Area Forecast Discussion
Issued by NWS Central Illinois

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KILX 240929

Area Forecast Discussion
329 AM CST Sat Jan 24 2015

.SHORT TERM...(Today)

A weak surface trof is expected to push across the area this morning
switching our winds more into a west to northwest direction. In
addition, latest satellite data and surface observations indicate
another band of clouds approaching from the northwest, immediately
behind the weak frontal boundary. Based on its current movement, it
appears the eastern half of the forecast area will be affected the
most from the southeastward moving clouds later this morning. This
will have an impact on afternoon highs with our east and northeast
counties trending a bit below guidance, with low to mid 40s common,
while over west central and southwest Illinois, not as much cloud
cover is expected and as a result we should push into the mid or
upper 40s this afternoon.


.LONG TERM...(Tonight through Friday)

00Z forecast model suite has trended further south and west surface
low pressure track going se into central IA (1003 mb) by 06Z/midnight
tonight, into south central IL by 18Z/noon Sunday, and nearing the
eastern KY and WV border by 06Z/midnight Sunday night. Have trended
a bit higher with qpf (averaging around a quarter of an inch) over
central IL Sunday along with cooler temps Sunday/Sunday night and
bringing chances of snow further south with the cooler air/further
south track of storm system. Have increasing chances of light rain
after midnight tonight over central IL with just slight chances of
light rain late tonight in southeast IL from I-70 southeast. Light
snow could mix with light rain late tonight north of I-74, but
most areas should be rain overnight with lows in the low to mid
30s. Raised pops to 60-90% Sunday with highest pops northern
counties where rain changes to snow especially late Sunday
morning/afternoon. Have snow chances as far south as I-70 by late
Sunday afternoon with southeast IL seeing light snow too during
Sunday evening before ending overnight Sunday night. Have 1-2
inches of snow ne of a Canton to Lincoln to Paris line Sunday and
Sunday evening with locally higher amounts 2-3 inches in far ne
CWA over Marshall and northeast Vermilion counties. A winter
weather advisory may eventually be needed in ne counties but will
issue SPS for now due to models shifting track of low pressure
past few runs. Highs Sunday range from mid 30s northern counties
to 40-45F from Springfield to Terre Haute south with mid 40s near
Lawrenceville. Temperatures will likely be slipping Sunday

Another clipper system diving se across the western Great Lakes
Monday and Monday night to bring a chance of light snow showers to
northern/ne counties with best chances of accumulating light snow
appears to be ne of central IL. Highs Monday range from low to mid
30s from I-74 ne to the upper 30s to around 40F in sw counties. Dry
conditions expected Tue/Wed as high pressure settles into the upper
MS river valley Tue and into the Ohio river valley Wed. Highs in the
mid 30s to near 40F on Tue and climbing into the upper 30s to mid
40s Wed, with upper 40s from Jacksonville sw.

Surface low pressure system tracks into the Midwest and southern
Great Lakes region Wed night and Thu bringing a 20-30% chance of
light rain/snow. Models have trended quicker with this feature.
Above normal highs Thursday in the low to mid 40s with upper 40s in
southeast IL. Temps then cool behind this feature with highs in the
30s Friday and even colder temperatures expected next weekend with
another chance of light snow next Saturday.


.AVIATION...(For the 06Z TAFS through 06Z Saturday night)

Some minor adjustments. Mid clouds and southwesterly flow ahead of
an approaching boundary. Boundary and llvl moisture starting to
spread low clouds north of the ILX terminals...but expected to
develop along PIA/BMI/CMI line by morning. BKN MVFR in the
morning...anticipated to move through and out of the region later
in the day, accompanied by a more nwrly wind. May see the forecast
improve a little quicker, but for now...keeping the MVFR cigs in
there in the north. More optimistic across SPI and DEC and
scattering the 2kft deck in the morning and dominating with cirrus
per HRRR and Bufkit soundings.





AVIATION...HJS is the U.S. government's official web portal to all federal, state and local government web resources and services.