403
FXUS63 KILX 081111
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
511 AM CST Fri Nov 8 2024

.KEY MESSAGES...

- Patchy fog will affect central and southeast IL into mid morning
  and be most common from I-70 northward to the IL river valley.
  Visibilities will be restricted to 1-3 miles at times and
  possibly below a mile especially near waterways and/or low
  lying areas.

- There is a greater than 80 percent chance for rain across most
  of central and southeast Illinois late Saturday afternoon or
  Saturday night, along with a few thunderstorms. Precipitation
  amounts look to range from a quarter to a half inch in most of
  central IL, with a half to three quarter inch amounts possible
  near the Wabash river.

&&

.DISCUSSION...
Issued at 330 AM CST Fri Nov 8 2024

Early morning surface map shows 1028 mb high pressure near Omaha
NE and ridging eastward into central IL//IN. This is providing
clear skies and light to calm winds over central/se IL and
allowing patchy fog to develop past few hours especially from
I-70 to the IL river valley. Terre Haute and Taylorville vsby is
down to 1/2 mile at 330 am and 2.5 miles at Springfield at 3 am.
Patchy shallow ground fog should lift by mid morning (15Z/9 am).

Latest CAMs bring high pressure toward Lake Superior by 6 pm and
ridging southward into IL and will provide a nice late fall day to
central/se IL with north to NW winds less than 10 mph and a fair
amount of sunshine with some increasing high/cirrus clouds from
the sw later this morning or afternoon. Highs in the lower 60s
over much of the area, which is 5-7 degrees above normal highs in
the mid 50s central IL and upper 50s southeast IL.

High pressure to strengthen to 1032 mb as it drifts eastward
into the eastern Great Lakes and southeast Ontario Province by
daybreak Saturday and ridging back into WI and ne IL. Models have
trended slower with increasing high clouds and also trending a bit
cooler with lows tonight especially eastern/ne areas. Lows in the
mid to upper 30s in east central IL and around 40F to lower 40s
western and sw CWA.

A strong 557 dm 500 mb cutoff low over western NM to eject ne and
deepen to 548 dm over northeast Nebraska by sunset Saturday, and
move into the upper MS river valley and central WI by midday
Sunday. Much of CWA should still be dry Sat morning as clouds
increase, with slight chance of light rain from Jacksonville sw
late Sat morning. Main push of moisture arrives during Sat
afternoon/evening, with areas near the Indiana border likely
staying dry until early Saturday evening. Isolated thunderstorms
possible but severe storms not expected Sat night. Weak
instability (20% chance of CAPES at or just above 100 j/kg)
arrives in west central IL late Sat afternoon and over much of CWA
especially east of the IL river Sat night and se IL early Sunday
morning. Highs Sat range from mid to upper 50s west of I-57,
coolest from Galesburg to Macomb and Quincy west, and lower 60s in
eastern IL with ESE to SE winds 8-16 mph. Rain showers to
diminish from the west late Sat night into Sunday morning with a
quarter to half inch likely by noon Sunday. Areas near the Wabash
river could see a half to three quarter inches.

Low pressure lifts into eastern upper MI by sunset Sunday and
pushes showers east/ne of CWA Sunday afternoon, with breezy sw
winds developing over area and decreasing clouds (clouds lingering
longest in southeast IL). Highs Sunday range from around 60F nw
of the IL river and mid to upper 60s in southeast IL after
relatively mild lows Sat night in the upper 40s/lower 50s.

Dry weather returns to the area Sunday night through Tuesday
evening with mostly clear skies overall and temps near or a bit
above normal with highs in the upper 50s to around 60F. Lows in
the lower 40s, except 35-40F on Monday night.

Next weather system well off the Pacific Northwest Coast to have
low pressure/trof moving into the Midwest on Wednesday and cold
front moving into IL Wed afternoon. This will bring next best
chance of rain showers around Wednesday into Wed evening with
cooler temperatures (actually near normal readings) arriving
Thu/Fri behind this system. Highs in the low to mid 50s Thu/Fri
with lows in the low to mid 30s Thu night.

The Climate Prediction Center (CPC) 6-10 Day Outlook for Nov 13-17
and CPC`s 8-14 Day Outlook for Nov 15-21 both have a 70-80%
chance of above normal temperatures over Illinois, and a 35-45%
chance of above normal precipitation.

07

&&

.AVIATION...  (For the 12z TAFs through 12z Saturday Morning)
Issued at 511 AM CST Fri Nov 8 2024

Patchy fog, primarily MVFR visibility, will be near KSPI-KDEC-KCMI
through about 14-15z. Cannot rule out brief drops to IFR/LIFR that
have been noted farther south at KTAZ-KMTO over the past couple
hours, but probabilities are too low to include in TAFs.
Otherwise VFR forecast with only high clouds through tonight. High
pressure just to our north will keep winds light/under 10 kt from
the northwest today, veering northeast tonight.

25

&&

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

$$