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fxus63 kilx 150716 

Area forecast discussion
National Weather Service Lincoln Illinois
216 am CDT sun Sep 15 2019

issued at 201 am CDT sun Sep 15 2019

Scattered showers and storms are possible mainly along and north
of I-72 this morning, dry weather will prevail through the
afternoon. A few additional isolated showers or storms are
possible this evening. Dry weather then resumes into the middle of
the upcoming week as high pressure builds across the region.
Temperatures will average above normal over the next several days,
with afternoon highs in the upper 80s to around 90.


Short term...(today and tonight)
issued at 201 am CDT sun Sep 15 2019

Early this morning, low level jet driven storms will continue to
move east across northern Illinois, but will gradually build south
into central Illinois likely in a decaying or weakening state as
the low level jet veers and weakens. Storms may be possible as far south as
the I-72 corridor through mid morning, then coverage should
diminish. At this time, it appears the threat for severe weather
is fairly low, but will have to monitor a few of the stronger
storms that could produce large hail.

This afternoon, guidance suggests that the atmosphere will once
again become moderately unstable ahead of an approaching weak
surface trough. There is no notable support aloft, so the trough
will struggle to move into the area and forcing will be weak.
Still, some guidance suggests that a few isolated to widely
scattered storms will be possible late this afternoon or evening.
Very weak shear in place will result in pulse storms, so the
overall severe threat will be low, but could see some locally
strong winds or heavy rain. Most areas will remain dry this


Long term...(monday through saturday)
issued at 201 am CDT sun Sep 15 2019

A strong upper ridge will be in place across the central Great
Plains to begin the week while an expansive surface high will be
centered over the Midwest. These features will shift east slowly
through midweek with the upper ridge becoming centered across the
local area Tuesday and Wednesday. Dry weather will prevail under
the influence of the high through the first half of the week, and
temperatures will be quite warm each day, topping out in the upper
80s to around 90f. Humidity will also return through this time
frame with dew points in the upper 60s to around 70f.

Meanwhile, a couple waves moving in from the West Coast will bear
close watching as they approach the local area through the latter
half of the week. Initial shortwave over northern California late Monday
will become more compact as it lifts to the northern Great Plains
Wednesday. Models have come into much better agreement with the
motion of this system lifting the system into Ontario on Thursday
and causing the upper ridge to buckle slightly. An attendant
surface cold front will push into the upper Midwest Thursday with
the tail end of the front pushing towards an unstable air mass in
place across central Illinois. The local area does remain well
displaced from the upper level support with weak upper flow and
shear, while forcing is mainly limited to the low level
convergence along the front. These limiting factors may help keep
storm coverage limited with diminishing chances overnight, as
depicted by the European model (ecmwf) and Gem.

A stronger trough is progged to move onshore over the West Coast
Wednesday night moving into the Great Plains late Friday into
Saturday. This wave is progged to push the upper ridge off to the
East Coast, and could result in more unsettled weather for central
Illinois next weekend.


Aviation...(for the 06z tafs through 06z Sunday night)
issued at 1148 PM CDT Sat Sep 14 2019

Scattered thunderstorms are possible late tonight into Sunday
morning, with the highest chances at kpia and kbmi from 10z-16z,
and lower chances for showers at kspi, kdec, and kcmi. Additional
thunderstorms are possible for kpia and kbmi after 23z, however
low probabilities only warrant thunderstorms in the vicinity mention at this point. Brief
isolated MVFR cigs/vsbys and gusty winds are possible in
thunderstorms, but otherwise, VFR conditions are expected with
increasing high and mid level clouds through tonight. Winds S
around 10 kts through tonight, then becoming SW 10-14 kts with
gusts 15-20 kts after 16z.


Ilx watches/warnings/advisories...


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