Area Forecast Discussion
Issued by NWS Central Illinois

Home | Current Version | Previous Version | Graphics & Text | 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 250829

Area Forecast Discussion
National Weather Service Lincoln IL
329 AM CDT Thu May 25 2017

.SHORT TERM...(Today and tonight)
ISSUED AT 306 AM CDT Thu May 25 2017

The deep upper level trough that has been driving the weather for
the Midwest over the last several days is still over the Eastern
Ohio River Valley...with the axis stretching from Lake Superior
down through the Central Gulf Coast. Early this morning, patchy
stratus clouds dominated the eastern half of the state. With the
low continuing to drift eastward... expect the clouds to slowly
retreat to the east, but in areas that clear out...expect some
cumulus development to replace it. Light northwesterly winds and
high temps in the 70s. Tonight will be mild as well, with
increasing clouds as a weak wave approaches the region. Models
still not offering much in the way of consistence in handling this
wave. Pop chances very light mainly in the west tonight.


.LONG TERM...(Friday through Wednesday)
ISSUED AT 306 AM CDT Thu May 25 2017

Pop chances on Friday a little higher as the wave moves into
Central Illinois. Last few runs have been much weaker with the
wave and the resulting QPF. General lift and uncertainty with
regards to the location of the front is a cause of concern for the
forecast. Initial front on Friday can provide a focus for the weak
wave aloft...but the same front lifting northward across the state
on Saturday has the potential for some severe weather. Significant
MUCAPE across the region invof and behind the lifting warm front
throughout the day. Once again, the main concern is the location
of that boundary. By late in the afternoon, the NAM has it much
further to the south and a more southerly track of the surface
low. Same time frame in the GFS is far more dire for Central IL
and moving the front through ILX in the afternoon. SPC also
recognizes the uncertainty and still puts a slight risk in the Day
3 outlook. Not surprisingly, the temperatures/southerly breezes in
the forecast ahead of that system push max temps from the mid 70s
to the lower 80s, contributing to the overall instability of the
airmass. The storm system moves through the Midwest through the
remainder of the weekend. Parts of Sunday evening will be dry...
depending on the progress of the system... but pops return into
the forecast Monday, though weak, under cyclonic flow. GFS is far
more aggressive with precip development and at this point the
models diverge even farther with handling the exit of the precip
as the GFS lingers with the trough and a weak sfc ridge in the
Plains. Temperatures remain just below normal through the latter
half of the forecast.


.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 103 AM CDT Thu May 25 2017

Forecast IFR stratus spreading westward from IN border this
morning and some patchy fog bringing vis down as well to 2-3sm.
Improving conditions in the morning with the sunshine burning
through and clouds clearing from west to east. NW winds
dominate...generally less than 10 kts.




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