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
000
FXUS63 KILX 030450
AFDILX

Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1150 PM CDT Tue Sep 2 2014

.UPDATE...
ISSUED AT 920 PM CDT TUE SEP 2 2014

Current forecast looks to be on track. Skies are mostly clear, but
should become clear overnight. With winds becoming light and
variable, light fog should develop overnight thanks to lots of
leftover low level moisture from the previous nights rain. So, no
forecast update needed at this time.

&&

.SHORT TERM...(This evening through Wednesday)
ISSUED AT 254 PM CDT TUE SEP 2 2014

18z/1pm surface analysis shows slow-moving cold front extending from
Chicago to just east of Quincy.  Ahead of the front, central
Illinois remains partly to mostly cloudy and there have even been a
few showers E/NE of Bloomington over the past hour.  Will continue
to carry slight chance PoPs across the eastern KILX CWA through the
afternoon accordingly.  Frontal boundary will continue to push
slowly eastward tonight, eventually washing out across central
Illinois.  Winds will go light/variable due to the weak pressure
gradient and with skies expected to clear, fog will likely develop
overnight.  NAM forecast soundings suggest the most widespread fog
will form across east-central Illinois where skies will clear the
slowest this afternoon.  Have therefore included areas of fog after
midnight along/east of I-57, with patchy fog further west across the
remainder of the area.  After early morning fog dissipates, skies
will initially be mostly sunny before clouds begin to increase in
advance of an approaching warm front on Wednesday.  Based on 12z
NAM/GFS, have slowed the introduction of PoPs until afternoon.

&&

.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 254 PM CDT TUE SEP 2 2014

Low pressure moving from the Plains toward the western Great Lakes
on Wed night will begin a significant push of warm air from the
southern Plains into Illinois. A shortwave clipping N IL in the
could trigger a few storms from Peoria and northward overnight. By
Thursday, the warm front will re-define north of Illinois, as 850mb
temps of 20-24C surge into our counties. Gusty south winds will aid
in moisture transport pushing humidity levels up, as surface
dewpoints climb into the mid 70s. Mixing that warm air to the ground
supports high temps into the upper 80s and lower 90s, depending on
the amount of sunshine we get into the afternoon. The 12z guidance
are slowing down the advance of storms into IL on Thursday, except
for the GFS, so sunshine could prevail for much of the day. Peak
heat index readings could reach between 100-105F.

Storm chances increase later Thursday night as the cold front
approaches NW IL. Rain chances become widespread across the KILX
forecast area for Friday and Friday night, as the cold front
progresses across IL. Severe potential is hard to pin-point this
early, but very heavy rainfall will be possible as PWAT values climb
toward 2". Friday will be another warm and muggy day ahead of the
cold front, but not quite as hot due to increasing cloud cover and
showers/storms.

The cold front will begin to slow down Friday night, allowing
scattered storms to linger across our southeast counties into
Saturday.

A significant airmass change will follow that frontal passage, as
cool and dry Canadian high pressure builds southeast into the
western Great Lakes. Highs from Saturday through Tuesday will be
mainly in the 70s, with lows mainly in the 50s, with Sunday night
the coldest night.

Storm chances increase next week Tuesday as a cold front arrives
from the west.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1150 PM CDT TUE SEP 2 2014

Skies are mostly clear at all TAF sites. This should continue
remainder of the overnight hours. With skies clear and winds light
and variable overnight, expecting light fog to develop at all
sites late tonight. All sites will have light fog with TEMPO of
MVFR vis except for CMI and BMI being at 2sm during the TEMPO
period of 10-12z. Once this dissipates, scattered SC will develop
for the rest of the morning and into the afternoon. Then skies
will clear tomorrow evening. Winds will become southerly at just
under 10kts, during the morning hours and then continue through
the rest of the TAF forecast period.

&&

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

$$

UPDATE...AUTEN
SHORT TERM...BARNES
LONG TERM...SHIMON
AVIATION...AUTEN





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