Area Forecast Discussion
Issued by NWS Central Illinois
FXUS63 KILX 111118
Area Forecast Discussion
National Weather Service Lincoln IL
618 AM CDT Fri Jul 11 2014
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.
ISSUED 618 AM CDT Fri Jul 11 2014
VFR conditions will prevail at all TAF sites next 24hrs. High
clouds will advect into the area during the morning hours and
should become broken as well. These conditions will prevail
through the afternoon hours as well. Then around 00z, clouds
should begin to lower to around 10kft with scattered SC or CU.
These lower clouds should be in conjunction with a developing warm
front over the northern part of the area. These lower clouds will
then thicken during the night as the front develops. Pcpn will
develop along the front but lots of uncertainty as to timing and
where the front/pcpn will be. So will just have VCTS at all sites
starting around midnight or little after. Winds will primarily be
east to southeast to begin the TAFs, but then become southeast to
south the remainder of the period.