612
FXUS63 KILX 121727
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1227 PM CDT Sat Apr 12 2025

.KEY MESSAGES...

- Freeze Warning and Frost Advisory in effect until 9 AM this
  morning (south of Macomb to Bloomington line where growing
  season has started) with lows in the low to mid 30s.

- Breezy south winds Sunday with gusts 25-35 mph, with strongest
  winds between the IL river and I-70. Breezy WNW winds Monday
  with gusts 25-35 mph in central IL, strongest winds north of
  Peoria.

- Slight chance of showers Monday morning as cold front passes
  through. Better chance of showers and isolated thunderstorms
  Wednesday night into Friday.

&&

.DISCUSSION...
Issued at 400 AM CDT Sat Apr 12 2025

Expanded the frost advisory westward to including Schuyler, Mason,
Cass, Scott and Morgan counties which is in effect until 9 am.
Continued freeze warning until 9 am for east central/se IL with
lows in the lower 30s. Predawn surface map shows 1023 mb high
pressure over IL providing nearly clear skies over the prairie
state (few high cirrus clouds over west central/nw IL) with light
to calm winds. Temps were generally in the 30s across CWA at 330
am, ranging from 31 in Lincoln and 32F in Rantoul, Danville and
Paris to 40-41F in Flora, Peoria and Springfield. Aloft a deep
upper level trof was over the Atlantic States with upper level
ridge over the Rockies and into the central Great Plains.

High pressure to drift eastward into Ohio, KY/TN by sunset and
providing a nice spring day to central/se IL. Light winds
becoming southerly 5-15 mph this afternoon. Ample sunshine this
morning, with mid/high clouds increase from mid afternoon into the
evening. Highs mostly in the lower 60s today, with eastern IL
around 60F and mid 60s over west central IL.

Upper level ridge to nose into IL tonight while a disturbances
rides over the top of it into WI/western Great Lakes. Brunt of its
showers should pass north of central IL late evening/overnight and
just have slight chance of showers northern Stark and Marshall
counties around midnight tonight. Could be sprinkles possible
overnight over central IL but mainly see increasing mid/high
clouds. South winds increase to breezy levels during overnight
especially over the IL river valley where south winds gusts 25-30
mph by dawn Sunday. Milder lows overnight in the upper 40s over
the IL river valley and low to mid 40s in eastern IL.

A storm system over the Pacific Northwest to track into the
eastern Dakotas by sunset Sunday and surface low pressure
deepening to around 995 mb during Sunday night into northern WI
and upper MI. Strong pressure gradient gives south winds gusting
25-35 mph on Sunday especially between the IL river and I-70. HREF
has 35-60% chance of wind gusts around 40 mph or higher Sunday
morning between IL river and I-70. Skies become partly sunny with
milder highs in the low to mid 70s, coolest in eastern IL. Upper
70s possible over west central IL west of a Galesburg to
Jacksonville line. This will be the warmest day since Wed/Apr 2.
Mild lows Sunday night in the low to mid 50s in central IL and
upper 50s to near 60F in southeast IL.

As deepening low pressure moves east of Lake Superior by Monday
afternoon, it pushes a cold front se through central IL late
Sunday night and Mon morning and exits se of the Wabash river
valley by noon Monday. Limited moisture over CWA with just slight
chance of showers Mon morning. Better chance of convection Mon
afternoon east and se of IL where SPC Day 3 has slight to marginal
risk of severe storms over much of OH/WV into central/northern KY
and southeast Indiana. Stronger WNW winds develop behind cold
front with gusts 25-35 mph in central IL, strongest winds north of
Peoria where LREF has 30-45% chance of over 35 mph wind gusts
north of Peoria by 1 pm Monday. Highs Monday in the mid 60s
central IL and upper 60s se of I-70.

Breezy NW winds continue on Tuesday over the area as strong low
pressure moves into central Quebec with deep mid/upper level trof
over the Great Lakes and into the Ohio/TN river valley. Models
keep qpf/precipitation mostly east of IL Monday night and Tue.
Cooler highs Tue of 55-60F, coolest from I-74 ne. 1022-1024 mb
high pressure settles over WI/IL by dawn Wed with clearing skies
and lighter winds. Cool lows Tue night in the mid to upper 30s,
coolest in east central IL where patchy frost possible by daybreak
Wed.

A disturbance to eject out of CO into the mid MS river valley Wed
night and Thu bringing next chance of showers and isolated
thunderstorms. Highs Wed in the mid to upper 60s. Surface low
passes north of central IL on Friday with continued chance of
showers and possible thunderstorms Thu night and Friday. Highs
Thu/Fri in the upper 60s/lower 70s. Cold front to pass se through
central IL around Fri night and into southern IL next Saturday and
could keep chance of showers and isolated thunderstorms going
into Sat especially southern CWA. Models have trended wetter over
area during this time period. Cooler highs in the lower 60s next
Saturday. High pressure projected to build over the Great Lakes on
Easter Sunday hopefully will bring dry condtions to
central/northern IL though frontal boundary lurking to our south
and sw could start lifting back ne with a southern stream storm
system over the central/southern plains.

07

&&

.AVIATION...  (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1227 PM CDT Sat Apr 12 2025

VFR conditions reign through 18z tomorrow. Some high level clouds
will move in the area overnight but stay above 10k feet AGL. Winds
out of the south will be light today and tonight but will increase
by tomorrow morning gusting to 30-35 knots by mid morning.

Copple

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$