Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 071959

Area Forecast Discussion
National Weather Service Lincoln IL
259 PM CDT Mon Jul 7 2014

ISSUED 259 PM CDT Mon Jul 7 2014

Main focus for this forecast will be the thunderstorms expected to
impact the area late tonight through tomorrow. More thunderstorms
will be possible late in the week and into next weekend as well.
Models continue to have a good handle on the overall pattern and
surface features, and finally look similar with location and
timing of pcpn next 24hrs. There are some differences with the
pcpn, but overall they all look similar in timing of the pcpn,
start and finish, with NAM being slowest with exiting the pcpn.
Still, a blend in the models, combined with persistence looks like
a good forecast.

SHORT TERM...Tonight through Thursday night

Pcpn could be ongoing in the extreme southeast part of the cwa
late this afternoon, but should get pushed out of the area
quickly. Am expecting the remainder of the evening hours, til
midnight to be dry as this boundary gets south of the area and the
next weather system does not get into the area til just after
midnight. Models all point to an MCS developing somewhere around
NW MO/NE KS/ SW MO/SE IA late this evening. Temp and moisture
convergence, Omega, and other dynamics support this location and
scenario tonight. This MCS is expected to move east to southeast
tonight and begin to effect west central IL around midnight and
then move ESE through the southern half of the state after
midnight tonight. Along with this, there is a sfc front to be the
focus of the storms and good low level jet pumping the high
moisture content air into the front. So, storms with heavy
rainfall, intense lightning, and damaging winds will be possible
late tonight and into tomorrow morning. Highest pops for tomorrow
will be in the southeast as this will be near the track of this
MCS. These storms should move out of the area quickly and leave
dry weather for remainder of the short term period, through
Thursday night.

Temps will finally cool and be at or below normal for the period.
Model guidance looked ok.

LONG TERM...Friday through Monday

Upper level flow will remain out of the northwest with ridging
taking place well west. However, in the northwest flow, another
frontal system will develop out in the plains and slowly move east
toward the area. The first time this system should effect the area
with pcpn is Fri night, with slight chance pops. Mentionable pops
will begin Friday night and continue through the remainder of the
forecast period. Temps will start cool but then warm back up to
more hot and humid weather by the weekend.


ISSUED 1254 PM CDT Mon Jul 7 2014

Scattered thunderstorms will develop in advance of a weak cold
front this afternoon: however, based on latest satellite/radar
imagery, it appears the convection will remain south of the
central Illinois terminals. Next significant chance for convection
will hold off until late tonight when a complex of thunderstorms
tracks E/SE out of Missouri/Iowa. Exact evolution and track of
complex remains in question: however, latest guidance suggests it
may remain mostly south of the I-74 corridor. As a result, have
maintained only VCTS at the northern TAF sites overnight. Further
southwest closer to expected track of the storms, have included
TEMPO groups for thunder at both KSPI and KDEC between 07z and
11z. Once storms push off to the east early Tuesday morning, a
return to mostly sunny conditions with a NW wind of around 10 mph
is expected.



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