Decatur, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

518
FXUS63 KILX 142330
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
530 PM CST Thu Nov 14 2024

.KEY MESSAGES...

- Dry weather, cloudy skies, and seasonable temperatures linger
  into the weekend.

- Temperatures warm up into the 60s for highs for the new week
  ahead of frontal passages by midweek.

- Several more chances for precipitation in the forecast through
  the end of next week.

&&

.DISCUSSION...
Issued at 226 PM CST Thu Nov 14 2024

Low clouds linger over central Illinois today and will stick around
into the weekend, due to a a post-frontal inversion. The drizzly
conditions should relax this afternoon but the grey skies shall
continue. Lows tonight hang around the 40s. Breezy winds will
relax overnight tonight.

As a high pressure sets up over the region tomorrow, dry weather
will follow and temperatures will warm through the weekend. By
Sunday, highs will be above normal, getting up into the 60s through
Tuesday. A midweek frontal system will move through, dropping
temperatures back down to seasonable (50s) Wednesday and (40s)
Thursday. Overnight lows by midweek will be in the 30s, nearing
freezing. It`s too early to make any decisions or conclusions but
there is a signal for potential wind chills in the upper teens to
low 20s late next week.

There is a low pressure system that looks to develop over New Mexico
this weekend that will lift up to the Midwest by early next week. We
have plenty of time for this forecast to bounce around before it
will settle on an outcome. This system will bring multiple rounds of
precipitation to the CWA. The first round being rain and maybe a few
thunderstorms Monday. Severe weather is not expected at this time.
The second round will come overnight Wednesday to Friday. This one
COULD have some sort of frozen/wintry precipitation associated.
However, accumulation shouldn`t be impactful and the warm ground
temperatures would allow for anything that falls to melt rather
quickly. Nevertheless, we could see our first snowflakes of the
season by next weekend. The chances aren`t great and things could
change, but it is a nonzero chance at this time. Stay tuned for
further developments.

Copple

&&

.AVIATION...  (For the 00z TAFs through 00z Friday Evening)
Issued at 530 PM CST Thu Nov 14 2024

Moisture trapped below an inversion aloft will keep a layer of low
cloud cover entrenched over central IL most if not all of the next
24 hours. With high pressure shifting over the area Friday
afternoon, we could see a thinning of the cloud layer, and
potentially some breaking up of the layer, however most physical
models keep the layer intact through 00Z Saturday, especially in
eastern portions of the state, with statistical guidance
conflicting with this scenario to a large degree, and breaking up
the cloud cover before 18Z. Have gone with the more pessimistic
physical model idea that is more typical during the cool season
until southwesterly flow returns with high pressure moved to the
east. Therefore, have kept MVFR through 00Z east of KPIA-KSPI,
with VFR at KPIA-KSPI by 21Z. Also included tempo for IFR cigs
10Z-14Z as guidance points to a gradual lowering of cigs and some
thin fog at that point. Winds NW 6-12 kts this evening, decreasing
to under 8 kts by 10Z. Winds light and variable by 21Z.

37

&&

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

&&

$$