Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 280412
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1112 PM CDT Mon Mar 27 2017

.UPDATE...
Issued at 835 PM CDT Mon Mar 27 2017

The storm system that produced the strong convection along and
south of the Ohio River today has pushed into southern Indiana
this evening and will continue to track away from central Illinois
tonight. Widespread clouds and scattered light showers continue
over central and east central Illinois in the wake of the storm
system, with the rain starting to push east of the area later
this evening, while the clouds unfortunately will dominate the
area well into the day on Tuesday. Forecast soundings indicate a
weak subsidence inversion setting up across the region holding the
low level moisture/clouds in place through a good portion of the
day. A few of the high resolution model forecast soundings
indicate we may see some breaks develop in the afternoon as weak
high pressure settles in before more rain threatens the area late
Wednesday into Thursday. Have made some adjustments to the timing
of the rain out of our area late this evening across east central
and southeast Illinois. We should have the updated ZFP out by
900 pm.

&&

.SHORT TERM...(This evening through Tuesday)
ISSUED AT 239 PM CDT Mon Mar 27 2017

Well-defined swirl in water vapor imagery continues to push eastward
across the southern third of Missouri this afternoon, with a
convective cluster pushed into western parts of Kentucky and
Tennessee. Warm front was located just south of I-70, and the
showers north of it have been devoid of lightning activity as a
result. The surface low riding along the boundary should be crossing
southeast Illinois late this afternoon, and lingering precipitation
will quickly taper off as the low pulls away. Have pulled back
thunder mention to areas south of I-70 for the remainder of the
afternoon, and removed the mention for the evening. Dry conditions
will prevail after midnight.

Northeast flow will persist across the forecast area into Tuesday.
Forecast soundings and low-level model humidity plots show that the
clouds will be in no hurry to leave, with no low level scouring
taking place. Temperatures most areas should still reach the lower
60s, with some upper 50s north of I-74 where there will be some
residual cooler air from the flow off of Lake Michigan.

.LONG TERM...(Tuesday night through Monday)
ISSUED AT 239 PM CDT Mon Mar 27 2017

High pressure over the Midwest Tuesday night will provide for dry
conditions, followed by the onset of rain chances in west central IL
Wednesday morning as warm advection aloft develops ahead of a low
approaching via the southern Plains. Models have converged
relatively well at this point with the low tracking NW through
southern IL late Thursday evening. Ahead of the low several hundred
to over 1000 J/KG MUCAPE is likely to surge northeastward combined
with potential for significant bulk shear. As a result...SPC has
targeted a marginal risk of severe thunderstorms by early Thursday
morning as far northeast as Springfield to Effingham...and this
severe thunderstorm risk could spread eastward through the day
Thursday impacting more of central IL. Have added thunderstorm
mention for the early morning period Thursday, and continued
thunderstorm mention for Thursday afternoon and evening through
around the I-72 corridor and areas southward.

Dry conditions look to spread eastward across the state Friday as
showers from the departing storm system taper off. The next
potential storm system is on Sunday or Monday, however model
differences in handling this system remain significant. Despite
model differences...current model/ensemble forecasts indicating a
more southern track than the past few systems. Chance PoPs are
therefore included in afternoon forecast package for portions of the
forecast area Sun/Mon, however precipitation coverage predictability
remains low.

Temperatures still look to be running a few degrees above
normal...mainly mid 50s to mid 60s through the weekend. Main
temperature feature is periods of cooler temperatures Thursday
through Saturday as cooler easterly to northerly winds surge into
the area due to the circulation around the low. Expect highs ranging
from the low 50s in Galesburg to around 60 in Lawrenceville during
this time period. Lows for the period generally 40s...although a few
30s for northern portions of the forecast area Thursday night
through Saturday night.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1100 PM CDT Mon Mar 27 2017

MVFR and local IFR cigs are expected across our area for
the overnight hours into Tuesday morning. Still seeing some
breaks in the overcast with cigs up in the VFR category. However,
satellite data indicates widespread MVFR and IFR cigs to our west
and northwest as the storm system to our southeast continues to
move away from the region. Forecast soundings suggest we may start
to see cigs improve tomorrow afternoon and satellite data does
indicate some clearing taking place to our north late this evening
which may get into our area later tomorrow. North to northeast
winds will continue tonight at 5 to 10 kts, with mostly northeast
winds at 8 to 13 kts on Tuesday.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...Smith
SHORT TERM...Geelhart
LONG TERM...37
AVIATION...Smith


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