday moving across the forecast area Thursday night into
Friday. Although timing will preclude the benefit from solar
heating, there will be plenty of instability ahead of this cold
front to lead to the potential for strong to severe weather once
again.

Attention then will turn to the weekend as the western trough
digs into the Central Plains and a broad wave rotates around the
bottom of the ridge setting up diffluence induced rain
chances...and yet another chance for severe weather later
Saturday into Sunday. Despite all the storm systems, it should
be noted that these will not result in all-day rain outs.

In the wake of the weekend wave, upper flow will finally turn
northwesterly bringing a respite from the extended period of
storm chances.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 644 PM CDT Wed May 22 2024

VFR conditions are expected through 06z then chances for
deteriorating flight conditions and thunderstorms increase.
Highest thunderstorm chances are at BBG and SGF and future
updates may need to include prevailing groups. MVFR ceilings
also look to build in and last through the morning. VFR and dry
conditions are then expected for late Friday morning through the
afternoon and evening. Winds will remain light and variable,
becoming southerly for Friday afternoon.

&&

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

&&

$$

MESOSCALE...Burchfield
SHORT TERM...Runnels
LONG TERM...Runnels
AVIATION...Burchfield