Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 270830

Area Forecast Discussion
National Weather Service Lincoln IL
330 AM CDT Mon Mar 27 2017

.SHORT TERM...(Today and tonight)
ISSUED AT 330 AM CDT Mon Mar 27 2017

Low pressure area in eastern OK will lift northeast toward the Ohio
river valley today. Showers and a chance of thunderstorms is
expected north of this track into central IL later today and into
this evening. Instability and shear parameters appear favorable for
some of the storms south of an I-70 to be strong enough for a small
threat for severe weather. So agree with SPC analysis of shifting
the slight risk for sever weather south of yesterday`s Day 2
forecast. All models, including the HiRes models agree that the
precip should end by 06z tonight. Temperatures will remain very warm
today and then mild tonight.


.LONG TERM...(Tuesday through Sunday)
ISSUED AT 330 AM CDT Mon Mar 27 2017

A brief break in the precip for Tues and Tues night as upper level
ridging keeps the region dry. Easterly winds through Wednesday
results in a rather neutral temp influence and max temps run very
close to climatological norms/degree or two above. 00Z runs have
sped up the approach of the system on Wednesday morning...with the
easterly winds holding off some of the advance of the precip across
western IL through the afternoon.   Precip dominates the forecast
through Friday this run...ending a bit quicker than last couple runs
as well.  This is altering how the early weekend looks (dry and cool
on Saturday), and although the models are starting to show more
similarities in the solution for the upper low over the southern
Plains late in the weekend, the models are hanging on to some
showery activity for Sunday.  Clearly moving through a pattern shift
in the first part of the work week and although the GFS and ECMWF
are showing mostly a dry forecast, the blends are picking up pops
from other solutions.  Not completely convinced, and although the
models do look better this run... there is still an adjustment
working through the the low gets kicked across the
southeastern quadrant of the country by the low diving into the Pac


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1100 PM CDT Sun Mar 26 2017

Little change from previous thinking. One system departs, another
to make an entrance starting Monday morning. The main forecast
concern will be with cigs and vsbys overnight. How far north the
improving trend in the cigs will be and if any clearing does take
place, will that bring in lower vsbys in fog? Current satellite
data indicates the VFR cigs were currently along and south of a
SPI to DEC line and were edging slowly north this evening.
Forecast soundings indicate the areas along I-72 including SPI,
DEC and CMI will see some temporary improvements in the cigs
late tonight before the next system starts to move into west
central Illinois by dawn Monday. This will bring in additional
low cigs to those sites that did improve overnight. Most areas
tomorrow should be at MVFR/IFR with occasional LIFR conditions
across PIA and BMI in showers and fog as the storm system tracks
to the south of the TAF sites later Monday afternoon and evening.
The thunder chances (VCTS) would be mainly along our southern TAF
sites of SPI, DEC and CMI into the afternoon hours.

Light west to southwest winds will become easterly on Monday
morning and increase to 10 to 15 kts with winds backing more
into a northerly direction after 20z as the storm sytems shifts
across far southern Illinois. A northwest wind is expected
Monday night with speeds of 10 kts or less.




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