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 192016

Area Forecast Discussion
National Weather Service Lincoln IL
316 PM CDT Tue Sep 19 2017

.SHORT TERM...(This evening through Wednesday)
ISSUED AT 315 PM CDT Tue Sep 19 2017

Afternoon cumulus cloud cover will rapidly dissipate this evening as
an upper level ridge moves over the area. A pressure trough over the
Plains will start to initiate light southeast winds over the western
half of the state overnight limiting fog potential, however given
dewpoints in the mid and upper 60s, light winds, and the upper level
ridge, should be able to form fog over the eastern half of the
state. For Wednesday...models generally hold off any precipitation
with an approaching cold front until late afternoon so held off any
mention of thunder until then for areas N/W of Peoria. Strong
warming in SW flow should result in highs reaching around 90 degrees
to around 93 degrees for Springfield and Jacksonville. Tonight, lows
should remain mild, in the mid 60s.


.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 315 PM CDT Tue Sep 19 2017

The pattern of a longwave trough over the western U.S. and Ridge
over the eastern U.S. will amplify late this week and through the
weekend, resulting in a prolonged period of much above normal
temperatures. Initially, however a weakening cold front dragging
through the Mid Mississippi Valley will bring at least a slight
chance of thunderstorms Wednesday and Wednesday night as far east as
I-55. Subsequently...the southwesterly flow between the western
trough and eastern ridge will bring 17-20C 850 mb temperatures
Thursday through Monday. Highs mainly in the lower 90s will be
likely through Saturday, but have kept upper 80s Sunday and Monday
due to long range forecast uncertainty. The eastern ridge looks to
break down by the early to middle of next week as the western trough
progresses through the Plains and into the Midwest, likely
diminishing the late summer heat wave. A cold front associated with
this pattern change may also bring some thunderstorms back to
central IL and have included chance PoPs I-55 westward Tuesday.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1234 PM CDT Tue Sep 19 2017

MVFR cigs will be prevalent through early afternoon as morning
fog and low stratus clouds slowly lift and scatter. With cloud
bases expected to rise to only around 3000 feet, some terminals
may remain MVFR until 00Z. Based on satellite cloud cover trends,
kept MVFR at only KPIA-KBMI through 00Z. Tonight, fog may
redevelop. Expecting best chances for fog at KCMI where the
influence of an approaching cold front on winds will be least.

Winds light and variable...becoming south 5-10 kts by Wednesday





AVIATION...37 is the U.S. government's official web portal to all federal, state and local government web resources and services.