Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 291552

Area Forecast Discussion
National Weather Service Lincoln IL
1052 AM CDT Sat Apr 29 2017

Issued at 1050 AM CDT Sat Apr 29 2017

Will continue the flash flood watch through Sunday night for areas
southeast of the IL river for 3-5 inches of rain. A large area of
rains with thunderstorms and locally heavy rains was spreading
north of I-70 and into northern CWA by late this morning. A
frontal boundary was just south of I-70 and extended sw into se MO
and se OK to 999 mb surface low pressure over central Texas. Radar
mosaic was showing 1-3 inches of rain has fallen south of I-72
past 24 hours, with heaviest amounts of 2-3 inches over Clark,
Crawford, Cumberland, southern Edgar, southern Coles and eastern
Jasper counties. Latest hi-res models of HRRR, RAP and NAM and
lifting warm front slowly north to between I-70 and I-72 during
this afternoon and this to shift heavy rain band further north as
well, with less coverage in southeast IL. The latest HRRR models
spread convection east into southeast IL during early/mid evening.
SPC day1 outlook continues slight risk later this afternoon into
mid evening south of I-72 where 15% risk of large hail and
damaging wind gusts and 2-5% risk of tornadoes. Temps currently
range from the upper 40s from Jacksonville to Bloomington nw where
ne winds 15-25 mph and gusts of 25 to 35 mph adding a damp chill
to the air. Milder temps in the mid 60s along highway 50 in
southeast IL. Highs this afternoon to contrast from around 50F
from Peoria nw to 75-80F in southeast IL in the warm sector where
some sunshine will appear this afternoon.


.SHORT TERM...(Today and tonight)
ISSUED AT 333 AM CDT Sat Apr 29 2017

Deep upper low currently over the four corners region....with a
stationary front draped from the Southern Plains up into the Ohio
River Valley. Impulses traveling from SW to NE along the boundary
developing plenty of thunderstorms with heavy precip in a large
swath across much of the country. WPC QPF tonight has maintained a
total of 3-5" with locally more possible in the south and east.
Have left the flash flood watch at this point with the highest
QPF expected southeast of the IL River Valley. Day One Outlook is
placing a slight risk from Springfield to Danville for today and
the potential for individual storms to potentially become severe
with large hail and damaging wind gusts later this
afternoon/evening as a break in the precip is persisting in the
model runs ahead of the slow advance of the upper low, allowing a
little destabilization even in the wake of plenty of prev
convection...and potential MCS this evening.

.LONG TERM...(Sunday through Friday)
ISSUED AT 300 AM CDT Sat Apr 29 2017

Warm front lifting to the north, but showers and thunderstorms
continuing through the day and into the evening hours until the
cold front sweeps through the region, eventually clearing up the
precip after midnight. Before it goes, however, the cold front
moving through the region Sun afternoon/evening will still have an
increased risk of severe weather highly contingent on the timing.
SPC day 2 outlook keeping the slight risk to the south for
now...but the marginal risk is over the rest of the state. Monday
will still maintain low pops for some residual showers in cyclonic
flow/instability showers through the afternoon. Temperatures
considerably cooler again with highs in the 50s for Monday.
Temperatures start an extremely slow warm up to the mid 60s by the
end of the week as the pattern shifts to a more zonal flow through
midweek before another upper wave dives into the Midwest,
amplifying the flow over the region and bringing back a cooler air
advection with northerly winds at the surface to wrap up the week.


.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 607 AM CDT Sat Apr 29 2017

The rare ob coming in periodically with VFR conditions... but
mainly MVFR-IFR. Persistent and widespread precip with very
diffuse thunder spread across Central IL resulting in TAFS that
carry thunder for a very long time today. VCTS later in the
forecast just to handle the lack of confidence about a potential
break in the precip. Otherwise, low clouds, limited vis, and rain


Flash Flood Watch through Monday morning for ILZ031-037-038-



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