Normal, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

217
FXUS63 KILX 220527
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1127 PM CST Sat Dec 21 2024

.KEY MESSAGES...

- Seasonably cool and dry weather will persist through Sunday
  evening with temperatures turning milder thereafter with highs
  likely in the 50s Thursday through Saturday.

- Patchy freezing drizzle is possible late Sunday night into mid
  Monday morning over central IL, especially from I-74 north.
  Otherwise an unsettled week lies ahead with daily chances for
  rain Monday through Saturday.

&&

.DISCUSSION...
Issued at 300 PM CST Sat Dec 21 2024

Mid afternoon surface map shows strong high pressure (1034+ mb)
ridging from James Bay Canada into central WI and west central
and northwest IL. Nearby high pressure providing fairly light
winds under 10 mph along with a fair amount of sunshine over
central IL. Scattered to broken stratocumulus clouds (bases 3-4k
ft) redeveloped this afternoon over areas along and south of a
Litchfield to Shelbyville to Robinson. Temps at 230 pm were mostly
in the lower 30s in central IL, but ranged from the mid to upper
20s over light snow pack from Lacon to Bloomington to Rantoul
northeast, to the mid 30s in southeast IL.

Diurnally driven stratocumulus clouds to dissipate at sundown in
southeast IL. Otherwise fair weather is expected tonight into
Sunday over central/se IL as high pressure drifts eastward across
the Great Lakes region and Ohio river valley during tonight and
into Quebec and NY and ridging into the mid Atlantic States by
sunset Sunday. Will see some passing mid and high clouds pass by
into Sunday especially over northern/ne CWA where skies become
partly to mostly cloudy by late Sunday afternoon from I-72 north.
Also will see winds veer more southerly by Sunday with gusts
20-27 mph Sunday afternoon over central IL and possibly a bit
higher gusts Sunday night over areas north of I-70. Lows overnight
in the lower 20s, except upper teens from I-74 northeast.
Seasonable highs Sunday in the upper 30s to around 40F, mildest
from Springfield sw.

Weak low pressure to move to near the SD/IA border by sunset
Sunday and lift into west central WI by sunrise Monday while
lifting a warm front ne over central IL during Sunday night.
Increase low level moisture over central and northern IL by
overnight Sunday night into Monday morning to develop chances of
light precipitation/drizzle. Surface temps near or just below
freezing into early Monday morning over ne CWA could give a brief
period of patchy freezing drizzle mainly ne of Lincoln. A weak
front pushes se into central IL Monday afternoon and could produce
chances of light rain showers mainly from highway 51 east while
qpf amounts will be very light if they happen at all. Milder highs
Monday of 42-48F, mildest from Springfield sw. Have 20-40% chance
of light rain showers in southeast IL Monday night as weak front
pushes into southeast IL late Mon night. Lows Mon night range from
around 30F from Lincoln and Champaign north to the mid 30s in
southeast IL.

A southern stream storm system/trof takes shape over the southern
plains Tue and ejects into the MS river valley Tue night into
Christmas day. This to bring 20-40% chance of light rain into
central IL Tue afternoon with likely pops in sw IL. Highs Tue in
the lower 40s central IL and mid 40s southeast IL. Our highest
pops arrive Tue night with likely pops east of I-55. Lows Tue
night in the mid to upper 30s with areas from Galesburg to Lacon
near or just above freezing for lows Tue night. Models differ with
how wet Christmas day could be over central/se IL with GFS pushing
most of qpf east of CWA Wed afternoon while GEM and ECMWF models
have light qpf over much of CWA on Wed. NBM pops are blended with
30-50% pops Wed, though diminish to slight chance along and west
of IL river Wed afternoon.

Another southern stream mid/upper level low/trof ejects over the
southern Rockies Wed and eject ne into MO or Iowa by Fri morning
and likely bring more rain to the area from Thu afternoon into
Friday with unsettled weather likely continuing over IL into
Saturday. South to SE winds continue to warm temperatures as week
progresses, with high 50-55F on Thu- Saturday in central IL and
mid to upper 50s southeast IL.

The Climate Prediction Center (CPC) 8-14 Day Outlook for Dec
29-Jan 4 favors about normal temperatures over CWA (60% chance of
above normal temperatures for central/se IL).

07

&&

.AVIATION...  (For the 06z TAFs through 06z Sunday Night)
Issued at 1127 PM CST Sat Dec 21 2024

VFR conditions expected over the upcoming 24 hours, with periods
of mid and high level cloud cover. Any MVFR cigs associated with
the next weather system are expected to hold off until after 06Z
Monday, possibly as late as 18Z. Winds SE around 5 kts overnight,
becoming SSE and increasing to around 15G25 kts by 16Z.

37

&&

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

$$