Area Forecast Discussion
Issued by NWS Central Illinois
FXUS63 KILX 111743
Area Forecast Discussion
National Weather Service Lincoln IL
1243 PM CDT Fri Jul 11 2014
ISSUED 1036 AM CDT Fri Jul 11 2014
High pressure ridge sliding eastward slightly...and some sct
showers just to the Northwest. Better chances expected in the
overnight hours, but some isolated showers not impossible later
this afternoon. Temperatures, both max and hourlys are on track
and doing well within the forecast. Warming into the lower to mid
80s for most of Central Illinois today with sct cu for the
afternoon. No updates anticipated at this time.
ISSUED 1224 PM CDT Fri Jul 11 2014
A lot of differences between models with the handling of the next
system and the frontal boundary expected to form/move through the
CWA tonight. Overall, models have differed on timing and have
trended the upper air disturbance further to the north. With that
in mind, keeping mention of thunder to the north for the overnight
hours, slowly pushing it south, per the 4km wrf solution, as it is
so far the most accurate reflection of current conditions. Also
staying with VC until better coverage is anticipated.
Showers/thunderstorms expected, but will withhold predominant
mention until confidence increases. Both GFS and NAM falling
behind in current conditions with convection in central Iowa.
South southeasterly winds dominate.
ISSUED 330 AM CDT Fri Jul 11 2014
SHORT TERM...Today through Monday night
1024 mb high pressure over the central and eastern Great Lakes
region was still ridging into central/ne IL early this morning and
bringing another seasonably cool night with temps in the mid 50s
to lower 60s with fair skies and light to calm winds. High
pressure to drift east into New England this afternoon/evening
with return sse flow developing over IL and starting to bring in
warmer and more humid air. 00Z models continue to trend slower
with arrival of convection chances this afternoon/evening with
eastern IL likely staying dry while 20-30% chance of showers and
isolated thunderstorms over IL river valley this afternoon and evening.
Best chances of showers and thunderstorms appears to be after
midnight tonight especially over northern counties from MCS with
heavy rains moving out of IA across northern IL. SPC keeps slight
risk area nw of IL tonight over NE and western IA. Highs today in
the low to mid 80s as skies become partly sunny with more clouds
nw over IL river valley and more sunshine in southeast IL where
mostly sunny skies prevail much of the day. Dewpoints to climb in
to the low to mid 60s this afternoon.
Convection chances will be highest over northern areas Saturday
while just isolated convection in southeast IL by Saturday afternoon.
Tropical airmass returns to IL with dewpoints back into the low to
mid 70s and highs in the mid 80s to around 90F Sat and Sunday.
Afternoon heat indices peak in mid to upper 90s this weekend which
is below heat advisory criteria. SPC has slight risk of severe
storms north of I-72 for mainly wind Saturday night with another
MCS with short wave moving from IA across northern half of IL. SPC
has slight risk of severe storms from I-55 southeast Sunday
(mainly Sunday afternoon & early Sunday evening for wind) as cold front
pushes se thru central IL. Models have trended quicker with this
front from earlier runs so have cooled highs northern areas a bit
on Sunday but still mid 80s.
Best chances of showers and thunderstorms shifts into southeast IL
Monday and Monday night closer to frontal boundary pushing
southeast of IL. Highs range from 80F IL river valley to mid 80s in
southeast IL and still humid here with dewpoints in the lower 70s.
LONG TERM...Tuesday through Friday
Extended models continue to show unseasonably strong cutoff low
digging southward from central Canada into the western Great Lakes
Monday night, and staying near the Great Lakes into middle of next week.
This to bring much cooler and less humid air into central IL with
highs in the low to mid 70s Tue (near 70F northern areas) and
slowly modifying thereafter. Can not rule out very isolated
afternoon showers each afternoon but chances appears less than 20%
so left them out of forecast for now. Highs to modify into upper
70s to near 80F late next work week.