-- Discussion containing changed information from previous version are highlighted. --
348
FXUS63 KSGF 230545
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
1245 AM CDT Mon Sep 23 2024

.KEY MESSAGES...

- Marginal (1 of 5) Risk for severe thunderstorms today and
  Monday afternoon and evening. Main hazards will be damaging
  wind gusts up to 60 mph, small hail, and brief heavy
  downpours.

- Multiple rounds of widespread showers and thunderstorms are
  expected through Monday night (40-85% chance). Most locations
  will see an additional 0.50 to 2 inches of rainfall through
  Monday, with a flooding threat across the eastern Ozarks from
  localized higher amounts of 3 to 6 inches.

- Much cooler temperatures will occur this week with highs in
  the 70s.

- Rainfall chances (30-50%) are increasing for late in the week
  however confidence remains low with the track of the system.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 230 PM CDT Sun Sep 22 2024

Current Conditions and Synoptic Pattern: Water vapor and upper
air analysis showed an upper level disturbance spinning across
Colorado and Nebraska. Broad southwest flow aloft was occuring
across our area with a moist and unstable airmass in place. The
12Z KSGF sounding measured a PW value of 1.7in and 1000j/kg of
MU CAPE. Most of the area was dry early this afternoon however
we were watching a few features. One being a weak boundary
that was diffuse but could be seen on satellite imagery from
roughly Branson to Eminence. A few showers and storms were
beginning to develop along this boundary as convective temps
have been reached. The actual cold front (with temps in the 60s
behind it) was still just northwest of the CWA from roughly
Kansas City to Eureka, Kansas. Several breaks in the clouds have
allowed for temps to climb into the low 80s across the area.

This afternoon through this evening: Latest high res guidance
suggests that the highest chance of thunderstorms this afternoon
will occur along the weak boundary to the southeast of
Springfield. 2000j/kg of ML CAPE and 30kts of effective shear
will allow for a few organized storms which may produce some
downbursts to 60mph. Heavy rainfall rates will occur with the
strongest storms given the high PW values. More uncertain is
development along the actual front as it moves into the area.
Would expect at least a few showers and storms to develop along
the front this afternoon and evening and have kept pops in the
20-40% range. It is possible that many areas remain dry through
early evening.

Tonight: Strong lift will occur both from an increasing low
level jet nosing into the area along with upper level jet
interactions. The cold front will also be moving through the
area. An area of showers and thunderstorms will likely move
from northeast Oklahoma into southwest Missouri generally after
9pm, lasting through the overnight hours. Forecast soundings
from the RAP suggest MU CAPE values around 1300j/kg and PW
values around 1.8in therefore thunderstorms with heavy rainfall
rates will likely occur.

Monday: An area of showers and storms will likely continue
through most of the day as lift will remain present. A weak
surface low looks to move up the front during the afternoon. If
enough instability can develop across south central Missouri
then a few severe thunderstorms would develop. Confidence
remains low with respect to any severe potential however we will
need to watch the area along the Missouri/Arkansas border for a
wind and hail threat. Northerly winds, clouds and rain looks to
keep temperatures much cooler than previous days and have gone
closer to the 25th percentile with highs in the lower to middle
60s north of Springfield to around 70 elsewhere. Rainfall will
slowly end Monday night as the trough starts to move east.

Rainfall Amounts: Overall rainfall amounts have been too high
for today thus far (forecast versus observed). However it does
appear that rainfall tonight and Monday will be heavier for
areas south of I-44 and east of Highway 65. There remains a high
spread in total qpf from the HREF with the Joplin area between
0.2-0.9in, Springfield area between 0.9-2 inches and West
Plains/Alton areas between 2.3-4.8 inches. Localized flash
flooding will be possible across the eastern Ozarks where the
rainfall will linger the longest.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 230 PM CDT Sun Sep 22 2024

Confidence decreases as we head through the week due to the
track of a couple of upper level features. One feature is an
upper low that will drop south into the northern plains Tuesday.
Ensemble clusters still have varying differences on the track of
this low. If the low tracks over us then we will likely remain
cloudy and very cool (highs in the low 70s) Tuesday and
Wednesday. The other key feature will be the development of a
tropical cyclone in the Gulf of Mexico this week. Ensembles
generally take this feature into the southeast US with some
potential that it gets entangled with the upper low over our
area and moves west. If this occurs then our rainfall chances
will increase towards the end of the week. While confidence in
this scenario is low, rain chances have now increased into the
30-50% range Thursday through Saturday, especially across the
eastern Ozarks. Confidence is high however that temperatures
will remain below average this week with highs likely remaining
in the 70s.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
-- Changed Discussion --
Issued at 1245 AM CDT Mon Sep 23 2024

Medium-high confidence that conditions will oscillate between
MVFR and IFR throughout the TAF period at all TAF sites as there
is a 60-80% chance of ceilings staying below 1 kft through the
period. There is a slight chance (20-30%) that TAF sites fall
into LIFR at times, especially during periods of precipitation.
Indeed, BBG is currently oscillating between IFR and LIFR.

Additionally, there is a 60-80% chance that showers and/or
thunderstorms will impact the TAF sites at some point during
the period. Confidence on timing is still low, but expect at
least two rounds of storms to move through the vicinities of the
TAF sites. The first round will be between 10-15Z and the
second round later this afternoon in the 18-03Z timeframe.
Generally, showers and thunderstorms will be in southwest
Missouri the whole TAF period, but those marked in the TAFs are
the higher confidence timeframes for higher coverage around the
sites.

Otherwise, winds will remain relatively calm at 3-8 kts out of
the north.
-- End Changed Discussion --


&&

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

&&

$$

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