Springfield, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

044
FXUS63 KILX 070735
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
235 AM CDT Mon Apr 7 2025

.KEY MESSAGES...

- Cold temperatures will be in place this morning with lows near
  the freezing mark. Even colder temperatures are expected Tuesday
  morning with temps dipping into the 20s. A freeze warning is in
  effect from midnight tonight until 9 am Tuesday from Rushville
  to Danville south where the growing season has started.

&&

.DISCUSSION...
Issued at 225 AM CDT Mon Apr 7 2025

COLD START TO THE WEEK...
Early this morning, low pressure is located over far northern
lower Michigan with a cold front extending southwest across
northern Illinois into Iowa. High pressure is located over the
southern Great Plains with ridging extending across central
Illinois. Favorable radiational cooling across central Illinois
under the influence of the ridge axis is allowing temps to fall
down to near the freezing mark and frost to develop. This could
impact sensitive vegetation where the growing season has
commenced, particularly across the southern half of the state. The
cold front will push south across central Illinois this morning
with high temps running about 10 degrees colder today compared to
yesterday. Highs will range from the mid to upper 40s along the
I-74 corridor to mid to upper 50s south of I-70.

With the placement of the surface ridge axis cutting off any
significant moisture return, expect the front to pass through most
of central Illinois dry. Cold air advection behind the front will
drive steep low level lapse rates with very weak SBCAPE of 25-50
J/kg developing. This may allow for a few sprinkles to develop,
especially near the I-74 corridor.

High pressure will build across the Upper Midwest overnight and
shift into Illinois early Tuesday morning. This will set the stage
once again for favorable radiational cooling conditions within an
even colder air mass. Ensemble probabilities from the both the
HREF and NBM show near certainty (100%) for temps to fall below
freezing across all of central and southeast Illinois. The
probability for a hard freeze (temps less than 28degF) are roughly
50% (south) to 70% (north) from the NBM.

RAIN RETURNS MIDWEEK...
As we reach midweek, upper level pattern is characterized by
modest ridging over the West Coast and troughing in the east. An
upper level disturbance digging across the Upper Midwest in the
northwest flow will drive surface cyclogenesis with a deepening
surface low expected to track from the mid Missouri Valley
Wednesday morning across central and northern Illinois Wednesday
night. Surface high over the mid Atlantic coast will extend
southwest into the Gulf during this time with unfavorable low
level trajectories for any significant moisture return into the
Midwest. Guidance suggests dew points will only build into the 40s
across central Illinois with passage of the midweek system.
Prefer to see mid 50 dewpoints in order to support severe
weather, so despite the close proximity of the low track and
otherwise favorable kinematics, does not appear we will be able to
achieve much in the way of instability to support severe weather.
A few storms cannot be ruled out with MLCAPE values advertised by
the GFS up to around 250 J/kg with forecast soundings also
showing some weak elevated instability. NBM mean 24-hr QPF runs
only around 0.2-0.3 across central Illinois Wednesday with 90th
percentile values (showing a reasonable high end forecast)
running roughly half an inch to just less than an inch. Highest
precip amounts are expected near the low track along and north
I-74.

Lingering low level cyclonic flow will support some additional
light rain chances on Thursday, then cold air advection driving
steep low level lapse rates will support additional scattered
showers Friday. High pressure builds across the region next
weekend allowing a break from the precip with warmer temps
gradually spreading into the region from the west behind the ridge
axis.

Deubelbeiss

&&

.AVIATION...  (For the 06z TAFs through 06z Monday Night)
Issued at 1154 PM CDT Sun Apr 6 2025

VFR conditions will prevail through the period. The main concern
this TAF period is the timing of a cold front which will shift
winds from southwesterly to northwesterly, with gusts to 20-25
knots behind the front. This wind shift is expected to occur from
north to south between 12-15z. Scattered diurnal Cu should develop
today around 4-5 kft. Winds trend lighter after 00z, out of the
northeast.

Erwin

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Freeze Warning from midnight tonight to 9 AM CDT Tuesday for
ILZ040>057-061>063-066>068-071>073.

&&

$$