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Area forecast discussion 
National Weather Service Lincoln Illinois
1024 am CDT Sat Sep 5 2015

issued at 1020 am CDT Sat Sep 5 2015

Convection that intensified to our north and shifted slowly
southeast into parts of Vermilion County was finally beginning
to weaken, with infrared satellite data showing cloud tops warming
over the past hour. Additional convection firing off an outflow
boundary to our north not in a hurry to drop southeast at the
present time but will need to be watched across our north
and northeast counties again for this afternoon. Extensive cloud
cover tracking southeast from southwest Wisconsin through north
central Illinois may play a part in our temperatures this
afternoon but the last few loops showing some breaks developing
on the southern end of the cloud shield. Have updated the
precip trends in our area for this afternoon, keeping the higher
pops across the northeast half of the area with only minor
adjustments to temperatures at this time for this afternoon.
Update should be out by 1045 am.


Short term...(today)
issued at 335 am CDT Sat Sep 5 2015

Convective remnants continues to slowly drop southeast into
northwestern IL late tonight and this could reach into northern
parts of the cwa this morning. Other showers/storms have developed
along the weak boundary in northern/northeastern IL...where
scattered storms developed yesterday evening. Believe isolated
storms will be possible again this morning in the north part of
the cwa and then again in northeast parts of the cwa along the
persistent weak boundary...mainly along and north of I-74. Along
and south of this boundary...southerly winds will once again bring
unseasonably warm air into the area this afternoon with highs in
the lower to middle 80s. Combined with dewpoints around
expecting heat index values in the 95 to 100 range again.

Long term...(tonight through friday)
issued at 335 am CDT Sat Sep 5 2015

Isolated convection that forms along weak boundary in our NE
counties this afternoon may linger until middle evening. Otherwise dry
conditions expected tonight through Sunday evening across central/southeast
Illinois. 00z forecast models show a strong upper level ridge from Texas
to Illinois through this Labor Day weekend, and continue the late Summer
heat wave a few more days. Used persistence for highs Sunday in
the low to middle 90s (similar highs since Thursday/Sep 3) and highs in
the upper 80s to lower 90s on Monday/Labor Day...slightly cooler
due to more cloud cover and increased chances of
showers/thunderstorms by Monday afternoon especially from I-55 northwest.
Dewpoints of 65-70f will give heat indices of 95-100f Sunday
afternoon and in the 90s Monday afternoon. Muggy lows in the upper
60s and lower 70s from tonight through Monday night.

An upper trough near the West Coast will slowly move east and try to
break down the upper level ridge over Illinois by middle of next week. A
weakening frontal boundary to approach northwest Illinois later Sunday night into
Monday and bring a chance of showers/thunderstorms northwest of Illinois River
later Sunday night and spreading further southeast into central Illinois during
day Monday. Areas southeast of Champaign...Decatur and Taylorville likely
stay dry and hotter on Monday. Storm Prediction Center keeps marginal risk of severe
storms west of County Warning Area from Quincy west Monday/Monday night. Chances of
convection increase overnight Monday night into Tuesday as a stronger
wave moves closer to central Illinois. Southeast Illinois south of I-70 mostly
stay dry yet during this time with chances of convection spreading
into southeast Illinois Tuesday night/Wed. Chances of showers/thunderstorms
appears to continue through next Friday due to slow movement of
frontal boundary. Cooler temperatures expected during middle of next week
with warm highs Tuesday ranging from lower 80s northwest of Illinois River to near
90f southeast of I-70. Highs Wednesday 80-85f and cool down to middle to
upper 70s by Friday.


Aviation...(for the 12z tafs through 12z Sunday morning)
issued at 630 am CDT Sat Sep 5 2015

Believe VFR conditions will prevail at all taf sites next 24hrs.
Mid and high clouds are seen on radar effecting all taf sites this
morning, followed by scattered cumulus developing later this morning
and into the afternoon. Some light fog is also occurring at cmi
and believe this will be the only site to have it this morning so
will just have a tempo group for one hour for it. Weak boundary
still over northeastern third of the state and like yesterday,
isolated storms could develop along this boundary again and could
possibly effect some of the taf sites. Unsure if any one site
will have convection so will not include at this time and let day
or evening shifts add once it begins to develop. Winds will be
southerly today and then become light and variable again this
evening and overnight.


Ilx watches/warnings/advisories...


short term...auten
long term...07

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