305
FXUS63 KSGF 050020
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
620 PM CST Wed Dec 4 2024

.KEY MESSAGES...

- A strong cold front will push through the region tonight with a
  return to below normal temperatures through Friday.

- Temperatures rebound this weekend ahead of a system that
  brings rain chances late Sunday into early Monday.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 254 PM CST Wed Dec 4 2024

Scattered to broken cloud cover over southern sections of Missouri
early this morning has since eroded. Southwesterly surface flow that
was initially responsible for drawing warmer air into the region has
turned westerly along a weak cold front/surface trough. Mostly sunny
conditions has supported deeper mixing, leading to gusty winds and
mild afternoon temperatures. Surface obs show a majority of the
gusts peaking around 25 mph with few near-30 mph gusts, along with
temperature in the low to mid-50s.

The mild air is short-lived today with the arrival of a strong cold
front late tonight. A strong surface high is expected to build
southeast from the Plains, west of a broad surface low over the
Great Lakes. IR satellite and isobaric surface analysis shows the
front extending southwest of the low from the Great Lakes into Iowa
this afternoon. Hi-res guidance remains on track for frontal passage
late this evening with the strength of cold air advection peaking
after 04z tonight. There is high confidence that this air mass will
be solidly 10-15 degrees (perhaps as much as 20 degrees) below
normal (normal highs around 50/normal lows around 30) through
Thursday night. NBM quartiles show roughly 5 degrees of spread
between the lower quartile and upper quartiles (25th/75th
percentile) with lows tonight in mid-teens to mid-20s. Additionally,
surface winds stay elevated, especially over eastern sections of the
forecast area, where wind fields are stronger and will support gusts
along the cold front in the 06z-12z timeframe. Wind chills in the
single digits will be widespread through at least the northern
2/3rds of the forecast area with teens running along the MO/AR
border early Thursday morning.

The coldest of the air will stretch from Thursday into early Friday
morning. Northerly flow will persist around the 1040 mb surface high
centered over the Dakotas. The ridge works southward through the
day, centering overhead Thursday evening into Thursday night. Clear
skies and light winds will result in efficient cooling with lows
Friday morning ranging from the low-teens to near 20 degrees.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 254 PM CST Wed Dec 4 2024

Southwesterly surface flow will wrap around the western periphery of
the surface high as it sinks southward during the day Friday. This
will mark the beginning of a moderating trend with temperatures, but
is expected to be more gradually as mid/upper toughing
encompass the northeastern chunk of the CONUS. This continues to
result in northwesterly flow aloft, holding temperatures in the
40s. The mid- level ridge continues to strengthen and expand
over the southeastern section of the U.S. over the weekend,
gradually warming temperatures into the 50s as southwesterly
flow deepens.

The southeastern ridge may become a player in the overall pattern as
we approach the late weekend and early next week. NBM quartiles
remain fairly tight through Sunday. The system to watch will be the
closed low over the southwestern U.S., which is initially cutoff
from steering flow over the U.S./Mexican border. The aforementioned
southeastern ridge begins to shift east into the western Atlantic
late in the weekend. The close low evolves into a weaker, open
shortwave that become more progressive with time and eject northeast
through the Lower Mississippi Valley. Global guidance takes a bulk
of the moisture to the southeast with precipitation amounts trending
lower. This is consequently where spread begin to increase with long
range ensembles. Highest chances (60-80%) for rain now only clip
southeast sections of the forecast area. Probabilistic LREF data
shows a 20-30% chance of reaching or exceeding 0.25 inches of 24
hour rainfall (ending 12pm Monday) running from Springfield to Osage
Beach and points east. Beyond Monday, spread continues to with a
general trend toward cooler temperatures with cooler air moving in
behind the system.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 618 PM CST Wed Dec 4 2024

VFR conditions will persist through the TAF period. Winds will
be light, but with some gust potential late tonight into early
Thursday morning.

&&

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

&&

$$

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