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Area forecast discussion
National Weather Service Lincoln Illinois
417 am CDT sun Jun 16 2019

Short term...(today and tonight)
issued at 400 am CDT sun Jun 16 2019

Add Clay, Richland and Lawrence counties into the Flash Flood
Watch through 7 am this morning. Cancelled the Flash Flood Watch
for Mason, Logan, DeWitt, Cass, Menard, Scott, Morgan and Sangamon
counties as moderate to heavy rains have shifted southeast of this
area early this morning. An additional 1 to 2 inches of rain is
expected portions of east central and especially southeast Illinois with
locally higher amounts possible along and south of Highway 50. A
short wave over southeast Illinois causing this convection will exit by
mid morning with convection becoming more isolated as the morning
progresses.

A frontal boundary over northern Illinois/in early this morning will sag
southward into northern County Warning Area late this morning and into central Illinois
this afternoon, reaching near I-70 by sunset. Airmass gets
quite unstable this afternoon over southern County Warning Area with convective available potential energy rising
to 2000-3500 j/kg by 21z/4 PM south of I-72, where showers and
thunderstorms will likely redevelop from I-72 south. 0-6 km bulk
shear is 30-40 kts in southeast Illinois early Sunday afternoon and
gradually weakens to 20-30 kts by late Sunday afternoon. Storm Prediction Center day1
outlook has marginal risk of severe storms se of a Danville to
Shelbyville line this afternoon until sunset this evening for
mainly damaging winds but isolated hail possible too. Also a
marginal risk of excessive rainfall today and tonight over se half
of County Warning Area where pcpn water values are 1.5 to 1.9 inches from I-72
south. Convection chances will diminish from I-72 south later this
evening and overnight as instability weakens. Warm and humid
today with highs in the mid 80s, with lower 80s northern County Warning Area. Lows
tonight range from the upper 50s and lower 60s NW County Warning Area and 64 to
68f over southeast Illinois.

&&

Long term...(monday through saturday)
issued at 400 am CDT sun Jun 16 2019

Weak surface low pressure moves into central MO Mon afternoon and
while frontal boundary lingers between I-72 and I-70 on Monday.
Storm Prediction Center day2 outlook continues a marginal risk of severe
thunderstorms Monday afternoon into Mon evening from Danville to
Taylorville southeast where 5% risk of damaging winds and large
hail again. The instability/convective available potential energy are not quite as high Mon
afternoon over southeast IL, though the bulk shear values are
higher at 35-45 kts. Southeast half of County Warning Area also has a marginal
risk of excessive rainfall Monday afternoon into Mon night.
Northern/northwest County Warning Area to again be drier on Monday and Monday night. Highs
Monday in the upper 70s in central Illinois and lower 80s in southeast
Illinois.

Have smaller chances of convection on Tuesday with chance pops in
southeast Illinois closer to a lingering frontal boundary. The marginal
risk of severe storms and excessive rainfall has shifted south/se
of County Warning Area on Tue and Tue night. Though some instability lingers se
County Warning Area with convective available potential energy of 1000-1700 j/kg though weak bulk shear values
less than 20 kts. Highs Tue mostly in the lower 80s.

A stronger short wave trof is projected to track east over the MO
valley Tue night and into Illinois by Wed evening. This will increase
chances of showers/thunderstorms overnight Tue night into Wed with
likely pops on Wed, and over southeast Illinois Wed evening. Instability
looks weak on Wed though moderate to heavy rains will be possible
especially Wed afternoon, and into Wed evening over Wabash River
valley. Highs Wed in upper 70s/lower 80s, warmest in southeast Illinois.

Looks like a lull in convection on Thu and Thu night with dry
conditions or slight pops in forecast then. Some upper level
ridging into Illinois on Friday to bring summerlike temps and humidity
levels back to the area, similar to today, with highs in the 80s
on Fri and Sat. Yet another short wave trof to move into the
Midwest and bring more showers and thunderstorms late this week,
though some timing differences between models with its arrival.
Gem waits until Sat to bring qpf to County Warning Area while ECMWF has qpf
northern County Warning Area Fri night, and GFS is wetter with qpf across County Warning Area Fri
night. Instability parameters and bulk shear values increase again
by Sat afternoon and could bring more chances of strong to severe
storms along with moderate to heavy rains. Models show upper
level ridge still near Illinois next weekend into Mon/Jun 24 which would
keep summertime warmth and humidity around, along with daily
chances of showers and thunderstorms.



&&

Aviation...(for the 06z tafs through 06z Sunday night)
issued at 1255 am CDT sun Jun 16 2019

A band of showers and thunderstorms currently focused along I-72
will produce IFR to MVFR conditions next 1-2 hours before
diminishing. Also having west-northwest winds 15-20 kts with gusts of 25-35
kts with stronger thunderstorms. Northern taf sites of pia and bmi
will see light rain showers diminish next few hours, though IFR to
low end MVFR ceilings will be possible overnight into mid morning
Sunday over central Illinois in wake of mesoscale convective system activity. A frontal boundary
will sag southward over central Illinois Sunday afternoon and drift
south of I-72 by sunset Sunday evening. This may produce a band of
convection Sunday afternoon and early Sunday evening especially
along I-72. West-southwest winds of 5-10 kts prevail thru Sunday afternoon,
then veer NE during Sunday evening.

&&

Ilx watches/warnings/advisories...
Flash Flood Watch until 7 am CDT this morning for ilz044>046-
052>057-061>063-066>068-071>073.

&&

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