808
FXUS63 KSGF 081140
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
540 AM CST Fri Nov 8 2024

.KEY MESSAGES...

- High probability (80-95%) for widespread rain with another
  system moving through tonight and Saturday. Rainfall amounts
  from 0.25" to 0.75". Localized amounts around 1.50" to 2.00"
  along and west of the I-49 corridor.

- Additional potential (20-40%) for showers and thunderstorms
  next Tuesday night and Wednesday.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 330 AM CST Fri Nov 8 2024

It is quite easy to pick out the mid- and upper-level low across
the Four Corners region in current water vapor imagery. East of
the low across the southern Plains states, a broad area of
divergence and diffluence aloft paired with a deepening surface
low pressure system is producing widespread areas of rain and
thunderstorms. These are situated north of the developing warm
front draped across central to east TX. Radar imagery does show
some weak echoes clipping our Kansas counties, but given a
large portion of the atmosphere is dry according to our 00Z
observed sounding, these returns are not expected to hit the
ground yet. High clouds from this system are also spreading over
our forecast area, which will keep low surface temperatures in
the 40s (warmer along the southern border). This cloud cover
will persist through Saturday, keeping high temperatures a
little cool in the upper 50s and lower 60s today and Saturday,
and low temperatures a little warmer in the middle 40s to lower
50s tonight and Saturday night.


80-95% chance for widespread rain tonight and Saturday:

The cut-off low will slowly progress eastward this morning as
the jet and positive vorticity advection maxima revolve from the
south to the east side. Once the jet and PVA maxima become
established on the ENE side of the cut-off low, the wave will
accelerate northeastward through the Central Plains late tonight
through Saturday. A quickly occluding surface cyclone will
follow suit, with an occluded front traversing our area late
tonight into Saturday, bringing 80-95% chances for rain across
our whole area.

20-40% chances of showers will first begin along the I-49
corridor after 2 PM today. These will linger through the
afternoon and early evening as the system slowly progresses
east, as previously mentioned. Once the system accelerates,
chances will increase to 70-90% for the I-49 corridor around
8-10 PM this evening. These high chances will then spread
eastward over the course of the night and Saturday morning.

The latest CAMs suggest that rain will initially start out as a
widespread shield across our western forecast area before
progressively becoming more scattered as the rain spreads
eastward and the occluding surface low retrogrades
northwestward, and thins out the moisture supply.

Rain chances are expected to exit much of the area by Saturday
night, with 20-50% chances lingering in the eastern Ozarks
through Sunday morning. Clearing skies behind the system will
allow highs in the middle 60s Sunday and lows in the lower 40s
Sunday night.


Rainfall amounts from 0.25-0.75", localized amounts of 1.50-2":

The evolution to more scattered showers and thunderstorms as the
rain spreads eastward late tonight and Saturday morning will
keep totals a bit lower than previously forecast east of I-49.
HREF LPMMs depict widespread areas of 0.25-0.75" east of I-49,
which is noticeably lower than the NBM mean at 0.75-1.00". The
lower values make more sense, however, due to CAMs depicting
more scattered coverage over this area. The exception to the
lower totals is along and west of the I-49 corridor. Here, the
initial slow progression of the cut-off low will bring multiple
rounds of more widespread rain, allowing totals to reach the
1.00 inch mark with localized amounts up to 1.50-2.00",
especially in our southeast Kansas counties.

Despite the widespread lower totals, HREF depicts a tongue of
100-200 J/kg MUCAPE, which is just enough for isolated embedded
thunderstorms. Additionally, PWATs are forecast to reach the
1.25-1.50" mark thanks to 99th percentile moisture all the way
through 500 mb. These combined factors will allow for areas to
receive locally higher amounts where thunderstorms track.
Nevertheless, no severe or flooding threat is expected thanks to
the accelerating system and lower forecasted rainfall amounts.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Issued at 330 AM CST Fri Nov 8 2024

After the short-term system exits the area, there will be a
brief period of warm air advection beneath amplified ridging
ahead of the next system moving through the west CONUS. This
will allow highs Monday and Tuesday to warm into the middle 60s
to lower 70s. Lows during this period will be in the lower to
middle 40s Monday night, and upper 40s Tuesday night.


20-40% chance for rain next Tuesday night and Wednesday:

The next system then arrives Tuesday night and Wednesday. Model
disagreement in trough timing, position, and intensity is still
high as shown by ensemble cluster analysis. This is still
leading to broad areas of 20-40% chances of showers and
thunderstorms. Despite the uncertainty in the trough, the high
amplitude of the wave will bring through a cold front that
should force some form of showers and thunderstorms across the
region. Subsequent forecasts will hone in on better details.

After the cold front moves through, temperatures will cool. The
degree of cooling is still uncertain, largely because of the
aforementioned uncertainties with the trough. NBM spreads are
still high, but the current forecast calls for highs in the
upper 50s to lower 60s with lows in the upper 30s to lower 40s
Wednesday through Thursday.


In the extended range, confidence is increasing that above
normal temperatures and precipitation will continue through
mid-November, per the CPC 8-14 day outlook. This is largely due
to ensembles developing yet another deep trough across the west
CONUS that will translate eastward into the central CONUS during
the 8-16 day period.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 540 AM CST Fri Nov 8 2024

MVFR cigs at BBG and JLN should gradually clear out through
14-16Z, leaving BKN to OVC middle and high level clouds for the
rest of the TAF period. Easterly winds will pick up to 10-15
kts with gusts up to 20-25 kts at times.

Widespread rain chances will then filter into the region after
18Z for JLN and after 00Z for SGF and BBG. Precipitation will
start out as periods of light rain before gradually becoming
greater in coverage and intensity. The best chance for a
thunderstorm (still <20%), will be in JLN between 05-11Z.

&&

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

&&

$$

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