Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 211957

Area Forecast Discussion
National Weather Service Lincoln IL
257 PM CDT SUN AUG 21 2016

.SHORT TERM...(This evening through Monday)
ISSUED AT 257 PM CDT Sun Aug 21 2016

Surface will build and move from Missouri to Indiana over the next
day providing mostly clear skies for central and southeast IL as it
does so...aside from scattered shallow afternoon cumulus clouds. A
cool night is in store as cool air settles in behind yesterday`s
cold front and winds taper off overnight allowing good radiational
cooling. Expect lows in the mid 50s tonight...down a few to several
degrees further from last night. Dewpoints have fallen to the upper
50s this afternoon and forecast soundings indicate a further drying
through tonight just above the surface. As a result...fog should not
be able to form as moisture depth will be too shallow. Highs around
80 expected Monday...up a few degrees from southerly flow
and warm advection return with the high positioned east of the area
for the daytime.


.LONG TERM...(Monday night through Sunday)
ISSUED AT 257 PM CDT Sun Aug 21 2016

Quiet weather should prevail across central and southeast Illinois
through the daytime hours Tuesday. However, changes in the local
weather pattern will be occurring that will lead to a periodically
wet mid-week forecast period. The surface high that is helping to
provide our current dry/cool weather will drift off the east, with
southerly low-level return flow developing. At the same time, upper-
level heights will be rising considerably from their current levels
by Tuesday. This scenario supports conditions turning warmer and
more humid once again by Tuesday, but the rainfall threat should
still hold off until late Tuesday night for the most part. Then, a
vigorous upper wave, currently pushing into British Columbia and the
Pacific Northwest, will track along the U.S./Canada border and reach
the Upper Midwest/Northwest Ontario area by early Wednesday. This
wave, and a weaker lead wave ejecting out of the southwest U.S.,
will push a weather system/frontal boundary into the area by late
Tuesday night into Thursday. The main frontal boundary will be slow
moving as it nearly parallels the upper flow, keeping area under
this extended risk of showers/storms. The latest model consensus has
the front moving a little more quickly, suggesting Thursday night
will be mostly dry.

After a brief break in the precipitation risk on Friday, chances
return during the weekend. The upper-level flow remains pretty zonal
behind the mid-week front, allowing upstream short wave energy to
quickly return.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1243 PM CDT Sun Aug 21 2016

VFR conditions will prevail at all TAF sites next 24hrs. FEW-
SCT035 cloud cover expected for afternoon...then clearing around
00Z. Winds NW around 10 kts decreasing to under 6 kts around 00Z.


.ILX Watches/Warnings/Advisories...


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