NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION. Privacy and Cookie policy

FXUS63 KILX 042315 AFDILX

Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 515 PM CST Mon Dec 4 2023

DISCUSSION
Issued at 220 PM CST Mon Dec 4 2023

Key Messages:

* Light rain or a rain/snow mix late tonight into Tuesday morning.

* Big warmup late this week with temperatures looking to be about 10- 15 degrees warmer than normal.

* A storm system will impact the Midwest this weekend, but there remain significant differences on details.

Surface ridging extends from the Plains states northward into Wisconsin this afternoon, keeping things dry and winds light.
Widespread cloud cover in place as of 2 pm may scatter out for a brief time this evening underneath large scale subsidence, but should quickly return ahead of the next system arriving later tonight.

An Alberta Clipper will slide southeast through northwest flow aloft tonight, bringing another shot at widespread light precipitation.
Temperature profiles support all rain for most, though slightly cooler temperatures near freezing north of I-74 could allow snow to mix in at times. Most of the precipitation should exit the area sometime around sunrise, though some lingering showers (20% chance)
can be seen through the daytime hours of Tuesday as we remain underneath cyclonic flow. QPF amounts are generally below 0.15" with snow accumulations staying north of here.

Surface high pressure will overspread the area Tuesday night into Wednesday as upper ridging works into the Plains states. Southerly return flow ramps up on Wednesday, working to bring milder temperatures and breezy conditions back to the area. Temperatures on Wednesday will be within a few degrees of normal (low to mid 40s)
with highs looking to warm into the middle to upper 50s by Thursday and Friday. The 75th percentile of the NBM is even highlighting a few low 60 degree maximum temperatures on Friday, which would put us about 15 degrees warmer than normal for this time of the year. It's not a warm day in the off season around here without wind though.
Thursday will be the breeziest day with the NBM suggesting a 40-60% chance of seeing gusts in excess of 30 mph.

The pattern becomes unsettled going into the weekend with a few upper features of note that will bring our next chance for precipitation. A northern stream shortwave trough will send a cold front into the area sometime early this weekend.
Simultaneously a southern stream shortwave originating from the dessert southwest will eject northward and spin up a surface low somewhere in the vicinity of the middle Mississippi Valley this weekend. There remain large differences in every aspect of this system, which will ultimately determine timing, track, and what type of precipitation we get. We still have some time to work out the details, but this system does bear watching. Temperatures turn cooler behind the weekend system, but will still be near seasonal values.

NMA

AVIATION
(For the 00z TAFs through 00z Tuesday Evening)
Issued at 515 PM CST Mon Dec 4 2023

A large area of MVFR cigs over central IL could see a surge of higher cigs as a shortwave ridge crosses the area just ahead of another weather system. These higher cigs only look probably at KSPI from around 04Z-07Z. A return to MVFR cigs is likely with light rain crossing the terminals from around 06Z-12Z, then a break in low cloud cover is again possible mainly for KSPI.
Precipitation could mix with snow at KPIA, KBMI, and KCMI before ending, however this possibility looks too low for mention in TAFs at this point, although a mix of snow looks much more likely 20-40 SM north of I-74. After a cold front passes over the area, another surge of low cloud cover in the IFR to lower MVFR range is expected as northwesterly winds develop after around 18Z.

37

ILX WATCHES/WARNINGS/ADVISORIES
None.

toggle option: (graph/table)

Full Color Weather Map

Link to Loop


Other links: GEOS-West     Contential US     Full GOES-East

Central Illinois, IL,